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This is a continuation of application Ser. No. 07/774,982, filed on Oct. 15, 1991, which was abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a semiconductor device and a process for producing the same. The present invention is used, for example, for a semiconductor device comprising a plurality of elements formed on one substrate, the elements being separated from each other for insulation.
2. Description of the Related Art
The applicant of the present invention has previously filed a patent application, i.e., U.S. patent application Ser. No. 07/597,698, directed to a semiconductor device comprising a plurality of elements formed on one substrate, the elements being separated from each other for insulation.
This semiconductor device is an apparatus developed for preventing the occurrence of noise from adjacent semiconductor elements formed on the substrate. In this device, a conductive layer is formed so as to surround an element forming region where a semiconductor element comprising an SOI (silicon on insulator) device is formed, and an SiO 2 film is formed as an insulating film around the conductive layer to utilize the conductive layer as an electric shielding layer.
In the above-described U.S. patent application Ser. No. 07/597,698, however, it has been found that, since the SiO 2 film is formed under the SOI layer, when a strain attributable to the thermal expansion coefficient difference occurs within the SOI layer, the strain brings about a crystal defect due to a reduction in the film thickness now in use.
A multilayer interconnection is one means used for solving this problem. In this means, to combat a tensile stress exerted by an interlayer-insulation film (SiO 2 film) formed for insulating the (n)th layer from the (n+1)th layer, an Si 3 N 4 film is formed on or under the interlayer-insulation film to exert a compressive stress and thereby relieve the tensile stress.
In the use of the above-described technical means for solving the above-described problem it has been found that, when the Si 3 N 4 film is formed on the SiO 2 film, since the element forming region and the Si 3 N 4 film are in direct contact with each other, the compressive stress of the Si 3 N 4 film acts on the element forming region, and thus a crystal defect occurs within the element forming region.
SUMMARY OF THE INVENTION
Accordingly, the present invention has been created with a view to solving the above-described problem, and an object of the present invention is to provide a semiconductor device capable of stabilizing the electrical characteristics of a semiconductor element without causing a crystal defect within the element forming region, and to provide a process for producing the same.
To attain the above-described object, a first aspect of the present invention is directed to a semiconductor device wherein a semiconductor element is formed in a predetermined region surrounded by an insulating film, comprising: an electric shielding layer formed so as to surround said insulating film, and a stress relief film for relieving the thermal stress of said insulating film, the stress relief film being formed between the insulating film underlying the predetermined region and the electric shielding layer.
A second aspect of the present invention is directed to a semiconductor device comprising: a substrate; a polycrystalline film formed at least on the substrate; an element forming layer formed at least on the polycrystalline film, and at the same time, having a semiconductor element formed in a predetermined region thereof; a polycrystalline layer formed from a main surface of the element forming layer so as to reach the polycrystalline film and to surround the predetermined region in cooperation with the polycrystalline film; a stress relief film formed at least on the polycrystalline film, other than a portion where the polycrystalline layer is formed; an insulating film formed within the region surrounded by the polycrystalline layer along the stress relief film and the polycrystalline layer; and an electrode for applying a potential to the polycrystalline film and the polycrystalline layer to thereby form an electric shielding layer.
A third aspect of the present invention is directed to a process for producing a semiconductor device, comprising: a first step of forming a wafer comprising a polycrystalline film, a nitride film, an insulating film and an element forming layer, in that order, at least on a substrate; a second step of removing a predetermined portion by etching from a main surface of the element forming layer so as to reach the nitride film to form a trench portion in such a manner that a predetermined region of the element forming layer is surrounded by said nitride film and the trench portion; a third step of forming an oxide film at the trench portion through a thermal oxidation treatment; a fourth step of removing the nitride film by etching until the trench portion reaches the polycrystalline film formed under the trench portion; a fifth step of burying a polycrystalline layer in the trench portion subjected to the fourth step; and a sixth step of forming a semiconductor element within the predetermined region surrounded by the insulating film and the oxide film, and at the same time, forming an electrode portion on the surface of the polycrystalline layer.
A fourth aspect of the present invention is directed to a semiconductor device comprising: a substrate; a first monocrystalline semiconductor layer formed at least on the substrate; an electrode layer formed under the substrate; a second monocrystalline semiconductor layer formed on a predetermined portion of the first monocrystalline semiconductor layer, and at the same time, having a power device formed therein; a first insulating film formed at least on the first monocrystalline semiconductor layer other than the predetermined portion; a polycrystalline film formed on the first insulating film, the polycrystalline film at an end face thereof near the second monocrystalline semiconductor comprising an oxide film; an element forming layer formed at least on the polycrystalline film and having a semiconductor element formed in a predetermined region thereof; a polycrystalline layer formed from a main surface of the element forming layer so as to reach the polycrystalline film and surround the predetermined region in cooperation with the polycrystalline film; a stress relief film formed at least on the polycrystalline film other than a portion where the polycrystalline layer is formed; a second insulating film formed within a region surrounded by the stress relief film and the polycrystalline layer along the stress relief film and the polycrystalline layer; and an electrode portion for applying a potential to the polycrystalline film and the polycrystalline layer to thereby form an electric shielding layer.
A fifth aspect of the present invention is directed to a process for producing a semiconductor device, comprising: a first step of forming a wafer comprising a first monocrystalline layer, a first insulating film, a polycrystalline film, a nitride film, a second insulating film and an element forming layer, in that order, on the surface of a substrate; a second step of removing a predetermined portion by etching from a main surface of the element forming layer so as to reach the nitride film to form a trench portion and a device forming region in such a manner that a predetermined region of the element forming layer is surrounded by the nitride film and the trench portion; a third step of removing the nitride film and the polycrystalline film underlying the device forming region and then conducting a thermal oxidation treatment to form an oxide film on the end face of the polycrystalline film facing the trench portion and the device forming region; a fourth step of removing the film formed on the polycrystalline film by etching until the trench portion reaches the underlying polycrystalline film; a fifth step of removing the film formed on the first monocrystalline semiconductor layer by etching so as to reach the first monocrystalline semiconductor layer underlying the device forming region and then forming a second monocrystalline semiconductor layer on the first monocrystalline semiconductor layer; a sixth step of forming a polycrystalline layer within the trench portion; and a seventh step of forming an electrode layer on the reverse side of the substrate, forming a semiconductor element in the predetermined region surrounded by the second insulating film and the oxide film, and forming a power device in the device forming region.
According to the first aspect of the present invention, the electric shielding layer is formed so as to surround the insulating film surrounding the predetermined region.
Therefore, since the periphery of a predetermined region where a semiconductor element is formed is surrounded by an insulating film and an electric shielding layer, this region can be electrically isolated from the other regions. Further, the stress relief film formed between the insulating film underlying the predetermined region and the above-described electric shielding layer relieves the thermal stress of the insulating film.
Further, according to a second aspect of the present invention, the polycrystalline layer is formed from the main surface of the element forming layer so as to reach the polycrystalline film, and the insulating film is formed within a region surrounded by the stress relief film and the polycrystalline layer along the stress relief film and the polycrystalline layer.
Therefore, the conductive polycrystalline layer and polycrystalline film surrounding the predetermined region can serve as an electric shielding layer. Further, since the second insulating film is formed along the stress relief film and the polycrystalline layer, this region can be electrically insulated from the other regions.
According to a third aspect of the present invention, in the second step, a predetermined portion is removed by etching from the main surface of the element forming layer so as to reach the nitride film to form a trench portion, and in the third step, a thermal oxidation treatment is conducted to form an oxide film at the trench portion. Further, in the fifth step, a polycrystalline layer is buried in the trench portion subjected to the fourth step.
Therefore, when an oxide film is formed at the trench portion, since the underlying layer of the trench portion comprises a nitride film due to the second step, the polycrystalline film underlying the nitride film is not oxidized even by the thermal oxidation treatment, which enables only the periphery of the trench portion to be oxidized.
According to the fourth aspect of the present invention, the predetermined region where a semiconductor element is formed is formed so as to be surrounded by the second insulating film, which is formed along the stress relief film and the polycrystalline layer. Further, the polycrystalline film at an end face thereof near the second monocrystalline semiconductor layer comprises an oxide film.
Therefore, the conductive polycrystalline layer and the conductive polycrystalline film surrounding the predetermined region can serve as an electric shielding layer. Further, since the second insulating film is formed along the stress relief film and the polycrystalline layer, the above-described predetermined region can be electrically insulated from the other regions, for example, a power device forming region. Further, since an oxide film is formed on the polycrystalline film at an end face thereof near the second monocrystalline semiconductor layer, the electric shielding layer cannot influence the power device forming region.
According to the fifth aspect of the present invention, in the second step, a predetermined portion is removed by etching from the main surface of the element forming layer so as to reach the nitride film to form a trench portion and a device forming region in such a manner that a predetermined region of the element forming layer is surrounded by the nitride film and the trench portion.
In the third step, an thermal oxidation treatment is conducted to form an oxide film on the end face of the polycrystalline film facing the trench portion and the device forming region. In the fourth step, the film formed on the polycrystalline film is removed by etching until the trench portion reaches the underlying polycrystalline film. In the seventh step, an electrode layer is formed on the reverse side of the substrate, a semiconductor element is formed in the predetermined region surrounded by the second insulating film and the oxide film, and a power device is formed in the device forming region.
Therefore, when an oxide film is formed in the trench portion, since the underlying layer of the trench portion comprises a nitride film formed by the second step, the polycrystalline film underlying the nitride film is not oxidized even by the thermal oxidation treatment, which allows only the periphery of the trench portion to be oxidized. Further, since an oxide film is formed on the polycrystalline film at its end face near the second monocrystalline semiconductor layer, the oxide film can prevent the electric shielding layer from having an influence on the power device forming region.
According to the second through fifth aspects of the present inventions described above, the stress relief film or nitride film formed on the polycrystalline film exclusive of the portion in which an polycrystalline layer is formed exerts a compressive stress on the element forming layer. Further, the insulating film formed within a region surrounded by the stress relief film or nitride film and the polycrystalline layer along the polycrystalline layer and the stress relief film or nitride film exerts a tensile stress on the element forming layer.
As described above, the first aspect of the present invention exhibits an excellent effect such that, since the predetermined region in which a semiconductor element is formed is electrically insulated from the other region, it is possible to stabilize the electrical characteristics of the semiconductor element. Further, since the thermal stress of the insulating film is relieved by the stress relief film, it is possible to attain an excellent effect such that a semiconductor device can be formed within a predetermined region without causing a crystal defect.
According to the second aspect of the present invention, since the predetermined region in which a semiconductor element is formed can be electrically insulated from the other regions, it is possible to attain an excellent effect such that the electrical characteristics of the semiconductor element can be stabilized.
According to the third aspect of the present invention, since the nitride film formed for the purpose of relieving the tensile stress caused by the insulating film is effectively utilized during the manufacturing process, it is possible to attain an excellent effect such that an semiconductor device can be produced with a minimum increase in the number of steps for forming an electric shielding layer, an insulating film and a nitride film within the semiconductor device.
According to the fourth aspect of the present invention, since the predetermined region in which a semiconductor element is formed can be electrically insulated from the power device forming region in which a power device is formed, it is possible to attain such an excellent effect that the stabilization of the electrical characteristics of the semiconductor element provided in each region can be realized. Further, since the influence of the electric shielding layer on the power device forming region is prevented by an oxide film formed on the polycrystalline film at its end face near the second monocrystalline semiconductor layer, it is possible to attain such an excellent effect that the stabilization of the electrical characteristics can be realized also on the power device formed in the power device forming region.
According to the fifth aspect of the present invention, since the nitride film formed for the purpose of relieving the tensile stress caused by the second insulating film is effectively utilized during the manufacturing process, it is possible to attain such an excellent effect that an semiconductor device can be produced with a minimized increase in the number of steps for forming an electric shielding layer, an insulating film and a nitride film within the semiconductor device. Further, since the influence of the electric shielding layer on the power device forming region is prevented by an oxide film formed on the polycrystalline film at its end face near the second monocrystalline semiconductor layer, it is possible to attain an excellent effect such that the electrical characteristics can be stabilized for the power device formed in the power device forming region.
Further, according to the present invention, since the stress relief film or the nitride film exerts a compressive stress on the element forming layer and the second insulating film exerts a tensile stress on the element forming layer, it is possible to attain an excellent effect such that the inside of the element forming layer can be maintained in such a state that the stress thereon is relieved.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view of a semiconductor device according to a first embodiment of the present invention;
FIG. 2(a) and FIG. 2(b) are each a cross-sectional view of a semiconductor device in the step of forming a substrate in the first embodiment;
FIG. 3 is a cross-sectional view of a semiconductor device in the lamination step in the first embodiment;
FIG. 4 is a cross-sectional view of a semiconductor device in the step of forming a trench portion in the first embodiment;
FIG. 5 is a cross-sectional view of a semiconductor device in the thermal oxidation step in the first embodiment;
FIG. 6 is a cross-sectional view of a semiconductor device in the step of removing silicon nitride in the first embodiment;
FIG. 7 is a cross-sectional view of a semiconductor device in the burying step in the first embodiment;
FIG. 8 is a cross-sectional view of a semiconductor device in the leveling step in the first embodiment;
FIG. 9 is a cross-sectional view of a semiconductor device according to a second embodiment of the present invention;
FIG. 10(a) and FIG. 10(b) are each a cross-sectional view of a semiconductor device in the step of forming a substrate in the second embodiment;
FIG. 11 is a cross-sectional view of a semiconductor device in the lamination step in the second embodiment;
FIG. 12 is a cross-sectional view of a semiconductor device in the step of forming a trench portion in the second embodiment;
FIG. 13 is a cross-sectional view of a semiconductor device in the step of forming a region in the second embodiment;
FIG. 14 is a cross-sectional view of a semiconductor device in the thermal oxidation step in the second embodiment;
FIG. 15 is a cross-sectional view of a semiconductor device in the step of removing silicon nitride in the second embodiment;
FIG. 16 is a cross-sectional view of a semiconductor device in the step of removing silicon oxide in the second embodiment;
FIG. 17 is a cross-sectional view of a semiconductor device in the burying step in the second embodiment;
FIG. 18 is a cross-sectional view of a semiconductor device in the leveling step in the second embodiment;
FIG. 19 is a cross-sectional view of a semiconductor device in the step of depositing silicon nitride according to another manufacturing process with respect to the relief of the stress applied to the first embodiment;
FIG. 20 is a cross-sectional view of a semiconductor device in the etching step according to another manufacturing process with respect to the relief of the stress applied to the first embodiment;
FIG. 21 is a cross-sectional view of a semiconductor device in the step of depositing polysilicon according to another manufacturing process with respect to the relief of the stress applied to the first embodiment; and
FIG. 22 is a cross-sectional view of a semiconductor device formed according to another manufacturing process with respect to the relief of the stress.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will now be described by way of examples with reference to the attached drawings.
EXAMPLE 1
FIG. 1 is a cross-sectional view of the first embodiment of the semiconductor device according to the present invention.
In FIG. 1, an SiO 2 film 7 is formed on a monocrystalline Si substrate 6, and a polycrystalline silicon film or poly-Si film 5 is formed thereon.
Further, a polycrystalline silicon layer or a poly-Si layer 10 is formed on the poly-Si film 5 at a predetermined portion thereof, and an Si 3 N 4 film 4 is formed as a stress relief film on the other portion thereof.
An SiO 2 film 3 is formed on the Si 3 N 4 film 4, and an N + epitaxial layer 2 as an element forming layer and an N - monocrystalline Si substrate 1 are successively deposited thereon. A bipolar transistor 14 is formed in each SOI region.
In this case, since the conductive poly-Si covers the side portion and the bottom portion of each SOI region, the application of a potential to the poly-Si through an A1 electrode 13 enables the poly-Si film 5 and the poly-Si layer 10 to serve as an electric shielding layer.
Thus, according to the above-described constitution, the individual SOI regions are separated for insulation with an oxide film 9 as an insulating film therebetween, and the poly-Si film serves as an electric shielding layer, so that each SOI region can be electrically stabilized. The above-described SiO 2 film 3 and the oxide film 9 serve as an insulating film.
Further, an SiO 2 film 3 and an Si 3 N 4 film 4 are formed near the bond interface between the Si substrate 1 and the Si substrate 6. The SiO 2 film 3 and the Si 3 N 4 film 4 serves to relieve the stress caused within the SOI layer. Specifically, the SiO 2 film 3 exerts a tensile stress on the SOI layer, and the Si 3 N 4 film 4 exerts a compressive stress on the SOI layer. As a result, in a region where an SOI layer is formed, the SOI can be formed in such a state that the stress is relieved.
Further, since the poly-Si film 5 underlies the Si 3 N 4 film 4, even when a crystal defect occurs within the poly-Si film 5 due to the compressive stress of the Si 3 N 4 film 4, no problem occurs because the poly-Si film 5 serves merely as an electric shielding layer electric current passes.
The process for producing the semiconductor device shown in FIG. 1 will now be described with reference to FIGS. 2(a) and (b) and FIGS. 3 to 8. FIGS. 3 to 8 are cross-sectional views of a semiconductor device shown in the order of the steps of producing the semiconductor device.
Step of Forming Substrate (FIGS. 2(a), 2(b))
As shown in FIG. 2(a) an N + epitaxial layer 2 having a predetermined thickness is formed by N + epitaxial growth on an N - -type monocrystalline Si substrate 1 having a (100) face orientation and an electric resistivity of 3 to 10 Ω.cm.
It is also possible to diffuse an impurity, such as As or Sb, instead of the utilization of the N + epitaxial growth.
Subsequently, a 0.2 to 2 μm-thick SiO 2 film 3 is formed on the N + epitaxial layer 2, either by thermal oxidation at 900° to 1100° C. or by chemical vapor deposition (CVD), and a 0.1 to 0.3 μm-thick Si 3 N 4 film 4 is deposited on the SiO 2 film 3 by the low pressure-CVD (LPCVD) process.
Then, a 1 to 10 μm-thick poly-Si film 5 doped with impurities, such as As and P, in a high concentration is deposited on the Si 3 N 4 film 4 by the LPCVD process, and the surface of the poly-Si film 5 is mirror polished by a chemical polishing process until the surface smoothness becomes 30 Å or less (preferably 10 Å or less).
Thus, a substrate having a cross section shown in FIG. 2(a) is obtained through the above-described manufacturing procedure. In this first embodiment, use was made of a poly-Si film doped with impurities such as As and P. When the poly-Si film is thin, it is possible to conduct the deposition of an undoped poly-Si film followed by the formation of the poly-Si film 5 by the diffusion process or ion implantation process.
Separately from the above-described Si substrate 1, the following Si substrate 6 is formed, as shown in FIG. 2(b).
Specifically, an N - monocrystalline Si substrate 6 having a (100) face orientation and an electrical resistivity of 3 to 10 Ω.cm is heat-treated at 900° to 1100° C., and a 0.2 to 2 μm-thick SiO 2 film 7 is formed on the Si substrate 6. This procedure yields a substrate having a cross section shown in FIG. 2(b).
Lamination Step (FIG. 3)
The surface of the poly-Si film 5 of the Si substrate 1 shown in FIG. 2(a) and the surface of the SiO 2 film 7 of the Si substrate 6 shown in FIG. 2(b) are subjected to a hydrophilic treatment by using a mixed solution comprising aqueous hydrogen peroxide (H 2 O 2 ) and sulfuric acid (H 2 SO 4 ), dehydrated, dried, and then laminated to each other. The laminate is subjected to a bonding of the wafers in nitrogen at 600° to 1100° C. for 1 to 2 hr.
Subsequently, the Si substrate 1 is mirror polished to a desired thickness. In this case, for example, when a bipolar transistor is formed on the substrate, the Si substrate 1 is mirror polished to a thickness of about 3 to 10 μm, but when a MOS transistor is formed, the Si substrate 1 is mirror polished to a thickness of 5 μm or less.
Thus, a structure having a cross section shown in FIG. 3 is obtained through the above-described manufacturing procedure, i.e., an SOI layer is formed. The above-described step of forming a substrate and the step of lamination correspond to the first step.
Step of Forming Trench Portion (FIG. 4)
A resist is coated in a predetermined pattern on the Si substrate 1. The Si substrate 1 at portions thereof not coated with the resist, the N + epitaxial layer 2, and the SiO 2 film 3 are removed by dry etching or the like to form a trench portion 8, thereby forming a structure having a cross section as shown in FIG. 4. The above-described step of forming a trench portion corresponds to the second step.
Step of Thermal Oxidation Treatment (FIG. 5)
Then, thermal oxidation is conducted at 900° to 1100° C. to form an oxide film (SiO 2 film) 9 having a thickness of 0.1 to 1 μm, and a structure having a cross section shown in FIG. 5 is obtained.
In this case, since the poly-Si film 5 is formed under the Si 3 N 4 film 4, the Si 3 N 4 film 4 serves as a mask, so that the poly-Si film 5 is not oxidized. The above-described step of thermal oxidation corresponds to the third step.
Step of Removing Silicon Nitride (FIG. 6)
Then, as shown in the cross-sectional view of FIG. 6, the Si 3 N 4 film 4 underlying the trench portion 8 is removed by plasma etching or etching with hot phosphoric acid. The above-described step of removing silicon nitride corresponds to the fourth step.
Burying Step (FIG. 7)
Then, as shown in FIG. 7, a poly-Si layer 10 is deposited all over the surface of the structure by the LPCVD process until the poly-Si layer 10 fills up the trench portion 8. The above-described burying step corresponds to the fifth step.
Leveling Step (FIG. 8)
Then, as shown in FIG. 8, the poly-Si layer 10 deposited on the oxide film 9 is leveled or flattened by a selective polishing. This causes the poly-Si layer 10 to remain only in the trench portion 8.
Step of Forming an Element (FIG. 1)
Then, as shown in FIG. 1, an N + -diffusion layer, 11, a p-type diffusion layer 12 and aluminum electrode 13 are provided in each SOI region, by a known semiconductor fabrication technique, to form a bipolar transistor 14. The above-described leveling step and the step of forming an element correspond to the fifth step.
EXAMPLE 2
The second embodiment will now be described. In the second embodiment, a description will be given of a semiconductor device wherein an SOI device and a power device are integrally formed.
FIG. 9 is a cross-sectional view of a second embodiment of the semiconductor device of the present invention.
In FIG. 9, an N - epitaxial layer 26 corresponding to a first monocrystalline semiconductor layer is formed on the surface of a Si substrate 25, and a drain electrode 44 corresponding to an electrode layer is formed on the reverse side of the Si substrate 25.
Further, an N - epitaxial layer 33 corresponding to a second monocrystalline semiconductor is formed on the film at a predetermined portion thereof, and an SiO 2 film 27 corresponding to a first insulating film is formed on a portion other than the predetermined portion. A power MOS transistor 43 is formed in the N - epitaxial layer 33.
A poly-Si film 24 corresponding to a polycrystalline film is formed on the SiO 2 film 27, a poly-Si layer 28 corresponding to a polycrystalline layer is formed on the film at a predetermined portion thereof, and an Si 3 N 4 film 23 corresponding to a nitride film is formed on a portion other than the predetermined portion.
An SiO 2 film 22 is formed on the Si 3 N 4 film 23, and an N + epitaxial layer 21 as an element forming layer and an N - type Si substrate 20 are successively deposited on the film.
In this case, since the conductive poly-Si film covers the side portion and the bottom portion of each SOI region, the application of a potential to the poly-Si film through an aluminum electrode 38 enables the poly-Si film to serve as an electric shielding layer.
Thus, according to the above-described constitution, the individual SOI regions are separated for insulation with an oxide film 30 and an SiO 2 film 22 as an insulating film therebetween, and the poly-Si film serves as an electric shielding layer, so that each SOI region can be electrically stabilized without the influence of large variations in the drain displacement of the Si substrate 25 caused, for example, by the operation of a vertical power MOS transistor. The above-described SiO 2 film 22 and oxide film 30 correspond to the second insulating film.
Further, SiO 2 films 22, 27 and an Si 3 N 4 film 23 are formed near the bond interface between the Si substrate 20 and the Si substrate 25. The SiO 2 films 22, 27 and the Si 3 N 4 film 23 serves to relieve the stress caused within the SOI layer. Specifically, the SiO 2 films 22, 27 exert a tensile stress on the SOI layer, and the Si 3 N 4 film 23 exerts a compressive stress on the SOI layer. As a result, in a region where an SOI layer is formed, the SOI can be formed in such a state that the stress is relieved.
The process of manufacturing the semiconductor device shown in FIG. 9 will now be described with reference to FIGS. 10(a) and (b) and FIGS. 11 to 18. FIGS. 11 to 18 are cross-sectional views of a semiconductor device shown in the order of the steps of producing the semiconductor device.
Step of Forming Substrate (FIGS. 10(a), 10(b))
First, a wafer having a cross section as shown in FIG. 10(a) is formed. The description of the process of producing this wafer will be omitted, as it is produced in the same manner as that of the wafer having a cross section as shown in FIG. 2(a).
Separately from the above-described Si substrate 20, the following Si substrate 25 is formed.
Specifically, an N - epitaxial layer 26 having a predetermined thickness is formed by N - epitaxial growth on an N + type Si substrate 25 having (100) face orientation and an electrical resistivity of 3 to 10 Ω.cm. Subsequently, a heat treatment is conducted at 900° to 1100° C., and a 0.2 to 2 μm-thick SiO 2 film 27 is formed on the N - epitaxial layer 26. Thereafter, the resulting structure is subjected to the above-described manufacturing procedure to form a substrate having a cross section shown in FIG. 10(b).
Lamination Step (FIG. 11)
The surface of the poly-Si film 24 of the Si substrate 20 shown in FIG. 10(a) and the surface of the SiO 2 film 27 of the Si substrate 25 shown in FIG. 10(b) are subjected to a hydrophilic treatment by using a mixed solution comprising aqueous hydrogen peroxide (H 2 O 2 ) and sulfuric acid (H 2 SO 4 ), dehydrated, dried and then laminated to each other. The laminate is then subjected to a Joining of the wafers in nitrogen of 600° to 1100° C. for 1 to 2 hr.
Subsequently, the Si substrate 20 is mirror polished to a desired thickness. In this case, for example, when a bipolar transistor is formed on the substrate, the Si Substrate 20 is mirror polished to a thickness of 3 to 10 μm, and when an MOS transistor is formed, the Si substrate 20 is mirror polished to a thickness of 5 μm or less.
Thus, a structure having a cross section shown in FIG. 11 is obtained through the above-described manufacturing procedure, i.e., an SOI layer is formed. The above-described step of forming a substrate and the lamination step correspond to the first step.
Step of Forming Trench Portion (FIG. 12)
A resist having a predetermined pattern is coated on the Si substrate 20. The Si substrate 20 at portions thereof not coated with the resist, the N + epitaxial layer 21 and the SiO 2 film 22 are removed by dry etching or the like to form a trench portion 28, thereby forming a structure having a cross section as shown in FIG. 12. The above-described step of forming a trench portion corresponds to the second step.
Step of Forming a Region (FIG. 13)
Then, as shown in FIG. 13, a resist is coated on the structure except for forming a region 29 where a power MOS transistor is to be formed, and the Si 3 N 4 film 4 and the poly-Si 5 in the formed region are removed by etching or the like.
Step of Thermal Oxidation Treatment (FIG. 14)
Then, thermal oxidation is conducted at 900° to 1100° C. to form an oxide film (SiO 2 film) 30 having a thickness of 0.1 to 1 μm, and thus a structure having a cross section shown in FIG. 14 is obtained.
In this case, an oxide film is formed in the poly-Si film 24 at an end face thereof facing the formed region 29, by the above-described oxidation treatment. The above-described forming step and the thermal oxidation step correspond to the third step.
Step of Removing Silicon Nitride (FIG. 15)
Then, as shown in the cross-sectional view of FIG. 15, a resist film 31 is coated on the power MOS transistor forming region 29, and the Si 3 N 4 film 23 underlying the trench portion 28 is removed by plasma etching or etching with hot phosphoric acid. The above-described step of removing silicon nitride corresponds to the fourth step.
Step of Removing Silicon Oxide (FIG. 16)
Then, as shown in the cross-sectional view of FIG. 16, after the removal of the resist film 31, in order to remove the SiO 2 film 27 in the power MOS transistor forming region 29, a resist film 32 is coated on the portions other than the power MOS transistor forming region, and the SiO 2 film 27 in the power MOS transistor forming region 29 is removed by etching or the like.
The underlying N - epitaxial layer 26 may be removed to a desired thickness.
Burying Step (FIG. 17)
Then, the resist film 32 of the wafer subjected to the above-described step of removing the silicon oxide is removed, and the structure is then placed in an epitaxial growth apparatus to conduct an epitaxial growth.
Since the power MOS transistor forming region 29 comprises a single crystal, the epitaxial growth causes an N - epitaxial layer 33 comprising a monocrystalline Si to be formed on the surface of the N - epitaxial layer 26.
On the other hand, in portions other than the power MOS transistor forming region 29, since the growth is conducted while using the poly-Si film 24 as the base, a poly-Si layer 34 corresponding to a polycrystalline layer is formed so as to cover the SiO 2 film 27 and the oxide film 30.
Thus, a structure having a cross section as shown in FIG. 17 is obtained through the above-described manufacturing procedure. In the second embodiment, since the resistance value of the poly-Si layer 34 buried in the trench portion 28 is relatively high, the resistance value may be lowered by either previously burying the poly-Si layer having a high concentration in this portion after removing silicon nitride (FIG. 15), or introducing impurities by diffusion or ion implantation after the leveling step, as described later.
The above-described step of removing silicon oxide and the above-described burying step correspond to the fifth step and the sixth step, respectively.
Leveling Step (FIG. 18)
Then, as shown in FIG. 18 the poly-Si layer 34 deposited on the oxide film 30 and the N-epitaxial layer 33 comprising monocrystalline Si are leveled by selective polishing. This causes the poly-Si layer 34 to remain only in the trench portion 28.
Step of Forming Element (FIG. 9)
Then, an N + -type diffusion layer 36, a p-type diffusion layer 37 and an aluminum electrode 38 are provided in the forming region 35 shown in FIG. 18, by a known semiconductor fabrication technique, to form a bipolar transistor 39.
Further, an N + -type diffusion layer 40, a p-type diffusion layer 41, an aluminum electrode 38 and a gate electrode 42 are provided in the forming region 29 shown in FIG. 18, by a known semiconductor fabrication technique, and a drain electrode 44 is formed on the reverse side of the Si substrate 25 to form a power MOS transistor 43. The above-described leveling step and the step of forming an element correspond to the seventh step.
It is possible to form, besides the above-described bipolar transistor, a semiconductor element such as a CMOS transistor, and a combination of the bipolar transistor with the CMOS transistor.
Thus, a semiconductor device having a cross section as shown in FIG. 9 according to the second embodiment is produced through the above-described manufacturing procedure.
A process for producing a semiconductor device which enables the stress within the SOI layer to be further relieved, i.e., enables one of the objects of the present invention to be attained, will now be described.
Since this process can be applied to any of the first and second embodiments, a description will now be given only of the first embodiment.
FIGS. 19 to 21 are cross-sectional views of a semiconductor device shown in the order of the steps of producing the semiconductor. This process is conducted between the step of the thermal oxidation treatment and the step of removing silicon nitride.
Step of Depositing Silicon Nitride (FIG. 19)
An Si 3 N 4 layer 45 is deposited by the LPCVD process on the semiconductor device having a cross section as shown in FIG. 5 subjected to the step of the thermal oxidation treatment, and thus a structure having a cross section as shown in FIG. 19 is obtained.
Step of Etching (FIG. 20)
Then, the Si 3 N 4 layer 45 deposited on the oxide film 9 by the above-described step and the Si 3 N 4 layer 4 underlying the trench portion 8 are removed by directional RIE (reactive ion etching). In this step, the Si 3 N 4 layer deposited on the side of the trench portion 8 is not removed to form a structure having a cross section as shown in FIG. 20 (the step of depositing polysilicon).
Steps of Depositing Polysilicon (FIG. 21), Leveling and Forming Element (FIG. 22)
Subsequently, a poly-Si layer 10 is deposited by the LPCVD process to form a structure having a cross section as shown in FIG. 21. Thereafter, the structure is subjected to the leveling step and the step of forming an element, to form a structure having a cross section as shown in FIG. 22. In the step of forming an element, a bipolar transistor 46 and an MOS transistor 47 are formed.
Thus, in the above-described steps, since the stress of the oxide film (SiO 2 film) formed on the side of the trench portion is also relieved, it is possible to form a semiconductor device wherein the stress relief is further taken into consideration.
It is apparent, however, that the stress can be sufficiently relieved by the manufacturing procedure described above in connection with each embodiment, without the use of the above-described process.
Since there is a general tendency towards a reduction in the film thickness and an increase in the integration density, the film thickness in the element forming region is thin. Therefore, in portions where the SiO 2 film is formed, the area of the SiO 2 film formed on the Si 3 N 4 film is considerably larger than the area of the SiO 2 film formed around the poly-Si layer so that, as described in the above embodiments, the stress can be sufficiently relieved by forming the Si 3 N 4 film under the SiO 2 film having the largest area.
It is of course understood that the present invention also can be effectively applied to an SOI-type semiconductor device not provided with an electric shielding layer disposed around an insulating film surrounding a region in which a semiconductor element is formed.
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An SOI-type semiconductor device in which electrical elements formed on one semiconductor substrate are isolated from each other by an insulating film and a shield layer, to ensure a stable operation of the electrical elements against electrical noise etc., and at the same time, a stress relief film is formed between the insulating film and the shield layer to ensure that an SOI layer is stabilized by being free from crystal defects. A process for producing same is also disclosed.
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This is a division of application Ser. No. 658,273, filed Feb. 17, 1976, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a method and apparatus for harvesting and processing head lettuce and more particularly to a method and apparatus wherein all steps are performed at or near the field in which the lettuce is grown and with sufficient promptness after picking that deterioration of the lettuce is minimized or eliminated.
2. Description of the Prior Art
The known prior art procedure for harvesting and processing lettuce involves severing lettuce heads that are growing on the field and placing the lettuce heads in a field box or bin. In the known prior art, when the bin is full it is transported to a vacuum cooler at some remote location. A plurality of field bins are loaded into a vacuum cooler at one time for batch processing so that it frequently occurs that one or more bins are retained outside the vacuum cooler for a sufficient period of time that deterioration can take place. The prior art procedure is then to transport the now relatively cool heads to a processing plant at a remote site at which the heads are inspected, shredded, treated and packaged. Because of the substantial time between severing the head from the field and shredding of the head, the outer leaves of the head typically dry out much more than the heart of the head so that either the outer leaves must be discarded or a shredded product of non-uniform character is produced.
A method for retarding further deterioration of shredded lettuce is disclosed in U.S. Pat. No. 3,849,581 (426-145). Such method however is practiced only after the delays attending the prior art procedure described above; notwithstanding the apparent efficacy of the method, it is not able to restore lettuce that has already deteriorated due to exposure.
SUMMARY OF THE INVENTION
A head of lettuce, after it is severed from the field in which it grows, is a fragile food article of limited longevity. For optimum shelf life lettuce must be retained in an environment having closely controlled temperature and humidity characteristics. Such fragility of head lettuce has contributed to substantial waste both in the field and at the site of the ultimate consumer. In the field and in processing plants it is usual to strip and discard the exterior leaves if the lettuce has been exposed to ambient temperatures for any significant period. Because lettuce processing and shipment has required in certain instances up to a week or more, the consumer must either quickly use lettuce or risk its deterioration beyond edibility even when stored at reduced temperature.
According to the present invention head lettuce is severed from the field, shredded, and placed in a container that is constructed to prevent the temperature of the lettuce from rising above the ambient temperature, all within the period of about one minute or less. Thus since the lettuce never experiences a temperature rise significantly above that present while it is growing in a field, the present invention affords a significant increase in the quality and quantity of the yield.
An object of the invention is to provide a method and apparatus for processing lettuce so that the maximum yield of edible lettuce is obtained. The present invention affords achievement of this object by shredding the lettuce immediately after severing the same from the field and retaining such shredded lettuce in an insulated or refrigerated enclosure.
A feature and advantage afforded by achievement of the last object is that a more uniform product is provided because it eliminates differential drying which is present when lettuce is stored in head form for a substantial period of time.
Another feature and advantage attending achievement of the last stated object is the elimination of labor costs necessary in peeling off outer leaves that deteriorate when heads are stored for an extended period and elimination of the cost of disposing of the deteriorated outer leaves.
A further object of the invention is to provide method and apparatus for cleaning and packing the lettuce for shipment immediately after shredding the same so as to maximize freshness and minimize waste. This object is achieved according to the present invention by providing a self-contained mobile processing plant that can be transported to a site on or adjacent to a field. The mobile structure includes all facilities for chilling, cleaning and packing the lettuce and operates at optimum efficiency because of the proximity of the equipment to the field and the consequent reduction in elapsed time between picking and processing.
Yet another object of the invention is to provide a method and apparatus for simultaneously chilling, washing and adding preservatives to the chopped lettuce. This object is achieved by providing a quantity of water into which the preservatives can be added, chilling the water and creating a fine spray of the chilled water on a path. The shredded lettuce is conveyed along the path and tumbled at the same time so that it is cleaned, cooled and subjected to chemical preservative treatment.
A still further object is to provide a centrifuge of simplified and balanced construction. A centrifuge according to the invention can be constructed to operate smoothly without stringent manufacturing tolerances.
Yet a further object of the invention is to maximize the quantity of edible lettuce harvested from a given field. Irrespective of the care exercised in preparing, planting and caring for a lettuce field, there is inevitably a few misshapen heads which are not marketable in the fresh lettuce market but which nonetheless are composed of fully edible leaves. In known prior art lettuce harvesting techniques, such misshapen heads were not picked, but were plowed under after harvesting is completed. Because the present invention chops the lettuce at a very early stage in the practice thereof, such misshapen heads can be reduced into a saleable and highly edible product.
Yet another object of the invention is to provide apparatus that efficiently harvests the lettuce irrespective of the ambient temperature during harvesting. The apparatus includes a highly efficient chiller through which the lettuce can be transported when ambient temperatures are high, e.g., in excess of about 70° F. Because the lettuce is delivered to the chiller through a hose or tube, the chiller can be easily bypassed when the ambient temperature is less than about 70°, sufficient cooling being achieved in such relatively low ambient temperature conditions by transporting the lettuce through the hose with chilled water.
Contributing to the achievement of the object stated next above is the provision of a remotely located centrifuge; in low ambient temperature conditions the residence time of the lettuce within the hose in a water borne condition from the inlet equipment to the centrifuge is sufficient to reduce the temperature of the lettuce to the desired low temperature.
The foregoing, together with other objects, features and advantages will be more apparent after referring to the following specification and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a truck equipped with apparatus for practicing the method of the invention.
FIG. 2 is a fragmentary view of a portion of the lettuce conveyor of FIG. 1.
FIG. 3 is a perspective view of the mobile processing apparatus of the invention.
FIG. 4 is a cross-sectional elevation view of the shredded lettuce chilling apparatus employed in practicing the present invention.
FIG. 5 is a cross-sectional view taken along line 5--5 of FIG. 4.
FIG. 6 is an elevation view of the centrifuges of the present invention.
FIG. 7 is a view at enlarged scale of a fragment of FIG. 6.
FIG. 8 is a view taken along line 8--8 of FIG. 6.
FIG. 9 is a fragmentary elevation view showing a modification of the processing apparatus of FIG. 3.
FIG. 10 is a view taken along a plane designated by line 10--10 of FIG. 9.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring more particularly to the drawings and to FIG. 1 reference character R indicates rows of growing head lettuce, adjacent rows being separated by furrows F. A truck T has wheels spaced apart by an amount equivalent to the spacing of furrows F so that the truck can traverse the field without adversely affecting the lettuce heads growing in rows R. Carried on the side of truck T is a vertically oriented shaft 12 on which is mounted for pivotal movement about the axis of the shaft a carriage 14. Secured to the bottom of carriage 14 is a conveyor 15 which includes a horizontal frame 16. The structure is so proportioned that frame 16 is positioned at a level above the surface of rows R sufficient that it clears the lettuce heads growing in such rows and low enough so that field hands can conveniently deposit severed lettuce heads on the conveyor supported by conveyor frame 16.
Conveyor frame 16 supports a cup conveyor having a plurality of cups 18 which are fixed to roller chains or the like, one such roller chain being identified schematically at 20 in FIG. 2. Frame 16 has a distal end 22 at which sprockets are journaled for guiding the cup conveyor so that the upper run thereof moves from the distal end toward truck T. Inward of carrier 14 the conveyor has a right angle support 24, there being at such location sprockets over which the roller chains move to carry cups 18 upward along a vertical conveyor run 26. At the top of conveyor run 26 are supported sprockets, one of which is shown schematically in FIG. 2 at 30 for guiding the roller chain 20 at that point in the conveyor. Each cup 18 is supported on the roller chains by a pivot pin 32, the pivot pin being secured to the cup above the center of gravity of the cup so that the cups are biased to an upright position.
In operation cup conveyor 15 is operated so that the cups on the upper flight of the horizontal frame 16 move toward the truck, i.e. from left to right as viewed in FIG. 1. The truck traverses the field at a relatively slow speed so that field hands walking behind the conveyor can sever lettuce heads from the field, remove the core of the lettuce head, discard the outer leaves of the head and place the lettuce head in one of the cups 18. Cups 18 are proportioned so that they accommodate one and only one lettuce head, whereby as the heads travel on the conveyor, they do not rub against one another or against any machine parts. At the upper end of vertical conveyor section 26 is a fixed cam 34 which cooperates with a finger 36 mounted on each cup 18 so that as the cups move past cam 34 they are tilted thereby discharging the lettuce heads therefrom.
In receiving relation to the cup conveyor is an inlet hopper 38 which constitutes part of a conventional shredder 40. One suitable commercially available shredder is an Urschel Model H, manufactured by Urschel Laboratories, Valparaiso, Ind.; such shredder can be set to cut the lettuce either into long relatively thin pieces or into relatively large (e.g. 11/2 inch×11/2 inch) square or rectangular pieces. Shredder 40 is supported on the rear of truck T near the top thereof and has a discharge directed to the truck interior.
The floor of truck T is defined by a conveyor belt 42 that has a width substantially coextensive with the truck and is driven forward or rearward by an extremely slow drive mechanism not shown. Accordingly as the truck traverses the field and shredded lettuce is introduced into the truck from shredder 40, the mass of shredded lettuce accumulated within the truck moves slowly forward to effect uniform distribution of the shredded lettuce within the truck. Truck T includes an enclosure surrounded and enclosed by a hollow wall W formed by spaced apart panels 43 and 43'. A blower or refrigeration unit U delivers air to the volume defined between panels 43 and 43'. If unit U is a blower, it delivers air at ambient temperature and the structure is capable of preventing the lettuce temperature from rising above ambient. If unit U is a refrigerator, the temperature of the lettuce is also prevented from exceeding ambient and is indeed reduced.
In operation the truck moves over the field in furrows F and a crew of field hands walks behind conveyor 15. The field hands manually sever the lettuce heads from rows R and, after coring the lettuce heads and removing the outer leaves, place the heads individually in cups 18. Because each lettuce head is supported in a single cup 18, the head is not subjected to bouncing or rubbing whereby the outermost leaves are not bruised or otherwise adversely affected.
The heads proceed in single file along the conveyor and up vertical section 26 until the heads are dumped one by one into hopper 38 in response to contact of cam 34 by finger 36. Single file presentation of the lettuce heads to shredder 40 optimizes the efficiency of the shredder, because it works against a substantially constant load and is not subjected to surges of input as is the case where many heads are dumped into the input hopper at one time. Moreover, delivery of the heads one-at-a-time to the shredder eliminates bridging of hopper 38 by a plurality of heads. Thus the shredder works smoothly without operator attention and consumes minimal power. The shredded lettuce is discharged into the interior of truck T and because conveyor floor 42 moves slowly forward, a uniformly distributed mass of lettuce within the truck is formed. Conveyor 16 is typically operated at about 85 feet per minute so that the time elapsing between severing the head and introducing the shreded lettuce into truck T is less than one minute. Accordingly the outer leaves of the head do not dry out or loose turgidity whereby the mass of shredded lettuce within truck T is of uniform quality. The insulated and/or refrigerated truck enclosure prevents significant deterioration or temperature rise of the shredded lettuce contained therein. When truck T is full conveyor 15 is pivoted about the axis of shaft 12, to a position shown in FIG. 3, so that the truck can efficiently move from the field at relatively high speed.
On or adjacent the field is a mobile processing van V, a pumping conveyor P and a centrifuge enclosure C. Truck T backs into a position in alignment with an inlet opening 44 in pumping conveyor P and a tailgate or ramp 46 is folded down to form a discharge path for the shredded lettuce. Conveyor 42 is operated in a reverse direction so that the shredded lettuce supported thereon is discharged over ramp 46 into an input trough 48. Input trough 48 is a conventional device available from the Key Equipment Company, Milton-Freewater, Ore. Water and the shredded lettuce are pumped through the trough to an outlet by a pump 49 such as a 3-inch Model NL, manufactured by the Cornell Pump Company, Portland, Ore. Within the enclosure of pump conveyor P there is sufficient space on either side of ramp 46 for a workman to stand and move the lettuce into trough 48 and remove any spurious material therefrom. The water is delivered to trough 48 through a line 82 and is chilled or refrigerated by a unit within van V to be described before it reaches the trough. Accordingly the reduction of temperature of the lettuce commences as it is discharged into the trough. Because an efficient field crew can fill a truck T in about one hour and because the truck is insulated and/or refrigerated, the temperature differential between the shredded lettuce and the water within trough 48 is minimized thereby requiring less energy to chill the shredded lettuce down to a temperature slightly above freezing.
There is additional space within pump conveyor P for one or more inspectors to stand adjacent trough 48 and remove from the trough any spurious articles or defective portions. The shredded lettuce and water are pumped through a discharge hose 50 up to a level at or near the top of van V. The discharge hose 50 extends through a coupling 51 and a gasketed opening 52 in a rear panel of van V and into a chiller-washer unit 54.
Chiller-washer unit 54 includes a drum 56 supported for rotation on a generally horizontal axis. At one end drum 56 is supplied with a ring gear 58 which meshes with a pinion 60 driven by a drive motor (not shown). Consequently drum 56 revolves in a counterclockwise direction as viewed in FIG. 5. The wall of drum 56 is perforated as at 62 so that water entering the drum can drain therefrom. Such water is introduced into the drum by spraying from a plurality of nozzles 64 which are supported by and supplied with water from a water pipe 66 which extends interior of the drum in a location above the central axis thereof. As seen in FIG. 4, nozzles 64 are arranged to produce an obliquely directed spray toward the outlet or right hand end, as viewed in FIG. 4, of the chiller-washer apparatus. Such oblique orientation together with the presence of helical flights 68 on the interior of drum 56 cause the shredded lettuce to move through the chiller-washer. There are nozzles 64a (see FIG. 5) that are directed in a downward-forward position; there are nozzles 64b that are oriented to impinge on drum 56 above the lower extremity thereof. Nozzles 64b are oriented obliquely of vertical in both the axial direction of drum 56 and the radial direction of the drum. The latter orientation of nozzles 64b is particularly effective, in view of the rotation of drum 56, in assuring impingement on all lettuce surfaces as the lettuce rises on the drum surface in response to drum rotation. Because there is a large number of nozzles 64 and because the spray from each is relatively fine, all surfaces of the lettuce are treated with water delivered to pipe 66 without employing a substantial quantity of water. Accordingly the water can be efficiently chilled to a temperature above freezing and no greater than about 40°.
For chilling the water there is disposed in water receiving relation of the water flowing through perforate portions 62 of the drum a receiving pan 70 located below the drum. An imperforate deflector 71 deflects water from nozzles 64b that passes through drum 56 into the receiving pan. Receiving pan 70 has a plurality of strategically located discharge openings 72 which are arranged so that water falling therethrough is distributed so as to traverse refrigerating coils 74 in heat exchanging relationship therewith. Accordingly, by the time the water reaches a pool 76 at the bottom of an impervious housing 78 within which coils 74 are disposed, the temperature of the water is reduced to the desired temperature. A circulating pump 80 withdraws water from pool 76 and delivers it through pipe 66. There is also an outlet 82 from pool 76 which delivers chilled water to trough 48 in pumping conveyor P. Accordingly one refrigeration system (associated with coil 74 and indicated schematically at 84) maintains the water temperature so that it is effective in rapidly chilling the shredded lettuce as it is processed in the apparatus of the invention and so that the lettuce emerges from chiller-washer 54 at the temperature of the water, e.g. 34° F.
Various preservatives, such as those described in the above cited U.S. Pat. No. 3,849,581 are useful in retarding deterioration of the lettuce. Insofar as the present invention is concerned, the employment of preservatives is optional. Such preservatives are supplied in drums 86 and can be added to pool 76 by means of a pump 88 which is controlled in a conventional way to deliver the preservatives at a correct rate. Accordingly as the shredded lettuce egresses from the chiller-washer, it is at a temperature sufficiently low as to retard significant deterioration and it has been treated with such preservative materials as may be desired to enhance further the longevity thereof.
Lettuce egressing from chiller-washer 54 is discharged into an impervious housing 90 having an upper inlet opening 91 of a size corresponding to the diameter of drum 56 so that the housing receives lettuce and water from the drum. Housing 90 converges downward to a relatively small diameter outlet 92 for output to a pump 93 which is of the type identified hereinabove by reference numeral 49 and installed within pumping conveyor P. Pump 93 has an outlet hose 94 through which lettuce and chilled water are discharged. The opposite end of hose 94 extends through a coupling 95 and the wall of processing van V to a Y fitting 96 mounted in centrifuge enclosure C. The outlet legs of Y fitting 96 are connected through alternately operated solenoid valves 98 and 100 which are arranged to discharge the water borne lettuce into respective centrifuges 102 and 104.
Each centrifuge 102, 104 includes an outer impervious fixed drum housing or curb 106 which is carried by structural support members 108. Extending centrally of each housing 106 is a shaft 110 which is supported by an upper bearing 112 and a lower bearing 114. Each shaft 110 has at the upper end thereof a drive mechanism respetively indicated at 116 and 118 which drive shafts 110 of the respective centrifuges.
Secured to each shaft 110 is a plurality of spokes 120 which support a rigid ring 122 in concentric relation to shaft 110; depending from and rigid with ring 122 is a perforated basket 124 which is disposed concentrically within fixed impervious housing 106 such that the water that passes through the perforations in drum 124 in response to rotation of the device is confined within the impervious housing. Such water gravitates to a manifold 126 for return to pool 76 through a pipe 127, a filter 127f and a pump 127p. The lower end of perforated basket 124 is reinforced by a ring 123 which defines a bevelled surface 123b. There is a conical wall 128 having an angle of convergence corresponding to the bevel angle of surface 123b so that when the conical wall is in an upward, closed position (shown at the right hand side of FIG. 6), a water tight joint between ring 123 and the conical wall is established.
The upper end of conical wall 128 is fixed to a bushing 129 which slidably circumscribes shaft 110. The lower end of conical wall 128 is supported by a plurality of spokes 130 which radiate from a circular plate 131 which is supported for reciprocal movement on shaft 110 by a bearing seal 133 which is backed by a cylindric flange 134 fixed to the lower surface of the circular plate. Secured to the periphery of circular plate 131 and depending therefrom is an impervious cylindrical wall 135. For cooperating with the inner surface of cylindrical wall 135 to define an air chamber there is a piston plate 136 fixed to shaft 110, the outer periphery of the piston plate having seals 137 which form an airtight seal against the inner wall of cylinder 135 to define an air chamber 138.
The lower end of shaft 110 is formed with an axial bore 139 and a radial bore 140 which cooperate to establish an air path between the exterior chamber 138 and the interior thereof. It will be appreciated that air applied to the lower extremity of bore 139 will pressurize chamber 138 to cause circular plate 131 and conical wall 128 to move upward into a position to close the centrifuge. Release of the air pressure permits the conical wall the the elements fixed thereto to fall in response to the force of gravity so as to permit opening of the centrifuge and discharge of the contents thereof.
In one system designed according to the present invention basket 124 has a diameter of about 34 inches and a vertical dimension in the same order of magnitude. Such structure, particularly when filled with wet lettuce and rotated at a fast speed, is subject to substantial stresses. Because conical wall is rigidly supported by spokes 130 and because of the substantial force imposed by air chamber 138, the conical wall when engaged with the bevelled surface 123b provides a structure of sufficient strength to withstand such stresses.
Disposed below centrifuges 102 and 104 are impervious troughs 147a and 147b respectively which are sloped toward a site intermediate the troughs for discharge onto a conveyor 148. Conveyor 148 extends into van V through a duct or tunnel 149 which houses the conveyor and establishes communication between van V and centrifuge enclosure C so that cold air produced in the former will circulate into the latter.
Because centrifuges 102 and 104 and the lettuce and water introduced thereinto are heavy and are subjected to extremely high speeds and centrifugal forces, it is important that the centrifuge enclosure C be firmly anchored. For this purpose there is a concrete foundation 150, one such foundation being constructed at each site where the apparatus will be operated. The sites are typically sufficiently close to lettuce fields that truck T, when filled with shredded lettuce, can reach the processing van within a short time so as to assure continuous product flow and to reduce the possibility of deterioration of the lettuce.
Foundation 150 has a base portion 152 which bears on the earth's surface to support the weight of the foundation and the weight of centrifuge enclosure C superposed thereon. Projecting upward from the periphery of the base portion is a wall 154 which defines a rectangular support surface generally congruent to the rectangular perimeter of centrifuge enclosure C. The enclosure has a rectangular base frame formed by suitable structural members, such as box beams 156, on which the centrifuges, a framework and enclosure walls are fixed. The framework includes cross beams 157 which reinforce the frame and afford support for the centrifuges. Secured to the exterior peripheral surface of structural members 156 is a row of tubular members 158, there being imbedded in foundation wall 154 at equally spaced apart intervals a plurality of tubular members 160. The exterior surface of foundation wall 158 is notched as at 162 to afford access to the lower end of tubular members 160. Through bolts 164 are extended through aligned tubular members 158 and 160, and nuts 166 are engaged on the opposite end of the through bolts to fix securely centrifuge enclosure C to the foundation.
The height above grade of the support surface defined by foundation wall 154 is established approximately equal to the height above grade of a flat bed truck, e.g. about 54 inches. In order to install centrifuge enclosure C on foundation 150, the truck carrying the enclosure is placed adjacent foundation 150 and the enclosure is slid from the bed of the truck onto the foundation. When tubular members 158 on the enclosure are aligned with respective tubular members 160 within the foundation, bolts 164 and nuts 166 are installed and operation can proceed without excessive vibration in view of the substantial mass of the foundation and the fact that the foundation is embedded in the earth's surface. Interior of foundation wall 154, a drain pipe 167 is provided so as to maintain the interior in a dry condition.
In accordance with the present invention centrifuge 102 and 104 are operated alternately on a cycle of between about two to six minutes. That is to say, solenoid valve 98 is closed and valve 100 is opened for a period. This deposits shredded lettuce into centrifuge 104. When the centrifuge is full, drive 118 is activated to spin the centrifuge and cause water remaining on the surface of the shredded lettuce to move outward through perforate basket 124 for eventual discharge through pipe 127 to pool 76. During the loading and high speed spinning of centrifuge 104, air pressure chamber 138 associated with that centrifuge maintains the centrifuge in a closed condition. Air is released from the chamber associated with centrifuge 102 so that the conical wall drops to permit the lettuce in centrifuge 102 to discharge, the discharge occurring a path, such as identified by arrow 146, so that the shredded lettuce falls by gravity onto a table 147a. At this time all surface moisture on the lettuce has been removed so that the lettuce is substantially dry. Because centrifuge enclosure C and van V are maintained at a temperature no greater than about 40° , the lettuce is fresh and turgid.
The dry cold lettuce is deposited onto conveyor 148 by gravity and is transported by the conveyor through tunnel 149 and into van V. See FIG. 3. The lettuce discharges from the end of conveyor 148 onto a table 168 which has a generally inverted V-shape so that the lettuce tends to move laterally outward of the center or mid-line of the table. At the outward edge or lateral extremity of table 168 there is a plurality of openings which communicate with downward depending funnels or chutes 170. Oriented below each chute 170 is a scale platform 172 on which is supported a container such as a plastic bag or the like 174. A readout for each scale 172 (not shown) is provided at the eye level of a workman so that when a preselected weight of shredded lettuce has been moved into container 174 through chute 170, the container can be removed from the funnel, evacuated, and tied off or similarly closed in accordance with conventional procedure. It should be noted that table 168 is proportioned such that there is sufficient space between the extremity of the table and the side wall of van V for workmen to stand on either side of the table and package the lettuce as it is discharged from conveyor 148. The space is sufficient to accommodate vacuum apparatus for evacuating air from containers 174 prior to closure, if such is required in a particular situation. When containers 174 are closed, several such containers are placed in a shipping carton 176. Cartons 176 are transported by a conveyor (not shown) to a sealing station 178 where the cartons of shredded lettuce containers are sealed. From sealing station 178 the sealed filled cartons are placed on a roller conveyor, the distal end of which is seen at 180 disposed within a semi-trailer S. The side wall of van V is provided with an opening (not shown) so that the packaged products can be promptly and efficiently loaded into trailer S. Trailer S is typically refrigerated, and when it is full, it is ready to be transported over the road to the consumer's location.
Included within van V at the forward end thereof is a power station 182 where there are located generating facilities for providing the power to power the equipment and refrigerate the air within van V and enclosure C. Rearward of power station 182 is a carton setup station 184 at which one or more operators can take carton flats and set them up for transfer on a conveyor 186 to receive a plurality of lettuce packages 174 therein. Thus the path of movement of the cartons commences at carton setup station 184, proceeds on conveyor 186 to a location adjacent table 168 where the cartons are filled with a preselected number of lettuce containers, and thence to sealing station 178 from which, after the cartons are sealed, they are transported via roller conveyor 180 to semi-trailer S.
To summarize the operation of the method and apparatus of the invention, it will be assumed that trailer T has been filled with shredded lettuce as described above. Because van V, pumping conveyor P and centrifuge enclosure C are portable or mobile structures, they are positioned closely adjacent the field traversed by truck T in consequence of which the lettuce is extremely fresh when it is discharged into trough 48 of pumping conveyor P. The water in trough 48 is maintained at a temperature no greater than about 40° so that chilling is commenced immediately on discharge of shredded lettuce into the trough. Because of the clear space along the trough and on opposite sides of chute 46, workmen can manually move the lettuce into the processing line and can remove any spurious objects or defective lettuce pieces. When the lettuce has completed its traverse of trough 48, it is pumped upward through discharge hose 50 into chiller-washer 54.
Traverse of the lettuce through the chiller-washer results in efficient chilling of the lettuce, because the relatively fine sprays produced by nozzles 64 afford impingement on each and every lettuce piece with a stream of chilled water. The rotation of drum 56, the presence of flight 68 and the oblique orientation of nozzles 64 cooperate to expose all surfaces of each lettuce piece to the chilled water. This completes heat extraction from the lettuce as sell as affording efficient and uniform addition of preservatives dissolved in the water from drum 86. Throughout the traverse of the lettuce through chiller-washer 54 the water is circulated over coils 74 so that heat energy therein is quickly removed whereby upon delivery into housing 90, the temperature of the lettuce is substantially that of the water, i.e. above freezing but no greater than about 40°. The lettuce and cold water are pumped through hose 94; during traverse of hose 94 the low temperature of the lettuce is maintained. Depending upon which solenoid valve 98, 100 is open, the lettuce and water are delivered to one or the other of the centrifuges 102 and 104. Because the centrifuges operate alternately, pump 93 can operate continuously so that the movement of the lettuce through the apparatus is continuous. After treatment in the centrifuge for an appropriate period (e.g. 2-6 minutes), air is discharged from chamber 138 so that cone 128 drops and permits gravity discharge of the shredded lettuce onto one of the tables 147a, 147b for delivery to conveyor 148 and transport to table 168. At this stage all free surface water has been removed from the lettuce pieces. The now dry, chilled lettuce is moved across one of tables 147a, 147b to conveyor 148 and thence to table 168. Workmen standing adjacent to table 168 move the lettuce into chutes 170 and the containers supported thereunder. In a typical practice of the invention, the containers have a capacity of 10 pounds and when that weight is indicated by the readouts associated with scales 172, the workman removes the container, evacuates the air therefrom, seals it and places it in a carton 176. Typically cartons 176 are sized to contain three packages or 30 pounds of shredded lettuce whereupon the packages are conveyed to station 178 for sealing and subsequent loading into semi-trailer S.
The total elapsed time between severing the lettuce head from the field and placing it in conveyor 16 until it is treated, chilled and sealed in containers 174 can range from about 1/2 hour to about 2 hours and during the entire time the lettuce is protected by insulated or refrigerated truck T and the low temperature atmosphere within pumping conveyor P, van V and centrifuge enclosure C. The capacity of the apparatus is such that shredded lettuce from three trucks T can be handled on a substantially continuous basis. In this preferred mode of practice of the invention, one truck T traverses the lettuce field with a crew of pickers while a second truck T discharges its load into pumping conveyor P and a third truck travels between the field and the processing van.
Because of the repeated exposure to cold water of lettuce leaves traversing chiller 54, the lettuce can be rapidly reduced to less than 40° F. from ambient temperatures of up to 80 or 90 degrees or more. When the ambient temperature and therefore the temperature of the lettuce is lower, however, it is not essential that the lettuce be conveyed through the chiller to reduce the temperature of the lettuce to a temperature below 40° F. More specifically, in ambient temperatures of 55°-60° F., it has been found that sufficient heat is extracted from the lettuce by pumping the same directly from the outlet of trough 48 to the centrifuges in centrifuge enclosure C. To ready the apparatus for operation in such relatively low ambient temperature environment, it is only necessary to disconnect couplings 51 and 95 and provide a hose that directly connects hose 50 to Y fitting 96. The cool water delivered to trough 48 from pool 76 in the refrigeration system has been found sufficient to reduce the lettuce to a temperature below 40° by the time it reaches the centrifuge. This is the case because the water to lettuce ratio is approximately 10 to 1 and the residence time within the hose from coupling 51 to coupling 95 (about 4-12 seconds) is sufficient to cool the lettuce. Thus the invention affords versatility by being operable in a wide range of ambient temperatures at maximum efficiency and optimum power consumption at all such temperatures.
In the modification shown in FIGS. 9 and 10, the inlet trough and food pump are mounted within the van thereby eliminating the need for a separate pump conveyor unit P. In the detailed description of FIGS. 9 and 10, reference numerals employed in connection with FIG. 3 with the addition of a prime will be employed to identify corresponding parts. In FIG. 9 is shown the rear fragment of a van V' having therein a chiller 54', an impervious water storage and cooling container 78' and other processing and packaging equipment described hereinabove in connection with FIG. 3. Rigid with and extending rearward from van V' is a protective enclosure 190 the bottom of which is formed by a rigid frame 191 including longitudinally extending structural members 192 and 194 and transverse reinforcing members 196. Supported on such frame is an inlet trough 48' and a horizontal platform 197 which has a forward edge overlying the trough to facilitate introduction of lettuce thereinto. The frame is supported to the rear of the frame members underlying van V' by pivot points 198, the forward ends of frame members 192 and 194 having angularly upward extending portions 200 which position the frame at a low level so that chopped lettuce from truck T can be discharged into trough 48' via gravity. A cold water inlet pipe 82' delivers water to one end of the trough and at the opposite end of the trough is a food pump 49' of the type referred to hereinabove for pumping the cold water and lettuce through discharge hose 50'. The lettuce is conveyed through chiller 54', when the ambient temperature is relatively high, and directly to the centrifuges, when the ambient temperature is relatively low.
In order to achieve gravity feed from truck T into trough 48' it is desirable that trough 48' be supported at a low level, seen in FIG. 9. However, for movement of van V' over the road it is imperative to raise the trough and its supporting structure to an elevated position. For achieving this purpose there is a pivoting mechanism to raise the trough frame to the broken line position shown in FIG. 9. Exemplifying such mechanism is a cable 202 trained around a sheave 204 and then wound on a motor driven winch 206. Thus when it is desired to ready van V' for receipt of chopped lettuce from truck T, cable 202 is released until frame 191 reaches the horizontal position shown by solid lines in FIG. 9. When it is desired to prepare van V' for over the road movement, winch 209 is activated to raise frame 191 to the broken line position of FIG. 9.
Because operation of the embodiment of FIGS. 9 and 10 is substantially identical to that described above, the operation of the embodiment will not be explained in detail at this point. It is sufficient to say that setup time is shortened because the inlet trough is integral with van V'. By lowering tail gate 46 of truck T, resting its outer end on platform 197, and actuating conveyor 42 within the truck, the lettuce is moved over the platform and into trough 48' for delivery to the processing apparatus within the van.
Thus the freshness and turgidity of the lettuce is retained, and because the temperature rise of the lettuce is minimized, a minimum amount of power is required to chill the lettuce to a proper storage and shipping temperature. Depending the distances involved, fresh, clean ready-to-eat shredded lettuce can arrive at the consumer the day following the day during which it is picked. Because the method and apparatus of the invention are arranged for rapid handling of the lettuce in a protected and reduced temperature atmosphere at all times, the freshness and turgidity of the lettuce is maintained so that the product when it reaches the consumer has substantial shelf life. This should be contrasted with typical prior art methods in which more than one day elapses before the lettuce reaches a shredding and processing plant. During the one day period the lettuce is subjected to deterioration whereby much lettuce is wasted or the quality of the final product is lowered.
Thus it will be seen that the present invention provides a method and apparatus for harvesting and processing lettuce which produces a shredded lettuce product of unparalleled freshness and consequent long shelf life. Because of the efficient and rapid handling of lettuce, the power necessary to clean and chill the lettuce is minimized whereby it is entirely feasible to provide mobile processing apparatus that can be moved from field to field and area to area depending on the maturity of the crops. Not only is waste minimized, but the cost of removing and disposing of outer lettuce leaves incurred in prior art procedures is reduced, if not eliminated. Finally the apparatus is arranged to efficiently utilize manual labor so that the total number of laborers is held to an absolute minimum. Although one embodiment of the invention has been shown and described it will be obvious that other adaptations and modifications can be made without departing from the true scope and spirit of the invention.
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A method and apparatus for harvesting and processing head lettuce wherein the lettuce is shredded immediately upon harvesting and before deterioration occurs. The shredded lettuce is retained in an insulated or refrigerated enclosure and then promptly transported to a mobile processing trailer where it is further cleaned and chilled and finally packaged for shipment. The practice of the method and apparatus permits the lettuce to be on its way to the consumer on the same day that it is harvested from the field.
A method and apparatus for simultaneously chilling, washing and adding preservatives to the chilled lettuce in a continuous fashion. A mobile enclosure embodying the apparatus and adapted to perform the method wherein the lettuce is maintained at a reduced temperature throughout all stages of processing.
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CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of a co-pending application entitled "Improved Roller Bar Construction", Ser. No. 864,770, filed Feb. 15, 1978 now abandoned.
BACKGROUND AND SUMMARY OF THE INVENTION
The present invention relates generally to a novel construction for awning roller or lead bars, and more particularly concerns a method of constructing roller bars for extendible awnings of the roll-up type popularly utilized with recreational vehicles.
The vigorous pursuit of leisure time activities by Americans has fostered the growth of several diverse industries. Among these industries, the construction of recreational vehicles and their accessories has found a wide market. In particular, trailers, vans and motor homes are favorites with families that enjoy traveling or camping. Extendible awnings have become, in turn, one of the most popular accessories for such recreational vehicles. These awnings generally include a sheet of flexible canopy material secured along one end of the vehicle and secured along the opposite end to a roller bar supported by uprights. Besides the weight of the canopy, wind and precipitation loads further contribute to the stress on the roller bar. Frequently, a valance, screen or sunshade is also attached to the roller bar. To meet the structural requirements, roller bars heretofore have been of extruded or drawn construction. However, roller bars constructed according to the prior art tended to be both heavy and expensive.
The present invention comprises a roller bar construction particularly adapted for use with recreational vehicle awnings which overcomes the foregoing and other problems long since associated with the prior art. In accordance with the broader aspects of the invention, a straight, predetermined length of thin-walled tubing is first provided such as by roll forming the tubing from a sheet of metal. The outer configuration of the tubing provides strength and stiffening, and a reinforcing medium may be provided inside the roller bar, if desired or necessary. By means of this invention, roller bars can be constructed with significant cost and weight savings.
In accordance with more specific aspects of the invention, a section of thin-walled tubing is roll formed from a sheet of metal. Longitudinal profiles are then roll formed into the tubing for partial reinforcement of the tubing to resist bending stresses. However, it will be appreciated that even after formation of the profiles therein, additional reinforcement may be desirable. An expandable material, such as a foamed plastic, is then injected into at least a portion of the space defining the core of the tubing. The expansion and subsequent stabilization of the material into a rigid foam core further strengthens the tubing to provide a strong, light-weight roller bar.
In accordance with another aspect of the invention, the tubing may be roll formed having eight equilateral sidewalls and having a slideway formed along the midregion of at least one of said walls. The roller tubing is formed of a continuous sheet having two longitudinal edges with U-shaped folds for interlocking the edges together to form a closed tubing. Crooks are provided to recess the folds such that the exterior surface of the roller bar is substantially even.
The slideway includes a longitudinal aperture extending along the midregion of one of the equilateral sidewalls. Two slideway walls extend from the edges of the aperture inwardly at about 45° angle with the sidewall. A curved third slideway wall extends between the other two slideway walls to form a substantially triangularly shaped slideway. A plurality of such slideways may be formed in the tubing, and all corners of the roller bar may be rounded.
A roll formed octagonal roller bar with one or more longitudinal slideways will have sufficient strength for many awning applications. However, if additional strengthening is necessary or desirable, a foamed plastic may be injected into at least a portion of the roller bar, or inserts conforming to the shape of the roller bar may be spaced within the bar to provide reinforcement.
The roller bar of the present invention may include one or more longitudinal slideways for attaching awnings, valances, screens and the like to the roller bar. In another embodiment, the roller bar is formed with a continuous exterior surface, and the awning is attached to the roller bar by fasteners or adhesives, or by insertion of the roller bar through a loop sewn on the edge of the awning, or by a combination thereof.
DESCRIPTION OF THE DRAWINGS
A more complete understanding of the invention may be had by reference to the following detailed description when taken in conjunction with the accompanying drawings, wherein:
FIG. 1 is an illustration of a recreational vehicle including an awning with a leader or roller bar;
FIG. 2 is an enlarged cross sectional view of a roller bar typifying of the prior art;
FIGS. 3, 4 and 5 are enlarged cross sectional views of roller bars constructed in accordance with the present invention;
FIG. 6 is an illustration of a step in the roller bar construction of the invention;
FIGS. 7 and 8 are broken sectional views of roller bars constructed according to the invention;
FIG. 9 is a cross sectional view of an octagonal roller bar of the present invention having eight equilateral sides, interlocking folds and two triangular shaped slideways;
FIG. 10 is a cross section of a cylindrical roller bar of the present invention having a continuous exterior configuration;
FIG. 11 is a broken away view of a roller bar showing a dumbbell insert;
FIG. 12 is a broken away view of a roller bar showing an octagonal insert; and
FIG. 13 is a perspective view of a roller bar extending through a loop on the edge of an awning with fasteners and adhesives attaching the awning to the roller bar.
DETAILED DESCRIPTION
Referring now to the drawings, and particularly to FIG. 1 thereof, there is illustrated a recreational vehicle 10 having awnings 12 and 14 with which the leader or roller bar construction of the present invention is particularly suited. Each of the awnings 12 and 14 includes a generally rectangular canopy 16 formed of a flexible material, such as canvas or vinyl. Secured along one side to vehicle 10, each canopy 16 is connected to and supported by a roller or lead bar 18 along the opposite side. Bars 18 in turn are supported by uprights 20. Particularly with the larger awning 12, side braces 22, only one of which is shown, are often utilized to lend additional stability to the awning. The relatively smaller awning 14 is employed to protect a small opening, such as a window. The relatively larger awning 12 is most popularly used to construct a temporary enclosure adjacent to the recreational vehicle 10. For example, awning 12 may extend up to eight feet from and up to twenty feet along vehicle 10 and may be utilized for a car port, breezeway, porch or the like. The roller bar construction of the present invention is suitable for either awning 12 or awning 14, however it is most beneficial in conjunction with the higher stress requirements of a large awning. Allthough depicted in FIG. 10 as a trailer, it will be understood that recreational vehicle 10 could be a camper, van, motor home or any other type of recreational vehicle utilizing collapsible awnings.
Referring now to FIG. 2, there is shown a cross section of a roller bar 18 representative of the prior art. Bar 18 comprises a hollow tube of extruded or drawn metal characterized by a relatively thick wall. Steel or aluminum is often the metal utilized to form bar 18 of the prior art. Three longitudinal channels 24 together with ribs 26 can be extruded into the wall of bar 18. Channels 24 are utilized to receive and secure the edge of canopy 16, and the edges of a valance 28 and a screen or wall 30, if desired. While channels 24 and ribs 26 may contribute to the structural vigor of bar 18, it will be understood that the substantial wall thickness of prior art bar 18 is the primary structural factor. Moreover, the extrusion process is relatively complex and therefore expensive. Consequently, bars 18 constructed in accordance with the prior art are unnecessarily costly and heavy.
With reference to FIGS. 3, 4 and 5, there are shown cross sectional views of roller bars 40 constructed according to the present invention. Bar 40 constitutes a significant improvement over bar 18 hereinbefore described, and is particularly suited for use with awnings on recreational vehicles. Improved roller bar 40 is lighter and less expensive than those found in the prior art, while meeting the same structural requirements.
In the construction of roller bar 40, a straight, predetermined length of tubing 42 having a hollow core is first provided. Tubing 42 is preferably of circular cross section and is characterized by thin-walled construction. Tubing 42 can be constructed of any suitable rigid material, such as steel, aluminum or plastic. For example, a length of aluminum tubing having a three inch outside diameter and a wall thickness ranging from approximately 0.015 to 0.060 inches has been found satisfactory. Tubing 42 thus comprises an elongate, thin-walled cylinder.
The desired longitudinal profiles 44 are then formed into the outside surface of tubing 42. Profiles 44 may be of any desired configuration suitable for serving as slideways having exterior apertures for attachment of the edges of a canopy, screen, wall or valance. FIGS. 3, 4 and 5 show examples of three alternative profiles 44 which could be formed in tubing 42. Although the examples of FIGS. 3-5 depict three profiles per roller bar, it will be understood that the desired number of profiles 44 can be any plurality. In one embodiment of the present invention, at least one longitudinal profile with an exterior aperture is formed in tubing 42 to provide for the connection of a canopy similar to canopy 16. A plurality of longitudinal profiles 44 can be produced at regular circumferential intervals, preferably, around tubing 42 by means of a conventional roll forming process. The formation of profiles 44 not only provides the desired slideways therein, but serves to partially reinforce tubing 42. Tubing 42 is thus stiffened by longitudinal profiles 44.
Turning to FIG. 6, an expandable material is then injected from nozzle 46 into the hollow core of tubing 42 for additional reinforcement. Nozzle 46 is connected to a source (not shown) of expandable material in liquid form. The material discharged from nozzle 46 can be a foamed plastic, or an expandable polymer such as polystyrene, polyethylene or polyurethane, which expands to a low density cellular state. As shown in FIG. 6, the expandable material is injected through holes 48 into tubing 42. However, it will be understood that the tubing can be filled from either end without holes 48. After injection into tubing 42, the material expands to fill at least a portion of the core of tubing 42. With the stabilization of the foamed material within tubing 42, a rigid core 50 is formed therein. Core 50 is characterized by low density and high rigidity so as to longitudinally reinforce tubing 42 and to provide a lightweight roller bar 40 in full satisfaction of the structural requirements. For the greatest strength, core 50 extends completely through bar 40 as shown in FIG. 7. For some applications, it may be sufficient to provide for sections of core 50 within bar 40 as is depicted in FIG. 8. It will also be understood that bar 40 is suitable for some applications without reinforcement.
Referring now to FIG. 9, there is shown a cross sectional view of a roller bar 60 illustrating one embodiment of the present invention. Roller bar 60 includes eight equilateral sidewalls 62, 64, 66, 68, 70, 72, 74 and 76, each intersecting at an angle of approximately 135° to form a substantially equilateral octagonal cross sectional profile. The diameter or width of roller bar 60 from wall to wall is approximately three inches.
Roller bar 60 is formed from one continuous sheet of metal, preferably 28 to 24 gauge galvanized steel, having two longitudinal edges on which U-shaped folds 78 and 80 are formed. The U-shaped folds 78 and 80 are interlocked to form a closed tubing, and crooks 82 and 84 are formed adjacent folds 78 and 80, respectively, to recess the two folds inwardly towards the center of roller bar 60. Extending, respectively, from crooks 82 and 84 are sidewall portions 86 and 88. Thus, the sidewall 62 is formed by sidewall portions 86 and 88, crooks 82 and 84, and the folds 78 and 80. By recessing the folds 78 and 80, the exterior portion of fold 78 is substantially coplanar with the sidewall portions 86 and 88, and the exterior surfaces of sidewall 62 is substantially flat.
The sidewall 66 of roller bar 60 includes two sidewall portions 90 and 92 and a longitudinal aperture 94 extending along the midregion of sidewall 66 separating the sidewall portions 90 and 92. Two slideway walls 96 and 98 extend from the sidewall portions 90 and 92, respectively, forming an angle A of approximately 45° with respect to the two sidewall portions. Extending between slideway walls 96 and 98 is a curved slideway wall 100. Because of the curvature of slideway wall 100, the angle between wall 100 and walls 96 and 98 is greater than 45°, and is approximately 50°. The combination of slideway walls 96, 98 and 100 forms a longitudinal slideway 102 having a triangular cross section and communicating with the exterior of roller bar 60 through aperture 94.
An identical slideway 104 is formed along sidewall 74 by slideway walls 106, 108 and 110. Slideway 104 communicates with the exterior of roller bar 60 through an aperture 112. Also, slideway walls 106 and 108 extend from wall portions 114 and 116, respectively, forming an angle therewith which is approximately 45°. Likewise, the angles formed between slideway wall 110 and walls 106 and 108 are approximately 50°. It should be noted that all corners between all walls and wall portions may be rounded as shown in FIG. 9 in accordance with conventional roll forming techniques.
The construction disclosed in FIG. 9 is considered an important aspect of the present invention. It has been found that this structure is well adapted for strength and durability as a roller bar for an awning. Although the octagonal configuration of roller bar 60 and the slideways 102 and 104 provide sufficient strength and stiffness for many awning applications, it will be understood that roller bar 60 may be reinforced with foam or inserts as described with respect to alternate embodiments of the present invention. Additionally, it has been found that the structure shown in FIG. 9 is relatively easy to manufacture by roll forming techniques.
Referring now to FIG. 10, there is shown a roller bar 118 constituting an alternate embodiment of the present invention. Roller bar 118 has a substantially circular cross section and is formed by conventional roll forming techniques from a sheet of metal. Folds 120 and 122 are formed along the longitudinal edges of roller bar 118 and are interlocked to form a substantially closed tubing. A crook 124 recesses fold 122 inwardly with respect to roller bar 118 to provide a substantially round exterior cylindrical surface on roller bar 118 in the region of folds 120 and 122. Roller bar 118 also includes reinforcing material 126 for stiffening and strengthening the roller bar. Reinforcing material may be a foam material that is injected into the roller bar 118 in the liquid state as discussed above in conjunction with FIG. 6. Alternately, reinforcing material 126 may comprise a pre-formed shape made of foam or from various solid materials.
Referring now to FIG. 11, a substantially cylindrical roller bar 128 is shown partially cut away to reveal a dumbbell insert 130. The dumbbell insert 130 includes two plugs 132 and 134 dimensioned to conform to the interior configuration of roller bar 128. The plugs 132 and 134 are connected by a tapered transverse bar 136 for preventing either of the plugs 132 or 134 from skewing inside roller bar 128. In the preferred embodiment, plugs 132 and 134 are approximately 11/2 inches thick and approximately 3 inches in diameter. Referring now to FIG. 12, an octagonal roller bar 138 is shown partially broken away to reveal an octagonal plug 140 disposed within the roller bar. Plug 140 conforms to the interior configuration of roller bar 138 and functions to strengthen and stiffen the roller bar.
Referring now to FIGS. 11 and 12, it will be understood that a plurality of inserts, such as insert 130 or plug 140, may be placed inside a roller bar at spaced positions to provide regular reinforcement along the roller bar. It will also be understood that the octagonal plug 140 may be combined with another octagonal plug in a dumbbell configuration as disclosed in FIG. 11 to prevent skewing inside the roller bar. Suitable materials for the insert 130, the plug 140, and other shapes for reinforcing roller bars include various foam materials, natural and synthetic rubber materials, plastics, wood, metals, etc.
Referring now to FIG. 13, there is disclosed a substantially cylindrical roller bar 142 inserted within a loop portion 144 formed on the leading edge of an awning 146. The loop portion 144 is formed by turning the leading edge of the awning 146 back on itself and sewing a seam 148 along the leading edge. In this configuration, it is not necessary to use a slideway to attach a roller bar to an awning.
Fasteners 152 and/or adhesive 150 may be used to further secure the loop portion 144 to the roller bar 142. Fasteners 152 are sheet metal screws used to firmly clamp the loop portion 144 against the roller bar 142. Adhesive 150 is placed between the loop portion 144 and the roller bar 142 to secure the loop portion to the roller bar. Adhesive 150 may be any of numerous modern adhesives suitable for gluing plastic to plastic or plastic to metal. Other fastening means may be used to secure the awning to the roller bar in accordance with particular requirements.
From the foregoing, it will be understood that the present invention comprises an improved leader or roller bar construction for awnings which incorporates numerous advantages over the prior art. The advantages deriving from the invention will readily suggest themselves to those skilled in the art.
Although particular embodiments of the invention have been illustrated in the accompanying drawings and described in the foregoing detailed description, it will be understood that the invention is not limited to the embodiments disclosed, but is intended to embrace any alternatives, modifications, or rearrangements and substitutions of parts and elements as fall within the spirit and scope of the invention.
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An awning roller bar or lead bar is formed from a relatively thin material for attachment to the leading edge of an awning. In one embodiment, the roller bar includes at least one slideway having an exterior aperture for receiving and securing the edge of a canopy to the tubing. In another embodiment the roller bar has a plurality of planar walls, a pair of interlocking folds and a substantially triangular slideway. If desired, more than one slideway can be formed in the tubing to provide for the attachment of a screen, valance, sunshade or the like. For reinforcement, an expandable material is injected into at least a portion of the tubing core. The expansion and subsequent stabilization of the foamed material strengthens the tubing to provide a roller bar of rigid construction and light weight. Alternately, rigid inserts may be spaced apart within the roller bar to provide reinforcement, or, in some instances, the configuration of the roller bar, itself will provide the strength necessary to support the awning.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to automatic test equipment of the type used to test integrated circuits either singly or in combination with other circuits, and in particular, to a technique for deskewing signals supplied to a device being tested in such a system.
2. Description of the Prior Art
Numerous types of automated test equipment for the testing of individual integrated circuits or groups of integrated circuits are known. For example, the Fairchild Test Systems Division of Fairchild Camera & Instrument Corporation, assignee of this invention, manufactures systems known as Sentry® test systems. In such a system an individual integrated circuit is positioned in a suitable fixture to permit application of stimuli signals to various pins of the device, and reception of the resulting output signals from the device. By comparing the resulting output signals with those known to be produced by a satisfactory device, or expected by circuit analysis and calculations or other analytical techniques, the functionality and/or performance of the device being tested may be determined. Typically in such systems, a digital computer is used to control a timing module which supplies a variety of timing signals to a format control. The format control, in response to the timing module, generates signals of appropriate waveform and supplies them to a series of pin electronic circuits, each associated with a pin of the device under test. Signals from the device under test are returned to the pin electronic circuits and to a failure response unit for detecting the functionality and/or performance of the device being tested.
As increasing numbers of functions are placed on single integrated circuits or groups of integrated circuits, and as the performance of such circuits improves, the performance of the test system itself must be improved to enable it to detect variations in the performance of the integrated circuit being tested. One well-known problem in the manufacture and use of automatic test equipment is the timing skew of both the input signals supplied to the device under test, and the output signals received from the device under test. If the stimulation signals are not deskewed, the proper functioning and/or performance of the device being tested cannot be determined. In typical prior art systems, deskewing was accomplished using extensive manual adjustments of potentiometers associated with each pin of the automatic test equipment. In one prior art 120 pin system, each pin has 8 potentiometers associated with it for deskewing various signals supplied to, or received from, that pin. Thus, almost 1,000 potentiometers had to be manually adjusted in order to suitably align the system to perform tests. Because the settings of the particular potentiometers affected each other, it was often necessary to adjust each potentiometer more than once during alignment of the system. Obviously this was a lengthy, labor intensive, and expensive operation.
Another problem in prior art test systems is the generation and deskewing of inverted waveforms. In some modes of operation of automatic test equipment it is desirable to supply first one waveform, and then its complement, to the device under test. As explained above it is desirable that both such signals be deskewed.
Furthermore, with the operational speed of individual test systems approaching 20 megaHertz, skew tolerances of no more than +1 nanosecond maximum and +500 picoseconds typical are necessary. Using conventional prior art techniques, tolerances to within one nanosecond have been achieved, but only if tests are conducted immediately after alignment of the test system and only using small subsets of the system's timing and format capabilities. As the system is continuously used, the reliability of the alignment diminishes. Consequently, when a test engineer determines that yields of the devices being tested are varying, he does not know whether there is indeed a yield variation, or whether the test equipment has deviated from specifications.
SUMMARY OF THE INVENTION
This invention eliminates the manual adjustment of potentiometers necessary with prior art test apparatus. The invention enables adjusting system skew over all formats and timing generators to within tolerances not heretofore achievable. Furthermore, by eliminating the extensive manual adjustments necessary, the invention shortens "down time" for system alignment from about a half day to approximately 15 minutes. The shorter alignment time enables the system to be more frequently aligned resulting in increased reliability of test results.
In one embodiment apparatus for supplying deskewed signals comprises: generating means for generating an electrical signal of desired duration, the signal including a leading edge and a trailing edge; differentiation means coupled to the generating means for separating the electrical signal into a pair of signals, one of the pair being a leading edge signal and the other a trailing edge signal; logic gate means connected to receive the pair of signals and supply one of the pair along a set path and the other of the pair along a reset path; set and reset time delay means, each connected to the corresponding path to delay the signal thereon by a desired time; latch means connected to the set and reset time delay means to receive signals therefrom and reform the electrical signal of desired duration; and control means coupled to the logic gate means for controlling to which of the set and reset paths each of the pair of signals is supplied.
In the preferred embodiment the set and reset time delay means comprise apparatus for delaying an electrical signal present at a selected node and include a first multiplexing means for connecting one of a plurality n of input terminals to an output terminal, a plurality of adjustable length delay lines, each coupled between a different set of input terminals to thereby cause the electrical signal to be supplied to each input terminal after the first input terminal after passing through at least one delay line, and means for supplying the signal to be delayed to the first input terminal.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a system block diagram of a typical test system illustrating the interrelationship of the timing module, the format control circuits, and the pin electronics circuits.
FIG. 2 is a more detailed schematic of the format control circuit associated with each pin of the device under test.
FIG. 3 is a detailed schematic of the coarse deskew circuit shown in FIG. 2.
FIG. 4 is a detailed schematic of the vernier deskew circuit shown in FIG. 2.
FIG. 5 is a more detailed schematic of the format control and deskew unit.
FIG. 6 is a timing diagram illustrating the function of the apparatus shown in FIG. 5.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a block diagram of a typical test system illustrating one use of our invention. As shown in FIG. 1 the test system includes a test system computer 10 which transmits control information and receives subsystem status reports, interrupt requests and test data from the device under test 90. In general various registers within the computer 10 allow control of each pin of the device under test 90, while other portions of the test system computer 10 compare outputs from the device under test 90 with a stored expected output pattern. The overall operation of the test system will be determined by a stored program in the test system computer 10.
The test system computer 10 will control a timing module 20 which allows the user of the test system to relatively accurately place edges of various timing signals supplied to the device under test. In a typical embodiment timing module 20 will contain 16 timing generators which position 32 independent timing edges. Thus the device under test 90 may be tested with various timing conditions to emulate combinations of input signals to which the device under test would be subjected in its intended application. The sequence and pattern control 30 allows the creation of various sequences and patterns of input data to be supplied to the device under test 90 to measure and/or detect its performance in response to such sequences or patterns. A precision measurement unit 40 allows quantitative voltage and current measurements at individual pins of the device under test 90, and allows forcing specified voltages or currents on desired pins of the device under test 90. Power and voltage supplies 50 are necessary for the operation of the device under test 90. The timing signals and desired sequence and patterns are combined and deskewed in the format control and deskew circuit 60, and then sent to the pin electronics circuit 80 and the device under test 90. The resulting output signals from the device under test are compared to known voltages at the pin electronics circuit and output signals from that circuit are deskewed and their timing checked. The data are supplied to a failure response unit 70 and compared with the expected data. Incorrect output signals from the device under test cause the failure response unit 70 to interrupt the testing procedure being carried out by the test system computer 10.
In a typical test sequence a pulse from one of the timing generators within timing module 20 passes through the format control and deskew unit 60 and arrives at the device under test 90. A response from the device under test 90 comes back through the pin electronics circuit 80 to the deskew circuit and to the failure response unit 70, which tells the remainder of the test system whether the device under test 90 has passed or failed the test. In the preferred embodiment there will be a format control and deskew circuit 60, a failure reponse unit 70, and a pin electronics circuit 80 associated with each pin of the device under test 90.
In many integrated circuits the pins of the device are designed to be simultaneously stimulated. Thus, if a pulse is sent from the timing module 20, for example, to all of the address pins of a circuit, it is desirable that all of the signals arrive at the device under test as simultaneously as possible. Because there are many timing generators, and many different modes of signals supplied to various pins, the signals which arrive at the device under test 90 may arrive through numerous different possible paths, resulting in substantial variations in propagation delay for the pulses. The format control and deskew circuit discussed in conjunction with FIGS. 2, 3, and 4 enable the signals directed to the various pins of the device under test to arrive there at the same time within design tolerances. Furthermore, these circuits allow automatic adjustment of the time delay applied by the deskewing circuit. In addition other deskewing circuits 35 and 36 allow deskewing of the output data from the device under test 90 so that the output data and the expected data from the format control and deskew unit 60 arrive at the failure response unit 70 at the same time within design tolerances. Furthermore, since the timing generators and deskew elements are independently adjustable, the deskew elements are equally usable for maintaining a precise time difference between different pins of the device under test. Thus, if the different pins of the device under test are both input pins driven by different timing generators, the timing generators can be set to the same value and the deskew circuits can be set to appropriately determine values such that the timed signals arrive simultaneously at the different pins of the device under test. Later, if one or both timing generators is set to a different value, the timing difference between the two pins will be determined by the timing difference between the two generators rather than by the differences in the circuitry used to couple the different timing generators to the different pins of the device under test. Similarly, if the different pins of the device under test are both output pins. Similarly, if the different pins of the device under test are a combination of input pins and output pins and pins which could be input pins at one time and output pins at another time.
FIG. 2 is a more detailed block diagram of the format control and deskew circuit 60. As shown a group of timing signals supplied by the timing generators present in timing module 20 are supplied over a plurality of lines to a well known multiplexer 12. Control signals from the test system computer 10 are also supplied to multiplexer 12 to thereby select one of the timing signals from the timing generators. The particular timing signal selected will depend upon the test to be performed on the device under test. The selected timing signal is then supplied from multiplexer 12 to differentiation network 15 over a pair of lines 13 and 14. A vernier deskew unit 17, operating under control of register 18, which in turn is controlled by the test system computer, maintains the desired pulse width of the timing signal supplied to differentiation network 15. The operation of vernier deskew unit 17 and register 18 is the same as the operation of the other vernier deskew units shown in FIG. 2, and will be explained below.
Using well-known techniques, differentiation network 15 extracts from the timing signal a leading edge signal and a trailing edge signal. The leading edge signal on line 19 and the trailing edge signal on line 21 are supplied to format control logic 23. A typical timing signal is shown near lines 19 and 21, together with the leading edge and trailing edge signals extracted by differentiation network 15 from the timing signal.
In general, a typical test signal to be created as a result of the format control logic 23 will include a train of pulses of different durations and characteristics designed to test a particular aspect of the integrated circuit being tested. The test signal supplied by format control logic 23 will be dependent upon the desired test to be performed by the user of the test apparatus. In general the format control logic 23 will be controlled by a stored program resident in the test system computer 10. The format control logic 23 translates the leading and trailing edge signals on lines 19 and 21 into set and reset signals which are supplied from the format control logic on lines 24 and 25. The set and reset signals will be appropriately chosen by format control logic 23 to cause latch 53 to switch in a desired manner to supply signals to the pin electronics circuit 80. In general either of the leading edge or the trailing edge signal may be used to set or reset latch 53 dependent upon the test program desired.
The set and reset signals supplied on lines 24 and 25 are each supplied to a coarse deskew unit 31 and 32, respectively, and to vernier deskew units 33 and 34, respectively. The coarse and vernier deskew units function to impose a desired time delay on the set and reset signals before they are supplied to the pin electronics 80. As discussed above, in testing integrated circuits it is desirable to simultaneously impose the test signals on various pins of the integrated circuit. Because of the different path delays inherent in the various paths by which signals may reach the integrated circuit being tested, some of the signals will need to be delayed more than other signals. The coarse and vernier deskew units shown in FIG. 2 will delay the signals passing through them by an amount specified by the test system computer controlling the registers associated with each deskew unit. For example, register 41, in response to data from the test system computer 10, will control the operation of coarse deskew unit 31 to impose the desired time delay on the set edge signal on line 24. The particular operation of the coarse and vernier deskew units shown in FIG. 2 will be explained in conjunction with FIGS. 3 and 4.
After appropriate deskewing, the set and reset signals are supplied to latch 53. Latch 53 functions to recombine the set and reset signals into a single pulse having the characteristics specified by the program in the test system computer. Latch 53 is used to supply the pulse to a driver in the pin electronics circuit 80. As discussed in conjunction with FIG. 1, this signal is imposed on a single pin of the integrated circuit being tested.
If the pin being tested is an output pin, rather than an input pin, signals from it are received by the comparator in pin electronics circuit 80. These signals are in turn supplied through coarse and vernier deskew units 35 and 36. These units function in the same manner as coarse and vernier deskew units 31-34, and are under control of registers 45 and 46. After deskewing, the output signals from the pin of the device under test 90 are supplied to a failure response unit 70 where they are compared with the expected output response.
FIG. 3 is a detailed schematic of any one of the coarse deskew units shown schematically in FIG. 2. The coarse deskew unit includes a multiplexer 61 and a plurality of logic gates 62-67. The logic gates are serially connected to receive sequentially the input signal supplied on node 68, designated "signal in." The other terminal of logic gate 62 is connected to a power supply V BB , although it could also be connected to the complementary signal to signal in. A well-known network of pull down resistors and delay and filter capacitors are also provided. The logic gate network shown is commerically available, and in the preferred embodiment comprises two ECL 10116 integrated circuits. The multiplexer 61 is also commerically available as ECL part 10164. In operation multiplexer 61 will connect one of inputs I 0 to I 6 to the line 69 designated "signal out" in FIG. 3. Which of inputs I 0 to I 6 will be connected to line 69 depends upon the three address bits S 0 , S 1 , and S 2 supplied to multiplexer 61. These three address bits are supplied from a register which is discussed in conjunction with FIG. 4. Of course, if desired, a separate register could be positioned in proximity to the circuit shown in FIG. 3. Accordingly, the signal on line 68 may be delayed by between 0 and 6 gate delays before being supplied as "signal out" on line 69. For example, if it is desired to impose a three gate delay between the node 68 and node 69, then input I 3 will be coupled to output line 69. Accordingly, the signal on line 68 will pass through each of logic gates 62, 63, and 64 before being supplied to line 69, thereby incurring a three gate delay in transmission. For the specified ECL parts each gate will delay the signal by approximately two nanoseconds, and accordingly the apparatus depicted in FIG. 3 will have a range of approximately 12 nanoseconds and a resolution of two nanoseconds.
FIG. 4 is a schematic diagram of any of the vernier deskew units used in FIG. 2. The vernier deskew unit includes a multiplexer 71 and a plurality of delay lines 72. One extended loop of each delay line 72 is connected between each pair of inputs I 0 -I 7 of multiplexer 71. An input signal is supplied on line 74. Depending upon the state of the address bits S 0 , S 1 , and S 2 , multiplexer 71 will connect one of inputs I 0 -I 7 to the output line 75. As evident from FIG. 4, the choice of which input is connected to the multiplexer output 75 will determine the amount of the delay line through which the signal will pass between input terminal 74 and the output terminal 75. For example, if input I 4 is selected in response to the address bits S 0 -S 2 , then the signal supplied on line 74 will pass through all of the delay line between input I 0 and input I 4 , and then will be switched onto output 75. In the preferred embodiment multiplexer 71 comprises an ECL 10164 multiplexer, and delay lines 72 comprise electrically conductive traces on the ceramic substrate upon which multiplexer 71 is mounted. Each delay line 76 includes a plurality of shorting bars such as 77 and 78 which may be used to change the length of the delay line. These shorting bars allow compensation for variations in the propagation delay of multiplexer 71. For the embodiment shown in FIG. 4 the electrical signal supplied on line 74 will flow through delay line 76 and shorting bar 77 back to input node I l . For longer time delays, one or more shorting bars may be destroyed. For example, if a delay in propagation of the input signal between node I 0 and I 1 is desired corresponding to the time required for signals to flow through line 76, shorting bar 79, and back to node I 1 , then shorting bars 77 and 78 may be destroyed. In the preferred embodiment the shorting bars also comprise electrically conductive traces on the ceramic substrate which traces may be destroyed using any desired technique, for example, by using a laser to vaporize the electrically conductive material. In another embodiment the delay line 72 will comprise electrically conductive regions on a printed circuit board. Fabricating the delay lines in either manner allows repair of improperly destroyed shorting bars using conductive epoxy.
As shown in FIGS. 2, 3, and 4 each multiplexer in either the coarse deskew unit or the vernier deskew unit is controlled by the state of a register associated therewith. A typical register 73 receives data signals, clock signals, and a reset signal, and in turn supplies a three bit address to multiplexer 61 and a three bit address to multiplexer 71. In the preferred embodiment the six bit register 73 comprises an ECL register 10186. Other well known registers may also be used.
In the preferred embodiment the ceramic substrate containing multiplexer 71 is connected to appropriate measurement equipment and the difference in propagation delay between the input terminals I 0 and I 1 is adjusted by destroying appropriate shorting bars to be 312 picoseconds, including any delay inherent within multiplexer 71 itself. This may be achieved in the manner described above by destruction of appropriate shorting bars in the first delay line 76. (If finer resolution is desired additional shorting bars may be utilized with closer spacings.) The length of the delay line between each subsequent pair of input terminals is also adjusted to create steps of 312 picoseconds. For example, the length of the delay line between terminals I 4 and I 5 is adjusted to cause the delay of the output signal on line 75 to be increased by 312 picoseconds if input I 5 is selected rather than input I 4 . In this manner a range of 2,184 picoseconds is achieved with a resolution of 312 picoseconds. The vernier control of FIG. 4, together with the coarse control of FIG. 3, provide an overall range of 14.18 nanoseconds and a resolution of 312 picoseconds.
To calibrate the overall system described in FIG. 2 a particular timing signal is selected and arbitrary settings of the coarse and vernier delay circuits are made. The timing signal is transmitted through the format control and deskew logic 60 to the pin electronic circuit 80, and back. Using the test system itself the time delay of the signal is measured. The coarse and vernier deskew units are then adjusted to achieve the desired time delay for that particular timing signal so all signals will arrive at the pin electronics output simultaneously. The necessary address information for all registers is then stored, for example, on magnetic tape, magnetic disc, or using other known means. The next timing signal is selected and the process is repeated. This calibration is performed for each timing signal and for each format supplied by format control logic 23, and all data is similarly stored. Then, at the time of testing of a device, the particular data is retrieved from storage and supplied to the appropriate registers to create the necessary time delays required in the various signal paths.
FIG. 5 is a schematic diagram illustrating the manner in which signals may be deskewed. The apparatus shown in FIG. 5 is particularly advantageous because it allows the signals to be deskewed during test system operation. Using the techniques of this invention, it is unnecessary to stop operation of the test system to supply an inverted waveform, even for the brief period which would be necessary to load new data into the registers associated with each coarse and vernier deskew unit. This enables substantially faster test system operation.
The operation of the system for deskewing signals will be explained in conjunction with FIGS. 5 and 6. The timing signal from the timing generator 20 is supplied on lines 13 and 14 shown in FIG. 5. The uppermost signal designated "timing signal generator" in FIG. 6 shows the ideal pulse from the timing generator to have a width "X". By the time the signal from the timing generator has passed through multiplexer 12, however, a width error ε has been added to the pulse width X. This error is shown in the second signal in FIG. 6 designated "Timing Signal at Mux 12."
A first adjustment made to this timing signal is to correct its width. This correction is achieved by the vernier deskew unit 17 under control of the register 18, which in turn is controlled by the test system computer as explained above. If the width error ε is sufficiently large, or if a wider range of time delays are required, a coarse deskew unit like that depicted in FIG. 3 could be serially connected to the vernier deskew unit 17. After the width of the signal is corrected, an offset error may remain, as also shown in the signal designated "width corrected" in FIG. 6. As shown in FIG. 5 the width corrected signal is now supplied to differentiation network 15 where it is divided into leading and trailing edge signals which are supplied on lines 19 and 21, respectively. The leading and trailing edge signals are designated "edge separation" in FIG. 6.
FIG. 5 also shows format control logic 23 which includes a format selector 90, and a network of gates 80-85 to perform edge path selection. The leading edge signal on line 19 is supplied to gates 80 and 82, while the trailing edge signal on line 21 is supplied to gates 81 and 83. As also shown in FIG. 5, gates 80 and 81 are connected through a wired OR gate 84 to coarse and vernier deskew units 86, while gates 82 and 83 are coupled through wired OR gate 85 to coarse and vernier deskew units 89. Deskew unit 86 is coupled to a set terminal of latch 53, while deskew unit 89 is coupled to a reset terminal of latch 53.
Either of the leading or trailing edge signals may be supplied to either of the set or reset terminals of latch 53 by enabling appropriate gates 80 through 83. For example, if the leading edge signal is to be supplied to the reset terminal, then gate 82 will be enabled, and gate 80 disabled, by the format selector 90. Correspondingly, if the trailing edge signal on line 21 is to be supplied to the set terminal, then gate 81 will be enabled, and gate 83 disabled by format selector 90.
The coarse and vernier deskew unit designated 86 corresponds to the coarse and vernier deskew units 31 and 33 shown in FIG. 2, while the coarse and vernier deskew unit 89 corresponds to the coarse and vernier deskew units 32 and 34 shown in FIG. 2. Registers 87 correspond to registers 41 and 43, while registers 88 correspond to registers 42 and 44 in FIG. 2.
To supply deskewed inverted signals without stopping the test system operation to reload the registers 87 and 88, the format selector 90, typically a multiplexer or Hex D flip-flop 100151, causes the leading and trailing edge signals to pass through separate delay paths, and then, to provide an inverted waveform, causes the leading and trailing edge signals to pass through different delay paths. Because the signals take different paths, there will be slightly different timing delays associated with each signal. This error could be eliminated by reprogramming the contents of the registers 87 and 88 in the manner described above in conjunction with the discussion of calibration of the overall system. Because this procedure, although it occupies only milliseconds, consumes an undesirably long period of time when one is concerned with testing large numbers of circuits, a more efficient process is desirable. This techniques is described below.
The set and reset time delays introduced by deskew units 86 and 89 are set at their midpoints, as is the vernier deskew unit 17. A pulse of interest is set to the device under test and the time delay of the signal is measured. Using the vernier deskew unit 17 the pulse width is adjusted, as shown in conjunction with FIG. 6, until the pulse width is the desired value. As previously discussed, however, this results in an offset error. The set and reset deskew units 86 and 89 are then programmed to have the same time delay value, an amount sufficient to compensate for the offset error. In this manner the time delay associated with each of the set and reset paths is equal, so both the inverted and non-inverted waveforms have identical time delays when supplied to the device under test.
Although embodiments of the invention have been described above, these are intended to illustrate the invention rather than limit it. For example, in addition to applications involving electronic test equipment, the invention may be applied to other applications in which electrical signals are to be delayed or synchronized.
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Apparatus is provided for supplying deskewed signals. The apparatus includes a timing generator (20) for generating a pulse of desired duration, a deskew unit (17) connected to receive a pulse and adjust its width to compensate for previous errors, a differentiation network (15) for dividing the pulse into a leading and trailing edge signal, a plurality of logic gates (80 through 85) for receiving the pair of signals and supplying one of the pair along a set path and the other of the pair along a reset path, a deskew unit (86 and 89) associated with each path for delaying the signals thereon, and a latch (53) coupled to the deskew units to reform the electrical signal. Logic gates (80 through 85) operate under control of a format selector (90).
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BACKGROUND OF THE INVENTION
The present invention relates to a new and improved construction of a dewatering apparatus for dewatering water-solid mixtures, especially suspensions of fiber stock, for instance cellulose or paper fibers, and which is of the type containing two wires which coactingly form with one another an infeed funnel, wherein the two wires are guided over a dewatering cylinder and thereafter pass through at least one press location.
Such type of dewatering apparatus has been disclosed to the art, for instance, in the German language brochure entitled "Escher Wyss Maschinen und Anlagen fur die Stoffaufbereitung", at pages 22 and 23, under the designation "Siebpresse".
SUMMARY OF THE INVENTION
It is a primary object of the present invention to improve upon this prior art construction of dewatering apparatus which has found acceptance in practice, specifically with the intent of reducing the costs of the dewatering apparatus while providing a decisively greater capacity or efficiency.
Still a further significant object of the present invention is directed to a new and improved dewatering apparatus which is relatively simple in construction and design, quite economical to manufacture, extremely reliable in operation, not readily subject to breakdown or malfunction, and requires a minimum of maintenance and servicing.
A further important object of the present invention is directed to a simplified construction of dewatering apparatus which provides for a high dewatering capacity for the dewatering of various water-solid mixtures, especially suspensions of fiber stocks.
Now in order to implement these and still further objects of the invention, which will become more readily apparent as the description proceeds, the dewatering apparatus of the present development is manifested by the features that, the infeed or inlet funnel is constructed as a pre-dewatering funnel containing pervious walls in the manner of wire tables, and over which there is guided in each case one of the wires. Furthermore, following the dewatering cylinder there is arranged at least one further dewatering cylinder over which there are guided both of the wires with reversed or opposite curvature, and the dewatering cylinders are free of pressing locations formed by press rolls.
Because of the pre-dewatering path there is formed a thicker solid web between the wires with the same velocity, whereby the capacity or output of the dewatering apparatus is markedly increased. The dewatering cylinders can possess a smaller diameter than would be possible if a single dewatering cylinder were used, and this, in turn, leads to an increase in the dewatering action or effect by virtue of the wire tension. The dewatering cylinders are not subjected to the pressure of press rolls, so that they can be constructed to be lighter and less expensive. By virtue of the fact that the wires are guided over the dewatering cylinders with, in each case, reverse or opposite curvature, that is to say, they are guided in a serpentine path, specifically along a substantially S-shaped path of travel, there is advantageously obtained a displacement of both wires towards one another during passage of the wires over the dewatering cylinders, so that there results a favorable relayering or repositioning of the processed material located between the wires.
The dewatering cylinders can be preferably arranged such that their axes essentially are located in the same horizontal plane, and, in each case, the next following or downstream arranged dewatering cylinder possesses a smaller diameter than the preceding or upstream arranged dewatering cylinder. Due to the arrangement of the axes of the dewatering cylinders in a substantially horizontal plane there are obtained advantageous conditions for the outflow of the expressed or pressed out water. A reduction in the diameter of the subsequently arranged dewatering cylinder, with the same wire tension, results in an increase in the press or pressure force, so that there is obtained an ascending course of such press force, something which likewise favors the dewatering action.
The last dewatering cylinder can have arranged thereafter a first press roll which coacts with at least one second press roll. Since the first press roll does not act, like with the state-of-the-art art arrangement, upon the dewatering cylinder, there is obtained the advantage that the dewatering cylinder can be constructed to be appreciably lighter, and this, in turn, contributes to reducing the costs of the dewatering apparatus. On the other hand, there can be realized an appreciably more intensified pressing or squeezing action between two press rolls than between a press roll and a dewatering cylinder.
Both of the wires can conjointly travel essentially vertically downwardly from the last dewatering cylinder to the first press roll, and the lengthwise axis of the first press roll can be located beneath the lengthwise axis of the last dewatering cylinder at least by the amount of its radius. This arrangement especially allows for catching of the expressed or pressed out water, since there can be arranged at the side of the first press roll a scraper or stripper device provided with an outfeed trough or the like.
The second press roll can be arranged at the side of the first press roll facing away from the second dewatering cylinder. Such constitutes an arrangement which, for reasons of catching the expressed or pressed out material, is advantageous for the withdrawal of the squeezed out water as well as for the accessibility to the rolls.
Preferably, the separation location of both wires from one another can be located at the second press roll. Accordingly, the second press roll can possess a solid surface and can be provided with a removal device for the dewatered fiber stock material. All of these measures lead to an optimum removal or pick-up of the dewatered fiber stock material from the second press roll.
In the event that there is desired an increase in the pressing action, then there can be arranged a third press roll beneath the first press roll. In this way there can be realized an increase in the squeezing or pressing action without any additional spatial requirements, with simultaneous optimum outflow of the expressed or squeezed out water.
The third press roll can preferably possess a grooved or channeled surface and at the same time can serve as a wire guide roll for a related one of the returning wire runs. The grooved surface facilitates outflow of the expressed water from the press locations between the first press roll and the third press roll. By virtue of the fact that the returned wire run is guided over the third press roll there is achieved a simplification in the construction of the dewatering apparatus, since there can be dispensed with the use of an appropriate wire guide roll.
Furthermore, there can be arranged in the pre-dewatering funnel, below its liquid level which is formed during operation, a distributor vat or the like for the infed stock suspension. Beneath the upper boundary or wall of such distributor vat there opens at least one infeed pipe or line for the fiber stock suspension. Consequently, there is attained a uniform distribution of the fiber stock suspension over the width of the dewatering apparatus.
Additionally, the dewatering apparatus can possess a first housing portion at which there are arranged both of the dewatering cylinders and at least one press roll. Further, there can be provided two upper housing portions which serve for supporting a respective one of the previous walls, one of the press rolls as well as for mounting guide rolls for the wires.
A particularly simple construction of the dewatering apparatus can be realized if the housing portions consist of substantially flat or planar side plates and connection plates interconnecting such side plates and extending perpendicular thereto and at least one connection rod. With such construction there is simultaneously obtained an undisturbed outflow of the water.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood and objects other than those set forth above, will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein:
FIG. 1 schematically illustrates a dewatering apparatus and serving to explain the wire guiding and the arrangement of the pre-dewatering funnel together with the dewatering cylinders and press rolls;
FIG. 2 is a side view of the dewatering apparatus depicted in FIG. 1 and showing details of the construction of the housing arrangement thereof;
FIG. 3 is a cross-sectional view of the dewatering apparatus depicted in FIG. 2, taken substantially along the section line III--III thereof, and wherein, however, there have only been illustrated the housing parts; and
FIG. 4 is a cross-sectional view of the arrangement of FIG. 2, similar to the showing of FIG. 3, but the section this time being taken substantially along the section line IV--IV of FIG. 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Describing now the drawings, it is to be understood that only enough of the construction of the dewatering apparatus has been depicted as will enable those skilled in the art to readily understand the underlying principles and concepts of the present development, while simplifying the illustration of the drawings. Turning attention now specifically to FIG. 1, there has been schematically illustrated an exemplary embodiment of dewatering apparatus, wherein there have been deemphasized in the showing of such FIG. 1 the parts of the housing of such dewatering apparatus in order to more clearly reveal other significant structure thereof. Regarding such dewatering apparatus depicted in detail in FIG. 1, it will be seen that the same contains two wires 1 and 2 which are guided over suitable guide rolls 3, regulation rolls 4 and tensioning rolls 5. A pre-dewatering funnel or funnel member 6 is located at a substantially wedge-shaped region of both wires 1 and 2. This pre-dewatering funnel 6 contains pervious walls or wall members 7 which are constructed in the manner of wire tables and upon which there are moved, during operation of the dewatering apparatus, the two wires 1 and 2, as shown. The pervious walls 7 contain support ledges 8 upon which slidingly downwardly move the wires 1 and 2, respectively. These pervious walls 7 further contain spacer ledges 10 located between the support ledges 8 and support or carrier plates 11 upon which there are affixed the support ledges 8 and the spacer ledges 10, as shown. The water effluxing out of the pre-dewatering funnel 6 through the wires 1 and 2 can laterally outflow through channels 12 between the support ledges 8 and the spacer ledges 10.
Following the pre-dewatering funnel 6 both of the downwardly traveling wires 1 and 2 are conjointly guided over a first dewatering cylinder 13, a second dewatering cylinder 14, a first press roll 15 and a second press roll 16. Coacting with the first press roll 15 is a lower situated third press roll 17. The press rolls 15 and 17 are advantageously mounted upon pivotable press levers or lever members 18 and 19, respectively, which can be actuated by compressed or pressurized air bellows 20 or equivalent actuators, as best seen by referring to FIG. 1.
Both of the dewatering cylinders 13 and 14 are of known construction and provided with an open outer surface, that is to say, their not particularly referenced cylindrical outer surfaces or jackets are equipped, for instance, with bores or continuous slots. The first dewatering cylinder 13 is provided with support walls 21 which enable lateral outflow of the expressed or squeezed out water and water entering from the outside into the interior of the dewatering cylinder 13, as the case may be. The same purpose is also fulfilled by the openings 22 of the dewatering cylinder 14 which extend in the axial direction of such dewatering cylinder.
As will be further recognized by referring to FIG. 1, both of the dewatering cylinders 13 and 14 are arranged with their lengthwise axes located in essentially the same horizontal plane E. Additionally, it will be seen that the diameter D 2 of the second dewatering cylinder 14 is smaller than the diameter D 1 of the first dewatering cylinder 13.
The first press roll 15 is located beneath the plane E at a spacing which is greater than its roll radius R. Both of the wires 1 and 2 travel between the second dewatering cylinder 14 and the first press roll 15 in an essentially vertical downward direction, as shown in FIG. 1.
The second press roll 16 is located at the side of the first press roll 15 which faces away from the second dewatering cylinder 14. The line-shaped press location or pressure nip P between both of the press rolls 15 and 16 is located in the third quadrant of the first press roll 15, which quandrant has been conveniently designated by reference character III in FIG. 1. The third press roll 17 is located beneath the first press roll 15, and specifically, approximately as illustrated with its lengthwise axis located in a substantially vertical plane F which extends through or contains the lengthwise axis of the coacting first press roll 15.
The separation or parting location T of the wires 1 and 2 is located at the second press roll 16. This second press roll 16 preferably possesses a solid surface, so that the adherence of the expressed material at such press roll 16 is enhanced. This second press roll 16 is furthermore provided with a removal device 23, for instance in the form of a scraper or doctor blade or equivalent structure, which ensures that the expressed or pressed out material will drop off of the surface of the second press roll 16 and from the related wire 2 into a suitable removal container or vat 24.
The pre-dewatering funnel 6 is provided beneath its liquid level W, which regulates or sets itself during operation of the dewatering apparatus, with a distributor vat or trough 25 or equivalent structure. Opening into such distributor vat 25 beneath its upper boundary or end wall is an infeed pipe or conduit 26 for the fiber stock suspension which is to be dewatered.
FIGS. 2 to 4 show details of the construction of the housing apparatus depicted in FIG. 1, wherein for reasons of clarity in the illustration the movable parts illustrated and described in conjunction with such FIG. 1 have only been shown in phantom or broken lines.
According to the showing of FIGS. 2 to 4 the housing of the inventive dewatering apparatus is composed of three housing parts or components, namely, a lower first housing part or portion 30, an upper second housing part or portion 31, and an upper third housing part or portion 32. The housing part 32 is secured to the housing part 30 by any suitable and therefore not particularly illustrated threaded bolts or equivalent fastening expedients. The housing part 31 is attached to the housing part 30 with the aid of the supports 33 and 34 or equivalent attachment structure, which additionally are further provided with removable intermediate parts or elements 35 and 36 which enable removal of the wire 1. In order to dismantle the wire 2 the lower housing part or portion 30 is erected upon similar supports 37 which are operatively associated with the intermediate parts or elements 38. The dismantling of the intermediate parts 35, 36 and 38 is accomplished in conventional manner by a lateral support structure, the so-called cantilevers.
FIGS. 3 and 4 illustrate in sectional view the construction of the housing parts from substantially planar or flat side plates, 40, 41, 42, 43, 44 and 45. The side plates are interconnected by connection plates 46, 47, 48, 49, 50 extending perpendicular thereto as well as by a connection rod or rod member 51. As best seen by reverting to FIG. 2, the connection plates simultaneously have assigned thereat important tasks as concerns the supporting of the individual parts. Thus, there are supported upon the plate member 46 the compressed air bellows 20 of the arm member 18. The plates 47 and 48 simultaneously serve for supporting the wire tables 7. A horizontal plate 52 which is not particularly visible in the sectional view depicted in FIG. 4 which has been taken along the line IV--IV of FIG. 2 but is also shown in FIG. 2 serves for supporting the compressed air bellows 20 of the lever 19.
As also will be apparent by reverting to FIG. 1 of the drawings, the wire 1 is also provided at the region of the guide roll 3 with a scraper 23 or equivalent structure.
At the region between the second dewatering cylinder 14 and the first press roll 15 there is located a combined scraper and vat unit 27 for the outflow of the pressed-out or expressed water.
A further increase in the dewatering capacity or output of the inventive dewatering apparatus can be attained, according to the showing of FIG. 1, in that scraper or stripper devices, for instance scrapers 28, are arranged within the pre-dewatering funnel 6 and serve to remove the previously formed web, so that there can be formed a new web. This new web is formed with a higher stock density of the suspension, something which is advantageous for the output or capacity of the dewatering apparatus.
While there are shown and described present preferred embodiments of the invention, it is to be distinctly understood that the invention is not limited thereto, but may be otherwise variously embodied and practiced within the scope of the following claims. Accordingly,
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A dewatering apparatus is disclosed containing a pre-dewatering funnel possessing pervious walls over which there are guided two wires. Arranged after the pre-dewatering funnel are two dewatering cylinders over which both of the wires are guided along a substantially S-shaped path of travel. A press roll is arranged after the last dewatering cylinder, this press roll coacting with further press rolls.
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FIELD OF THE INVENTION
[0001] The present invention relates generally to providing a new client interface to an existing application. More specifically, the invention employs trainable user interface translator software to monitor data streams between a client device and the existing application to create data packet maps that may be used in creating new interfaces. The invention has applications in the field of business software.
BACKGROUND OF THE INVENTION
[0002] As client interfaces associated with existing computer systems become outdated or incompatible with newer client devices, it is often necessary to provide an alternative client interface to existing applications. For example, a merchandise supplier may want to make its inventory software available to personnel using hand-held wireless devices to increase efficiency. However, the data on existing systems is often difficult to access, either because of the proprietary nature of the system or because the data is in a nonstandard format. Current methods of creating a new client interface are limited to accessing data manually, which is time-intensive and costly, or rewriting the host application, in which case large amounts of existing business logic must be recreated. For businesses with existing systems, a faster and more effective way to update a client interface could result in more efficient business practices, higher customer satisfaction, and higher revenues.
[0003] There are rapidly developing technologies and associated devices (for example, Web, wireless, voice, etc.) in which users need to access data residing on existing computer systems. These existing systems range in variety from legacy mainframe applications to Microsoft Windows applications. Many existing systems have no standard protocols by which newer devices can access their data, and yet newer devices are often the key to the most efficient business practices. What is needed is a way to efficiently provide an additional interface to an existing system. A method which achieves this objective while enabling utilization of the error-checking functionality of the existing computer system would be beneficial.
[0004] Data often needs to be transferred between existing computer systems and these newer devices. For example, when a financial institution converts its operations to an application service provider (ASP), it must migrate large amounts of the data on its legacy system to applications used by the ASP. However, most existing systems do not support the standard protocols for transferring data to the newer devices. In the case of business applications, this may result in lower productivity and unsatisfied customers. What is needed is a way to quickly get data into and out of an existing system.
[0005] Additionally, manufacturers of existing computer applications often restrict data accessibility within their systems. Businesses that own proprietary systems often need to access such data within that system. For example, a business may want to move its operations from a proprietary system to a more open system. However, the data within the proprietary system may not easily be accessed because of license agreements. What is needed is a way to get data into and out of a closed or proprietary system.
[0006] Data streams associated with a user interface often need to be monitored because the functionality of existing systems must frequently be rapidly updated to a new appearance or for use with newer technologies. The traditional method of monitoring data streams is to analyze the data directly through a published format. However, if the data format is not published or the system is proprietary, this task can be difficult or impossible. What is needed is a way to more effectively monitor the data streams used to provide a user interface without causing some existing computer system performance degradation.
SUMMARY OF THE INVENTION
[0007] The present invention is a system for and method of providing a new client interface to an existing application. The embodiments described below share the ability to monitor, reinterpret, and reformat data packet streams by means of a shaper computer operating a software training application. The techniques employed in the current invention build upon “trainable user interface translator” technology (referred to below as “TeleShaper” technology) as described in U.S. Pat. Nos. 5,627,977 and 5,889,516, which are assigned to the assignee of the present application and the contents of which are hereby incorporated by reference in their entirety into the present application.
[0008] In one aspect, the present invention is a trainable system for providing a new client interface to an existing application, comprising a shaper computer operating a trainable user interface translator application and further comprising and storing a shaper rule set and data packet format maps identifying data formats acceptable to a host application, and an auxiliary database for storing training data sets, a training terminal electrically connected to the shaper computer for establishing the shaper rule set and data packet format maps during a training session, a host computer electrically connected to the shaper computer and a first client device operating first client software, the host computer operating the host application, thereby generating data streams to and from the first client software that may be monitored and analyzed by the shaper computer to establish the shaper rule set and data packet format maps, a second client device electrically connected to the shaper computer upon which a new client interface is implemented, wherein the shaper computer communicates user data between the new client interface and the host application, whereby the trainable user interface translator application remaps the user data according to the data packet format maps defined during the training session and transmits the remapped user data to the second client device for presentation in the new client interface. The various electrical connections of the system may be established either directly, or alternatively by one or more networks.
[0009] In another embodiment, the host computer and the first client device are the same computer.
[0010] In another embodiment, the shaper computer and the second client device are the same computer.
[0011] In another aspect, the present invention is a method of training the system above to provide a new client interface to the host application, comprising the steps of selecting training data sets designed to fully exercise the host application, entering a training data set into the trainable user interface translator application, operating the trainable user interface translator application via the training terminal and first client device to exercise the host application to generate streams of data packets between the host application and the first client device, analyzing the format of the data packets to create packet maps and storing the packet maps, entering new training data via the training terminal into the trainable user interface translator application, which creates modified data packets according to the packet maps and transmits the modified data packets to the host computer, which in turn updates data stored in the data storage device and generates response data packets, exercising the host application via the first client device to review the presence of updated data, repeating the steps above with data expected to create exceptions and errors in the operation of the host application, and determining if all data packet formats have been mapped, and if not repeating the steps above.
[0012] In another aspect, the present invention is a method of using a trained system to provide a new client interface to the host application, comprising the steps of designing and implementing a new client interface on the second client device, starting via the training terminal the trainable user interface translator application and selecting a data packet format map, operating the second client device to communicate with the host application via the shaper computer, which remaps data packets transmitted from the host application according to the data packet format maps and forwarding remapped data packets to the second client device for presentation in the new client interface, and determining whether to continue using the new client interface, and if so, reverting to the previous step.
[0013] The present invention provides an updated interface to an existing application, while utilizing the error-checking functionality within the business logic of an existing application. It accomplishes these objectives in a manner that is noninvasive to the existing system.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] [0014]FIG. 1 is a schematic diagram of a system for providing a new client interface to an existing application.
[0015] [0015]FIG. 2 is a flow diagram illustrating a method of training a trainable system to provide a new client interface to an existing application.
[0016] [0016]FIG. 3 is a flow diagram illustrating a method of using a trained system to provide a new client interface to an existing application.
DETAILED DESCRIPTION
[0017] Preferred embodiments of the invention will now be described with reference to the accompanying drawings.
[0018] The present invention is a system for and method of providing a new interface to an existing application. The system non-invasively monitors and analyzes the data stream associated with an existing application, generates data packet format maps during a training sequence, and then interfaces with the application's back-end by creating compatible data packets using data entered via a new interface and extracts response data for use in the new client interface. The new interface may be a new interactive client (e.g. a web or wireless browser) or a data connector used to integrate the application into a larger integrated system (e.g. via a middleware messaging manager).
[0019] The existing applications back-end is not modified. Rather, it continues to operate with the new interface effectively “emulating” the network behavior of the application's client interface. The network packets may be associated with a proprietary data transfer format, a standard protocol (e.g. HTML/HTTP), or a low level display protocol (e.g. X-Windows).
[0020] [0020]FIG. 1 is a schematic representation of a TeleShaper system 100 , which includes a host computer 120 , a TeleShaper computer 140 , a training terminal 154 , a first client device 130 , and a second client device 180 . Host computer 120 includes a data storage device 110 and a host application 121 . TeleShaper computer 140 includes a TeleShaper application 150 , a shaper rule set storage device 153 , and an auxiliary database 155 . TeleShaper system 100 also includes a first network 125 , a second network 132 , and a third network 133 , arranged as shown in the figure.
[0021] Host computer 120 and first client device 130 and TeleShaper computer 140 are interconnected via first network 125 . TeleShaper computer 140 is able to monitor network traffic between host computer 120 and first client device 130 . Training terminal 154 may connect to TeleShaper computer 140 via second network 132 . Second client device 180 may connect to TeleShaper computer 140 via third network 133 . First network 125 , second network 132 , and third network 133 may be intranet networks or the Internet. Alternatively, first network 125 , second network 132 , and third network 133 may be the same network. Further, in an alternative embodiment, a direct connection may be arranged between host computer 120 and TeleShaper computer 140 , between training terminal 154 and TeleShaper computer 140 , and between second client device 180 and TeleShaper computer 140 .
[0022] For example, host computer 120 may be an Windows-NT computer, or a similar system, and first client device 130 may be an IBM PC running application specific client software. Host application 121 may be a hospital's patient care software application. Host computer 120 and first client device 130 may be the same computer, in which case interprocess communications between the host process of host application 121 and the client process are monitored rather than network communication via first network 125 . For example, if host computer 120 is running Windows 95 and host computer 120 and first client device 130 are the same computer, the communication between host application 121 and the operating system is monitored.
[0023] Training terminal 154 is typically a PC client running telnet, but may also be a hardwired terminal or a display and keyboard directly connected to TeleShaper computer 140 .
[0024] A method of training TeleShaper system 100 to provide a new client interface to an existing application is now described with reference to FIG. 2.
[0025] Step 210 : Selecting Training Data Sets
[0026] In this step, the trainer selects training data sets that are designed to fully exercise host application 121 . The selection of the data sets is based on the trainer's understanding of the operation of host application 121 . The trainer records the data sets on paper, or on paper and in a data file stored on TeleShaper computer 140 . If host application 121 were patient care application, an example of training data might be a list of medicine administration sets composed of patient names, drug names, and administration times.
[0027] Step 220 . Entering Training Data into TeleShaper Application
[0028] In this step, the trainer enters the training data developed in step 210 into auxiliary database 155 for eventual processing in TeleShaper application 150 .
[0029] Step 230 : Exercising Host Application
[0030] In this step, the trainer, using training terminal 154 , places TeleShaper application 150 into training mode. The trainer then exercises host application 121 via first client device 130 , using the training data developed in step 210 . This results in streams of data “packets,” or data streams, passing between first client device 130 and host application 121 . These packets are recorded by TeleShaper computer 140 , which is monitoring traffic on network 124 .
[0031] Step 240 : Analyzing Data Stream
[0032] In this step, the trainer, via training terminal 154 , instructs TeleShaper application 150 to analyze the data streams generated recorded in step 230 . TeleShaper application 150 locates the variable data within the data packets in order to determine the layout of each data packet.
[0033] Step 245 : Creating Packet Maps
[0034] In this step, TeleShaper application 150 creates packet maps. These packet maps describe the data packet formats, such as fixed width, comma delimited, etc., and are stored in rule set storage device 153 . The offset within each packet at which to extract or insert variable data is recorded as well as additional formatting information necessary to create new properly formatted packets. This information might include, for example, checksum locations and methods, and offset tables that are part of the packet.
[0035] Step 250 : Transmitting Modified Packets
[0036] In this step, the trainer, using training terminal 154 , enters new training data into TeleShaper application 150 . TeleShaper application 150 then creates new data packets according to the packet maps defined in step 245 and transmits the data packets to host computer 120 , which will act on the data in the generated packets by updating data stored in data storage device 110 and also by generating response data. TeleShaper application 150 monitors and records the response data packets from host computer 120 and compares them to the expected format for response packets detected in step 240 .
[0037] Step 260 : Reviewing Data
[0038] In this step, the trainer, using first client device 130 , exercises host application 121 to review the presence of the test data stored by host application 121 in data storage device 110 . The trainer is then able to confirm that the training data used in step 250 was correctly interpreted and stored by host application 121 .
[0039] Step 270 : Repeating Steps 220 - 260 with Error and Exception Data
[0040] In this step, steps 220 - 260 are repeated with data that is expected to create exceptions and errors in the operation of host application 121 , so that the format of the response data packets associated with error and exceptions generated by host application 121 can be completely mapped.
[0041] Step 280 . Packet Formats Determined?
[0042] In this step, the trainer determines if the training data packet formats have been completely determined and stored in shaper rule set storage device 153 . If no, process 200 returns to step 210 ; if yes, process 200 ends.
[0043] A method of using TeleShaper system 100 to provide a new client interface to an existing application is now described with reference to FIG. 3.
[0044] Step 310 : Defining New Interface
[0045] In this step, the trainer designs a new interface for host application 121 using traditional tools (for example, Web development tools, wireless-enablement tools, database programming tools, etc.). The trainer then implements the new interface on TeleShaper computer 140 or second client device 180 . The new interface communicates with TeleShaper application 150 using standard protocols, such as ODBC, JDBC, etc., depending on the application.
[0046] Step 320 : Starting TeleShaper Application
[0047] In this step, the user, using training terminal 154 , starts TeleShaper application 150 . The user selects the appropriate packet map and host connectivity.
[0048] Step 330 : Executing New Interface
[0049] In this step, the user operates second client device 180 , which communicates with host application 121 via TeleShaper computer 140 . User data is transferred between host application 121 , remapped according to the packet maps defined in process 200 , and transmitted to second client device 180 , where it is presented to the user in the new interface. TeleShaper application 150 monitors all response packets and records any unexpected response packets as well as the associated data packet for later analysis. This allows process 200 to be repeated, if necessary to further refine the operation of the system.
[0050] Step 340 : Continue Executing New Interface?
[0051] In this step, the user determines whether to continue using the new interface on second client device 180 . If yes, process 300 returns to step 330 ; if no, process 300 ends. The new interface and associated data reformatting between host application 121 and second client device 180 continues as long as the user operates host application 121 or until TeleShaper application 150 is disabled.
[0052] Another use for process 300 is to provide a rapid means of creating an alternate interface to a Web site when communication between host application 121 and second client device 180 is a known protocol, such as HTML, XML, etc.
[0053] Other embodiments of the invention will be apparent to those skilled in the art from a consideration of the specification or practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with the true scope and spirit of the invention being indicated by the following claims.
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A system for and method of providing a new client interface to an existing application. The various embodiments described employ a trainable user interface translator application to monitor, analyze, and reformat data packet streams. The translator application analyzes data packet streams during a training session using a first client device and a training terminal, and stores format information in format data packet maps for subsequent use following creation of a new client interface.
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BACKGROUND OF THE INVENTION
[0001] This invention relates generally to washing machines and, more specifically, to a mechanism for coupling and de-coupling appropriate elements of a washing machine during selected portions of the wash cycle.
[0002] At least some known washing machines typically include a perforated basket for holding clothing or other articles to be washed, an agitator disposed within the basket which agitates the clothes in the basket, and a motor which drives the agitator and the basket. The articles to be washed are immersed in water with detergent and washed under the influence of an oscillating agitator. After agitation, the articles are rinsed with clean water and the basket is spun at sufficient speed to centrifugally extract the rinse water from the articles.
[0003] Generally, the agitator and basket are mounted on concentric shafts with the agitator shaft internal to the basket shaft. During agitation, the basket and basket shaft are motionless while the agitator shaft and agitator are free to oscillate to impart a cleaning action to the articles being washed. During spin cycles, the agitator shaft and basket shaft are engaged so that the agitator and basket spin in concert with no relative motion between the two. The coupling and uncoupling of the agitator and basket shafts is usually controlled by the mechanical drive system. However, the drive system could be simpler and less costly to manufacture if the coupling of the basket and agitator was controlled by a separate system.
BRIEF DESCRIPTION OF THE INVENTION
[0004] In one aspect, a coupling apparatus includes an inner shaft rotatably driven about a longitudinal axis of rotation, an outer shaft concentric with the inner shaft for selective rotation about the longitudinal axis, a coupling element movable between a first position engaging the inner shaft to the outer shaft for rotation therewith, and a second position disengaging the inner shaft from the outer shaft for relative rotation therebetween, and an actuating element connected to the coupling element and operable to move the coupling element between the first position and the second position.
[0005] In another aspect, a washing machine includes a wash tub, a perforated basket rotatably mounted within the tub, an agitation element disposed within the basket to agitate articles, an outer shaft connected to the basket to drive the basket, an inner shaft connected to the agitation element to drive the agitation element, a motor drivingly connected to the inner shaft, and a coupling mechanism to selectively couple the inner shaft and the outer shaft.
[0006] In another aspect, a method of coupling and de-coupling a shaft driven agitation element and basket in a washing machine, the agitation element being driven by an inner shaft and the basket being driven by an outer shaft, includes disposing the inner shaft within the outer shaft so that the inner and outer shafts share a common axis of rotation, providing a coupling element concentric with the inner and outer shafts movable between a first position engaging the outer shaft with the inner shaft for rotation therewith and a second position disengaging the shafts for relative motion therebetween, driving the inner shaft, and moving the coupling element between the first and second positions based on a portion of a wash cycle.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a perspective view partially broken away of an exemplary washing machine.
[0008] FIG. 2 is front elevational schematic view of the washing machine shown in FIG. 1 .
[0009] FIG. 3 is a left half cross sectional view of one embodiment of a coupling and de-coupling mechanism with the coupling disengaged.
[0010] FIG. 4 is a right half cross sectional view of the coupling of FIG. 3 with the coupling engaged.
[0011] FIG. 5 is a left half cross sectional view of another embodiment of a coupling and de-coupling mechanism with the coupling disengaged.
[0012] FIG. 6 is a right half cross sectional view of the coupling of FIG. 5 with the coupling engaged.
[0013] FIG. 7 is a left half cross sectional view of another embodiment of a coupling and de-coupling mechanism with the coupling disengaged.
[0014] FIG. 8 is a right half cross sectional view of the coupling of FIG. 7 with the coupling engaged.
[0015] FIG. 9 is a left half cross sectional view of yet another embodiment of a coupling and de-coupling mechanism with the coupling disengaged.
[0016] FIG. 10 is a right half cross sectional view of the coupling of FIG. 9 with the coupling engaged.
[0017] FIG. 11 is a cross sectional view of another embodiment of a coupling and de-coupling mechanism.
[0018] FIG. 12 is a left half cross sectional view of another embodiment of a coupling and de-coupling mechanism with the coupling disengaged.
[0019] FIG. 13 is a right half cross sectional view of the coupling of FIG. 12 with the coupling engaged.
DETAILED DESCRIPTION OF THE INVENTION
[0020] FIG. 1 is a perspective view partially broken away of an exemplary washing machine 50 including a cabinet 52 and a cover 54 . A backsplash 56 extends from cover 54 , and a control panel 58 including a plurality of input selectors 60 is coupled to backsplash 56 . Control panel 58 and input selectors 60 collectively form a user interface input for operator selection of machine cycles and features, and in one embodiment, a display 61 indicates selected features, a countdown timer, and other items of interest to machine users. A lid 62 is mounted to cover 54 and is rotatable about a hinge (not shown) between an open position (not shown) facilitating access to a wash tub 64 located within cabinet 52 , and a closed position (shown in FIG. 1 ) forming an enclosure over wash tub 64 . As illustrated in FIG. 1 , machine 50 is a vertical axis washing machine.
[0021] Tub 64 includes a bottom wall 66 and a sidewall 68 , and a basket 70 is rotatably mounted within wash tub 64 . A pump assembly 72 is located beneath tub 64 and basket 70 for gravity assisted flow when draining tub 64 . Pump assembly 72 includes a pump 74 and a motor 76 . A pump inlet hose 80 extends from a wash tub outlet 82 in tub bottom wall 66 to a pump inlet 84 , and a pump outlet hose 86 extends from a pump outlet 88 to an appliance washing machine water outlet 90 and ultimately to a building plumbing system discharge line (not shown) in flow communication with outlet 90 .
[0022] FIG. 2 is a front elevational schematic view of washing machine 50 including wash basket 70 movably disposed and rotatably mounted in wash tub 64 in a spaced apart relationship from tub side wall 64 and tub bottom 66 . Basket 70 includes a plurality of perforations therein to facilitate fluid communication between an interior of basket 70 and wash tub 64 .
[0023] A hot liquid valve 102 and a cold liquid valve 104 deliver fluid, such as water, to basket 70 and wash tub 64 through a respective hot liquid hose 106 and a cold liquid hose 108 . Liquid valves 102 , 104 and liquid hoses 106 , 108 together form a liquid supply connection for washing machine 50 and, when connected to a building plumbing system (not shown), provide a fresh water supply for use in washing machine 50 . Liquid valves 102 , 104 and liquid hoses 106 , 108 are connected to a basket inlet tube 110 , and fluid is dispersed from inlet tube 110 through a known nozzle assembly 112 having a number of openings therein to direct washing liquid into basket 70 at a given trajectory and velocity. A dispenser (not shown in FIG. 2 ), may also be provided to produce a wash solution by mixing fresh water with a known detergent or other composition for cleansing of articles in basket 70 .
[0024] In an alternative embodiment, a spray fill conduit 114 (shown in phantom in FIG. 2 ) may be employed in lieu of nozzle assembly 112 . Along the length of the spray fill conduit 114 are a plurality of openings arranged in a predetermined pattern to direct incoming streams of water in a downward tangential manner towards articles in basket 70 . The openings in spray fill conduit 114 are located a predetermined distance apart from one another to produce an overlapping coverage of liquid streams into basket 70 . Articles in basket 70 may therefore be uniformly wetted even when basket 70 is maintained in a stationary position.
[0025] An agitation element 116 , such as a vane agitator, impeller, auger, nutator, infuser, or oscillatory basket mechanism, or some combination thereof is disposed in basket 70 to impart an oscillatory motion to articles and liquid in basket 70 .
[0026] A wash cycle generally includes one or more agitation cycles alternated with one or more spin cycles. During agitation, agitation element 116 oscillates imparting a cleaning action to items being washed. During agitation, basket 70 is stationary. During the spin cycles, agitation element 116 and basket 70 rotate together with no relative motion therebetween.
[0027] FIG. 3 illustrates a left half cross sectional view of one embodiment of a coupling and de-coupling mechanism 400 to control the relative movements of agitation element 116 and basket 70 of washing machine 50 . In FIG. 3 , coupling mechanism 400 is disengaged. FIG. 4 illustrates a right half cross sectional view of the coupling and de-coupling mechanism of FIG. 3 , where the coupling is engaged. Coupling and de-coupling mechanism 400 operates on inner shaft 410 and a outer shaft 420 . Inner shaft 410 is internal to and concentric with outer shaft 420 . Inner shaft 410 is connected to and driven by a rotor 440 . Rotor 440 includes a central recessed portion 442 that receives a cylindrical coupler 430 . Coupler 430 includes a lower portion 432 including a plurality of splines 434 configured to engage a plurality of external splines 412 on inner shaft 410 . Coupler 430 is free to slide along inner shaft splines 412 . Coupler 430 includes an upper portion 438 that includes a plurality of splines 436 configured to engage a plurality of external splines 424 on outer shaft 420 . An actuator 450 moves coupler 430 along inner shaft splines 412 .
[0028] Coupler 430 moves up and down inner shaft splines 412 to engage and disengage inner shaft 410 with outer shaft 420 . During agitation, inner shaft 410 and outer shaft 420 are disengaged as shown in FIG. 3 . In FIG. 4 , coupler 430 rests in recess 442 of rotor 440 so that splines 436 on coupler upper portion 438 are not engaged with splines 424 on outer shaft 420 . Inner shaft 410 is thus free to move relative to outer shaft 420 . During spin cycles, actuator 450 moves coupler 430 upward along inner shaft 410 to engage splines 424 on outer shaft 420 as illustrated in FIG. 4 . In this position, inner shaft 410 and outer shaft 420 are engaged so that outer shaft 420 is driven by inner shaft 410 for simultaneous rotation during the spin cycle. In one embodiment, actuator 450 is a solenoid that is controlled by a controller coupled to control panel 58 .
[0029] In the embodiments of FIGS. 3 and 4 , the mating geometry between the coupling and shaft members is only in the shaft members with no special rotor bushing or boss design required to mesh the coupler in the engaged or disengaged positions. This allows the coupler to be designed to occupy a smaller space.
[0030] FIG. 5 illustrates a left half cross sectional view of another embodiment of a coupling and de-coupling mechanism 500 to control the relative movements of agitation element 116 and basket 70 of washing machine 50 . In FIG. 5 , coupling mechanism 500 is disengaged. FIG. 6 illustrates a right half cross sectional view of the coupling and de-coupling mechanism of FIG. 5 , where the coupling is engaged. Coupling and de-coupling mechanism 500 operates on inner shaft 510 and a outer shaft 520 . Inner shaft 510 is internal to and concentric with outer shaft 520 . Inner shaft 510 is connected to and driven by a rotor 540 . A coupler 530 includes a lower portion 532 and an upper portion 538 . Coupler 530 is concentric with inner shaft 510 and outer shaft 520 . Upper portion 538 of coupler 530 includes a plurality of internal splines 534 configured to engage a plurality of external splines 512 on inner shaft 510 . Upper portion 538 of coupler 530 includes a plurality of external splines 536 configured to engage a plurality of internal splines 524 on outer shaft 520 . Coupler 530 is free to slide along inner shaft splines 512 . An actuator 550 moves coupler 530 downward along inner shaft 510 on splines 512 . A biasing member 560 biases coupler 530 in an upward position. In one embodiment, biasing member 560 is a spring.
[0031] Coupler 530 moves up and down inner shaft splines 512 to engage and disengage inner shaft 510 with outer shaft 520 . During agitation, inner shaft 510 and outer shaft 520 are disengaged as shown in FIG. 5 . In FIG. 5 , coupler 530 is held in a downward position under the influence of actuator 550 against biasing member 560 . In this position, splines 536 on coupler upper portion 538 are not engaged with splines 524 on outer shaft 520 . Inner shaft 510 is thus free to move relative to outer shaft 520 . During spin cycles, actuator 550 is pivoted upward allowing biasing member 560 to force coupler 530 upward along inner shaft 510 to engage splines 524 on outer shaft 520 as illustrated in FIG. 6 . In this position, inner shaft 510 and outer shaft 520 are engaged so that outer shaft 520 is driven by inner shaft 510 for simultaneous rotation during the spin cycle.
[0032] In the embodiments of FIGS. 5 and 6 , the mating geometry between the coupling and shaft members is only in the shaft members with no special rotor bushing or boss design required to mesh the coupler in the engaged or disengaged positions. This allows the coupler to be designed to occupy a smaller space. In addition, the transfer of torque from the internal member between the shafts takes place in the same plane, effectively decreasing coupler flexure.
[0033] FIG. 7 illustrates a left half cross sectional view of another embodiment of a coupling and de-coupling mechanism 600 to control the relative movements of agitation element 116 and basket 70 of washing machine 50 . In FIG. 7 , coupling mechanism 600 is disengaged. FIG. 8 illustrates a right half cross sectional view of the coupling and de-coupling mechanism of FIG. 7 , where the coupling is engaged. Coupling and de-coupling mechanism 600 operates on inner shaft 610 and a outer shaft 620 . Inner shaft 610 is internal to and concentric with outer shaft 620 . Inner shaft 610 is connected to and driven by a rotor 640 . A cylindrical coupler 630 includes a lower portion 632 , an upright portion 638 , and a locking arm 639 extending radially outward from upright portion 638 . In one embodiment, coupler 630 includes at least two locking arms 639 to facilitate balancing of the mechanism. Locking arm 639 includes a locking notch 637 . Coupler 630 is concentric with inner shaft 610 and outer shaft 620 . Upright portion 638 of coupler 630 includes a plurality of internal splines 636 at an upper end thereof. Splines 636 are configured to engage a plurality of external splines 624 on outer shaft 620 . Lower portion 632 of coupler 630 includes a plurality of internal splines 634 configured to engage a plurality of external splines 612 on inner shaft 610 . Coupler 630 is free to slide along outer shaft splines 624 . Rotor 640 includes a central recessed portion 642 that receives lower portion 632 of coupler 630 when coupler 630 is at the lower end of its travel. Inner shaft 610 includes a spline free section 614 adjacent rotor recess 642 such that coupler 630 is disengaged from inner shaft 610 when coupler 630 is seated in rotor recess 642 . A coupler plate 672 is connected to the washer tub 670 and includes an arm 674 that includes a locking member 676 . Locking member 676 is configured to be received in locking notch 637 of locking arm 639 . A biasing member 660 is positioned between tub 670 and locking arm 639 . Biasing member 660 operates to bias coupler 63 Q toward rotor recess 642 . In one embodiment, biasing member 660 is a spring.
[0034] Coupler 630 moves up and down outer shaft splines 624 to engage and disengage inner shaft 610 with outer shaft 620 . During agitation, inner shaft 610 and outer shaft 620 are disengaged as shown in FIG. 7 . In FIG. 7 , coupler 630 is held in a downward position by biasing member 660 . In this position, splines 634 on coupler lower portion 632 are not engaged with splines 612 on inner shaft 610 . Inner shaft 610 is thus free to move relative to outer shaft 620 while locking member 676 is received in locking notch 637 to hold outer shaft 620 stationary. During spin cycles, an actuator (not shown in FIGS. 7 and 8 ) moves coupler 630 upward against biasing member 660 so that splines 634 on coupler 630 engage splines 612 on inner shaft 610 as illustrated in FIG. 8 . In this position, inner shaft 610 and outer shaft 620 are engaged so that outer shaft 620 is driven by inner shaft 610 for simultaneous rotation during the spin cycle. In another embodiment, inner shaft 610 is configured with splines 612 and spline free section 614 switched, positioning splines 612 adjacent rotor recess 642 and the relative positions of coupling arm 674 and locking arm 639 are reversed so that the agitate and spin positions of coupler 630 are reversed. That is, agitation occurs when coupler 630 is elevated and spin occurs when coupler 630 is lowered.
[0035] In the embodiments of FIGS. 7 and 8 , the mating geometry between the coupling and shaft members is only in the shaft members with no special rotor bushing or boss design required to mesh the coupler in the engaged or disengaged positions. Rotation of one shaft is inhibited while the other shaft is mobilized.
[0036] FIG. 9 illustrates a left half cross sectional view of yet another embodiment of a coupling and de-coupling mechanism 700 to control the relative movements of agitation element 116 and basket 70 of washing machine 50 . In FIG. 9 , coupling mechanism 700 is disengaged. FIG. 10 illustrates a right half cross sectional view of the coupling and de-coupling mechanism of FIG. 9 , where the coupling is engaged. Coupling and de-coupling mechanism 700 operates on inner shaft 710 and a outer shaft 720 . Inner shaft 710 is internal to and concentric with outer shaft 720 . Inner shaft 710 is connected to and driven by a rotor 740 . A cylindrical coupler 730 includes a lower portion 732 including a plurality of splines 734 configured to engaged a plurality of external splines 712 on inner shaft 710 . Coupler 730 is free to slide along inner shaft splines 712 . Coupler 730 includes an upwardly projecting rim 738 that includes teeth 736 . A hub 726 is attached to the lower end of outer shaft 720 and includes a flange 728 that includes a downwardly facing channel 718 that includes teeth 722 configured for engagement with teeth 736 on coupler rim 738 . An actuator (not shown in FIGS. 9 and 10 ) moves coupler 730 along inner shaft splines 712 .
[0037] Coupler 730 moves up and down inner shaft splines 712 to engage and disengage inner shaft 710 with outer shaft 720 . During agitation, inner shaft 710 and outer shaft 720 are disengaged as shown in FIG. 9 . In FIG. 9 , coupler 730 is moved downward on inner shaft 710 so that teeth 736 on coupler rim 738 are not engaged with teeth 722 on flange 728 . Inner shaft 710 is thus free to move relative to outer shaft 720 . During spin cycles, coupler 730 is moved upward along inner shaft splines 712 so that coupler rim teeth 736 engage teeth 722 on flange 728 as illustrated in FIG. 10 . In this position, inner shaft 710 and outer shaft 720 are engaged so that outer shaft 720 is driven by inner shaft 710 through hub 726 for simultaneous rotation during the spin cycle.
[0038] In the embodiments of FIGS. 9 and 10 , spline-to-spline misalignment failure during the coupling process is reduced. In addition, there is a lower force on the coupler geometry due to the larger radial interface point of mating.
[0039] In another embodiment, a coupling and de-coupling mechanism 800 to control the relative movements of agitation element 116 and basket 70 of washing machine 50 is illustrated in FIG. 11 . Coupling and de-coupling mechanism 800 operates on an inner shaft 810 and a outer shaft 820 . Inner shaft 810 is internal to and concentric with outer shaft 820 . Inner shaft 810 is connected to and driven by a rotor 840 . Inner shaft 810 includes a plurality of external splines 812 around a lower portion thereof. A magnetic fluid 850 fills the lower portion of a space 852 between inner shaft 810 and outer shaft 820 . A seal 854 seals the lower end of space 852 to retain fluid 850 . An electromagnet 830 at the base of inner shaft 810 is energized or de-energized to control the viscosity of magnetic fluid 850 .
[0040] During agitation, electromagnet 830 is not energized. When electromagnet 830 is not energized, the viscosity of magnetic fluid 850 is sufficiently low that splines 812 of inner shaft 810 do not grip magnetic fluid 850 so that relative motion between inner shaft 810 and outer shaft 820 takes place. During spin cycles, electromagnet 830 is energized increasing the viscosity of magnetic fluid 850 such that splines 812 grip magnetic fluid 850 so that inner shaft 810 and outer shaft 820 both rotate.
[0041] The embodiments of FIG. 11 do not entail the use of levers or mechanical actuating devices while offering variable coupling force and space savings.
[0042] FIG. 12 illustrates a left half cross sectional view of another embodiment of a coupling and de-coupling mechanism 900 to control the relative movements of agitation element 116 and basket 70 of washing machine 50 . In FIG. 12 , coupling mechanism 900 is disengaged. FIG. 13 illustrates a right half cross sectional view of the coupling and de-coupling mechanism of FIG. 12 , where coupling mechanism 900 is engaged. Coupling and de-coupling mechanism 900 operates on inner shaft 910 and a outer shaft 920 . Inner shaft 910 is internal to and concentric with outer shaft 920 . Inner shaft 910 is connected to and driven by a rotor 940 . A cylindrical coupler 930 includes a lower portion 932 , an upright portion 938 , and a locking flange 939 extending radially outward from upright portion 938 . Locking flange 939 includes an upwardly extending locking rim 937 . Coupler 930 is concentric with inner shaft 910 and outer shaft 920 . Upright portion 938 of coupler 930 includes a plurality of internal splines 936 at an upper end thereof. Splines 936 are configured to engage a plurality of external splines 924 on outer shaft 920 . Lower portion 932 of coupler 930 includes a plurality of internal splines 934 configured to engage a plurality of external splines 912 on inner shaft 910 . Coupler 930 is free to slide along outer shaft splines 924 . Rotor 940 includes a central recessed portion 942 that receives lower portion 932 of coupler 930 when coupler 930 is at the lower end of its travel. Inner shaft 910 includes a spline free section 914 adjacent rotor recess 942 such that coupler 930 is disengaged from inner shaft 910 when coupler 930 is seated in rotor recess 942 . A number of locking pawls 976 are pivotably attached to washer tub 970 through a plurality of pivot pins 972 . Locking rim 937 is configured to engage an outer edge of locking pawls 976 . Biasing member 960 is positioned between tub 970 and locking pawls 976 . Biasing member 960 operates to bias locking pawls 976 into engagement with outer shaft 920 holding outer shaft 920 stationary. In one embodiment, biasing member 960 is a spring.
[0043] Coupler 930 moves up and down outer shaft splines 924 to engage and disengage inner shaft 910 with outer shaft 920 . During agitation, inner shaft 910 and outer shaft 920 are disengaged as shown in FIG. 12 . In FIG. 12 , an actuator (not shown in FIGS. 12 and 13 ) moves coupler 930 to a downward position with coupler lower portion 932 within rotor recess 942 . In this position, splines 934 on coupler lower portion 932 are not engaged with splines 912 on inner shaft 910 . Inner shaft 910 is thus free to move relative to outer shaft 920 . Locking pawls 976 are engaged with outer shaft 920 to hold outer shaft 920 stationary. During spin cycles, an actuator (not shown in FIGS. 12 and 13 ) moves coupler 930 upward against biasing member 960 so that splines 934 on coupler 930 engage splines 912 on inner shaft 910 as illustrated in FIG. 13 . In this position, inner shaft 910 and outer shaft 920 are engaged so that outer shaft 920 is driven by inner shaft 910 for simultaneous rotation during the spin cycle. Locking rim 937 engages locking pawls 976 urging pawls 976 to pivot downward freeing outer shaft 920 for rotation.
[0044] In the embodiments of FIGS. 12 and 13 , the mating geometry between the coupling and shaft members is only in the shaft members with no special rotor bushing or boss design required to mesh the coupler in the engaged or disengaged positions. Rotation of one shaft is inhibited while the other shaft is mobilized.
[0045] While the invention has been described in terms of various specific embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the claims.
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A coupling apparatus includes an inner shaft rotatably driven about a longitudinal axis of rotation, an outer shaft concentric with the inner shaft for selective rotation about the longitudinal axis, a coupling element movable between a first position engaging the inner shaft to the outer shaft for rotation therewith, and a second position disengaging the inner shaft from the outer shaft for relative rotation therebetween, and an actuating element connected to the coupling element and operable to move the coupling element between the first position and the second position.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The disclosed invention relates to RAID array controllers, and more particularly to a method and computer program product for storing configuration information with historical data on disk.
2. Background Art
There are many applications, particularly in a business environment, where there are needs beyond what can be fulfilled by a single hard disk, regardless of its size, performance or quality level. Many businesses can't afford to have their systems go down for even an hour in the event of a disk failure. They need large storage subsystems with capacities in the terabytes. And they want to be able to insulate themselves from hardware failures to any extent possible. Some people working with multimedia files need fast data transfer exceeding what current drives can deliver, without spending a fortune on specialty drives. These situations require that the traditional “one hard disk per system” model be set aside and a new system employed. This technique is called Redundant Arrays of Inexpensive Disks or RAID. (“Inexpensive” is sometimes replaced with “Independent”, but the former term is the one that was used when the term “RAID” was first coined by the researchers at the University of California at Berkeley, who first investigated the use of multiple-drive arrays in 1987. See D. Patterson, G. Gibson, and R. Katz. “A Case for Redundant Array of Inexpensive Disks (RAID)”, Proceedings of ACM SIGMOD '88, pages 109-116, June 1988.
The fundamental structure of RAID is the array. An array is a collection of drives that is configured, formatted and managed in a particular way. The number of drives in the array, and the way that data is split between them, is what determines the RAID level, the capacity of the array, and its overall performance and data protection characteristics.
An array appears to the operating system to be a single logical hard disk. RAID employs the technique of striping, which involves partitioning each drive's storage space into units ranging from a sector (512 bytes) up to several megabytes. The stripes of all the disks are interleaved and addressed in order.
In a single-user system where large records, such as medical or other scientific images are stored, the stripes are typically set up to be relatively small (perhaps 64 k bytes) so that a single record often spans all disks and can be accessed quickly by reading all disks at the same time.
In a multi-user system, better performance requires establishing a stripe wide enough to hold the typical or maximum size record. This allows overlapped disk I/O (Input/Output) across drives.
Most modern, mid-range to high-end disk storage systems are arranged as RAID configurations. A number of RAID levels are known. RAID-0 “stripes” data across the disks. RAID-1 includes sets of N data disks and N mirror disks for storing copies of the data disks. RAID-3 includes sets of N data disks and one parity disk, and is accessed with synchronized spindles with hardware used to do the striping on the fly. RAID-4 also includes sets of N+1 disks, however, data transfers are performed in multi-block operations. RAID-5 distributes parity data across all disks in each set of N+1 disks. RAID levels 10, 30, 40, and 50 are hybrid levels that combine features of level 0, with features of levels 1, 3, and 5. One description of RAID types can be found at
http://searchstorage.techtarget.com/sDefinition/0,,sid5_gci214332,00.html.
In the early days of RAID, fault tolerance was provided through redundancy. However, problems occurred in situations where a drive failed in a system that runs 24 hours a day, 7 days a week or in a system that runs 12 hours a day but had a drive go bad first thing in the morning. The redundancy would let the array continue to function, but in a degraded state. The hard disks were typically installed deep inside the server case. This required the case to be opened to access the failed drive and replace it. In order to change out the failed drive, the other drives in the array would have to be powered off, interrupting all users of the system.
If a drive fails in a RAID array that includes redundancy, it is desirable to replace the drive immediately so the array can be returned to normal operation. There are two reasons for this: fault tolerance and performance. If the drive is running in a degraded mode due to a drive failure, until the drive is replaced, most RAID levels will be running with no fault protection at all. At the same time, the performance of the array will most likely be reduced, sometimes substantially.
An important feature that allows availability to remain high when hardware fails and must be replaced is drive swapping. Strictly speaking, the term “drive swapping” simply refers to changing one drive for another. There are several types of drive swapping available.
“Hot Swap”: A true hot swap is defined as one where the failed drive can be replaced while the rest of the system remains completely uninterrupted. This means the system carries on functioning, the bus keeps transferring data, and the hardware change is completely transparent.
“Warm Swap”: In a so-called warm swap, the power remains on to the hardware and the operating system continues to function, but all activity must be stopped on the bus to which the device is connected.
“Cold Swap”: With a cold swap, the system must be powered off before swapping out the disk drive.
Another approach to dealing with a bad drive is through the use of “hot spares.” One or more additional drives are attached to the controller but are not used by I/O operations to the array. If a failure occurs, the controller can use the spare drive as a replacement for the bad drive.
The main advantage that hot sparing has over hot swapping is that with a controller that supports hot sparing, the rebuild will be automatic. The controller detects that a drive has failed, disables the failed drive, and immediately rebuilds the data onto the hot spare. This is an advantage for anyone managing many arrays, or for systems that run unattended.
Hot sparing and hot swapping are independent but not mutually exclusive. They will work together, and often are used in that way. However, sparing is particularly important if the system does not have hot swap (or warm swap) capability. The reason is that sparing will allow the array to get back into normal operating mode quickly, reducing the time that the array must operate while it is vulnerable to a disk failure. At any time either during rebuild to the hot spare or after rebuild, the failed drive can be swapped with a new drive. Following the replacement, the new drive is usually assigned to the original array as a new-hot spare.
When a RAID array disk drive goes bad, the system must make changes to the configuration settings to prevent further writes and reads to and from the bad drive. Whenever a configuration change happens, the configuration changes have to be written out to all of the disks in the RAID array.
When the operating system or an application wants to access data on a hard disk before it has loaded native drivers for disk access, it traditionally employs BIOS services to do this. BIOS is the abbreviation for Basic Input/Output System. Various vendors, such as Acer America, San Jose, Calif., American Megatrends Inc., Norcross, Ga., and Phoenix Technologies Ltd., Milpatis, Calif., among many others, have their own versions of BIOS. The BIOS provides basic input and output routines for communicating between the software and the peripherals such as the keyboard, screen and the disk drive.
The BIOS is built-in software that determines what a computer can do without accessing programs from a disk. The BIOS generally contains all the code required to control the keyboard, display screen, disk drives, serial communications, and a number of miscellaneous functions. While the access is not necessarily optimal, it is done through an easy to use interface. Minimal code can access these devices until the more optimal drivers take over.
The BIOS is typically placed on a ROM (Read Only Memory) chip that comes with the computer (it is often called a ROM BIOS). This ensures that the BIOS will always be available and will not be damaged by disk failures. It also makes it possible for a computer to boot itself.
When a drive failure occurs, it is necessary to make a configuration change to the array. If this is not done, applications will continue to write to and read from the bad drive. This will inevitably result in data corruption. However, there is only a limited amount of space in system memory, which makes it extremely difficult to manage configuration changes during boot up.
Every RAID controller uses configuration data to store the array information. This is known as controller metadata. The configuration information includes, among other things, the RAID level, how many disks in the array, the drive name or number, the location of the data, especially the starting location, and any other data required to enable the RAID controller to configure the RAID sets and provide the correct data back to the user.
Configuration data is modified on a regular basis. This is especially, but not only, the case where the system contains multiple RAID controllers and multiple arrays. It is not uncommon for RAID controllers to change the number of disks in their array. For example, the controller may add disks to its array to change from a RAID-1 array to a RAID-5 array. In another example, a disk in a given array may develop a fault and must be taken out of service. In either situation, the configuration data for the RAID array changes. The stored configuration data must be updated. Configuration data is normally stored on disk. Typically, the only configuration data stored is the most recently applied configuration.
When users perform complex tasks, they sometimes make mistakes that result in missing RAID arrays or lost data. It is very difficult to find out what happened and recover the missing arrays and data. This can be devastating to a business that has large numbers of records stored in the arrays. It is imperative that there be some way to recover the missing or lost data. Therefore, what is needed is a method and system to easily reconfigure RAID arrays and to recover missing arrays and data.
BRIEF SUMMARY OF THE INVENTION
The invention comprises a method and related computer program product for storing first configuration information for a plurality of logical devices coupled to a RAID controller. Subsequent configuration information is stored for the plurality of logical devices coupled to the RAID controller while retaining previously written configuration information. Finally, in the event of a conflict in configuration information, the first and subsequent configuration information is compared to determine the cause of the conflict.
BRIEF DESCRIPTION OF THE DRAWINGS/FIGURES
FIG. 1 shows a diagrammatic view of main memory in a computer system.
FIG. 2 is a flowchart of a method of obtaining additional memory space during initialization.
FIG. 3 is a flowchart of a portion of a method used to mark bad disks in a RAID array.
FIG. 4 is a flowchart of a further portion of a method used to mark bad disks in a RAID array.
FIG. 5 shows an array comprising drives D 1 , D 2 , D 3 , and D 4 .
FIG. 6 shows two arrangements of controllers and associated drives.
FIG. 7 is a block diagram of a computer system on which the present invention can be implemented.
DETAILED DESCRIPTION OF THE INVENTION
While the present invention is described herein with reference to illustrative embodiments for particular applications, it should be understood that the invention is not limited thereto. Those skilled in the art with access to the teachings provided herein will recognize additional modifications, applications, and embodiments within the scope thereof and additional fields in which the invention would be of significant utility. This invention will be described in terms of a standard Intel® processor PC system. Those persons skilled in the relevant arts will recognize that this invention can be implemented with other processor PC systems equally as well.
The present invention is primarily directed to RAID controllers, and to redundant arrays. Redundant arrays are those in which the data is redundant, sufficiently so that if a drive fails, the data can be reconstructed from the remaining drives. Normally, during run time operations, a write failure or a read failure will never return an error to the caller (i.e., the application being executed). A drive failure error message occurs early during system boot up and initialization when BIOS is running.
An Interrupt is a signal from a peripheral device or a request from a program to perform a specific service. When an interrupt occurs, the currently executing program is temporarily suspended, and an interrupt routine begins execution to handle the condition that caused the interrupt. After the interrupt routine has completed its task, it issues the return instruction to resume the program.
There are two major types of interrupts—hardware interrupts and software interrupts. A software interrupt is an interrupt called by the INT instruction in a machine language program. A hardware device such as a disk drive, a keyboard or a mouse can trigger a hardware interrupt.
System memory contains a page of about 40 Hex vectors. These are locations in memory that are accessed to then point to specific code to be executed. Thus, for example, if the BIOS (Basic Input/Output Services) contains an Int13h command, I/O requests execute Int13h to access block data. During BIOS initialization (sometimes referred to as POST, or Power-On Self Test) the system interrupt vector(s) are programmed to access a specific code pointed to by that vendor's BIOS.
The primary interface to the BIOS is the software interrupt known as “Int13h”, where “Int” stands for interrupt and “13h” is the number 19 in hexadecimal notation. The Int13h interface supports many different commands that can be given to the BIOS, which then passes them on to the hard disk. These include the normal disk related tasks of reading, writing, formatting, and so on.
When running a BIOS Int13h driver, there is a very limited amount of space in system memory that can be used for code. If an error occurs on a RAID set that is doing all the calculations in this environment, it is not possible to properly mark the drive as broken or defective.
FIG. 1 shows a schematic diagram of system memory. In an exemplary embodiment, system memory contains 256 MB (megabytes) of storage space. It will be apparent to anyone skilled in the relevant art that this size is arbitrary. It is well known that in today's systems, memory can run anywhere from as low as 64 MB up to at least about 2 GB (gigabytes) or more. In any case, accessible BIOS memory takes up 1 MB of space. This is called “accessible memory” and comprises memory locations 00000 to 1 MB.
The BIOS routines must create, store and modify variables like any other routine. The BIOS stores these variables in the lower part of memory, typically starting at address 9A00:0000. BIOS functions occur through the individual routines contained in the BIOS interrupts 10H to 17H and 1AH. Usage of the functions is also standardized, to transfer data from the calling program to the interrupt and from the interrupt to the calling program.
The system memory occupying locations 0 though 0ffffffh is denoted as “conventional memory.” The amount of memory available for BIOS is 640 KB (Kilobytes), and goes from 0 through A00000. The first 40 address locations contain the interrupt vectors. System memory locations below A00000, starting below about location 96000, are called “data memory.” Memory locations between A000000 and FFFFFF, an additional 360 KB, is called “high memory.” All of the memory space above 1 MB is called “extended memory.” This is where modern operating systems are loaded and where they execute their applications.
In a computer system having a RAID array, it is necessary to configure the array to get array information, to process conflicts, to create or delete an array, and in general to perform any array manipulation. Whenever an array manipulation is required, 64 KB of system memory is needed to perform the configuration steps. However, system BIOS only allows about 30 KB of memory space to be used for configuration data.
Many systems have 32 or more RAID disks, and several RAID controllers. Configuration information for these disks requires more memory space than the 30 KB that is allowed by system BIOS. There is a need to utilize up to 64 KB of memory in the BIOS data structure area, to be used only during POST. The problem occurs because there was no single specific region of data structure space that is always available and free.
If the system attempts to use memory space below (approximately) memory location 960000, it may run into system BIOS data structures. This can result in partial or complete system failure when POST is completed, so that nothing works any more. To avoid this problem, the area that can be used is the EBDA (Extended BIOS Data Area), also sometimes known as the
Option ROM BIOS Data Area. The EBDA extends from somewhere above memory location 960000 to A000000. The closer one gets to memory location 960000 and below, the more likely it is that the operation will run into the system BIOS data area.
If a drive fails, it becomes necessary to update the configuration data. Changes to configuration parameters take place at initialization. To update the configuration data, it is desirable to have enough system memory available to manipulate the old data.
One aspect of the present invention, therefore, relates to obtaining 64 KB of conventional memory for use during POST and then returning that memory to BIOS after POST has been completed. The 64 KB figure was chosen because that is currently the maximum segment size in memory. Under current constraints, using more than 64 KB (e.g., 128 KB) of space would require manipulation of segments. Such manipulations require complex operations. Currently, 64 KB of space is more than enough to store configuration data. It should be clear to one skilled in the relevant arts that the amount of system memory to be temporarily moved to storage is not critical. It is a function of system design and process limitations.
A feature of the invention is to move whatever is in the 64 KB of selected space in conventional memory to disk during POST. This leaves that space open for configuration changes to be made during POST. At the end of POST, the data is returned from the disk to that 64 KB of space. The inventors have determined that the largest configuration packet that can be made under current constraints is about 49 KB, which is well within the 64 KB range used in this invention.
It is noted here that the data to be moved out of conventional memory temporarily can be stored in other locations than to disk. The data can be stored in flash or DRAM on the controller, for example. The temporary storage location is not critical, as long as the data is temporarily removed from conventional memory during the configuration process and is then returned to that conventional memory space at the conclusion of the configuration steps.
An exemplary method employing the features of the invention proceeds along the following steps as shown in the flowchart of FIG. 2 .
1. First, in step 202 , the system interrupts are disabled. This is done because some more advanced system BIOS's may utilize the 64 KB of space to write data for keyboards, displays, etc. By disabling the interrupts, no data will be written by the system BIOS.
2. Next, in step 204 , a check is made for available disks. The system checks to see if there are any disks that are initialized with metadata. Only initialized disks can have data written to them.
3. If a disk is available, then, in step 206 , the 64 KB of data in memory is written to that disk.
4. Then, in step 208 , an array configuration is performed.
5. After array configuration is completed, in step 210 , the data is restored from disk to conventional memory.
6. Thereafter, in step 212 , system interrupts are re-enabled.
7. System operations are then continued normally.
If in step 204 no disk is available, then the interrupts are re-enabled immediately. In this special case, there are no initialized drives. Therefore no configuration is necessary, and the 64 KB of memory space is not needed.
Configuration step 208 configures the array to get array information, to process conflicts, to create or delete an array, and in general to perform any array manipulation. Whenever an array manipulation is required, the 64 KB of system memory is needed to perform the configuration steps. The 64 KB of data could also be saved to flash, but that would be slower than saving it to disk and returning it to system memory.
One of the features of the invention is to disable interrupts, to prevent system BIOS from running during the array configuration process. If system BIOS were allowed to continue to run, it could require the use of the 64 KB that the configuration process is using. The result would be chaos and possible complete system failure.
This process works very well in POST during the initialization time, but it cannot be used during driver execution. Array configuration cannot be performed during the driver execution, because there is not enough space in system memory to allow for configuration at that time.
Another aspect of the invention relates to techniques to compensate for disk failures in redundant RAID arrays. Redundant arrays are primarily associated with R 1 and R 5 arrays; that is, any redundant array where a disk can fail. By way of example, suppose the array comprises a series of disks, for example, disks 1 - 6 . If disk 3 fails, that is, it returns an error when trying to write to the disk such that the data cannot be recovered, then disk 3 must be removed. If the disk is not removed, there will be data corruption down the line. This is because there is no way of knowing which disks were written to and which were not.
When a bad disk drive is discovered, the bad drive is marked “dead” for that array. A reconfiguration must be done so that all of the remaining disks can be written to with the appropriate data and the bad disk ignored. If that array contains a “hot spare,” the data will be rebuilt on the hot spare and configuration changes will again be made to take that into account. Once the configuration changes logically remove the “dead” drive from the array, that drive can be physically removed and replaced with a working drive that now becomes the “hot spare.” More configuration changes need to be made to enable access to the new hot spare if needed. It can be seen that the configuration data write process is continuous under these circumstances.
Going back to the memory diagram of FIG. 1 , executable code is loaded by the system RAM above A00000. The code that is loaded here should be less than 32 KB. Previously, this space limitation had been a problem. In the past, each function required its own card, such as video, keyboard, mouse, etc. If the system contained multiple cards (e.g., 5 cards), it would quickly run out of space. Today, all of these functions are contained on the motherboard. Therefore, typically there is a need to only use one additional card, such as an array controller card.
Data memory contains barely enough information to allow mapping of all the arrays to all the connected disks. There is not enough memory space available to store the configuration codes. During run time, when an I/O (e.g., a write command) comes in from the operating system through an Int13h call, it maps the command to the appropriate disks and returns a “done” command. However, the operating system cannot tell if a disk has failed. Until a configuration change is made to remove the failed disk from the array, Int13h will continue to attempt to write to the failed disk. More problems are created when the system tries to read from the array. The failed disk will cause the data being read out from the array to be corrupted.
Configuration changes cannot be made on the fly, that is, during run time. Since all configuration code has been eliminated from system memory due to space limitations, there is no ability to get enough memory to make changes when a disk fails. There is no memory available to do a reconfiguration during run time. During run time, the Int13h I/O calls come from the operating system, which operates in an entirely different environment than BIOS. Operating system interrupts cannot be disabled during run time. Doing so would wreak havoc on the entire system. Thus, the problem becomes one of how to reconfigure the configuration information when a disk fails during run time, when there is no memory available for the reconfiguration code.
The solution can be broken down into two parts. First, for read operations, the parity can be used to reconstruct the data from the good disks. The reconstructed data can be read back out. During a read cycle, since data is not being updated, there is no chance of corruption.
The solution for write operations is more complex. If an attempt is made to write to a bad disk, corruption will most likely occur. The technique for solving the write operation problem is shown in the flowchart of FIG. 3 . When the user attempts to write to disk at step 302 , the algorithm checks for a write failure at step 304 . If no write failure is detected, the process terminates. If a write failure is detected, at step 306 the failure information is written into flash (failure information includes which array and which disk has failed). At step 308 the system returns an error message to the caller (i.e., the application that issued the write command).
At step 310 , the process checks to determine whether the system can tolerate the error. In rare instances, the disk error is not fatal and the operating system driver or user making the call can tolerate the error. In that case, booting continues normally, and the array drivers are configured normally.
Normally, when the disk write error is returned, it causes the application that started the write to fail. In that case, the process proceeds to reboot, as shown in the flowchart of FIG. 4 , and generally designated as process 400 . Since the system is still in a very primitive state, the entire system will reboot.
Specifically, at step 402 , the reboot process begins. The system BIOS proceeds to step 404 , where it enters the initialization or POST of the RAID BIOS. When POST is executed, a check is made in step 406 as to whether a write error occurred during the previous Int13h execution. If a write error did occur, the RAID BIOS proceeds to step 408 , where the RAID array is reconfigured to logically remove the bad disk. During reboot, sufficient memory is freed up, as discussed above, to enable the reconfiguration process to proceed. Once the array has been reconfigured, at step 410 the Int13h driver is loaded. At step 412 , POST is completed and the RAID BIOS returns control to the system BIOS.
As noted above, when users perform complex operations, errors can occur that result in the loss of an array and/or data. This can be devastating to a business that has large numbers of records stored in the arrays. It is imperative that there be some way to recover the missing or lost data.
To solve the problem of recovering missing data, all of the configuration information is stored in duplicated ring buffers on all of the disks in the RAID controller. As new configuration data is generated, it is stored in the next available space in each ring buffer. Thus a history of configuration data is maintained in the RAID controller. By using the historical data, old configurations can be rebuilt and data can be restored.
FIG. 5 shows an array comprising disks D 1 , D 2 , D 3 , and D 4 . Each disk has segments for storing configuration data. FIG. 5 shows an example using two RAID sets, a RAID-1 array and a RAID-5 array. A RAID-1 array comprises at least two disks which mirror data. That is, each disk contains an exact copy of the same data as on the other disk. A RAID-1 array may or may not contain spare disks. In the example of FIG. 5 , the RAID-1 array comprises disks D 1 and D 2 . A RAID-5 array uses three or more disks, with zero or more spare-disks. In a RAID-5 array the parity information is distributed evenly among the participating drives. In the example, the RAID-5 array comprises disks D 1 , D 2 , D 3 , and D 4 .
In order to mirror the RAID 1 and the RAID 5 configuration sets, it is necessary to know where they are on disks D 1 , D 2 , D 3 and D 4 . Information about the location of the data on each of the drives must be stored. This is called the configuration data, or metadata. In order to keep track of the changing metadata, a ring buffer is used. In FIG. 5 , the ring buffers are regions of disks D 1 , D 2 , D 3 , and D 4 denoted as areas 591 , 592 , 593 , and 594 , respectively. The latest metadata is stored in the ring buffer, along with all of the previous metadata. As configuration changes occur, the new data are stored in the next available space in the ring buffer rather than overwriting previous data. The storage area is called a ring buffer because once the storage locations in the buffer are filled, new data overwrites the oldest stored data. In this way a history of metadata is maintained, typically for about 100 metadata changes.
As shown in FIG. 5 , the same metadata is always placed on every disk. No matter what disk is actually in the system, a complete picture of all of the arrays is on that disk. If disks D 1 -D 4 are newly initialized, the metadata ring buffers 591 , 592 , 593 , and 594 will all be empty. When a RAID1 array is created at 502 - 1 , 502 - 2 , the metadata ring buffers all store the information at locations 512 , 522 , 532 , and 542 of the entire RAID set.
If a second array is added, e.g., the RAID5 set represented by 504 - 1 , 504 - 2 , 502 - 3 , and 5024 , a new set of controller metadata is created and placed in the ring buffers at locations 514 , 524 , 534 , and 544 . Next, if a second RAID-5 set is created, R′ 5 , the ring buffers will have the metadata for all three of those arrays placed at locations 516 , 526 , 536 , and 546 .
As noted above, the ring buffers have a limited amount of storage space. Typically, configuration data consumes about 1 KB of space. Thus, storage for R 1 metadata requires 1 KB, storage for R 1 +R 5 requires 2 KB, and storage for R 1 +R 5 +R′ 5 requires 3 KB of space. Once all of the storage space in the ring buffers is filled, new metadata will be stored in locations 512 , 522 , 532 , and 542 again, thereby overwriting the metadata currently stored there.
FIG. 6A shows two controllers 602 and 604 . Controller 602 controls two drives, 606 and 608 in a mirrored RAID-1 set. Controller 604 controls three drives, 610 , 612 , and 614 in a RAID-5 set.
Suppose, as shown in FIG. 6B , drive 610 is removed from the RAID-5 set of controller 604 and is re-connected to controller 602 of the RAID-1 set. Drive 610 has old configuration data on it from its former association with the RAID-5 set of controller 604 . Drive 610 appears to have information for a RAID-5 set but is missing two drives. At some point, it may be desirable to create a RAID-5 set under controller 602 . The configuration data then needs to be updated on each of drives 606 , 608 , and 610 under controller 602 to read RAID-1 mirror plus RAID 5. However, drive 610 would not be identical to drives 606 and 608 because the earlier configuration data on drive 610 would be different from the earlier configuration data of drives 606 and 608 .
Over time, the location of the first set of configuration data in each of the drives would change. This is because the configuration data will be placed on different parts of the drives. The drives all generate a number to indicate which configuration data is current. So the next update of configuration data would be placed at position A on disk 606 , position B on disk 608 and position C on disk 610 since all of the drives are now controlled by the same controller 602 .
Assume that the ring buffer on disk 610 is fill. Therefore the new configuration data for the latest update would have to go to the top location (location C). When the system next checks for configuration data, it looks at disk 606 and finds that the configuration data in position A is the latest on that drive. The system then checks disk 608 and finds that the configuration data in location B is most current. Finally, the system looks at disk 610 and finds that the most current configuration data is at position C. The system then compares all three drives and notes that the latest configuration data is the same on all drives. The system will therefore use the configuration data on any one of the three drives.
If another drive 616 is then connected to controller 602 , as shown by the dashed line connection in FIG. 6B , the configuration data will be different on drive 616 from that of the other three drives connected to controller 602 . The history from controller 602 will not be copied over onto the newly added drive. Only the latest information will be copied into the new drive 616 . If there is a conflict between the drives, then the controller will look to earlier configuration data in the ring buffer to determine which is the valid data.
Configuration information that is stored includes: metadata, drive information, control information, and logical device information. Storing the configuration data in all of the drives and storing a history of configuration data enables a user to look back at prior configurations to determine where an error may have occurred.
The following description of a general purpose computer system is provided for completeness. The present invention can be implemented in hardware, or as a combination of software and hardware. Consequently, the invention may be implemented in the environment of a computer system or other processing system. An example of such a computer system 700 is shown in FIG. 7 . The computer system 700 includes one or more processors, such as processor 704 . Processor 704 can be a special purpose or a general purpose digital signal processor. The processor 704 is connected to a communication infrastructure 706 (for example, a bus or network). Various software implementations are described in terms of this exemplary computer system. After reading this description, it will become apparent to a person skilled in the relevant art how to implement the invention using other computer systems and/or computer architectures.
Computer system 700 also includes a main memory 705 , preferably random access memory (RAM), and may also include a secondary memory 710 . The secondary memory 710 may include, for example, a hard disk drive 712 , and/or a RAID array 716 , and/or a removable storage drive 714 , representing a floppy disk drive, a magnetic tape drive, an optical disk drive, etc. The removable storage drive 714 reads from and/or writes to a removable storage unit 718 in a well known manner. Removable storage unit 718 , represents a floppy disk, magnetic tape, optical disk, etc. As will be appreciated, the removable storage unit 718 includes a computer usable storage medium having stored therein computer software and/or data.
In alternative implementations, secondary memory 710 may include other similar means for allowing computer programs or other instructions to be loaded into computer system 700 . Such means may include, for example, a removable storage unit 722 and an interface 720 . Examples of such means may include a program cartridge and cartridge interface (such as that found in video game devices), a removable memory chip (such as an EPROM, or PROM) and associated socket, and other removable storage units 722 and interfaces 720 which allow software and data to be transferred from the removable storage unit 722 to computer system 700 .
Computer system 700 may also include a communications interface 724 . Communications interface 724 allows software and data to be transferred between computer system 700 and external devices. Examples of communications interface 724 may include a modem, a network interface (such as an Ethernet card), a communications port, a PCMCIA slot and card, etc. Software and data transferred via communications interface 724 are in the form of signals 728 which may be electronic, electromagnetic, optical or other signals capable of being received by communications interface 724 . These signals 728 are provided to communications interface 724 via a communications path 726 . Communications path 726 carries signals 728 and may be implemented using wire or cable, fiber optics, a phone line, a cellular phone link, an RF link and other communications channels.
The terms “computer program medium” and “computer usable medium” are used herein to generally refer to media such as removable storage drive 714 , a hard disk installed in hard disk drive 712 , and signals 728 . These computer program products are means for providing software to computer system 700 .
Computer programs (also called computer control logic) are stored in main memory 708 and/or secondary memory 710 . Computer programs may also be received via communications interface 724 . Such computer programs, when executed, enable the computer system 700 to implement the present invention as discussed herein. In particular, the computer programs, when executed, enable the processor 704 to implement the processes of the present invention. Where the invention is implemented using software, the software may be stored in a computer program product and loaded into computer system 700 using raid array 716 , removable storage drive 714 , hard drive 712 or communications interface 724 .
In another embodiment, features of the invention are implemented primarily in hardware using, for example, hardware components such as Application Specific Integrated Circuits (ASICs) and gate arrays. Implementation of a hardware state machine so as to perform the functions described herein will also be apparent to persons skilled in the relevant art(s).
While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example, and not limitation. It will be apparent to persons skilled in the relevant art that various changes in form and detail can be made therein without departing from the spirit and scope of the invention.
The present invention has been described above with the aid of functional building blocks and method steps illustrating the performance of specified functions and relationships thereof. The boundaries of these functional building blocks and method steps have been arbitrarily defined herein for the convenience of the description. Alternate boundaries can be defined so long as the specified functions and relationships thereof are appropriately performed. Any such alternate boundaries are thus within the scope and spirit of the claimed invention. One skilled in the art will recognize that these functional building blocks can be implemented by discrete components, application specific integrated circuits, processors executing appropriate software and the like or any combination thereof. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.
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A method and related computer program product for storing first configuration information for a plurality of logical devices coupled to a RAID controller. Subsequent configuration information is stored for the plurality of logical devices coupled to the RAID controller while retaining previously written configuration information. Finally, in the event of a conflict in configuration information, the first and subsequent configuration information is compared to determine the cause of the conflict.
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This application is a divisional of Ser. No. 07/839,919, now U.S. Pat. No. 5,277,636 issued Jan. 11, 1994.
BACKGROUND OF THE, INVENTION
1. This invention relates to a personal flotation device such as one which may be used for walking on water.
2. Description of the Art Practices
The first apparent use of personal flotation devices mounted to the feet is shown in Soule, U.S. Pat. No. 216,234 issued Jun. 3, 1879.
U.S. Pat. No. 3,835,494 issued Sep. 17, 1974, to Dougherty describes water walking pontoons which are useful for personal amusement. Dougherty's pontoons require that the user have the pontoon surround the legs up to and near the knee.
Webster, in U.S. Pat. No. 3,808,622 issued May 7, 1974, describes shoes for walking in water. In Webster, the shoes also require that the foot be placed within the elongated buoyant body member.
Joyce, in U.S. Pat. No. 4,034,430, issued Sep. 17, 1974 describes a pair of personal flotation devices which are held together by connecting means. The Joyce device also shows the insertion of the foot of the user into the flotation device.
Meredith, in U.S. Pat. No. 1,533,023, issued Apr. 7, 1925, describes a rudderless flotation device having foot means mounted such that the foot is above the surface of the flotation device, but completely encases the foot. Meredith also shows a hinged means for propelling the ski through the water.
U.S. Pat. No. 4,301,562, issued Nov. 24, 1981, discloses a further usage of the device wherein the: foot is inserted within the pontoon.
U.S. Pat. No. 4,117,562, issued Oct. 3, 1978, to Schaumann discloses a pair of buoyant flotation devices locked together by cords or other latching mechanism. The purpose of the latching mechanisms are to control the spread of the user's legs. A similar device is shown in U.S. Pat. No. 4,261,069, issued Apr. 14, 1981 to Schaumann. The water walker described in the later Schaumann patent employs an elongated indentation and an elongated protuberance to replace the locking mechanism, thereby controlling spread as in the earlier Schaumann patent.
The use of flotation devices is shown in an undated article, page 65, featuring David Kiner.
The present invention provides a flotation device which does not require the feet to be placed within the flotation device. A further feature of the present invention has two rudder members and disposed between the rudder members a means for trapping fluid when the device is directed by the user's foot in the aft direction.
A further feature of the present invention is to construct the personal flotation device such that an over-hang, preferably a non-planar device is utilized to control the spread of the feet while the device is in use. Yet a further aspect of the present invention is a pole for enhanced propulsion of the personal flotation device.
SUMMARY OF THE INVENTION
There is described herein a personal flotation device comprising an elongated member with a forward end, an aft end, a starboard side, a port side, an upper surface and a lower surface; wherein the upper and lower surfaces are disposed such that the upper surface contains means above the surface of the upper surface for restraining a human foot and the lower surface contains at least two rudder members running between the forward end and aft end of the device and having disposed between the rudder members means for trapping a fluid when the device is directed in the aft direction.
A further feature of the invention is a personal flotation device comprising an elongated member with a forward end, an aft end, a starboard side, a port side, an upper surface and a lower surface; wherein the upper and lower surfaces are disposed such that the upper surface contains means above the surface of the upper surface for restraining a human foot, the device further having an overhang in relation to the means for restraining the foot such that the overhang extends outward from the starboard side when used with a right foot or outward from the port side when used with a left foot.
A further aspect of the invention is a personal flotation device comprising an elongated member with a forward end, an aft end, a starboard side, a port side, an upper surface and a lower surface; wherein the upper and lower surfaces are disposed such that the upper surface contains means above the surface of the upper surface for restraining a human foot and the lower surface contains at least two rudder members running between the forward end and aft end of the device and having disposed between the rudder members means for trapping a fluid when the device directed in the aft direction, the device further having an overhang in relation to the means for restraining the foot such that the overhang extends outward from the starboard side when used with a right foot or outward from the port side when used with a left foot.
The invention contemplates a pole comprising a shaft member having at one end thereof a handgrip and located substantially at the other end thereof a cupping mechanism.
Also described herein is a pole comprising a shaft member having at one end thereof a handgrip and located substantially at the other end thereof a flotation mechanism.
The present invention contemplates the combination of two opposite aforedescribed personal flotation devices and two of the aforedescribed poles. The invention further contemplates the method of a person utilizing the personal flotation device and/or the pole in water for business or recreational purposes.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a personal flotation device in accordance with the present invention. Typically, there will be 2 symmetrical (mirror image) but opposing personal flotation devices utilized by a user.
FIG. 2 shows a cross-sectional view taken across line 2--2.
FIG. 3 shows a cross-sectional view taken across line 3--3.
FIG. 4 shows a cross-sectional view taken across line 4--4.
FIG. 5 shows a cross-sectional view taken across line 5--5.
FIG. 6 shows the use of a pole with trapping device which is permanently mounted.
FIG. 7 shows a pole with a flotation device and a paddle.
FIG. 8 shows a pole with a flotation device taken along line 8--8.
DETAILED DESCRIPTION OF THE INVENTION
With reference to the afore-mentioned drawings, the present invention is described as follows.
A personal flotation device is shown as FIG. 1. Typically, the personal flotation device will be utilized in pairs by a single human user.
In FIG. 1, the forward end of the personal flotation device (in this case, for the left foot), is shown at 13. The aft section of the personal flotation device is shown as 14. The starboard side of the flotation device is shown at 16, and the port side of the flotation device is shown at 15. The upper surface of the personal flotation device is shown as 10, and the lower surface is shown as 12.
FIG. 1 shows a foot-mounting means 17 mounted on the top of the flotation device. By placing the foot mounting device on top of the personal flotation device, more and more objects are accomplished. First, due to the unique flotation system, the present invention does not require that the user's leg be confined within the personal flotation device. Secondly, while it may appear that the personal flotation device would be less stable because of the higher center of gravity, the remainder of the invention, as shown in FIG. 2, later described, prevents the spread-eagle or splitting phenomenon. What is meant by the spread-eagle phenomenon is familiar to anyone who has stepped from a dock to a boat while maintaining one foot on the dock. As the water is fluid, the legs spread apart, and dire consequences often result. However, in the present invention, the use of the paired devices actually maintain the feet in a normal position without the risk of the spread-eagled effect.
The use of the unique flotation materials as later described herein also assist and allows the top mounting of the foot hold 17. As the flotation material is also effective in maintaining the device in an appropriate position, it is possible to minimize the width of the personal flotation device such that the users legs are in a more normal (standing or walking) position.
FIG. 2 shows a cross-section taken along line 2--2. The foothold 17 may be as used on a conventional water ski from which the user is towed by a boat. The features of the invention shown in FIG. 2 are a twin-hulled design with a arc surface 20 and twin hull rudders 21, which lie substantially below a hinged paddle means 24 with the paddles held in place by rod and spring means 22 such that when the personal flotation device is propelled in the forward direction the paddles are held against the bottom surface 12 and with the non hinged end of the paddle directed to the aft of the personal flotation device.
The paddles capture the fluid when the personal flotation device is directed in the aft direction and are prevented moving through a 180 degree arc by a paddle stop 23 to ensure fluid capture. The hinged paddle means 22 provide the ability to propel the personal flotation device in a forward direction when the opposite personal flotation device is pushed in the aft direction. The rudders 21 may be reinforced to allow the personal flotation device to be stood upon while on a solid surface, e.g. the bank of a lake. The rudders also assist in trapping and channelling the fluid in the desired direction.
In FIG. 2, 25 shows a buoyant flotation material such as a foam. Alternatively, in FIG. 3, 32 shows an air filled personal flotation device. The radius of the arc formed by 20 is typically between 40 and 60 cms, preferably 45 to 55 cms and most preferably 48 cms. The opposite radius on the other side of the personal flotation device is of similar proportions.
FIG. 3 shows a trapping mechanism 31 for capturing fluid without the need for a hinged mechanism. The trapping mechanism is typically a plurality of semicircular cups.
The twin-hulled rudders are preferably mounted such that the paddles or the cups do not contact the surface of the ground when the personal flotation device is on the shore. Stated otherwise, if the paddles were below the bottom of twin hulls 21, it would be subject to breakage. Thus, on relatively even ground, the paddles 24 are not subject to breakage due to the protective feature of twin hulls 21. The twin hulls run substantially the length of the personal flotation device from the forward to the aft end.
The overhang which is in a non-linear or non-planar perspective when taken from center point 25. The curved surface of the flotation device (FIG. 2 shows the left foot device) is non-planar, thereby having effective trapping water with the cup like action of the port side of the left personal device or the starboard side of the right flotation device.
A second important feature to the overhang is that the combination of the flotation material and the overhang allow for the greater support than a more flat surfaced device. The personal flotation device with the overhang and flotation material allows the user's ankles to be placed closer together when considering the relationship of the starboard side of the personal flotation device the left foot and the port side of the starboard personal flotation device.
FIG. 3 shows a cross-section comparable to FIG. 2. In FIG. 3, cups 31 are disposed to trap the fluid when using the first personal flotation device to propel the second personal flotation device through the fluid medium. While greater fluid resistance exists per the cross sectional view of the personal flotation device the solid mounting of the cups within the twin hull will offer greater ease in molding the device. That is, there is no need for moving parts on the device, and the device itself will be less subject to breakage. Consequently, using the cups of FIG. 3 rather than the paddles of FIG. 2, it is possible to extend the cups all the way to the bottom of the twin hull 21, or even beyond the twin hulls. Item 32 in FIG. 3 shows a hollow (air filled) personal flotation device.
FIG. 4 shows a cross section along line 4--4 thereby exposing the paddle mechanism.
FIG. 5 shows a cross section along line 5--5 thereby exposing the cupping mechanism for trapping fluid.
FIG. 6 shows a pole for assisting in propelling the personal flotation device through the fluid. A handgrip 61 similar to that for a downhill ski and a strap 62 to prevent loss of the pole are at one end of the pole. The shaft of the pole, preferably tubular, is shown as 63. The length of the shaft is variable depending upon the height of the user.
Also shown in FIG. 6 is a cupping mechanism 65 preferably filled with a buoyant material similar to that used as 25 or 32 in the personal flotation device, and covered with a hard plastic such as polyvinylchloride as is personal flotation device. A locking mechanism such as threaded bolt is shown as 64.
In FIG. 7 the end of the pole is shown with a modified elliptical cupping mechanism with a lower portion thereof 66 having further located away from the handgrip end of the pole a paddle 67 for further assisting in propelling the personal flotation device.
FIG. 8 shows a cross section taken along line 8--8 further describing the modified elliptical cupping mechanism. The pole 63 is conveniently set through the ellipse substantially at, or on one of the two foci of the ellipse. The handgrip 61 conveniently has finger holds (not shown) located in the same perpendicular direction as the longer portion of the modified elliptical cupping mechanism. The paddle 67 is itself conveniently arranged such that it is perpendicular to the long axis of the modified elliptical cupping mechanism.
The dimensions of the personal flotation device are largely a matter of preference. However, the following are suggested guidelines for obtaining a useful article.
The distance between the twin hulls 21 is conveniently 8 to 19 cms. The recessed area between the twin hulls 21 is conveniently 2 to 10 cms, preferably 3 to 7 cms. The overall distance between the bottom of 21 to the to the top surface 10 is 5 to 20 cms.
The overall length of the personal flotation device is conveniently 100 to 230 cms. The overall width of the personal flotation device taken at the foothold 17 is conveniently 15 to 50 cms. The paddles 24 are conveniently 2 to 7 cms from the hinged spring to the opposite end thereof.
Having fully described the present invention, the following claims which are appended, are intended to describe but not delineate the claimed invention.
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The present invention relates to personal flotation devices. The personal flotation devices are typically utilized in pairs with one or more poles for recreational or emergency rescue usage.
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BACKGROUND
[0001] This disclosure relates to improvements in leakage detection.
[0002] General usage leak detectors are known and used to detect leakage of relatively low temperature fluids in a system, such as water. A typical leak detection system utilizes an electric capacitor on the exterior of a pipe within the system. Water that leaks from the pipe contacts the capacitor, changing the capacitance and indicating a leak.
SUMMARY
[0003] A leak detector according to an exemplary aspect of the present disclosure includes a fabric including a conductor, the fabric having an electric property between the conductor and a reference, the electric property having a first value in response to the fabric being in a non-wetted state with regard to a working fluid and the electrical property having a second value different than the first value in response to the fabric being in a wetted state with regard to the working fluid.
[0004] In a further non-limiting embodiment of the foregoing example, the working fluid is a high temperature working fluid.
[0005] In a further non-limiting embodiment of any of the foregoing examples, the fabric is selected based on the high temperature working fluid.
[0006] In a further non-limiting embodiment of any of the foregoing examples, the working fluid is molten salt.
[0007] In a further non-limiting embodiment of any of the foregoing examples, the fabric is adjacent a conduit.
[0008] In a further non-limiting embodiment of any of the foregoing examples, the conduit contains the working fluid.
[0009] In a further non-limiting embodiment of any of the foregoing examples, the reference is a second conductor of the fabric.
[0010] In a further non-limiting embodiment of any of the foregoing examples, the reference is ground.
[0011] In a further non-limiting embodiment of any of the foregoing examples, the reference is a conduit.
[0012] A leak detection system according to an exemplary aspect of the present disclosure includes a conduit for carrying a working fluid, and a detector on the outside of the conduit, the detector including a fabric with a conductor having an electrical property that changes responsive to contact with the working fluid.
[0013] In a further non-limiting embodiment of the foregoing example, the fabric is a sleeve configured to fit on the outside of the conduit, the sleeve extending around a central axis and between axial ends and an inner surface and an outer surface relative to the central axis. The conductor has a portion that is embedded within the fabric between the inner surface and the outer surface.
[0014] In a further non-limiting embodiment of any of the foregoing examples, the sleeve includes at least one groove on at least one of the outer surface or the inner surface.
[0015] In a further non-limiting embodiment of any of the foregoing examples, the at least one groove is elongated and extends along a longitudinal axis that is perpendicular to a longitudinal axis defined by the sleeve.
[0016] A leak detector according to an exemplary aspect of the present disclosure includes a porous sleeve configured to fit on the outside of a conduit, the porous sleeve extending around a central axis and between axial ends and an inner surface and an outer surface relative to the central axis, and an electrical circuit having at least a portion that is carried by the porous sleeve, the electrical circuit having an electrical property that changes responsive to contact with a leaked fluid.
[0017] In a further non-limiting embodiment of the foregoing example, the electrical circuit includes a controller configured to activate an indicator in response to change in the electrical property.
[0018] In a further non-limiting embodiment of any of the foregoing examples, the porous sleeve is a fabric.
[0019] In a further non-limiting embodiment of any of the foregoing examples, the electrical circuit includes a portion that is dissolvable in the leaked fluid.
[0020] In a further non-limiting embodiment of any of the foregoing examples, the electrical circuit is open when free of any contact with the leaked fluid.
[0021] In a further non-limiting embodiment of any of the foregoing examples, the electrical circuit is closed when free of any contact with the leaked fluid.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The various features and advantages of the present disclosure will become apparent to those skilled in the art from the following detailed description. The drawings that accompany the detailed description can be briefly described as follows.
[0023] FIG. 1 shows an example leak detection system.
[0024] FIG. 2 shows a modified leak detection system having an electrical circuit that is normally closed.
[0025] FIG. 3 shows a cross-section through a conduit and portion of a leak detector.
[0026] FIG. 4 shows an example of a sleeve of a leak detector having a groove on an outer surface.
[0027] FIG. 5 shows another example sleeve of a leak detector having a groove on an inner surface.
[0028] FIG. 6 shows another example of a sleeve of a leak detector having multiple grooves that run parallel to electrical leads.
[0029] FIG. 7 shows an example of a porous sleeve of a leak detector.
[0030] FIG. 8 shows another example of a leak detector in which a conduit serves an electrical lead.
DETAILED DESCRIPTION
[0031] FIG. 1 illustrates an example leak detection system 20 including a leak detector 22 . In this example, the leak detection system 20 is adapted for a system that carries a relatively high temperature fluid, such as molten salt in a concentrated solar power plant. It is to be understood, however, that some or all of the embodiments disclosed herein can be also used in other systems or systems that utilize lower or higher temperature fluids. Other examples are the use of the leak detection system 20 for in-situ medical devices to detect leaking body fluids after surgery.
[0032] In the illustrated example, the leak detection system 20 includes a conduit 24 that carries a working fluid. The working fluid can be a molten salt, such as potassium nitrite salt, sodium nitrite salt, fluoride salt or a mixture of salts. The leak detector 22 is mounted on the outside of the conduit 24 and has an electrical property that changes in response to contact with the working fluid. Thus, the change in the electrical property indicates a leak of the working fluid from the conduit 24 . In this regard, the leak detector 22 can be located on a portion of the conduit 24 where leaked working fluid is likely to flow to. For instance, the leak detector 22 can be located at a vertically low portion on the conduit 24 such that any leaked working fluid gravitationally flows downward and over the leak detector 22 .
[0033] In the illustrated example, the leak detector 22 includes an electrical circuit 26 that has a conductor, first electrical lead 26 a, and a reference conductor, second electrical lead 26 b. The electrical leads 26 a / 26 b are connected to a controller 28 . For example, the controller 28 can include an indicator 30 , such as a visual indicator, audible indicator, etc., control logic, a power source or other additional features for controlling the operation of the leak detector 22 .
[0034] The electrical leads 26 a / 26 b are carried on a fabric 32 that is configured in this example as a sleeve to fit on the outside of the conduit 24 . As an example, the fabric 32 includes fibers 32 a that are arranged in a fiber network and pores 32 b extending between the fibers 32 b . The fibers 32 a can be natural, organic fibers, synthetic polymer fibers or other fibers suitable for the intended use. That is, the fabric 32 is selected based on the type and temperature of the working fluid. The fiber network is a woven structure, for example. The fabric 32 sleeve has an inner diameter corresponding to the diameter of the conduit 24 to enable the fabric 32 to be slid over the conduit 24 .
[0035] In this example, the fabric 32 sleeve is cylindrical and extends around a central axis A between axial ends 34 a / 34 b and an outer surface 36 a and an inner surface 36 b. As can be appreciated, the electrical leads 26 a / 26 b can be attached on the outer surface 36 a of the fabric 32 , attached on the inner surface 36 b of the fabric 32 or embedded within the fabric 32 between the outer surface 36 a and the inner surface 36 b.
[0036] In this example, the electrical circuit 26 is open when free of any contact with the working fluid. Leaked working fluid from the conduit 24 flows into the fabric 32 and bridges the electrical leads 26 a / 26 b to complete the circuit. In the completed circuit, electrical current can flow between the electrical leads 26 a / 26 b and change the state of an electrical property of the leaked detector 22 , to indicate a leak.
[0037] Alternatively, as shown in FIG. 2 , a modified electrical circuit 26 ′ is closed when free of any contact with the working fluid. In this example, the electrical circuit 26 ′ includes a portion 26 c that changes electrical properties when in contact with the working fluid. Thus, when there is no leak, current flows between the electrical leads 26 a / 26 b through the portion 26 c. However, upon leakage of the working fluid from the conduit 24 , the leaked working fluid dissolves or changes the electrical properties of the portion 26 c to change the state of the electrical circuit 26 ′. The change from one state to the other state indicates a leak.
[0038] FIG. 3 illustrates a cross-section showing a further example in which there is a layer of thermal insulation 40 between the conduit 24 and the leak detector 22 . In this example, the fabric 32 is mounted on the outside of the layer of thermal insulation 40 . Specifically, in systems such as concentrated solar power plants that carry working fluid at temperatures typically in excess of 500° F./260° C., the conduit 24 includes the layer of thermal insulation 40 to reduce thermal losses.
[0039] FIG. 4 illustrates another example fabric 132 that can be used in the leak detector 22 . In this disclosure, like reference numerals designate like elements where appropriate and reference numerals with the addition of one-hundred or multiples thereof designate modified elements that are understood to incorporate the same features and benefits of the corresponding elements. In this example, the fabric 132 includes at least one groove 150 on the outer surface 36 a thereof. The groove 150 is generally larger than the pores between the fabric fibers. The groove 150 facilitates directing any leaked working fluid into contact with the electrical leads 26 a / 26 b. For example, any leaked working fluid flowing over the sleeve 132 is caught within the groove 150 and thereby directed into contact with the electrical leads 26 a / 26 b. The groove 150 thus enhances leak detection where the fluid or molten salt might not otherwise contact the leads 26 a / 26 b.
[0040] FIG. 5 shows another example sleeve 232 having a groove 250 on the inner surface 36 b thereof. The groove 250 operates similar to the groove 150 described above.
[0041] FIG. 6 illustrates a further example of a fabric 332 that includes multiple grooves 350 on the outer surface 36 a. It is to be understood, however, that the grooves 350 may alternatively may be on the inner surface 36 b. Although only two grooves 350 are shown, additional grooves may be used. In this example, the grooves 350 are elongated in a direction that is generally parallel to the central axis A of the fabric 332 sleeve. The electrical leads 26 a / 26 b generally extend in a direction parallel to axis A′, which is perpendicular to the central axis A. Orienting the grooves 350 to be perpendicular to the electrical leads 26 a / 26 b facilitates directing any of the leaked working fluid into contact with the electrical leads 26 a / 26 b.
[0042] FIG. 7 illustrates another example fabric 432 , or porous sleeve in this example, that can be used in the leak detector 22 . In this example, the electrical leads 26 a / 26 b (only electrical lead 26 a shown) are embedded within the fabric 432 between the inner surface 34 b and the outer surface 34 a. The fabric 432 includes pores 460 through which any leaked working fluid can flow to contact and bridge the electrical leads 26 a / 26 b. The size of the pores 460 in the fabric 432 can be tailored to the viscosity of the working fluid, to provide a wicking action that facilitates leakage detection. Further, the fabric 432 protects the electrical leads 26 a / 26 b from outside damage.
[0043] FIG. 8 illustrates another example in which the conduit 24 serves as an electrical lead in place of the electrical lead 26 b. The conduit 24 is grounded at G such that any leaked working fluid from the conduit 24 bridges the fabric 532 to complete the circuit between the electrical lead 26 a ′ and the conduit 24 , which thus serves as the reference.
[0044] Although a combination of features is shown in the illustrated examples, not all of them need to be combined to realize the benefits of various embodiments of this disclosure. In other words, a system designed according to an embodiment of this disclosure will not necessarily include all of the features shown in any one of the Figures or all of the portions schematically shown in the Figures. Moreover, selected features of one example embodiment may be combined with selected features of other example embodiments.
[0045] The preceding description is exemplary rather than limiting in nature. Variations and modifications to the disclosed examples may become apparent to those skilled in the art that do not necessarily depart from the essence of this disclosure. The scope of legal protection given to this disclosure can only be determined by studying the following claims.
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A leak detector includes a fabric having a conductor. The fabric has an electric property between the conductor and a reference. The electric property has a first value in response to the fabric being in a non-wetted state with regard to a working fluid and the electrical property has a second value different than the first value in response to the fabric being in a wetted state with regard to the working fluid.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
[0002] Not applicable.
BACKGROUND OF THE INVENTION
[0003] This invention relates to the detection of fault occurrences in electrical or power distribution systems; and, more particularly, to a detector which first detects waveform transients which may be indicative of a fault occurring somewhere in the system, and then classifies the result of the detection as a likely fault occurrence or some other type of anomaly which is likely not a fault.
[0004] In an electrical distribution system, energy in the form of a 60 Hz waveform (50 Hz in some locales) is transmitted over the power lines of the system. These waveforms exhibit a wide variety of transient conditions which are continuously occurring. Many of these transients result from such routine things as a power switch being closed or opened to turn a piece of equipment “on” or “off”, or when the operating speed of a motor is changed. The characteristics of such transients, their duration, peaks, rise and fall times, degradation rate, etc., are generally known.
[0005] When a fault occurs somewhere in the system, a transient also results. Since faults often result in power outages, it is important for the utility to be able to timely detect their occurrence and the area over which the outage extends. The utility can then rapidly respond to correct the outage and restore service to the affected area. Otherwise, if the utility waits until a customer calls to report an outage, it means the customer has already been inconvenienced.
[0006] Fault detection schemes are known in the art. See, for example, U.S. Pat. No. 7,496,430 which is assigned to the same assignee as the present invention. The present invention, however, provides a quick and efficient method of recognizing and classifying faults so to enable a utility to timely identify outages and respond to them.
BRIEF SUMMARY OF THE INVENTION
[0007] The present disclosure is directed to a method for detecting the occurrence of faults in a power distribution system. An algorithm processes information obtained for transients occurring in waveforms which are monitored at a power distribution substation. The transients typically are indicative of the occurrence of a fault in the distribution network, and their timely detection leads to improved detection of power outages in the system.
[0008] The algorithm, which is fully implemented in software, includes a detector (receiver) module and a signal classification module. The detector module receives and processes the power-line waveform, and produces discrete, real-time samples of the waveform which are inspected to look for statistically anomalous patterns against a background of recent waveform data. Anomalous patterns include transients which occur during faults, but may also be transients which result from line load switching and regular load fluctuations caused, for example, by operation of a motor. The classifier module then distinguishes between fault-induced transients and the other transients. This is done by the classification module examining the anomalous pattern to identify a plurality of characteristics or properties commonly associated with fault transients as opposed to the other transients.
[0009] The detector module executes a detection algorithm that down samples a waveform to a predetermined frequency (120 Hz) so to substantially reduce computational complexity. The detector module further executes an adaptive detection algorithm that triggers when large changes occur in the samples over a relatively short period of time, i.e., the detection of transients. The classification module then determines whether or not a transient represents the signature of a fault occurrence based upon certain unique features found in the sample and associated with a fault signature.
[0010] The method of the invention is a passive method whose implementation provides quick and accurate classification of a transient as representative of a fault signature or the signature of some other type transient within the utility's power distribution system, and does so without imposing any additional burden on the system.
[0011] Other objects and features will be in part apparent and in part pointed out hereinafter.
[0012] The foregoing and other objects, features, and advantages of the invention as well as presently preferred embodiments thereof will become more apparent from the reading of the following description in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0013] The objects of the invention are achieved as set forth in the illustrative embodiments shown in the drawings which form a part of the specification.
[0014] FIG. 1 is a functional diagram of a fault detection and classification system of the present invention;
[0015] FIG. 2 is a representation of the characteristics a signature of a fault inducing transient on a power line;
[0016] FIG. 3 is a more-detailed block diagram representation of the detection system;
[0017] FIG. 4A represents the magnitude of an upward transient occurring within the power distribution system, and FIG. 4B the phase of the transient;
[0018] FIG. 5 is similar to FIG. 4A but with an analysis performed on the sample to determine if the transient shown therein has the signature of a fault condition.
[0019] Corresponding reference characters indicate corresponding parts throughout the several views of the drawings.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0020] The following detailed description illustrates the invention by way of example and not by way of limitation. This description clearly enables one skilled in the art to make and use the invention, and describes several embodiments, adaptations, variations, alternatives and uses of the invention, including what is presently believed to be the best mode of carrying out the invention. Additionally, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or carried out in various ways. Also, it will be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.
[0021] Referring to FIG. 1 , a transient detection and fault classification system of the present invention is indicated generally 10 . System 10 , as described hereinafter, comprises three modules; a detector module 12 , a classifier module 20 , and a polling module 30 . The purpose of system 10 is to first detect the occurrence of a transient and then based upon pre-established criteria to classify the transient as likely or not likely to represent the signature of a fault that can cause a power outage within a power distribution system. System 10 further functions to particularly classify transients representing faults which cause protective devices installed within the power distribution system to operate and to poll users on portions of the distribution system to determine the extent of any outage.
[0022] The method of the invention implemented by system 10 comprises a three stage approach to fault detection. In a first stage, the current waveform being monitored at the distribution substation is sampled by detector module 12 and the samples are processed to detect any statistical anomalies, i.e., transients, which may indicate a fault. Samples meeting pre-established criteria in this regard are forwarded to the second stage. At this stage, the samples are examined by signal classification (classifier) module 20 to determine if the characteristics of a transient they represent resemble a fault signature such as shown in FIG. 2 . If they do, then at the third stage, polling module 30 utilizes a power line communications system used by the utility to poll meters on the feeder phase(s) in question. Responses to the polling are used to finally determine both if an outage has occurred within the distribution system, and, if so, where.
[0023] System 10 operates by first examining the current on each feeder phase at a substation of the distribution system to detect any outage-inducing transient. The characteristics of a typical fault signature are shown in FIG. 2 . In FIG. 2 , a feeder current I(t) exhibits a classic outage-inducing transient. The amplitude of the transient, indicated TA in the figure, represents a substantial increase in a load somewhere in the system. The magnitude of transient TA depends on several factors including, for example, the cause of the fault. This can be lightning, an animal coming into contact with a feeder line and now acting as a conductor, a tree branch blown or falling onto the power line, or a short circuit within the system. It will be understood by those skilled in the art that faults occurring on the low side of a service transformer will have a lower current amplitude than similar faults occurring on the high side of the transformer.
[0024] The increased current of transient TA will flow through the affected portion of the power distribution system until one or more protective devices of the utility interrupts the circuit. The typical time for this to occur is from 2 to 6 cycles of the 60 Hz waveform propagated through the power distribution system (approximately 0.03-0.1 seconds). Operation of the protective device(s) ends the transient current; but, it also shuts off power to all of the utility's customers downstream from the protective device. This causes a loss in the load imposed on the system from what it was prior to occurrence of the transient. It will be understood by those skilled in the art that the magnitude of this loss is a function of the load imposed on the system by users of the system at the time of the fault. Accordingly, the impact will vary from circuit to circuit, location on a given circuit, and with time of day.
[0025] A number of factors are considered in formulating the algorithms used in detector portion 12 and classifier portion 20 of system 10 . One is a nearly constant change in current on a feeder as the result of an almost constant change in the load on a monitored circuit imposed by the utility's customers using that circuit. In this regard, small changes appear as low-intensity random events that vary widely over short periods of time. Large switching events are more troublesome to take into account. This is because, for example, the switching “on” of a large load to the system can result in a transient whose characteristics appear very similar to those which occur when a fault happens. For example, large motor switching often produces a transient having characteristics similar to those affected when a fault occurs.
[0026] Referring to FIG. 3 , a fault detection algorithm used by the method of the present invention is shown in block diagram form. In exercising the algorithm, an analog signal representing the feeder phase current I(t) is first converted to a digital signal using an analog-to-digital (A/D) converter 14 . In converter 14 , signal I(t) is sampled at a rate of, for example, 4320 Hz to produce the resulting digital signal.
[0027] The digital output signal from converter 14 is supplied to a demodulator module 16 which, using a two stage demodulation process, produces a 60 Hz complex-valued signal. In the first stage 16 a of module 16 , a coarse demodulation is performed; while, in a second stage 16 b , a fine demodulation is performed. In module 16 a , a complex current waveform is translated into a baseband signal. In module 16 b , small deviations in the carrier frequency of the baseband signal, which cannot be accounted for in module 16 a , are estimated and then removed from the baseband signal. The resultant signal output from module 16 b is then supplied to a detection module 18 and to a signal buffer 22 .
[0028] Module 18 examines samples of the signal for statistical changes that could possibly be indicative of a fault. When such a change is detected, module 18 provides an input to classifier module 20 . In response, module 20 examines the most recent set of data stored in signal buffer 22 , as well as incoming samples, and determines if the signal pattern resembles the signal shown in FIG. 2 . When the signal classifier finds such a signal an alert is provided to an upstream system to initiate a polling process.
[0029] For signal classification, the method of the invention incorporated into the algorithm employs a technique in which certain features are extracted and then used for fault classification. For each suspected fault event, a predetermined number of samples are provided to signal classification module 20 via buffer 22 . The samples represent complex value data obtained at a rate of 60 samples per second. Ninety-one (91) samples are used, for example, these corresponding to baseband information of the power line signal. The total number of samples includes 1 current sample, 30 previously obtained samples, and 60 incoming samples. Exemplary samples analyzed by signal classification module 20 are shown in FIGS. 4A and 4B in which FIG. 4A represents the magnitude of an upward transient occurring within the power distribution system, and FIG. 4B the phase of the transient.
[0030] A sample set such as shown in FIGS. 4A and 4B is provided to signal classification module 20 through buffer 22 . The function of module 20 is, as noted, to determine if this sample set represents a fault event. Studies suggest that there are three distinguishing features found in the magnitude of the samples representing a transient in a baseband sample set that can be used to classify the samples as representing a fault signal so it can be classified as such.
[0031] First, before computing feature parameters of the sample set, module 20 determines whether any transient appearing in the sample set is an upward or downward transient. As an example, FIG. 5 illustrates the same sample set as shown in FIG. 4A . In this sample set, the transient is shown as represented by the 31 st to the 40 th samples. A measurement F 1 represents the height of the transient and is the greatest magnitude of those samples between from the 31 st and the 40 th sample. The 31 st sample is selected because it is the sample that triggers detection module 18 . The 40 th sample is selected because the peak of the fault transient is assumed to have occurred before this sample.
[0032] Referring to FIG. 5 , a magnitude is determined for a sample (Point A) taken prior to the start or beginning of the transient. This Point A is the sample having the longest distance L 1 to a line L 2 extending between the magnitude of the first sample in the sample set and the maximum value max shown in FIG. 5 .
[0033] Next, a value F 2 is determined. This value represents the measure of how much current amplitude drops after the transient occurs. The value F 2 is expressed as a percentage and is defined as the ratio between B and F 1 , where B represents the distance from the maximum value of the transient (i.e., the height of the tallest sample between the 31 st and 40 th samples) to a point C which represents a minimum point between the sample with the maximum value and the 50 th sample. The 50 th sample is selected based on the assumption that the transient of a fault subsides before the 50 th sample. Field tests have shown that, in fault events, the current amplitude after the transient does not necessarily drop to a level lower than that of the current before the transient. Therefore, value F 2 can be less than 100% and the maximum value of F 2 is “capped” at 100%.
[0034] Third, a value F 3 is determined. This value represents a measure of the transient's width (duration of the transient) and is defined as the number of samples between the point A and a point D shown in FIG. 5 . Point A, as noted, represents the beginning of the transient. Point D represents the end of the transient and is the sample that has the longest distance L 3 to a line L 4 connecting the maximum value max to the 50 th sample. Again, the 50 th sample is used because of the assumption that the transient of a fault subsides before the 50 th sample. With respect to the lines L 1 and L 3 used to determine points A and D, it will be noted that, as shown in FIG. 5 , these lines extend perpendicular to the lines L 2 , L 4 they respectively intersect.
[0035] The features described and discussed above have been used to process data obtained in field tests of the system. A detector (not shown) was used to monitor 6 feeders, with 24 conductors (3 phases plus a neutral for each feeder). The detector had a detection threshold of 16 amps. When a suspected fault event occurred on any conductor, the detector captured data for all 24 conductors, it being understood by those skilled in the art that a single fault event may yield transients on different phases. Of 4220 events reported during one of these tests, 14 events were actually reported faults.
[0036] Table 1 shows the values F 1 -F 3 for the reported faults.
[0000]
F1 (AMP)
F2(%)
F3 (samples)
48.04
100
6
443.68
100
7
222.05
94.47
9
54.76
100
5
90.17
98.63
4
266.49
100
10
189.96
100
6
152.58
99.67
6
58.89
100
4
215.52
87.59
5
39.90
100
4
386.85
100
5
73.74
100
4
91.94
100
5
244.42
100
7
[0037] From the data in Table 1, the worst case values of the respective features are:
F 1 =39.90 A, F 2 =87.59%, and F 3 =10 samples.
Using this information, decision parameters are derived by setting limits on the values of the respective features.
[0039] Referring to Table 2, a concern in setting the limits is the rate at which false alarms may occur. If one set of limits is used, the false alarm rate may differ significantly for the same data than when a different set of limits is used. Table 2 illustrates the false alarm rate for separate limits on F 1 -F 3 .
[0000]
TABLE 2
False-alarms vs. decision surface parameters (100% detection)
False Alarms
False Alarm Rate
(35 days, 6
(events per
F1(Amp)
F2(%)
F3 (samples)
feeders)
day per feeder)
>16
>80
<11
33
0.1571
(detector's
threshold)
>20
>80
<11
15
0.0714
>25
>80
<11
12
0.0571
>30
>80
<11
11
0.0524
>16
>70
<11
47
0.2238
>16
>60
<11
54
0.2571
>16
>80
<13
376
1.7905
>16
>80
<15
646
3.0762
[0040] The purpose of system 10 and the algorithm it implements is to correctly classify every fault that causes medium voltage protective devices within the utility's power distribution system to operate, at the expense of having a “reasonable” level of false alarms. Studies have shown that a solid fault causes a significant change in the amplitude of power-line signals. By properly classifying the characteristics of actual faults, the classification algorithm appropriately utilizes the information contained in a baseband sample set.
[0041] Further, it will be appreciated that in any fault detection system, there is the possibility that some events will be mistaken for the occurrence of a fault and result in a “false alarm”. However, excessive false alarms reported by such a system ultimately will undermine a utility's confidence in the detection system being used with the result that alarms caused by the occurrence of real faults will tend to be ignored. False alarm rates can be reduced by reducing the sensitivity of the detection system, but this has the drawback that some actual faults will go undetected. Accordingly, there is trade-off between the rate of false alarms produced by the detection system and rate of actual alarms detected by the detection system. What this means is that the algorithms employed by system 10 must provide an acceptable (to the utility) balance between false and actual alarm rates so to provide a) adequate detection reliability; while, b) keeping waste of system resources due to false alarms (e.g., polling time) to an acceptable level.
[0042] Using data obtained from the tests it has been found that for a relatively large value of the F 1 threshold (F 1 >25 amps), the variations in the F 2 and F 3 thresholds do not significantly affect the number for false alarms. However, variations in the F 1 and F 3 thresholds significantly affect the number of missed classifications. This suggests that for a relatively large threshold value of F 1 , the thresholds of F 2 and F 3 can be “loosely” set so to minimize the number of missed classifications without substantially increasing the number of false alarms. For example, if F 1 has the large threshold noted above (>25 amps), it has been found that loose F 2 and F 3 thresholds (e.g., F 2 >87%, F 3 <12 samples) should be used to minimize the number of missed classifications. Then, for low F 1 thresholds (<25 amps), tightening the F 2 and F 3 thresholds (i.e., increasing the F 2 threshold or decreasing the F 3 threshold) can significantly reduce the number of false alarms.
[0043] Overall, the function of the pattern classifier is to implement decision rules regarding the selection among possible class patterns. This is achieved by first developing an understanding of the discriminating factors between classes and is based upon a combination of observations of the field data, and an understanding of each class' behavior. The attribute values for each class are determined as a result of the data acquired during testing and evaluation of this data.
[0044] Next, the method of the invention includes an additional classifier algorithm implemented within module 20 which can classify a transient pattern to be a feeder-switch event rather than a fault. When such a pattern is detected, system 10 provides an output to the utility or upstream system that the distribution network may have been reconfigured. Also, besides classification of fault and feeder-switching events, system 10 can also implement other classification algorithms depending a utility's particular needs or wants so to promote the most efficient delivery of electrical power throughout the utility's distribution system.
[0045] In view of the above, it will be seen that the several objects and advantages of the present disclosure have been achieved and other advantageous results have been obtained.
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Detection of fault occurrences within a power distribution system. A transient detector and fault classification system ( 10 ) implements an algorithm that detects transients which may result from the occurrence of a fault in the power distribution system. The system includes a detection module ( 18 ) which processes a set samples obtained from electrical waveforms propagated of through the power distribution system and appear to be statistically anomalous compared to other sample data. This is done using an adaptive detection algorithm that is applied when large changes occur in a waveform over a relatively short period of time. The identified samples are then provided to a signal classifier module ( 20 ) which processes sets of samples to classify a transient they represent as a likely fault occurrence or some other type of anomaly which is likely not a fault occurrence. If a transient is classified as representing a likely fault occurrence, a polling module ( 30 ) polls users of the distribution system to determine if a fault has occurred within the distribution system, and, if so, where.
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SUMMARY OF THE INVENTION
This invention relates to a partition and will have application to room partitions which may be radially adjusted.
Room partitions are useful, inexpensive articles used primarily to divide a large working area into a plurality of smaller private work areas. The assembly of the previously known partitions was not only time consuming and difficult but also highly inflexible in that radial adjustment of adjacent partitions could not be achieved without completely disconnecting one partition from an adjacent partition.
The partitions of this invention include a hook connection which permits more convenient and economical initial assembly and permits rapid subsequent radial adjustment of the partitions. A notched clamp secures the partitions in a selected position and is readily removable to permit rapid subsequent partition adjustment without complete removal of the hook connections.
Accordingly, it is an object of this invention to provide for a novel room partition.
Another object of this invention is to provide for a portable, radially adjustable room partition.
Another object of this invention is to provide for a room partition which is efficient and economical.
Another object of this invention is to provide for a room partition which is easily assembled and disassembled.
BRIEF DESCRIPTION OF THE DRAWINGS
A preferred embodiment of the invention has been depicted for purposes of illustration wherein:
FIG. 1 is a top perspective view of two room partitions constructed according to the principles of this invention, with the partitions shown in a generally coplanar orientation.
FIG. 2 is a fragmentary top perspective view of the partitions within the circle 2 of FIG. 1.
FIG. 3 is an exploded view of the partitions of FIG. 2.
FIG. 4 is fragmentary exploded top view of the partitions showing the partitions in a perpendicular orientation.
FIG. 5 is a fragmentary perspective view of the partitions of FIG. 4.
FIG. 6 is a fragmentary sectional view taken along line 6--6 of FIG. 2.
FIG. 7 is a fragmentary cross-sectional view taken along line 7--7 of FIG. 6.
FIG. 8 is a fragmentary bottom perspective view of the area within circle 8 of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred embodiment herein described is not intended to be exhaustive or to limit the invention to the precise form disclosed. It is chosen and described to explain the principles of the invention and its application and practical use to enable others skilled in the art to utilize the invention.
The drawings illustrate an embodiment wherein adjacent partitions are adjustable in five different positions relative to each other. For example, viewing along the top edge from one partition to the other, the second partition can be fixed, in a counter-clockwise mode, progressively at angles of from 90°, to 135°, to 180° (or, coplanar), to 225° and finally to 270° and it should be understood that this is by way of illustration only. Without the disk, each adjacent partition, with hooks in place, is free to rotate about the post between them. The disk may be notched other than as illustrated in order to permit freedom of design. By way of further example, the notches may be spaced 60° apart or at any desired angle. One could thereby create rooms having from four to five to six, etc., sides, or a variety of shapes limited only by one's imagination and creativity. This was not previously achievable except by great effort and expense.
Partition 10 shown in the drawings includes a plurality of individual partition members 12 (two shown), each of which has opposite side faces 14,16, top edge 18, bottom edge 20, and end caps 22 secured to partition member 12 by screws 21. Partition members 12 are preferably formed of rigid, durable material such as rigid PVC with faces 14,16 covered by a fabric or cloth material.
Positioned between member end caps 22 is a post 24 preferably formed of rigid tubular material. A hook 28 includes an anchor part 30 connected to a plate 32 which is fitted within vertical slot 31 of the end cap 22 as shown in FIG. 3. Hook 28 also includes integral return bent part 34 shaped so to fit over post 24. A cap 36 overlies member top edge 18 and hook anchor part 30 to further secure the hook 28. Cap 36 is secured to top edge 18 by screws 37. A hook 26 is utilized at the bottom edge of end caps 22 to secure partition members 12 to post 24. Constructed in this fashion, each partition member 12 is radially shiftable about post 24 between the coplanar orientation of FIGS. 1 and 2 and the perpendicular orientation of FIGS. 4 and 5.
A clamping disk 38 is fastened to post 24 adjacent member top edge 18 by a fastener 40. Disk 38 includes notches 42 generally equally spaced about its periphery, which accept and secure hook return bent part 34 in a selected position thereby establishing the spatial relationship between partition members 12. It will be understood that, while disk 38 is shown having grooves or notches spaced 45° apart, all that is needed for different relationships or angles between adjacent partitions is a set of disks with differently spaced notches. Each partition member 12 may include a vertical groove 44 in each end cap 22 to facillitate securement of horizontal shelves (not shown).
To adjust partition members 12, fastener 40 is loosened and clamping disk 38 raised until hook return bent part 34 is free of disk notches 42. Member 12 is then radially adjusted about post 24 into the desired position and disk 38 lowered until hook part 34 is confined within another disk notch 42. Fastener 40 is then turned to secure the disk in this position.
It is to be understood that the invention is not limited to the above description but may be modified within the scope of the appended claims.
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An adjustable room partition which includes individual partitions secured by hooks to a common post. A removable clamp having peripheral notches accepts and secures the hooks and serves to hold the partitions in a selected angular orientation.
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BACKGROUND OF THE INVENTION
This invention relates generally to an improved device for stabilizing the upper member of a plural-part housing for an underground shut-off valve.
The control valve associated with a branch line serving an individual gas or water consumer is commonly buried substantially below ground level proximate the main supplying the branch line. Access from ground level to such a valve may be had through a hollow housing or box surrounding the valve by means of a hand-operated rod insertable downwardly through the housing for engaging a valve operating member.
A common type of valve housing is characterized by discrete upper and lower tubular sections which are axially movable in a telescopic manner. While the primary function of the two-part housing is to provide access to an underground valve, its other important functions are to provide for easy adjustment of its top-to-bottom length and to isolate the lower housing section from any downward axial movement of the upper housing section after installation of the housing in the ground. It is contemplated that, as the housing is installed, the lower section will bear directly upon the main or some exterior surface of the valve itself; the upper section will telescope either inside or outside the lower member; and, the overall axial length of the telescoped sections will be adjusted so that the top end of the upper section and the access lid carried thereby will be at or very near ground level.
As typically constructed, the top portion of the upper member of a plural-part tubular housing is configured to have a radially enlarged head which terminates in a downwardly facing annular shoulder. As the excavation about the upper and lower sections is filled, this annular shoulder is underlain and supported by fill to establish the desired vertical position of the upper section. If a typical housing is installed in a street, sidewalk or driveway, a stable paving medium such as concrete or asphalt will surround the head formed on the upper section in vertically supporting relation thereto. On the other hand, should a housing be installed in a parkway or lawn area, vertical support for the upper section is provided solely by earth or other relatively unstable fill compressively embracing its outer cylindrical wall and underlying the aforementioned annular shoulder.
A longstanding problem is created when rain water, melt water or moisture from other sources softens, erodes or otherwise destabilizes the fill embedding the upper housing section. In this situation, the upper section of the housing is likely to settle in the moistened fill under its own weight or due, perhaps, to some casual force applied to the top of the housing or to the access lid carried thereby. In aggravated occurrences of fill destabilization, the upper section may be displaced downwardly to such an extent that its top surface as well as the access lid are situated well below ground level. Thereafter, pooling of water in the crater formed around the upper section accelerates erosion and exacerbates the sinking problem. Moreover, once the upper section sinks below ground level, its top end may become overlain with enough earth to support vegetative growth which thrives due to favorable conditions for composting of leaves and grass clippings trapped in the depression formed about the sunken valve housing. When the upper housing sinks and becomes obscured by earth, vegetation or both, visual location of the access lid becomes difficult if not impossible. The time expended by utility company personnel to locate, clear and remove such a fouled access lid is obviously increased. Even greater cost and customer inconvenience are involved in excavating and repositioning a sunken valve housing. Dangerous, perhaps deadly, consequences arise in case an access lid for a gas valve in a branch line serving a burning structure cannot be quickly located by utility company personnel or firefighters.
If a single-piece valve housing is substituted for a telescopic housing to forestall sinking of its access lid, erosion about the upper end of the housing and creation of a crater therearound may result in projection of the upper end of the housing above the adjacent terrain. Also, in accordance with the teaching of the prior art, the upper segment of a two-part housing could include a radially projecting flange or the like adjacent its underground end to provide vertical support should the fill be eroded away about the housing's upper end. In either case, the resulting above-ground projection of a valve housing has potential for personal injury and catastrophic damage to power-driven lawn care equipment.
The somewhat pertinent U.S. Pat. No. 4,475,844 issued to Arntyr et al shows a tubular drain pipe vertically positioned in the ground with a tubular neck of an overlying drain cover telescopically received in the top of the drain pipe. An annular support is coaxially seated upon the extreme upper end of the drain pipe and has a flange which extends radially from the top of the drain pipe a substantial distance. The entire flanged support is buried or anchored in the ground some distance below the drain cover. The stated purposes of the disclosed support are as follows:
1. The support flange improves the vertical supporting ability of the material (earth) immediately underlying the drain cover.
2. The support flange will deflect ground water radially away from the drain pipe to prevent softening of the ground layer surrounding the same.
3. If the exposed surface surrounding the drain cover should sink, the flange will be pressed downwardly against the top of the drain pipe to prevent any tendency of the drain pipe to heave upwardly.
4. In the case of light weight plastic drain pipes, the flanged support will be pressed downwardly by overlying earth against the upper end of the drain pipe to prevent its upward movement due to geostatic pressure.
While placement of the water-deflecting flange underground and below the drain cover is required for carrying out all the multiple purposes of the Arntyr et al invention, such placement of this type of support is not appropriate or useful in addressing the long standing valve housing problem outlined above. Destabilization of the upper housing section due to water entering around its exposed top end will not be prevented by a water-deflecting flange buried deep enough to rest upon the extreme upper end of the lower section of a two-part housing. Rather, what is required is a water-deflecting means which directs water away from the ground surface area surrounding the upper section thereby preventing softening and erosion of the fill that vertically supports the upper section.
SUMMARY OF THE INVENTION
The aforenoted problems and shortcomings of prior art housings for underground valves are substantially obviated by the present invention which provides an improved groundengaging disklike support mounted coaxially about the top end of the upper section of a conventional plural-part housing. The central opening of the disklike support has a radially extending flange which provides a seat for a flange projecting radially outwardly from the enlarged head of an upper housing section. When the upper section is fully inserted axially downwardly through the central disk opening, these flanges engage in abutting fashion whereby the upper section is effectively suspended by the disk; and, theextreme top surfaces of the upper section and an access lid carried thereby are in substantial registration with an upwardly facing surface of the disk. In this assembled condition, fill is tamped beneath the entire undersurface of the disk and around the upper housing section to maintain both the disk and the upper section in prescribed relation to ground level so that the access lid and the surrounding disk top surface remain visible.
In the manner of an umbrella, the disk's top wall slopes outwardly and downwardly about the top end of the upper housing section and serves to shed water to the outer circumferential edge of the disk. Deflection of water away from the outer tubular wall of the upper housing and away from its annular shoulder underlain by supporting fill substantially eliminates the problems of fill softening and erosion leading to sinking of the upper housing section below ground level.
Another object of this invention is to provide a hollow, centrally apertured discoid having a conical top wall and a planar base wall joined at their out peripheral edges and defining therebetween a substantially closed cavity.
Yet another object is to provide a hollow disk having a annular skirt depending about its outer peripheral edge to prevent reentry of deflected water under the base of the disk into the fill underlying the disk.
Still another object is to provide an umbrella-like disk which closely surrounds and supports the top of a valve housing wherein the disk has a hollow interior and connecting internal passages providing drains for any water entering between the disk and the housing. Such drain passages empty to the underside of the disk into that area of the underlying fill radially remote from the depending tubular body of the housing penetrating the center of the disk.
A still more detailed object is to provide a hollow disk of either a unitary or a two-piece construction both being molded of a suitably strong but inexpensive and lightweight plastic material.
Another specific object is achieved in a disk having an auxiliary wedging annulus insertable between the disk and the valve housing for tilting the disk with respect to the longitudinal centerline of the tubular valve housing surrounded by the disk. Through use of such a wedging device, the present invention can be employed to advantage with a valve housing installed in sloping terrain.
Still another detailed object is to provide a ground-supported stabilizer comprising a hollow body having a low vertical profile defined by an exposed upper wall that flexes downwardly when trod upon or when overridden by the wheel of a lawnmower or the like. Such flexing of the upper disk wall tends to cushion such forces thereby preventing, or at least reducing, compaction and downward displacement of the fill under the disk.
An ancillary object of this invention is to provide a simple means for securing the disk about the top of the upper section of the valve housing in fixed axial relation thereto to facilitate placement of fill under the disk during installation of the valve housing assembly.
These and other advantages and objects of this invention and the manner of obtaining them will become apparent and the invention will be best appreciated and fully understood by having reference to the following detailed description of the embodiments of the invention taken in conjunction with the accompanying drawings.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan view;
FIG. 2 is a sectional view taken generally along lines 2--2 of FIG. 1 illustrating the invention in its installed condition;
FIG. 3 is a sectional view taken generally along lines 3--3 of FIG. 1;
FIG. 4 is a partial sectional view showing an annular wedge in assembled condition;
FIG. 5 is a perspective view of the annular wedge shown in FIG. 4;
FIG. 6 is a sectional view similar to FIG. 2 showing an an alternate embodiment of the invention;
FIG. 7 is an enlarged fragment of the embodiment shown in FIG. 6;
FIG. 8 is a section taken along lines 8--8 of FIG. 6;
FIG. 9 is an enlarged fragment of the embodiment shown in FIG. 6; and,
FIG. 10 is a section taken generally along lines 10--10 of FIG. 9.
DETAILED DESCRIPTION OF THE INVENTION
The conventionally constructed plural-part valve housing illustrated in FIG. 2 is denoted in its entirety by numeral 20. Upper and lower housing sections 22 and 24, respectively, are generally tubular with the bottom end 26 of section 22 being telescopically received within the top end 28 of lower section 24. In a well-understood manner, the bottom end of lower section 24 extends downwardly through earth or other surrounding fill F into bearing contact with an underlying main or branch line in surrounding relation with a shut-off valve, not shown. An operating handle 30 for the shut-off valve projects upwardly into the housing 20 so that its headed upper end 32 may be conveniently engaged and rotated by a suitable tool inserted downwardly through the top of the upper section 22.
As best shown in FIGS. 2 and 3, the top portion of the upper tubular section 22 comprises a bell-shaped head 34 terminating in a radially projecting flange 36 defined by an annular top surface 38, an outer cylindrical wall 40, and an annular bottom surface 42 which returns inwardly to intersect the outer head wall 44. The bottom of the head 34 is defined by a neck 48 which creates a transitional shoulder surface 50 connecting the outer head surface 44 to the nominally sized portion of the upper section 22. Coaxially contained within the head 34 is an access plate or lid 52 having upper and lower flat surfaces 54 and 56, respectively, connected by a cylindrical outer wall 58. The lower lid surface 56 is seated upon the upper surface 60 of a notched annular flange 62 projecting from the inner head wall 64; and, the flat upper surface 54 of the plate is in registration with the annular top surface 38 of the head 34.
The lid 52 has a centerbore 66 penetrated by a locking shaft 67; and, the centerbore has a counterbore 68 which receives the hexagonal head 69 of the shaft 67. To the depending end of the shaft 67 is fixed a crossbar 70 which may be rotated from above lid 52 to align its extending arms under the flange 62, as seen in FIGS. 2, 3 and 8, to secure the lid 52 in its assembled condition with respect to the upper section 22. A suitable tool may be applied to the shaft head 69 to rotate the crossbar 70 into alignment with angularly opposed notches 71 relieved in the flange 62 whereupon the lid 52, as well as the shaft 67 and cross bar 70, may be withdrawn from the upper section 22 to gain access to the shut-off valve handle 30.
Turning now to the description of the novel features of the present invention, a first embodiment thereof comprises the unitary disk illustrated in FIGS. 1 through 4 and generally designated by numeral 72. Also disclosed hereinafter, is a second embodiment comprising the disk shown in FIGS. 6 through 10. The disk 72 generally comprises a hollow body in the shape of a truncated right circular cone. The disk structure includes a top wall 74 sloping downwardly and outwardly from the top edge of a generally cylindrical inner wall 76 which defines an axial centerbore 78 through the disk. A planar base wall 80 extends perpendicularly outwardly from the lower marginal opening of the centerbore 78 to join the sloped top wall 74 in a shared circular peripheral edge 82. Intermediate the open ends of the cylindrical wall 76, an integral annular flange 84 projects radially into the centerbore 78. The projection of the flange 84 is such that its top surface 86 provides an annular seat for the annular bottom surface 42 of the flange 36 for supporting the head 34 within the centerbore 78.
The horizontal base 80 of the disk bears directly upon underlying fill F in the manner of a supporting pad which distributes downwardly directed loading received from the upper section 22 over a relatively large area thereby reducing the unit pressure acting to compress or displace the fill. The axial support for the upper section provided by base 80 is substantially greater than that provided by the aforedescribed annular shoulder 50 acting alone.
The sloping upper disk wall 74 integrally connects the upper marginal opening of the vertical counterbore wall 76 to the disk's outer circumferential edge 82 to form a conical surface having a relatively low vertical profile or aspect. The slope of the wall 74 can be varied as desired by changing the outer diameter of the base 80 or the vertical dimension of the disk's inner cylindrical wall 76. One function of the sloped disk wall 74 is to deflect or shed water away from the exposed upper end of the housing 20 and to conduct such water to the outer edge 82 of the disk where it enters that portion of the fill F radially beyond the adjacent fill underlying the base 80. The disk edge 82 may have a depending continuation in the form of an annular skirt 88 having an axial dimension sufficient to limit seepage of deflected water back into the fill underlying the base 80. The skirt 88 additionally serves to provide lateral stability for the layer of fill F directly underlying and supporting the disk base 80.
While the disk could comprise a solid body, the perferred embodiment shown in FIG. 2 has a hollow interior space 88 defined by the aforenoted cylindrical wall 76, the sloped wall 74 and the flat base 80. A hollow disk has less weight acting downwardly upon the fill underlying the disk; and, other beneficial aspects of a hollow disk will become apparent hereafter.
When the disk 72 is fully assembled to the upper section 22 of the housing 20, as shown in FIGS. 2 and 3, the flange surface 42 bears upon the underlying disk flange surface 86; and, an annular clearance space between the flange surface 40 and the disk's centerbore wall 78 extends vertically between the top surface 38 of the head 34 and surface 86. Since it is desirable that such clearance be made great enough to permit assembly of the disk 72 to the section 22 in the field without special tools or methods, it is unavoidable that some water will enter this annular passage. To forestall the possibilty that such leakage will find its way through this clearance space into the fill under the disk, several angularly spaced apertures 90 extend radially through the cylindrical wall 76 to connect the aforenoted clearance space with the hollow interior 88 of the disk. Preferably these apertures slope downwardly from the clearance space into the disk interior with their upstream openings in substantial vertical alignment with the annular surface 86. Any significant quantity of water passing through apertures 90 and accumulating in the disk's interior 88 is then drained through several angularly spaced apertures 92 through the disk base 80. In order that drainage from the disk interior be received in the fill F under the base 80 at the least detrimental point, the apertures 92 are spaced proximate the outer periphery of base 80 and remote from the cylindrical inner wall 76 of the disk 72. From the foregoing detailed description, it will be appreciated that an advantageous structural feature of the disk is the provision of a fluid passage comprising aperture 90, disk interior 88 and aperture 92 to obviate deleterous effects of water entering between the upper section 22 and the disk.
The aforedescribed prior art valve housing 20 is typical of those used in connection with gas shut-off valves located beneath parkways or lawns adjacent residential structures; and, the method of installing such a housing is well understood. The principal objects of this invention are realized by mounting the disklike support 72 adjacent the top of such a prior art housing. Whether the disk 72 is put in place in connection with the initial installation of a valve housing or as a modification of a previously installed upper housing section 22 excavated to raise it from a sunken condition, the assembled upper housing member and disk 72 will be supported relative to the surrounding ground surface G, substantially as shown in FIG. 2, by underlying fill F. The upper end surface 38 of the head 34, the upper surface 54 of the lid 52, and a significant portion of the adjacent disk wall 74 should remain exposed, i.e., visible above ground level G. The extent to which the disk wall 74 projects above ground is variable between total exposure and none at all depending upon such factors as the diameter and slope of the disk wall 74, the expected depth and density of vegetative growth and debris on the ground, the maximum allowable vertical projection of the head 34 and lid 52 above ground level G, and whether the projecting disk's appearance is acceptable from an esthetic veiwpoint.
The outer diameter of the disk 72, hence the surface area of the disk's bottom wall 80 supportively bearing upon underlying fill F, may vary and will depend on such factors as the weight of the upper housing section 22 to be supported, the moisture content of the fill and its compactability at the time of initial installation, and the anticipated frequency and quantity of rain, snow melt, lawn sprinkling, etc. on and around the disk. The presence of soil and water conditions conducive to instability of the fill F would indicate, for example, that a disk having a greater diameter and perhaps a longer skirt 88 than shown in FIG. 2, should be installed about the upper section 22.
The following structural adjuncts of this invention greatly facilitate the installation of a valve housing penetrating the disclosed support disk 72. To secure the upper housing section 22 and the disk 72 to one another so that the disk is held from sliding down and interferring with placement and compaction of fill under the disk base 80, bent clips 94 shown in FIGS. 1 and 3, may be inserted in one or more apertures axially penetrating the cylindrical inner wall 76 of the disk 72. The lower end 96 of the clip is bent radially outwardly under the base 80; and, the upper end 98 of the clip is bent radially inwardly to overlie the upper surface 38 of the head 34. The clip cross section may be rectangular, as shown, or otherwise as desired provided only that the configuration and material selected for the clip provide adequate strength to resist unintended disassembly of upper section 22 and disk. The clips 94 may be left in place after fill is firmed in place; however, it is preferrable that the upper clip end 98 be removed so that incidental forces acting downwardly upon the disk wall 74 will not be coupled to the upper section 22.
Another feature of this invention facilitating its proper installation is the provision of the depth indicating rings 99 raised on the upper surface of disk wall 74. Where some portion of the wall 74 is buried below ground level G, as shown in FIG. 2, the radially spaced rings 99 provide ready visual indication as to whether the disk is located at a prescribed depth and whether the disk is supported by the underlying fill in a generally horizontal attitude.
If the terrain surrounding the upper housing section 22 is unavoidably sloped, the wedging annulus 100, shown in FIGS. 4 and 5, may be placed about the head 34 to tilt the disk 72 so that it lies parallel with the surrounding ground surface yet supports the upper section vertically. This annular member should be made of metal, hard plastic or similarly hard, durable material. The axial dimension of the cylindrical wall 102 varies with the thickest protion of the wall underlying the downhill side of the flange 36.
Another structural embodiment of the present invention is illustrated in FIGS. 6 through 10 where numeral 104 generally denotes a modified two-piece disk construction. Disk 104 comprises an upper element 106 and a lower element 108 which are coaxially assembled by means of interfitting projections and depressions provided by these elements. FIG. 6 shows that the upper disk element 106 exhibits a conical wall 110 having a depending annular skirt 112 and a centerbore 114 defined by a cylindrical wall 116. The lower element 108 includes an axial centerbore 118 defined by a cylindrical wall 120. A depending cylindrical wall 122 partially coaxially surrounds the wall 120 and is joined thereto by an annular web 124 having flat top surface 126 joined to a beveled surface 128. A planar circular base 130 has a central opening joined to the cylindrical wall 120 and a skirt 132 depending from its outer perimeter.
From FIG. 6 it will be understood that the lower disk element 108 fits coaxially inside the upper disk element 106 with their respective cylindrical walls 116 and 122 and their respective skirts 112 and 132 adjacent one another. A plurality of angularly spaced, hemisperical projections 134 extend radially from and about the cylindrical wall 122 and annular skirt 132 of the lower disk element. As best shown in Figs. 7; 9 and 10, these projections are received in similarly shaped and spaced depressions 136 recessed in the cylindrical wall 116 and the annular skirt 112.
When the upper and lower elements of the two-piece disk 104 are joined by the interfitting projections 134 and recesses 136, this embodiment of the invention coacts with the head 34 of an upper housing section 22 to support the same in a manner similar to the unitary disk 72 described earlier. The annular bottom surface 42 of the head flange 36 is seated upon the annular top surface 126 of the web 124. Water entering the clearance space between the cylindrical wall 40 of the flange 36 and the cylindrical wall 116 of the disk centerbore 114 will seep down through the arcuate interstices between the walls 116 and 122, into the hollow interior 140 of the disk 104, and then through the arcuate interstices between the skirts 112 and 132. The beveled surface 128 prevents seepage from passing between the surfaces 42 and 126 into the centerbore 118 of the lower disk element 108.
The provision of hollow interiors 88 and 140 for the disks 72 and 104, respectively, not only reduces disk weight and communicates leakage water directly through the disks, but also permits the sloped upper walls of these disks to flex inwardly or downwardly. Such movement tends to cushion impacting of the disks by foot traffic or by wheeled lawn care devices. This absorption of impact forces coupled with the generous bearing surface of the bottoms 80 and 130, respectively, of the disks reduces undesirable compaction and consequent downward movement of fill under the disks. The choice of a flexible material for the two-piece disk 104 not only provides flexure of its sloped disk wall 110 but also provides resilient, snap-acting means for connecting the upper and lower disk elements 106 and 108 of the two-piece embodiment shown in FIG. 6.
While the advantages provided by making the disk interiors hollow are substantial, there is a risk that these cavities could provide unwanted disk bouyancy if the underlying fill were to become saturated with water or if the disks were to be submerged during a flood. This potential problem has been nicely obviated by the drain apertures in disk bottom 80 and the intersticial spaces between the skirts 112 and 132 which will freely admit water into the cavities 88 and 140, respectively, to reduce or eliminate disk bouyancy tending to pull the upper housing section 22 out of the ground.
Preferrably the disks 72 and 104 described above are made of weather resistant, yet light weight and flexible plastic material. A non-rusting metal such as aluminum or magnesium could be employed; however, the resilience and flexability of these and other metals are less than that provided by certain well known plastic materials. It is also possible to make the disk of a plastic which is brightly colored or which exhibits iridescense or luminescense to render the exposed portion of the disk more readily visible.
The invention has been disclosed as both a single-piece construction and a two-piece construction. While both constructions serve the same purpose and function in substantially the same manner, the two-piece embodiment may be somewhat simpler to manufacture.
The foregoing description of the embodiments of the invention shown in the drawings is illustrative and explanatory only; and, various changes in size, shape and materials, as well as in specific details of the illustrated construction may be made without departing from the scope of the invention. Therefore, I do not intend to be limited to the details shown and described herein, but intend to cover all changes and modifications which are encompassed by the scope and spirit of the appended claims.
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A ground engaging hollow, disklike support mounted coaxially about the top end of the upper section of an underground valve box and having a conical top wall which sheds water to the outer edge of the disk to prevent softening and erosion of ground under the disklike support leading to vertical destabilization of the valve box.
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CROSS-REFERENCE TO RELATED APPLICATIONS, IF ANY
[0001] This application claims the benefit under 35 U.S.C. $119 (e) of co-pending provisional application Ser. No. 60/581,794, filed 22 Jun. 2004. Application Ser. No. 60/581,794 is hereby incorporated by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] This invention was developed during the course of Contracts No. M67854-04-C-3006 and No. M67854-05-C-6502 for MARCOR SYSCOM of the Department of Defense.
REFERENCE TO A MICROFICHE APPENDIX, IF ANY
[0003] Not applicable.
FIELD OF THE INVENTION
[0004] The present invention relates generally to the design and manufacture of a unique, durable and fire retardant military combat uniform garment, made from a multi-layered nonwoven composite fabric that exhibits excellent fire resistance, mechanical and physical properties, comfort, and economics. The objective is to displace more expensive and flammable traditional woven fabric based garments with functional nonwoven composite fabrics for military combat uniforms and outdoor sporting garments. Although nonwoven composite fabrics offer numerous technical advantages over the traditional woven fabrics in the area of functional apparel, as that of military uniform fabric, thus far the nonwoven based garments have been used only for disposable medical garments and lab coats because of their lack of textile-like qualities. The success in creating a durable and fire resistant nonwoven composite fabric based military garment is dependent on the appropriate selection and utilization of fibers and fiber blends, additive chemicals, web formation and multiple web bonding or consolidation techniques and finishing treatments. In addition to being lighter weight, soft, durable, highly tear resistant and fire resistant, the nonwoven composite fabric based garment of the current invention offers enhanced breathability or air permeability to provide relief from heat stress in extreme hot weather conditions, good insulation in cold weather, barrier against insects and sand particles, as well as other advantages.
BACKGROUND OF THE INVENTION
[0005] Nonwoven composite fabric manufacturing is the fastest and the most economical way of converting fibers to fabrics. Before discussing the importance of nonwoven composite fabrics for use in military and functional garment applications, it is important to outline the basics of the manufacturing of conventional woven fabrics used in the military garments and outdoor sports gear today to clearly distinguish the difference between the woven and nonwoven fabrics.
[0006] Yarn Formation: The manufacturing of conventional woven textile fabric that is presently used to make the military garments is a laborious and multi-step (over 15) process with very slow production speeds. The production of conventional textile fabrics from staple fibers begins with the opening of bales of compacted fibers, synthetic or natural, combing, and then carding, whereby the fibers are individualized and aligned, the web from the doffer of the card then combined to form a thick rope called sliver. Multiple strands of sliver are then processed on drawing frames to further align the fibers, blend, improve uniformity and reduce the sliver's diameter. The drawn sliver is then fed into a roving machine to produce roving with false twist to provide some integrity. The roving is then fed into the ring or rotor spinning machine to be spun into yarn. The smaller yarn packages from the spinning machines are placed onto a winder where they are transferred into larger spools. The yarns are then wound onto a warp beam to be woven into fabrics.
[0007] Woven Fabric Formation: The woven fabric from the loom consists of warp and weft yarns. The warp yarns run in the machine direction whereas the weft yarns run in the cross direction or perpendicular to the warp yarns. The warp beams supply the warp yarns by unwinding and the weft yarns are inserted by high-speed shuttle, air or water to complete the fabric design. The warp yarns themselves are subjected to a sizing treatment with starch to provide some stiffness and abrasion resistance to take them through the process of weaving. The sizing treatment is removed by scouring and bleaching after the fabric is made on the loom before the fabric can be dyed and finished. One of the limiting factors of woven fabrics, apart from being a multi-step process, is the very slow production speed, i.e. a few feet (1-2) per minute even on the most modern looms.
[0008] On the other hand, nonwoven composite fabrics, when properly designed and processed, offer both the technical and economic advantages, especially in the area of functional apparel. From an economics standpoint, the production of nonwoven fabrics and their composites using spunlaid and carded webs is known to be more efficient than traditional textile processes, with many fewer steps (less than 5) and faster production rates with machine speeds in the hundreds of yards per minute. From a technology standpoint, multiple layers of fibers with varying functionalities, such as water repellent or absorbent and fire retardant, can be incorporated to provide unique structures that are not possible to manufacture by traditional yarn spinning and weaving techniques.
[0009] Nonwoven Composite Fabric/Garment: Nonwoven composite fabrics based garments should be suitable for use in a wide variety of military and outdoor applications where the efficiency with which the garments/fabrics can be manufactured provides a significant economic advantage for these fabrics versus traditional woven textiles. However, nonwoven fabrics have been unable to penetrate the functional and everyday wear garment markets because of the commonly known disadvantages such as poorer aesthetics, abrasion resistance, launderability, tear resistance, recovery after stretching etc. when compared with woven fabrics. Many of the nonwoven processes are intended for creating disposable articles such as pillow covers, baby diapers, sanitary napkins, medical gowns etc. None of the currently available nonwoven technologies, when used alone, offer a durable fabric for apparel or garment end use application. The challenge has been to judiciously use several known bonding methods and finishing treatments while using proper fiber blends, additive, finishing chemicals and fabric construction. Attempts have been made to develop nonwoven fabrics for everyday wear such as shirts and pants as referenced in U.S. Pat. No. 3,933,304 where a washable spunlaced nonwoven cloth containing binder chemicals has been disclosed. U.S. Pat. No. 3,988,343 discloses a nylon fabric treated with binder chemicals, U.S. Pat. No. 5,874,159 discloses a spunlaced fabric containing a net made of a polymer that melts at lower temperature than base fibers and bonds with the nonwoven layers and thus providing the necessary durability during the end use application. More recently, U.S. Patent Application No. 2003/0166369 A1 describes a durable nonwoven garment with elastic recovery where a carded web is hydroentangled and modified with very high levels of acrylic binder before being assembled into a garment. The absence of any of these materials from the prior art in the commercial marketplace is an indication that there is still a need for further improvement and enhancement that is required with respect to the processing, finishing and assembling of nonwoven based materials for apparel usage, especially for stringent military applications.
[0010] Hydroentangled/Spunlaced Nonwovens: It is an established fact that the best nonwoven bonding technology that is available on a commercial basis today to create fabrics that somewhat mimic the properties of woven fabrics, is the hydroentangled or spunlaced nonwoven fabric technology. The entanglement and the twisting of the fibers that occur in the case of spunlace fabrics is somewhat similar to the twist in the yarns of the woven fabrics and thus, spunlace fabrics provide the best drape characteristics among the commercially available nonwoven fabrics. The use of the right type of nozzles, their length, design, diameter and number of holes per jet strip coupled with the position of the jet manifolds, the number of manifolds per side of the fabric and the water jet pressure critically impact the final fabric properties especially the bonding of fibers and thus the abrasion resistance. Even the spunlace nonwoven composites exhibit a higher degree of elongation or stretch than desired and poorer recovery from deformation. In addition, spunlace fabrics without any post thermal and chemical treatment have shown much poorer launderability and abrasion resistance compared to the woven fabrics. The loose end surface fibers need to be bound to the matrix of the fabric by both thermal and chemical bonding techniques.
[0011] The art of combining various nonwoven layers with and without support scrim through hydroentangling for multiple end use application is already established in the literature. Different nonwoven layers or webs, such as spunlaid or spunbonded, carded, wet-laid and needle-punched, can be combined with and without reinforcing scrim or nonwovens as referenced in U.S. Pat. No. 5,240,764, U.S. Pat. No. 5,334,446, U.S. Pat. No. 5,587,225, U.S. Pat. No. 6,669,799, U.S. Pat. No. 6,735,832 B1, and U.S. Patent Application No. 2005/0022321 A1 to provide unique composite structures for various end use applications. U.S. Patent Application No. 2004/0016091 by Rivera et al. discloses a method of forming a two-sided, nonwoven composite intended for use in durable three-dimensional imaged surfaces that is resistant to washing. The composite of the Rivera et al. application has been designed for applications other than functional apparel as the fibrous and scrim elements incorporated in the application do not withstand the rigors of the military and outdoor end use. In addition, according to the Rivera et al. application, the fiber layers are separated by the scrim to avoid intermixing of the layers, which leads to delamination and failure of the composite based garment. The current invention addresses the need for intimate bonding, additional thermal calendaring and chemical treatment for enhancing the abrasion resistance and wash durability, as well as the use of appropriate fiber blends, including fire retardant treatment to avoid melt drips, which is highly objectionable in the end use application.
[0012] Needle-Punched Nonwovens: Needle-punching is one of the oldest methods of bonding fibrous layers to create nonwoven and nonwoven composite fabrics. All types of fibers, synthetic and natural, can be used for needle punching. As in the case of hydroentnagling, the finer and longer the fiber, the better is the ability to needle and entangle with other fibers in the nonwoven matrix. There is an abundance of literature on the use and application of needle punching manufacturing methods for various end use applications. However, because of the fuzz created by the process the needled fabrics have been used for wiping cloths and shoe liners etc. and not considered for apparel garment applications. By the proper selection of the fiber blends, process conditions and subsequent thermal bonding and finishing treatment, it is possible to create a nonwoven composite fabric useful for military and outdoor garment applications. Modern needle looms are capable of running at over 2000 strokes per minute, with double needle beds providing production rates in hundreds of yards per minute.
[0013] Spunlaid Nonwoven: Spunlaid nonwoven webs comprise continuous synthetic filaments that are formed by melt extrusion of thermoplastic polymers, such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), and nylon 6 or nylon 66, or polypropylene, through a spinneret assembly, creating a plurality of continuous thermoplastic filaments. The filaments are then drawn, cooled, and entangled into a mat before being collected to form a nonwoven web. The web at this stage is unbonded and lacks any strength or integrity. Typically, the spunlaid webs are bonded by using thermal calendaring rolls by fusing the fibers at intermediate points to create a stronger fabric. These webs are called spunbonded webs and are used in a variety of applications ranging from baby diaper top sheets to geotextiles. The cross section of the filaments and the polymer blend composition can be varied as in traditional melting spinning. Several bicomponent filament configurations are commercially available in the marketplace. The most common being a core/sheath configuration spinneret die design that provides continuous spunlaid filaments with a higher melting polymer, such as polyester or nylon 66, in the core and a lower melting polymer, such as nylon 6 or polyethylene, on the sheath. The stronger polymer in the core contributes to the mechanical properties, whereas the polymer in the sheath contributes to bonding using thermal calendering and provides tie points among filaments by the applied heat and pressure. Another configuration of importance is the segmented pie die design with 4, 8, 16, 32 and even 64 segments that are contained within the cross section of the extruded continuous filaments. The polymers chosen to be included in the pies are completely immiscible with each other and are split into very fine denier, and sometimes even nanofibers, by the action of mechanical force such as those encountered during spunlacing. For spunlaid webs, the useful fiber denier ranges from 1-3 dpf and basis weight of the fabric ranges from 0.5 oz/yd 2 to 6 oz/yd 2 . One such spunlaid and hydroentangled nonwoven made from splittable bicomponent spunlaid webs, known as “EVOLON”, is commercially available from Freudenberg Nonwovens. Another prior art as referenced in U.S. Pat. No. 6,692,541 B2 discloses the method of making nonwoven fabric comprising splittable staple fibers. The main difference between this described material and the EVOLON product is that the latter is made from continuous spunlaid nonwoven filaments as opposed to splittable staple fibers as in the case of U.S. Pat. No. 6,692,541. Although attempts have been made to the use of nonwoven fabrics, prepared by these technologies, to create textile apparel, successful commercialization of these fabrics to displace the traditional woven and knitted fabrics has not been realized.
[0014] Carded Nonwoven: The carded nonwoven webs contain staple or cut fibers. Unlike the filaments of spunlaid nonwovens, it is possible to use both synthetic fibers such as polyester, nylon or polypropylene, natural fibers, such as cotton, and regenerated fibers, such as rayon and cellulose acetate. For carded webs, the useful fiber denier ranges from 1-6 dpf and the fiber length ranges from 0.5-3 inches. Basis weight of the fabric ranges from 0.5 oz/yd 2 to 6 oz/yd 2 . The fabric properties are determined by the optimization of fiber denier, length and construction. The compacted fibers from the bales are fed into various pre-opening and blending stations before being fed to the licker-in roll of the carding machine. The difference in surface velocity between the main cylinder and the numerous worker rolls or flat circulating wire strip located above the main cylinder is the reason for the thorough opening, individualization and parallel alignment of fiber web. The web can be cross-laid at a 45-degree angle using multiple layers to provide balanced properties in the machine and cross direction. As in the case of spunlaid web, the web integrity is possible only by bonding employing thermal calendering, needle punching or spunlacing techniques. One such nonwoven fabric commercially available from PGI Nonwovens that is used in various applications is called “MIRATEC” fabrics. As in the case of EVOLON fabrics, MIRATEC has been unable to penetrate the textile apparel markets either because of its poorer aesthetics, technical design or economics. Thus far, the products have been contemplated for use in non-durable garments or for industrial applications.
[0015] Military Uniforms and Outdoors Garments: The use of nonwovens in the military sector has been mostly for special and niche applications such as disposable apparel and shoe interlinings. Military garments made using nonwoven composites have the potential to offer relief from heat stress and better insulation from extreme weather conditions combined with good economics. However, the military and outdoor sporting applications require functional garments with specific performance attributes. The functional properties of current woven uniforms are fixed by the properties of the individual yarns that lie in a two-dimensional plane. The three-dimensional, nonwoven, composite, fabric offers numerous possibilities of utilizing various fibers and fiber blends and additive chemical technology to impart specific functional characteristics for the intended use.
[0016] Dyeing and Printing: The polyester based nonwovens are traditionally dyed using disperse dyes where heat is applied to open the fiber structure for mechanical incorporation of dye molecules. In the case of nylon-based nonwovens, the fabrics can be dyed using acid or basic dye molecules. Viscose rayon fibers can be dyed using direct or sulfur dyes. Deep shade is not a requirement for the military and outdoor garment fabrics; however, deep dyeing is possible with nylon-based garments.
[0017] Finishing Treatments: The finishing treatments consist of imparting abrasion resistance, wash durability, water repellency and fire resistance based on the needs of the end use application. The finishing treatments can be carried out using commonly known chemicals such as silicone, acrylate, melamine, urethane, etc. using spraying, padding and curing or knife coating techniques commonly known in the industry. Spraying or padding intumescent fire retardant finishing chemicals can provide additional improvements in the fire resistance characteristics. Whatever the finishing treatment may be, care must be taken to avoid stiffening the fabric and reducing breathability and physical properties.
SUMMARY OF THE INVENTION
[0018] The present invention is directed to the design and manufacture of a durable and fire resistant nonwoven based garment that meets the stringent performance requirements of military combat uniform clothing and outdoor sporting garments. In particular, the present invention contemplates that a durable garment is formed from a fire resistant, nonwoven composite fabric that consists of at least two fire resistant nonwoven fibrous webs that form the inside and outside layers of the garment with an optional rip-stop layer made from a loosely knitted fabric, sandwiched between the individual nonwoven webs/layers. All of the assembled layers are subjected to intimate mechanical bonding by hydroentanglement process using fluid energy or needle punching process to avoid delamination of the individual layers. In addition, the nonwoven composite fabric is subjected to thermal calendering/embossing and adhesive treatments to further enhance the durability during the end use application, especially in laundering. By formation of a nonwoven composite in this fashion, a durable and fire resistant garment is tailored for military and outdoor use.
[0019] In accordance with the present invention, a method of making a nonwoven based military and outdoor sporting garment includes the steps of first creating a nonwoven composite fabric that consists of an outside printable and abrasion and fire resistant nonwoven web/layer and an inside soft, moisture or sweat absorbent, pill and fire resistant nonwoven web/layer. The outside and inside fire resistant nonwoven webs/layers are initially combined by hydroentanglement with high pressure water jets or needle punching, with or without a rip-stop made of a loosely knitted fabric layer, to form the nonwoven composite fabric that makes the garment. While use of carded webs is preferred to make the layers of the garment, the outside and/or inside nonwoven webs may comprise spunlaid webs.
[0020] In a particularly preferred embodiment, the outside and inside layers of the garment contain carded webs with polyester, nylon and viscose rayon staple fibers, containing durable/wash resistant fire retardant chemicals. These webs are cross-lapped for obtaining balanced properties in the finished fabric. A middle rip-stop layer is sandwiched between the carded webs and bonding is by hydroentangling or needle-punching process. The resulting nonwoven composite fabric is found to provide a garment with excellent abrasion resistance.
[0021] In another embodiment, the outside and inside layers of the garment contain fire resistant spunlaid webs with bicomponent splittable filaments that are bonded with or without the middle-layer rip-stop through the hydroentangling process. The filaments are split to 16 segments of PET and nylon 6 or PBT or PTT microfilaments upon impinging with high pressure water jets during hydroentangling, thus providing the cover and the physical properties of the garment. A fire retardant melt additive is incorporated in one or both the polymers during the extrusion of the continuous filaments into spunlaid web.
[0022] In another embodiment, the outside and inside layers of the garment contain fire resistant spunlaid webs made of core/sheath type bicomponent filaments. The webs are bonded with or without the middle layer rip-stop through hydroentangling or needle punching process. The sheath is made of lower melting nylon 6 or PBT or PTT polymer and the core is made of higher melting PET polymer. A fire retardant melt additive is incorporated in either PET or nylon 6 or both.
[0023] In yet another embodiment, the outside, nonwoven layer of the garment is made of fire resistant spunlaid web with continuous, bicomponent splittable or bicomponent core/sheath filaments, while the inside layer contains a fire resistant carded web made of staple fibers. These webs are either hydroentangled or needle-punched with or without the middle layer rip-stop to form the required nonwoven composite fabric.
[0024] The staple fibers and the continuous filaments used for making the individual nonwoven layers of the present invention and the yarns used in the rip-stop knitted fabric are necessarily made from higher melting polymers, such as polyesters and nylons. The fibers have optimal fineness and length for hydroentangling.
[0025] The most preferred method to make the nonwoven composite of the present invention is to intimately bond the individual unbonded, nonwovens, via the hydroentangling process, where a fluid pressure of at least 3000 PSI is employed. To achieve the desired durability, it is contemplated that at least 5 jet strips or manifolds are placed on each side of the composite with a 100-mesh support screen to obtain the desired textile-like finish. Optionally, the webs may be re-passed through the jet strips with the sides reversed to obtain even further enhanced surface abrasion resistance.
[0026] Alternatively, the individual unbonded nonwovens are intimately bonded by subjecting the mentioned layers to the action of a needle loom with double beds of needles acting on the outer and inner layers of the garment. A minimum stroke of 1000 is employed with a minimum needle density of 3000 needles per liner yard of working width to achieve to achieve the required bonding to create the nonwoven composite fabric.
[0027] All of the nonwoven composite fabrics from the above mentioned methods are additionally subjected to the heat and pressure of thermal calendering/embossing rollers to bind most of all additional loose fiber on the surface into the body of the composite fabric. Optionally, numerous woven pattern designs can be contemplated for the embossing roll to achieve the desired aesthetic appearance on the surface of the nonwoven composite fabric without significantly altering the feel, physical and mechanical properties.
[0028] The nonwoven fabric composite of the garment is dyed and printed with camouflage patterns using traditional textile dyes such as disperse, acid, basic dyes, pigments, etc. using traditional textile dyeing and printing equipment.
[0029] All of the dyed and printed nonwoven composite fabrics are subjected to finishing treatments with acrylate, melamine and urethane binders to further enhance the abrasion resistance and wash durability. In addition, optional finishing treatment to enhance water repellency, absorbency and fire retardancy is accomplished using traditionally known textile chemicals such as silicones, phosphate ester, boric acid, etc., employing standard textile finishing equipment.
[0030] Apart from being able to process using traditional textile equipment as referenced above, the nonwoven composite fabrics are assembled into suitable military and outdoor sporting gear using commonly know stitching techniques using sewing threads and/or non-traditional seamless techniques as employed in laser and ultrasonic welding processes.
[0031] The above summary of the present invention is not intended to describe each illustrated embodiment or every implementation of the present invention. The detailed descriptions that follow more particularly exemplify these embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] FIG. 1 is a front view of the durable and fire resistant military garment made from nonwoven composite fabric.
[0033] FIG. 2 is a cross sectional view of one embodiment of the nonwoven layers of the durable and fire resistant military garment.
[0034] FIG. 3A is a magnified cross sectional view of bicomponet, splittable, continuous filament, fire retardant, spunlaid web.
[0035] FIG. 3B is a magnified cross sectional view of bicomponet, core/sheath, continuous filament, fire retardant, spunlaid web.
[0036] FIG. 4 is a flow diagram of the manufacturing set-up for creating the durable and fire retardant nonwoven composite fabric for the military garment.
[0037] FIG. 5 is a comparison of the fire resistance of the currently used, woven military uniform fabric with the nonwoven, composite fabric of the present invention.
[0038] FIG. 6A is a comparison of the comport properties of the currently used, woven military uniform fabric with the nonwoven, composite fabric of the present invention.
[0039] FIG. 6B is a comparison of the physical and mechanical properties of the currently used, woven military uniform fabric with the nonwoven, composite fabric of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0040] In the following detailed description of the invention, specific methods employed to create a unique and novel garment, based on nonwoven composite fabric, are elucidated to enable a full and thorough understanding of the current invention. It should however be recognized, that it is not intended in the following text to limit the invention only to the particular methods described. The specific terms employed to describe the uniqueness of the invention are merely used in the descriptive sense for the purpose of illustration and not for the purpose of limitation. It will be apparent that the invention is susceptible to numerous variations and changes within the spirit of the teachings herein.
[0041] Garment Construction: The present invention is directed to the design and manufacture of a durable, fire resistant, comfortable and economical garment, as shown in FIG. 1 , which is based on a nonwoven composite fabric suitable for use in military combat uniform clothing and outdoor sports gear. The nonwoven composite fabric used to make the military combat or outdoor sporting garment consists of a fire resistant outer nonwoven web/layer and a fire resistant inner nonwoven web/layer with an optional rip-stop layer, made from a loosely knitted fabric, sandwiched between the two said nonwoven layers, as shown in FIG. 2 . The outside fire resistant nonwoven layer of the garment is readily printable with traditional inks and pigments employed in the textile industry and highly abrasion resistant to withstand the rigors of battlefield conditions. Although there are numerous patent references available on the use of nonwoven layers with and without the use of supporting scrim in the literature, most of them have been applied for use in enhancing the woven or knitted fabric properties or for applications other than functional garments, such as a military combat uniform. The apparel use for these types of materials has been considered only for fusible interlinings of woven fabrics or for bottom weights and cuffs of garments. This has been due to the inherent limitations in creating acceptable nonwoven fabric based garments.
[0042] Rip-Stop Element: The art of incorporating a reinforcing scrim has been illustrated and widely published in the literature. The tear resistance of durable nonwoven composite fabric for the garments, especially for the military applications, can be significantly improved by incorporation of a rip-stop or loosely knit fabric with very good textile drape characteristics when inserted as the middle layer of the composite fabric. For the current invention, the middle layer knit material is preferably made of higher melting engineering polymers such as polyester and nylon.
[0043] Web Formation—Carded and Spunlaid: The manufacture of the current durable and fire resistant nonwoven composite fabric based garment, comprises the steps of providing an outer layer of the garment made of carded nonwoven web containing higher melting PET or PBT based fire resistant polyester staple fibers (PET fibers Type 271 from Invista, S.C., USA or PBT or PTT fibers from Palmetto Synthetics, SC, USA) or nylon staple fibers (nylon 6 and 66 fibers from Palmetto Synthetics, SC, USA) or bicomponent fibers (from Fiber Innovation Technology, Inc., TN, USA) either alone or in blends with other staple fibers, or spunlaid nonwoven web containing fire resistant continuous filaments, made using polyester (polyethylene terephthalate, 50-80% grade F61 HC PET resin from Eastman Chemicals, TN, USA, 10-30% PBT resin from Ticona, N.J., USA+20-10% NST 10470 PET FR concentrate from Nanosyntex, Inc., TN, USA) and/or nylon (nylon 6, BASF grade BS700 or nylon 66). An inner layer is made of carded or spunlaid web containing either continuous filaments of higher melting fire resistant polyester and/or nylon or a carded web containing fire resistant polyester and/or nylon or bicomponent staple fibers in blends with fire resistant viscose rayon fibers (Lenzing Lyocell FR fibers). Suitable fiber lengths for staple fibers range from 0.5-5 inches, and more specifically, from 1-3 inches and fineness for staple fibers and continuous filaments range from 0.5-5 denier per filament (dpf), and more specifically, 1-3 dpf. The cross section for continuous filaments is uniform round with bicomponent polymer splittable segmented pie or bicomponent core and sheath configuration, as shown in FIG. 3 . In the case of bicomponent filaments and staple fibers, PET is the main component at 50-80% by weight and nylon 6 or PBT or PTT is the minor component at 20-50% by weight. More specifically, in the case of the core/sheath configuration, PET forms the core at 70-80% by weight and lower melting nylon 6 or PBT or PTT forms the sheath at 20-30% by weight. The basis weight for individual nonwoven webs ranges from 0.5-10 oz/yd 2 , ard more specifically from 1.5-3 oz/yd 2 . The fibers are treated with fire retardant chemicals to avoid melt dripping of the synthetic resins when the garment is exposed to fire situations. For continuous filament spunlaid nonwovens, a suitable PET Halogen based FR concentrate, such as NST 10470 can be used. This chemical may be used anywhere from 10-20% within all of the fiber or only in the core or sheath of the bicomponent fiber to impart flame retardancy and is available from Nanosyntex, Inc., Morristown, Tenn., USA.
[0044] The continuous filament spunlaid web can be made using a commercially available spunbond machine with different bicomponent die configurations. A miniature machine of this type is available from Hills Inc., W. Melbourne, Fla., USA. The carded webs are obtained using commercial cotton system cards with flat tops, such as the one in Hollingsworth on Wheels, Inc., Greenville, SC, USA. An optional rip-stop layer made of a loosely knitted fabric containing higher melting polymers, such as polyester and nylon, may be positioned in between the outside and inside layer of the garment for enhancing the tear resistance of the entire garment. A loosely knitted fabric with the trade name PH 49 is commercially available from Apex Mills, Inwood, N.Y. The individual layers by themselves are weak, and do not qualify for use in the intended application. However, the composite fabric exhibits a synergistic improvement in physical and mechanical properties that provide distinct advantages in the end use application.
[0045] Bonding-Spunlace: The individual nonwoven layers are bonded to each other by a combination of bonding techniques to create the garment of FIG. 1 . With reference to FIG. 4 , therein is illustrated a manufacturing flow chart for producing the durable and fire resistant nonwoven composite fabric to assemble the garment. Two fire resistant carded webs or two spun-laid webs or their suitable combinations are placed on a conveyor belt with or without the optional rip-stop knitted fabric layer and subjected to initial bonding using high pressure water jets as in the hydroentangling or spunlacing process. The fibers from both the layers are intimately bonded at the interface creating a soft, textile-like yet very strong nonwoven composite. The fabric layers are subjected to a pre-wetting step using a water jet pressure of about 800 PSI and numerous hydroentangling jet manifolds at a minimum pressure of 3000 PSI. The hydroentangling or spunlacing machine has numerous water jet manifolds similar to that of commercial equipment from Fleissner GmBH, called a Fleissner Aquajet. It is sufficient, however, to position five water jet manifolds on each side of the composite to achieve complete bonding. Optionally, the composite fabric may be re-passed reversing the side of the fabric to smoothen the other side of the fabric as that comes in contact with the wire mesh cloth attached to the drums of the hydroentangling machine. Numerous literature is available on the process of hydroentangling machine. The fabric at this stage possesses equivalent abrasion resistance to that of a woven fabric, but still lacks wash durability, as the fibers have the tendency to rearrange themselves during the laundering process.
[0046] Bonding—Needle Punching: Alternatively, the individual unbonded fire resistant nonwoven layers with the optional rip-stop knitted fabric may be subjected to the action of barbed needles, termed the Needle-Punching process. This is one of the oldest techniques used in the making of nonwoven and composite structures. A Universal needle loom commercially available from DILO, Inc., Charlotte, N.C., can be used for the production of the textile-like flexible nonwoven composites. Modern high speed needle punching machines are capable of production rates in several hundred yards per minute with a double bed of needle boards operating at over 1500 strokes per minute containing over 5000 needles per yard. The inherent problem with the needle-punching process is the fuzz and potential damage to fiber leading to poorer abrasion and wash resistance properties.
[0047] Thermal Calendering: Thermal bonding/embossing is one of the critical steps in creating a nonwoven composite fabric for the military garments. The objective is not only to bind the unbonded or loose surface fibers to the body or matrix of the nonwoven composite fabric, but also to emboss a woven pattern design such as a plain, twill or linen onto the nonwoven fabric to simulate the aesthetic appeal of a woven fabric. The temperature, pressure at the calender nip and the machine speed need to be carefully controlled so that the embossing/bonding can be carried out without affecting the tear resistance, air permeability and drape of the nonwoven composite fabric.
[0048] Bonding/Embossing: A thermal calendering unit, as that of a commercial calendering and embossing unit from BF Perkins, may be used to impart a woven fabric like design, such as a twill or linen pattern, on the outside and/or inside layer of the garment by partially fusing the lower melting component or fibers. In addition, the pressure and heat employed during this process tends to bind the loose surface fibers back into the matrix or the body of the composite. In addition, the intermediate bond points provide stabilization against large scale fiber movement and thus avoiding any permanent deformation of the hydroentangled nonwoven composite. Pressure in excess of 500 PLI and temperature over 350 deg. F. can be utilized to partially fuse the fibers, to create anchor points, without significantly affecting the original drape, air permeability, or mechanical properties of the nonwoven composite fabric.
[0049] Dyeing and Printing: The bonded nonwoven composite fabric can be dyed and printed using traditional textile dyes and pigments made from disperse, acid and basic types, using standard textile equipment such as jet dyeing and screen printing machines. Thus far, dyeing and printing of nonwovens has been a challenge in the industry, but it is possible to obtain a uniform camouflage pattern as shown in FIG. 1 with the proper selection of fiber blends and fabric construction. The fabrics can then be printed with the camouflage design such as the new computer-generated pixel design printed on the US Marine Corps combat utility uniform or other camouflage designs for both woodland (green color) and desert (beige) areas. The colorfastness of the print pattern can be established along with wash durability of the current nonwovens. Since the predominant fiber in the nonwoven composite fabric is polyester, disperse dyeing and printing can be carried out to obtain the required camouflage design. In conjunction with disperse dyes, sulfate dyes/pigments can be used to dye/print the small portion of viscose rayon and acid or basic dyes/pigments can be used for nylon fibers.
[0050] Finishing Treatment: The printed nonwovens are treated with standard textile finishing additives/chemicals utilizing any number of techniques including but not limited to dip, pad, spray or knife coating methods. Some of these finishing chemicals may be added in the dye bath based on the compatibility of the different chemicals used for dyeing. The main focus in the finishing stage is to add the appropriate fiber binder chemical to further enhance the wash durability and abrasion resistance without significantly affecting the textile drape, air permeability or mechanical properties. The acrylic and melamine binder chemicals for cross-linking the synthetic fibers of nonwovens are available under the trade name Permax and Aerotex from Noveon, Charlotte, N.C., USA. Typical use of these chemicals is about 3% by weight of the nonwoven composite fabric. The polyester fibers by themselves are water repellent or hydrophobic. Optionally, however, the water repellency can be further enhanced by treating the outer layer surface with a water repellent silicone formulation commercially know as Dow Corning 75 SF. Typical use of 75 SF is used at about 1% by weight in conjunction with 0.2% of a catalyst formulation Dow Corning SYL-OFF 1171A. An additional fire retardant formulation can be applied to the entire fabric by spraying or dip coating techniques that render excellent fire resistant characteristics to the entire fabric, as illustrated in FIG. 5 . It can be readily seen from FIG. 5 that the standard military garment readily burns on application of a fire source within a few seconds, as opposed to the nonwoven composite fabric treated with the fire retardant chemical. Even a small addition (less than 5% by weight) is effective in rendering the fabric fire retardant without causing any melt drip, which is critical for the military garment application. The fire retardant formulation based on boric acid is available from Universal Fire Shield, Denver, Colo., USA. All of these formulations can be applied in single or multiple steps with coatings that are applied sequentially on top of each other.
[0051] Functional Properties of the Garment Fabric: The superior comfort and physical properties of the nonwoven composite fabric of the present military garment, compared to the conventional woven fabric used in the military garment today, are illustrated in FIGS. 6A and 6B . It is very evident that stronger garments can be made with lighter weight, more breathable and greater tear resistant using nonwoven composite fabric.
[0052] The nonwoven composite fabric used to make the garment of the present invention does not cause melt drip and self-extinguish when subjected to fire situations. The nonwoven composite fabric has a normalized grab tensile strength of at least 80 lbs in the machine and cross direction when tested per ASTM D5034, and tear strength of at least 5 lbs in the machine and cross direction when tested per ASTM D5734. The nonwoven composite fabric exhibits an air permeability value of at least 20 cubic foot per minute when tested per ASTM D737, a basis weight of less than 10 oz/yd 2 when tested per ASTM D3776 and a thickness of less than 50 mils when tested per ASTM D5729. The nonwoven composite fabric exhibits an equivalent abrasion resistance value as that of a woven military uniform fabric when tested on a Taber Machine according to ASTM D3884. In addition, the garment of the present invention is launderable and wrinkle-resistant.
[0053] Garment Assembly: The garment for military and outdoor sporting gear is assembled employing conventional sewing machines using standard nylon threads, as is readily apparent in FIG. 1 . Unlike the woven fabrics, there is no raveling and wastage of fabrics/yarns when stitching the garment of the present invention. In addition, because of higher synthetic fiber content, it is possible to assemble the military uniform using laser and ultrasonic bonding methods to provide leak-proof seams. This is of importance for manufacturing protective garments used against chemical and biological agents for Homeland Security applications.
[0054] Although specific emphasis has been made on the design and manufacture of military combat uniform and outdoor sporting garments using the nonwoven composite fabric of the present invention, other potential applications for fabrics of similar construction could be in the area of durable, wash and fire resistant medical garments, workmen uniforms, children clothing, other apparel, covers, tentage, awning, equipage items, etc.
[0055] From the foregoing, it will be observed that numerous modifications and variations can be affected without departing from the true spirit and scope of the novel concept of the present invention. It is to be understood that no limitation with respect to the specific embodiments illustrated herein is intended or should be inferred. The disclosure is intended to cover, by the appended claims, all such modifications as fall within the scope of the claims.
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The present invention is directed to the design and manufacture of a durable, fire resistant, comfortable and economical nonwoven composite fabric based garment, which meets the stringent requirements of military combat uniform clothing. The nonwoven based garment is designed to replace the traditional woven textile fabric used in the military and outdoor sporting garments today. The novel garment of the current invention is constructed using a unique nonwoven composite fabric that exhibits mechanical, physical, durability and comfort characteristics similar to or better than that of the current woven military uniform fabric. In particular, the present invention contemplates the nonwoven composite fabric used to make the garment is prepared by combining at least two separate fire resistant nonwoven webs forming the inside and outside layers of the garment. An optional rip-stop element such as a loosely knitted fabric may be sandwiched between the two nonwoven webs to improve the tear resistance of the entire garment. Hydroentangling or needle-punching processes and subsequent thermal calendering/embossing techniques combine the individual nonwoven webs of the garment before dyeing, printing and finishing with traditional textile chemicals to form a composite fabric for stitching to make the garment.
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TECHNICAL FIELD
This invention relates to distributing mineral fibers onto a collection surface to form a uniformly collected pack of mineral fibers, such as glass fibers. In one of its more specific aspects, this invention relates to deflecting a cylindrical veil of mineral fibers to form a uniformly distributed pack of the mineral fibers.
BACKGROUND OF THE INVENTION
A common method for forming mineral fibers involves supplying molten mineral material to a centrifuge having a plurality of holes in its peripheral wall, and centrifuging the mineral material through the peripheral wall to form fibers. The fibers can be further attenuated with a blower or a combustion chamber burner, or can be merely deflected downwardly by a non-attenuating blower to form a generally cylindrical veil of fibers. It is desirable to distribute the fibers uniformly across the width of the collecting surface, and it is a common practice to utilize nozzles emitting air or steam blasts to periodically deflect the veil for distribution of the fibers into a wider pack.
One of the problems associated with the fiber deflection systems of the prior art is that there is no coordination between the operation of the veil deflecting apparatus and the speed of the moving collecting surface. In mineral wool fiberizing systems having a plurality of fiberizers to direct fibers onto one collecting surface, the addition or deletion of one or more fiberizers usually requires an increase or decrease in the speed of the moving collecting surface. Changes in the speed of the collecting surface without resulting changes in the pattern of deflecting the fibers onto the collecting surface can result in degradation of the uniformity of the pack of mineral fibers. The present invention is directed toward a system for collecting mineral fibers in which the deflection of the veils of fibers is accomplished in response to the speed of the collecting surface.
SUMMARY OF THE INVENTION
According to this invention there is provided apparatus for collecting mineral fibers comprising a moving surface for receiving a flow of mineral fibers, sensing means for sensing the speed of the moving surface, control means for generating a signal in response to the sensed speed of the moving surface, and means for intermittently directing gases into the flow of mineral fibers in response to the signal.
In one embodiment of the invention, the sensing means comprises a tachometer producing a voltge signal.
In another embodiment of the invention, the control means comprises a voltage-to-frequency converter.
In a preferred embodiment, the invention comprises duty ratio control means for controlling the duration of each pulse during each cycle of a pulse signal.
In a more preferred embodiment of the invention, the duty ratio control means is adapted to enable the pulse duration percentage of the pulse signal to be preselected in increments of 1%.
In a preferred embodiment, the invention comprises a conveyor for receiving mineral fibers from more than one veil of mineral fibers, sensing means for sensing the speed of the conveyor, control means for generating a pulse signal, the frequency of the pulse signal being in response to the sensed speed of the conveyor, duty ratio control means for controlling the duration of each pulse during each cycle o the pulse signal, and means for intermittently directing gases into the veils of mineral fibers in response to the pulse signal.
In another preferred embodiment, the control means comprises means for dividing a frequency signal from pulses/second to pulses/minute.
In a more preferred embodiment, the control means comprises means for indexing each 100th pulse from the means for dividing.
In a most preferred embodiment, the duty ratio control means can comprise a pulse counter.
Also according to this invention, there is provided a method for collecting mineral fibers comprising directing a flow of mineral fibers onto a moving surface, sensing the speed of the moving surface, generating a signal in response to the sensed speed of the moving surface, and intermittently directing gases into the flow of mineral fibers in response to the signal.
In one embodiment, the invention comprises sensing the speed of the moving surface with a tachometer to produce a voltage signal.
In another embodiment, the invention comprises converting the voltage signal to a frequency signal.
In its most preferred embodiment, the invention comprises a method for collecting mineral fibers comprising directing more than one veil of mineral fibers onto a moving surface, sensing the speed of the moving surface, generating a pulse signal, the frequency of the pulse signal being in response to the sensed speed of the moving surface, controlling the duration of each pulse during each cycle of the pulse signal, and intermittently directing gases into the veils of mineral fibers in response to the pulse signal.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view in elevation of apparatus for collecting a flow of mineral fibers according to the principles of this invention.
FIG. 2 is a schematic plan view of the system for collecting two veils of mineral fibers according to the principles of the invention.
FIG. 3 is an electrical circuit diagram of the controls for the apparatus shown in FIGS. 1 and 2.
DESCRIPTION OF THE INVENTION
As shown in FIG. 1, molten mineral material, such as molten glass 10, is delivered to rotating spinner 12 which fiberizes the glass by centrifugal force. The glass fibers can be maintained in a plastic, attenuable state by annular burner 14. The glass fibers can be turned down into a flow of fibers such as cylindrical veil 16 by annular blower 18. The veil collects as insulation pack 20 on collecting surface 22 which can be a continuous, foraminous conveyor belt. Nozzles 24 are activated periodically to intermittently direct gases into the flow of mineral fibers to uniformly distribute the veil or flow of fibers across the width of the collecting surface. The nozzles can be supplied with air, steam or other gases via supply conduits 26, which can receive the supply of gases from a source, not shown. The supply conduits can be adapted with accumulators 28 to dampen the effect of the pulsation of the gases from the source of the gases. Valves 30 are operated to intermittently interrupt and then reestablish the supply of gases from the source going into the nozzles.
As shown in FIG. 2, the nozzles can be arranged so that a pair of opposed nozzles is adapted to act upon each veil of a multi-veil fiber forming and fiber distribution system. The dashed arrows indicate the direction of flow of gases from the nozzles. The conveyor can be driven by drive roll 34, which can be powered by any suitable means, such a motor, not shown. The conveyor can move in the direction of the arrow as indicated at the top of FIG. 2. As the collecting surface travels beneath the two or more fiberizing positions, the fibers accumulate on the collecting surface, forming the insulation pack. A line speed sensor such as tachometer 36 is operably connected to the drive roll to generate a voltage signal corresponding to the drive speed of the colllecting surface. It is to be understood that any other means suitable for generating a signal responsive to the speed of the collecting surface can be used.
As shown in FIG. 3, the voltage signal from the line speed sensor 36 is modified by voltage zero and span circuit 37. The voltage zero and span circuit comprises operational amplifier 38, such as LHOO42H, connected to the input from the line speed sensor via two diodes 40, which are connected in parallel to input terminals 2 and 3 of amplifier 38. The amplifier output is modified by zero-setting 10K potentiometer 42, which is connected to amplifier terminals 1, 4 and 5, and which enables the voltage signal from the line speed sensor to be referenced or zeroed to any desired number. For example, the potentiometer can be set to signal that any line speed sensed as being below a certain voltage would result in an output of zero volts from the operational amplifier. Span-setting 100K potentiometer 44, connected to amplifer terminals 2 and 6, is adapted to enable the setting of the span of the output from the operational amplifier. Thus, the output from the voltage zero and span circuit can be set to a predetermined reference zero, and applied to a predetermined voltage span. In one example of the invention, the input voltage from the tachometer into the voltage zero and span circuit was within the range of from 0 to 100 millivolts, while the output from the voltage zero and span apparatus was within the range of from 0 to 10 volts.
Voltage-to-frequency converter 46 converts the 0 to 10 volt signal of the voltage zero and span circuit into a frequency signal of from 0 to 10 Khz. The V/F converter can be Burr-Brown VFC-12LD, or equivalent. The frequency signal can be shaped and matched to the dividers and counters, hereinafter defined, by amplifier 48. The output from the V/F converter and amplifier 48 is applied to divider 47 and converter 49. The divider converts the signal from an hz signal to a pulse-per-minute signal. The divider can be comprised of counter 50 which can be Motorola MC14040-B and decoder 52 which can be Motorola MC14082-B. The divider supplies a pulse signal within the range of from 0 to 10,000 pulses per minute to pulse counter 57. The converter is adapted to index each 100th pulse coming from the divider. The converter can be comprised of counter 54, which can be Motorola MC14040-B and decoder 56 which can be Motorola MC14082-B.
The pulse counter can be comprised of tens counter 58 and units counter 60, both of which can be Motorola MC14052-B. Duty ratio controls 62 enable the preselection in increments of 1% of the percentage of time the lapper control valves will remain "on" during each pulse from the pulse signal emanating from the pulse counter. For each 100 pulses input from the divider into the pulse counter the nozzle control valves will remain "on" for the number of pulses indicated by the duty ratio controls. For example, when the duty ratio controls are set at 55%, for each 100 pulses entering the pulse counter from the divider the nozzle control valves will remain "on" until the pulse counter counts to 55 pulses, and then the nozzle control valves will be turned "off" for the remaining 45 pulses until the next indexed pulse begins a new cycle. The output signal of the pulse counter is connected through inverter 64 which can be Motorola MC14049-B, to an "on" light and "off" light, and is applied through current amplifier 66, such as ECG123A, to the nozzle control valves. The nozzle control valves control the intermittent flow of gases in response to the output signal from the pulse counter.
EXPLOITATION IN INDUSTRY
The invention will be found to be useful in the formation of fibers from molten glass for such uses as glass fiber thermal insulation products and glass fiber acoustical insulation products.
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A method and apparatus for collecting mineral fibers comprises a moving surface for receiving a flow of fibers, sensing means for sensing the speed of said moving surface, control means for generating a signal in response to the sensed speed of the moving surface, and means for intermittently directing gases into the flow of mineral fibers in response to the signal.
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RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 13/570,855, filed Aug. 9, 2012, which is incorporated herein by reference in its entirety.
FIELD
[0002] The present disclosure relates generally to systems and methods for authenticating mobile communications devices. More particularly, the present disclosure relates to systems and methods for authenticating mobile communications devices for websites and web services.
BACKGROUND
[0003] When accessing secure websites and web services a user generally is prompted to enter a username and password. Users often access the same websites and web services on a variety of computing devices, such as for example, a personal computer or a mobile communication device, such as for example, a smart phone.
[0004] The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present invention.
SUMMARY
[0005] In a first aspect, some embodiments disclosed herein relate to a method of authenticating mobile communications devices. The method comprises: generating a code corresponding to a user, the code configured to be rendered on a rendering device to produce a rendered code, the rendered code being readable by a mobile communications device having a code reading device, the rendered code comprising a secret token; storing the secret token along with information identifying the user on a first storage device associated with an authentication server; providing the code to the user; receiving, at the authentication server, at least one setup message from the mobile communications device, the at least one setup message comprising a device identifier and the secret token; comparing the received secret token and the secret token stored on the first storage device; and if the received secret token matches the secret token stored on the first storage device, storing, on a second storage device associated with the server, information identifying the user and a trusted device value corresponding to the device identifier.
[0006] In some embodiments, the first and second storage devices are the same storage device. In various embodiments, the first and second storage devices can be directly or indirectly coupled to the server.
[0007] In some embodiments, the setup message also comprises a user name. In some embodiments, the setup message also comprises a user password. In various embodiments, the user name and password are the user name and password used by the user to access the web service. For example, the username and password can be the user name and password used by the user to access the web service on a personal computer. In some embodiments, the method further comprises verifying the user name or the password or both prior to storing the traduced device value.
[0008] In some embodiments, the rendering device can be, for example but is not limited to, a display device or a printing device.
[0009] In some embodiments, the code comprises an identifier of a server for sending the setup message.
[0010] In various embodiments, the method further comprises: receiving, at the authentication server, information pertaining to a request by a requesting mobile communications device for access to a web service, the information comprising a requesting device identifier; determining whether the requesting device identifier corresponds to the trusted device value stored on the storage device; and denying access to the web service if the requesting device identifier does not correspond to the trusted device value.
[0011] In some embodiments, the authentication server comprises a web server hosting the web services.
[0012] In some embodiments, the web service is accessible to the user through a user ID and a password and the web service is further accessible to the mobile device through the requesting device identifier. In other words, in some embodiments, the device identifier is used in place of or instead of the user name and password to gain access to the web service through the mobile device.
[0013] In various embodiments, determining whether the requesting device identifier corresponds to trusted device value comprises determining whether the requesting device identifier comprises the device identifier encrypted with the secret token, and the method further comprises: denying access to the web service if the requesting device identifier does not comprise the device identifier encrypted with the secret token.
[0014] In various embodiments, the method further comprises encrypting the device identifier with the secret token to generate an encrypted device identifier. In some embodiments, the determination is made by comparing the encrypted device identifier with the trusted device value.
[0015] In various embodiments, the trusted device value corresponding to the device identifier stored on the storage device comprises the encrypted device identifier.
[0016] In various embodiments, the secret token is associated with an expiry time and the method further comprises: upon receiving the setup message, determining if the expiry time has been exceeded; and denying access to the web service if the expiry time has been exceeded.
[0017] In some embodiments, access to the web service is denied if the expiry time is exceeded prior to receiving the at least one setup message.
[0018] In various embodiments, the identifier comprises mobile device metadata.
[0019] In various embodiments, the code can be, but is not limited to a Quick Response (QR) code or a barcode.
[0020] In another aspect, some embodiments described herein relate to a system for authenticating mobile communications devices, the system comprising: a first storage device; a second storage device; and a processor, the processor configured to: generate a code corresponding to a user, the code configured to be rendered on a rendering device to produce a rendered code, the rendered code being readable by a mobile communications device having a code reading device, the rendered code comprising a secret token; store the secret token along with information identifying the user on a first storage device associated with an authentication server; transmit the code to a computing device; receive at least one setup message from a mobile communications device, the at least one setup message comprising a device identifier and the secret token; compare the received secret token and the secret token stored on the first storage device; and if the received secret token matches the secret token stored on the first storage device the, store, on the storage device, information identifying the user and a trusted device value corresponding to the device identifier.
[0021] In some embodiments, the first and second storage devices are the same storage device. In various embodiments, the first and second storage devices can be directly or indirectly coupled to the server.
[0022] In some embodiments, the setup message also comprises a user name. In some embodiments, the setup message also comprises a user password. In various embodiments, the user name and password are the user name and password used by the user to access the web service. For example, the username and password can be the user name and password used by the user to access the web service on a personal computer. In some embodiments, the processor is further configured to verify the user name or the password or both prior to storing the traduced device value.
[0023] In some embodiments, the rendering device can be, for example, but is not limited to, a display device or a printing device.
[0024] In some embodiments, the code comprises an identifier of a server for sending the setup message.
[0025] In some embodiments, the processor is further configured to: receive information pertaining to a request by a requesting mobile communications device for access to a web service, the information comprising a requesting device identifier; determine whether the requesting device identifier corresponds to the trusted device value stored on the storage device; and deny access to the web service if the requesting device identifier does not correspond to the trusted device value.
[0026] In some embodiments, the processor is further configured to: deny access to the web service if the requesting device identifier does not comprise the device identifier.
[0027] In various embodiments, the processor is further configured to: transmit the result of the determination step to a web server hosting the web service.
[0028] In some embodiments, the web service is accessible to the user through a user ID and a password; and wherein the web service is further accessible to the mobile device through the requesting device identifier. In other words, in some embodiments, the device identifier is used in place of or instead of the user name and password to gain access to the web service through the mobile device.
[0029] In various embodiments, the requesting device identifier corresponds to trusted device value comprises determining whether the requesting device identifier comprises the device identifier encrypted with the secret token.
[0030] In some embodiments, the trusted device value corresponding to the device identifier stored on the storage device comprises the encrypted device identifier.
[0031] In various embodiments, the secret token is associated with an expiry time; and the processor is further configured to: upon receiving the setup message, determine if the expiry time has been exceeded; and deny access to the web service if the expiry time has been exceeded.
[0032] In some embodiments, access to the web service is denied if the expiry time is exceeded prior to receiving the at least one setup message.
[0033] In various embodiments, the identifier comprises mobile device metadata.
[0034] In various embodiments, the code can be, but is not limited to a Quick Response (QR) code or a barcode.
[0035] In another aspect, embodiments described herein relate to a non-transitory machine-readable memory storing statements and instructions for execution by a processor for implementing a method of authenticating mobile communications devices. The method comprises: generating a code corresponding to a user, the code configured to be rendered on a rendering device to produce a rendered code, the rendered code being readable by a mobile communications device having a code reading device, the rendered code comprising a secret token; storing the secret token along with information identifying the user on a first storage device associated with an authentication server; providing the code to the user; receiving, at the authentication server, at least one setup message from the mobile communications device, the at least one setup message comprising a device identifier and the secret token; comparing the received secret token and the secret token stored on the first storage device; and if the received secret token matches the secret token stored on the first storage device, storing, on a second storage device associated with the server, information identifying the user and a trusted device value corresponding to the device identifier.
[0036] Other aspects and features of the present disclosure will become apparent to those of ordinarily skill in the art upon review of the following description of specific embodiments in conjunction with the accompanying figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0037] Embodiments of the present disclosure will now be described, by way of example only, with reference to the attached Figures.
[0038] FIG. 1 is a block diagram of an authentication system according to various embodiments;
[0039] FIG. 2 is a flowchart diagram of a method of authorizing a mobile communication device, according to various embodiments; and
[0040] FIG. 3 is a flowchart diagram of a method of authenticating a trusted device, according to various embodiments.
DETAILED DESCRIPTION
[0041] Generally, the present disclosure provides a method and system for authorizing a mobile communication device as a trusted device for access to a secure web service using a readable code. The term “web service” as used herein can refer to, for example, but is not limited to, any suitable web service, website, web application or web portal. As used herein the term “secure web service” is used to denote a web service that limits access to authorized users through, for example, but not limited to, the use of usernames, passwords, tokens or a combination thereof.
[0042] In various embodiments, the user is provided with a readable code for authorizing the device and, in some embodiments, the code is generated in response to a request from the user, which may be submitted to an authentication system. The code is read by, for example, using a code reading device that may be included or coupled to the mobile communications device that they wish to authorize as a trusted device. In various embodiments disclosed herein, the code includes instructions that are to be executed by the mobile device in order to become a trusted device. Accordingly, after the code is read by mobile communications device, the mobile communications device executes various functions based on information provided by the code in order to become a trusted device.
[0043] Reference is first made to FIG. 1 , which illustrates a block diagram of authentication system 10 , according to various embodiments. Authentication system 10 comprises an authentication server 12 . Authentication server 12 comprises a storage device 14 , and a processor 16 . Storage device 14 can be any appropriate storage device such as, for example, but not limited to, a solid-state device, a magnetic storage device, and optical storage device or combinations thereof, including, but not limited to, a hard disk drive and a flash drive. In some embodiments, authentication server 12 comprises an internet server.
[0044] Authentication server 12 , in various embodiments, is used to, for example, authenticate a mobile communication device 50 for access to a web service hosted by Web server 18 . Web server 18 can be any appropriate Web server that hosts a website or a web service. In various embodiments, web server 18 requires authentication for access to the web service or website hosted by it. In some embodiments, authentication server 12 is coupled to Web server 18 through any appropriate communication link, such as, for example, one or more networks, such as, for example, the Internet. In other embodiments, web server 18 and authentication server 12 are separate. In some embodiments, authentication server 12 comprises web server 18 . In some embodiments, web server 18 comprises an internet server.
[0045] In various embodiments, mobile communication device 50 can be any suitable mobile communication device, such as, for example, but not limited to, a smart phone or a tablet computer. In various embodiments, mobile communication device 50 comprises a code reading device 52 . In some embodiments, code reading device 52 is a digital camera. In some embodiments, mobile communication device 50 includes a program to interpret a code read by code reading device 52 .
[0046] Authentication server 12 is coupled to a computing device 60 through any appropriate communication link, such as for example, one or more networks, such as for example, but not limited to, the Internet, a cellular network, and a combination thereof. Computing device 60 can be any appropriate computing device, such as, for example, but not limited to, an internet server, a personal computer, a laptop computer, and a tablet computer. In various embodiments, computing device 60 comprises or is coupled, possibly through one or more networks, to a rendering device 62 such as, for example, but not limited to, a display device or a printing device. The display device can be any appropriate display device, including, but not limited to, a liquid crystal display (LCD), cathode ray tube (CRT) display, and a television. The printing device can be for example, but is not limited to, an inkjet printer, a laser printer, a photocopier, or a fax machine. In some embodiments, authentication server 12 may communicate with a standalone rendering device such as, but not limited to, a fax machine without an intervening computing device 60 .
[0047] Reference is now made to FIG. 2 , which is a flowchart diagram illustrating a method of authorizing a mobile communication device, according to various embodiments.
[0048] At 202 , authentication server 12 receives the request for authorizing a mobile communication device to become a trusted device for access to a web service. This request may be generated in any suitable manner. For example, in some embodiments, the user of the mobile communication device logs into a secure website (e.g. using a computing device 60 ) where the request is generated.
[0049] At 204 , authentication server 12 generates a code. In various embodiments, authentication server 12 generates computer readable instructions that can be used to instruct a computing device, such as computing device 60 , to render the code in a format that is readable by code reading device 52 . In various embodiments, the code includes a secret token, which may be for example a globally unique identifier (GUID), such as for example but not limited to a unique string of characters (including, but not limited to, letters or numbers or both). In some embodiments, the code also includes one or more Uniform Resource Locators (URLs). In some embodiments, the URL is used to designate an address from which mobile communications device 50 can obtain instructions and/or information for use in the method. In some embodiments, the URL designates an address of a device (e.g. authentication server 12 ) to which mobile communication device 50 can send a set up message. In some embodiments, the code is also associated with an expiry time. In some embodiments, the expiry time is included in the code. In some embodiments, the expiry time is recorded together with the secret token associated with the code at a storage device associated with authentication server 12 , when the code is generated such as for example storage device 14 . In some embodiments, this is achieved by 1) logging an expiry time on the server, including a timestamp of generation in the code; and 2) logging a timestamp of generation on the server-side, and having a server-side setting for expiry (so at the time of a web service call, the server compares the generation time to the current time including the “setting” for expiry length to establish if the code is still valid).
[0050] At 206 , the code is provided to the user. In some embodiments, this is accomplished by transmitting computer readable instructions for rendering the code from authentication server 12 to computing device 60 . In other embodiments, authentication server 12 may directly or indirectly communicate with a rendering device 62 , such as, for example, but not limited to, a fax machine.
[0051] At 208 , the code is rendered. In some embodiments, this is accomplished by computing device 60 rendering the code using rendering device 62 to produce a rendered code that is readable by code reading device 52 . For example, in some embodiments, rendering can include displaying the code on the display of computing device 60 . In other embodiments, rendering can include printing the code on paper using a printer, that may, for example, be coupled to computing device 60 either directly or through one or more networks. In various embodiments, the rendered code can appear in any readable format including, but not limited to, as a QR code or a bar code.
[0052] At 210 , the rendered code is read by code reading device 52 . In various embodiments, code reading device 52 comprises the camera of mobile device 50 . Accordingly, in some embodiments, the user of mobile device 50 , the user reads the code by using the code reading device to “visualize” the rendered code . As used herein, the term “visualize” can mean that the camera captures an image for the purposes of processing the code. However, this does not require that a picture be taken in the traditional sense as when an image is persistently stored on a disk. As mentioned above, in various embodiments, mobile device 50 includes logic (e.g. software and/or hardware) to interpret the code.
[0053] At 212 , based on the read code, communications device 50 stores the secret token that is included in the code on the local storage device of mobile communications device 50 . In some embodiments, the code includes a URL of an address from which mobile communications device 50 can obtain instructions and/or information. In some embodiments, the secret token is provided by the device identified by the URL. Accordingly, in some embodiments, if an item is said to be “included in the code” that can mean that the item is not actually present in the code but a way of obtaining the item is provided in the code. In other embodiments, the secret token is actually included in the code.
[0054] At 214 , mobile communications device 50 transmits a setup message based on the read code. In some embodiments, the code includes instructions and/or information for how and where to send the code. In other embodiments, the software on mobile communications device 50 is hard-coded to use a specific web server, or URL, or location to send the secret code. Accordingly, in some embodiments, this technology can be used as a component of software and can be locked to a specific authentication server or service. In some embodiments, the setup message is transmitted to web server 18 . In other embodiments, the set up message is transmitted to authentication server 12 . In some embodiments, the set up message includes a unique identifier (UID) of mobile communication device 50 . In various embodiments, the unique identifier is a globally unique identifier of the device and can include, for example, but is not limited to, an identifier generated based on device metadata or a unique identifier associated with the device including but not limited to any universally unique identifier (UUID), an International Mobile Equipment Identity (IMEI), or a Media Access Control (MAC) address. In some embodiments, the set up message also includes the secret token. In some embodiments where the code includes an expiry time, if the expiry time has lapsed, then mobile communication device 50 does not generate a set up message and the method ends such that mobile communications device does not become a trusted device for the web service unless further action is taken such as repeating the method with a valid code. In other embodiments, as described in greater detail below, the server 12 determines if the code has expired and if so, rejects it. In some such embodiments, the code may not have any expiry data or timestamp with it, and is simply tied to a secret code on the server side (which can be produced at the time the code was generated). In various embodiments, the setup message is encrypted.
[0055] At 216 , the set up message is received by either authentication server 12 or web server 18 . The setup message is used to link the unique identifier with the username and password used by the user to access the web service hosted by web server 18 . In some embodiments where the setup message is received by web server 18 , web server 18 forwards the setup message or a portion thereof to authentication server 12 . As will be understood by those skilled in the art, the set up message itself or the payload of the set up message (e.g. the secret token and the UID) can be encrypted in any suitable manner. In some embodiments, the set up message also includes information identifying the user (e.g. username and/or password). In other embodiments, the set up message does not include separate user identifying information, such as the username. In some such embodiments, the token is generated for and is uniquely associated with a specific user. This association is recorded server side at the time of generation (as described below in relation to 218 ) and therefore upon receipt of the token the server is able to identify the specific user. In some embodiments, for greater security, the username and password are transmitted (e.g. the user to enter this information before the setup message is transmitted) despite the unique association between a secret token and user. This may be done, for example, to prevent a different individual from making use of the code to gain access to the user's account.
[0056] At 218 , the UID and secret token are stored on storage device 14 along with information identifying the user such that the UID is tied to the user's account for the web service. In some embodiments, the unique identifier and secret token are stored on a storage device 14 .
[0057] Once mobile communication device 50 has been authorized, it can be referred to as a trusted device.
[0058] In some embodiments where an expiry date is used, at some point prior to authorizing a device and storing the information at 218 , authentication server 12 determines whether the expiry time associated with the code has lapsed. In some embodiments, when the code is generated, authentication server 12 stores the token along with the expiry time. When a setup message including the token is received, the associated expiry time is checked to ensure it has not lapsed. In some embodiments, if the expiry time has lapsed, authentication server 12 does not store the information and the mobile communications device 50 does not become a trusted device for the web service unless further action is taken such as repeating the method with a valid code.
[0059] Reference is now made to FIG. 3 , which illustrates a flowchart diagram of a method of authenticating a trusted device, according to various embodiments.
[0060] At 302 , mobile communications device 50 sends a request for access to the web service hosted by Web server 18 . In some embodiments, as part of the request, mobile communications device 50 transmits any suitable information for the purpose of authenticating the device. In some embodiments, mobile communications device 50 sends the unique identifier along with an encrypted unique identifier. In some embodiments, the encrypted unique identifier is encrypted using the secret token as an encryption key. In some embodiments, the message is encrypted by mobile communications device 50 prior to transmitting the message. In other words, in some embodiments the unique identifier and the encrypted unique identifier are further encrypted and transmitted as part of the request for access.
[0061] At 304 , the request is received by web server 18 . In some embodiments, web server 18 transmits a portion of the request to authentication server 12 for authentication based on the stored information on storage device 14 .
[0062] At 306 , authentication server 12 compares the information received from mobile communications device 50 with the information stored on storage device 14 for that user.
[0063] As mentioned above, in some embodiments, storage device 14 stores the encrypted unique identifier, which is encrypted using the secret token as an encryption key. In some such embodiments, the encrypted unique identifier is not decrypted. Instead, encryption is used and thereby greater security can be provided. In some such embodiments, the encrypted unique identifier provided by mobile device 50 is compared to the encrypted unique identifier stored on storage device 14 .
[0064] In other embodiments, the secret token is stored on storage device 14 and the authentication server decrypts the encrypted unique identifier and compares it to the unique identifier stored for the user of mobile communications device 50 .
[0065] At 308 , based on the results of the comparison, it is determined whether or not to grant access to the requesting mobile communications device 50 . In some embodiments, the determination is made by authentication server 12 . In other embodiments, the results of the comparison are transmitted to web server 18 , which then determines whether or not to grant access.
[0066] In the preceding description, for purposes of explanation, numerous details are set forth in order to provide a thorough understanding of the embodiments. However, it will be apparent to one skilled in the art that these specific details are not required. In other instances, well-known electrical structures and circuits are shown in block diagram form in order not to obscure the understanding. For example, specific details are not provided as to whether the embodiments described herein are implemented as a software routine, hardware circuit, firmware, or a combination thereof.
[0067] Some embodiments of the disclosure can be represented as a computer program product stored in a machine-readable medium (also referred to as a computer-readable medium, a processor-readable medium, or a computer usable medium having a computer-readable program code embodied therein). The machine-readable medium can be any suitable tangible, non-transitory medium, including magnetic, optical, or electrical storage device including a diskette, compact disk read only memory (CD-ROM), memory device (volatile or non-volatile), or similar storage mechanism. The machine-readable medium can contain various sets of instructions, code sequences, configuration information, or other data, which, when executed, cause a processor to perform steps in a method according to an embodiment of the disclosure. Those of ordinary skill in the art will appreciate that other instructions and operations necessary to implement the described implementations can also be stored on the machine-readable medium. The instructions stored on the machine-readable medium can be executed by a processor or other suitable processing device, and can interface with circuitry to perform the described tasks. The above-described embodiments are intended to be examples only. Alterations, modifications and variations can be effected to the particular embodiments by those of skill in the art without departing from the scope, which is defined solely by the claims appended hereto.
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A system and method for authenticating mobile communications devices. The method comprises: generating a code corresponding to a user configured to be rendered on a rendering device to produce a rendered code, the rendered code being readable by a mobile communications device having a code reading device, the rendered code comprising a secret token; storing the secret token along with information identifying the user on a first storage device; providing the code to the user; receiving, at the authentication server, a setup message from the mobile device, the message includes a device identifier and the secret token; comparing the received secret token and the secret token stored on the first storage device; if the received secret token matches the secret token stored on the first storage device, storing, on a second storage device, information identifying the user and a trusted device value corresponding to the device identifier.
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FIELD OF THE INVENTION
The present invention relates to a superoxide scavenger and a beverage containing such a superoxide scavenger.
BACKGROUND OF THE INVENTION
It is known that superoxide, or free radical O 2 − arising from the one-electron reduction of oxygen molecule, acts as an important protective factor in the body. For example, once the body is invaded by undesirable bacteria, virus, foreign matters or the like, phagocytes such as neutrophils, monocytes and macrophages are activated to exhibit dynamic functions such as migration and phagocytosis. Then, lysozomal enzyme and superoxide are resultingly yield and secreted to get involved directly or indirectly with the lysis and sterilization actions of the phagocytes, which allows the body to be protected from the invading foreign adversary.
Conversely, the excessive presence of the superoxide in the body causes various tissue disorders. The superoxide is generated in the body generally at the rate of 1% or less of oxygen absorbed into the body through respiration, and the generated superoxide is successively scavenged by the catalytic action of superoxide dismutase (SOD) contained in cells. However, if enzymatic actions are degraded as in an aged body, high concentration of the superoxide will be exhibited due to insufficient scavenging function. This leads to tissue disorders such as articular rheumatism or Behcet's Syndrome, or another symptoms arising from superoxide or lipoperoxide generated by the superoxide, such as myocardial infarction, cerebral apoplexy, cataract, blotches, freckles, wrinkles, diabetes, arterial sclerosis, stiff neck, or feeling of cold.
For example, some publications including Japan Patent No. 2667959 propose a cosmetic containing superoxide dismutase. Unfortunately, any cosmetic containing the superoxide dismutase has not been commercially successful because such an enzyme is subjected to deactivation resulting from its instability to heat and is extremely expensive.
An approach for exploring a suitable material having the action of scavenging superoxide other than the superoxide dismutase is described in Japanese Patent Laid-Open Publication No. Sho 64-50877, in which baicalein contained in Scutellaria root is used. However, only a small amount of baicalein is contained in Scutellaria root. Thus, even if a sufficient amount of baicalein is successively extracted, an overdear product will be provided.
SUMMARY OF THE INVENTION
In view of the aforementioned problems, it is therefore an object of the present invention to provide a superoxide scavenger comprising a desirable material which is different from any conventional unstable superoxide dismutase and is available at a low cost.
It is another object of the present invention to provide a beverage containing such a superoxide scavenger.
In order to achieve the above objects, according to a first aspect of the present invention, there is provided a superoxide scavenger comprising a composition extracted from a specific liquid prepared by: boiling a grain with a liquid to obtain a grain liquor; cooling the obtained grain liquor; adding a yeast into the cooled grain liquor; leaving the grain liquor with the yeast while supplying oxygen thereto; and sterilizing the resulting liquid by heating to obtain the specific liquid. Preferably, a bean is used as the grain.
According to a second aspect of the present invention, there is provided a beverage containing the aforementioned superoxide scavenger.
According to a third aspect of the present invention, there is provided a beverage containing a specific liquid prepared by: boiling a grain with a liquid to obtain a grain liquor; cooling the obtained grain liquor; adding a yeast into the cooled grain liquor; leaving the grain liquor with the yeast while supplying oxygen thereto; and sterilizing the resulting liquid by heating to obtain the specific liquid. Preferably, a bean is used as the grain.
The superoxide scavenger of the present invention can be stably remained even under a temperature of 80° C. or more. Further, using grains as a main ingredient allows the superoxide scavenger to be provided at a lower cost than that of any other conventional superoxide scavengers.
Other features and advantages of the present invention will be apparent from the following description.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A superoxide scavenger of the present invention comprises a composition extracted from a specific liquid prepared by: boiling a grain with a liquid to obtain a grain liquor; cooling the obtained grain liquor; adding a yeast into the cooled grain liquor; leaving the grain liquor with the yeast while supplying oxygen thereto; and sterilizing the resulting liquid by heating to obtain the specific liquid.
It is believed that the superoxide scavenger of the present invention scavenges superoxide based on the reaction of 2O 2 − +2H + →H 2 O 2 +O 2 . However, it has not been elucidated that what kind of plant extract in the ingredient could scavenge superoxide.
In manufacturing the superoxide scavenger of the present invention, a suitable grain may include bean, rice, wheat, corn, barnyardgrass, millet or the like. Preferably, a suitable bean includes soy bean, butter bean, red bean, peanut, fava bean, pea, horsebean, cowpea or the like. In order to obtain the grain liquor, 1 to 20 parts of water by weight is first added to 1 part of at least one selected grain. Then, the grain with water is boiled for 30 minutes or more, preferably for 30 minutes to 5 hours. The resulting liquid or hot grain liquor is naturally cooled or self-cooled and then the cooled liquid is filtered to obtain a desired initial grain liquor.
A suitable amount of yeast is added to the initial grain liquor, and the grain liquor with the yeast is left for about 1 to 6 months while supplying oxygen thereto. Preferably, suitable yeast includes any yeast belonging to Saccharomyes, such as beer yeast, wine yeast, sake yeast, or baker's yeast.
In a preferred embodiment, about 10 ml of the initial grain liquor may be first poured into a test tube at room temperature. Then, the yeast may be added into this liquor, and the liquor with the yeast may be left for 1 to 10 days to obtain a first intermediate liquid. Then, 100 ml of the initial grain liquor may be poured into a flask, and the first intermediate liquid may be added into this liquor. The liquor with the first intermediate liquid may be left for 1 to 10 days to obtain a second intermediate liquid. Then, 100 litters of the initial grain liquor may be poured into a tank, and the second intermediate liquid may be added into this liquor, followed by leaving the liquor with the second intermediate liquid for about 1 to 6 months to obtain a stock solution of superoxide scavenger.
The resulting stock solution of superoxide scavenger is sterilized by heating at about 70 to 130° C. for about 2 seconds to 60 minutes. While this sterilized stock solution of superoxide scavenger can be used as a superoxide scavenger as—is, it may be concentrated and further dried under a reduced pressure to use as a dried extract, if necessary.
Preferably, a beverage, such as a soft drink, of the present invention contains about 1 to 10% by weight of the stock solution of superoxide scavenger, in particular, about 5 to 10% by weight of the stock solution of superoxide scavenger.
EXAMPLE
In manufacturing the superoxide scavenger of the present invention, soybean was selected from beans as the grain. First, 600 g of soybeans were immersed in 300 litters of water, and the soybeans with water were left for 10 hours. Then, 100 litters of water was further added to the soybeans with water, and the beans with the increased water were boiled in a pan for 5 hours. Then, the boiled beans and water were naturally cooled or self-cooled. Then, the soybeans were removed to obtain an initial liquor of about 200 litters.
10 ml of the initial liquor was poured in to a test tube, and a suitable amount of sake yeast was added into the liquor. Then, the liquor with the sake yeast was left at room temperature for 2 days to obtain a first intermediate liquid. In the course of this operation, the liquor with the sake yeast was agitated at intervals to supply oxygen thereto.
Then, 100 ml of the initial liquor was poured into a flask, and the first intermediate liquid was added into this liquor. The liquor with the first intermediate liquid was left at room temperature for 2 days to obtain a second intermediate liquid. In the course of this operation, the liquor with the first intermediate liquid was also agitated at intervals to provide oxygen thereto. Then, the obtained second intermediate liquid was poured into the remaining initial liquor, and this liquor with the second intermediate liquid was left for 1 months. In the course of this operation, the liquor with the second intermediate liquid was also agitated at intervals to provide oxygen thereto.
According to the food heat-sterilization process defined by the Public Health Department Regulations, the obtained liquid was sterilized by heating at 85° C. for 30 minutes to obtain a stock solution of superoxide scavenger of the present invention. Using the obtained the stock solution of superoxide scavenger, a superoxide scavenging activity was determined as described below.
1. Measuring Method
Superoxide (activated oxygen) was generated by the hypoxanthine-xanthine oxidase system, and each sample to be measured was added into the obtained superoxide. Then, the superoxide scavenging activity (SOSA) for each sample was determined from the signal strength of ESR (electron spin resonance) spectrum obtained by using the spin-trap process. DETAPAC (di-ethylen triamine penta acetic acid) was added to eliminate metallic impurities.
2. Measuring Equipment and Measuring Condition
Using the ESR JES-REIX made by JEOL Ltd., the measurement was carried out under the following condition.
Observation magnetic field: 355.4±5 mT
Microwave output: 8 mV
Magnetic field modulation amplitude: 0.079 mT
Sweep time: 2 min
Microwave frequency: 100 kHz
The stock solution of superoxide according to the invention had a SOSA value of 20.1 unit/ml. Up to now, various comparative measurement values of the superoxide scavenging activity have been obtained, such as 0.2 unit/ml for tap water, 3.8 unit/ml for (pH 8.0) ionized alkaline water, 5.7 unit/ml for (pH 9.0) ionized alkaline water, and 3.6 unit/ml for magnetic water. Since the reproducibility of the measurements is ±0.5 unit/ml, it was verified that in the comparison of liquid to liquid, the stock solution of superoxide scavenger of the present invention had a higher superoxide scavenging activity than that of others. While the superoxide dismutase (Cu-Zu type SOD) made by Wako Pure Chemical Industries, Ltd. has a superoxide scavenging activity value of 3000 to 4000 unit/mg, it is not practicable to compare each superoxide scavenging activities of a solid superoxide scavenger, such as the above superoxide dismutase, and a liquid superoxide scavenger, such as the superoxide scavenger of the present invention, at this time.
In terms of the superoxide scavenging activities of the stock solution of superoxide scavenger described above, it can be expected that the superoxide in the body may be adequately scavenged to provide an improve health condition by regularly drinking the beverage containing the stock solution of superoxide scavenger or the superoxide scavenger extracted from such a stock solution.
The invention has now been explained with reference to specific embodiments. Other embodiments will be apparent to those of ordinary skill in the art. Therefore, it is not intended that the invention be limited, except as indicated by the appended claims, which form a part of this invention description.
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The present invention provides a superoxide scavenger comprising a desirable material which is different from any conventional unstable superoxide dismutase and is available at a low cost, and the present invention also provides a beverage containing such a superoxide scavenger. The superoxide scavenger and beverage of the present invention comprise a composition extracted from a specific liquid. This specific liquid is prepared by: boiling a grain with a liquid to obtain a grain liquor; cooling the obtained grain liquor; adding a yeast into the cooled grain liquor; leaving the grain liquor with the yeast while supplying oxygen thereto; and sterilizing the resulting liquid by heating to obtain the specific liquid.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to telecommunications systems and more particularly to securing data flow in Internet multicasting.
2. Description of Related Art
Many emerging Internet applications involve one-to-many or many-to-many communications, where one or multiple sources are sending to multiple receivers. Examples are the transmission of corporate messages to employees, communication of stock quotes to brokers, video and audio conferencing for remote meetings and telecommuting, and replicating databases and web site information. IP Multicast efficiently supports this type of transmission by enabling sources to send a single copy of message to multiple recipients who explicitly want to receive the information. This is far more efficient than requiring the source to send an individual copy of the message to each requester (referred to as point-to-point unicast), in which case the number of receivers is limited by the bandwidth available to the sender. It is also more efficient than broadcasting one copy of the message to all nodes (broadcast) on the network, since many nodes may not want the message, and because broadcasts are limited to a single subnet.
IP Multicasting is a receiver-based concept: a receiver joins a particular multicast session group and traffic is delivered to all members of that group by the network infrastructure. The sender does not need to maintain a list of receivers. Only one copy of a multicast message will pass over any link in the network, and copies of the message will be made only where paths diverge at a router. Thus multicast yields many performance improvements and conserves bandwidth end-to-end.
IP Multicasting is described in more detail in two documents published by the IP Multicast Initiative. The first is entitled “How IP Multicast Works” and the second is entitled “Introduction to IP Multicast Routing”. These documents are attached to the specification as Appendixes A and B, respectively. These documents are hereby incorporated by reference into the specification in their entirety.
A related approach to multicast security using encryption of datastreams is known in which a sender encrypts outgoing information for decryption at a receiver. This is commonly done using public key encryption techniques.
The Problems
IP Multicasting is based on a simple design—the sender simply sends the data to a multicast group address and the network automatically sends the data to everyone who expressed interest in receiving data on that multicast address. A significant problem is that this arrangement does not provide any security to data flow, that is, everyone can listen to a multicast session and everyone can send data to multicast sessions. As a result, there is no such thing as secure data flow in Internet multicasting sessions in the prior art. Further, since anyone can send to a multicast session, the potential for disruption by an interloper is significant.
SUMMARY OF THE INVENTION
Various aspects of the invention discussed herein provide apparatus, systems, processes, and computer program products for securing data flow in Internet Multicasting. This is done by splitting the multicast address space into two components, one for public multicast and one for private multicast. A public key of a public/private pair is installed on a domain name server or on a certification authority and is associated with the multicast address. A user, desiring to join a private multicast, provides certain information which is encrypted using the private key of the public/private key pair. Routing functions are typically performed by a switch at a node of a switching network or by a router in the network or by a computer which has a plurality of communications interfaces. As used herein, the term “routing element” applies to all. A routing element receives a join request, obtains the public key and compares some non-encrypted information with decrypted information for consistency. The routing element also performs certain other checks on the join request received. Only when the routing element is satisfied that the join request received is authentic does the routing element permit the join and forward the join request to the next routing element on the way to the source. Techniques are also provided for source-group specific joins and leaves which permit one to specify senders authorized to send to a receiver and to prevent unauthorized senders from sending data to the receiver.
One embodiment of the invention is directed to a routing element for routing multicast information. The routing element obtains a public key with which to decode part of a multicast join request to verify that a user is authorized to join a private multicast.
Another embodiment of the invention is directed to apparatus for participating in a multicast including a processor configured to send a private multicast join request.
Another embodiment of the invention is directed to a domain name server which stores records relating a multicast network address or alias with a public key of a public/private key encryption pair and which sends in response to a network address or alias received over a communications port, a public key corresponding to the address or alias.
Another embodiment of the invention is directed to a communications system for multicasting information from at least one source to a plurality of receivers, including a plurality of sub-networks and at least one router, connecting at least two sub-networks, configured to distinguish between public and private multicasts.
Another embodiment of the invention relates to a method of operating a communications system by providing a multicast address space having a subspace for public multicasts and a subspace for private multicasts.
Another embodiment of the invention relates to a method of sending a multicast join request, by sending first information including a user identification and an optional random key together with an encrypted version of said first information.
Another embodiment of the invention relates to a method of sending a multicast join request from a user by sending a list of bit-masks specifying at least one of a group of senders permitted to send to said user and a group of senders prohibited from sending to said user.
Another embodiment of the invention relates to a method of establishing a private multicast by creating a private/public key encryption pair, distributing private keys to authorized participants in the multicast; obtaining a private multicast address; and installing the public key for the multicast on a domain name server or on a certification authority.
Other embodiments of the invention relate to computer program products for carrying out the techniques described.
The foregoing and other features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings and Appendices A and B of this specification.
BRIEF DESCRIPTION OF DRAWINGS
The objects, features and advantages of the system of the present invention will be apparent from the following description in which:
FIG. 1 is block diagram of an exemplary network arrangement linking a plurality of sub-networks in accordance with one aspect of the invention.
FIG. 2 is a illustration of how a multicast address space may be partitioned into a private multicast address sub-space and public multicast address sub-space, in accordance with one aspect of the invention.
FIG. 3 is a database schema showing a typical domain name server record in accordance with the prior art.
FIG. 4 is a database schema of a domain name server modified in accordance with one aspect of the invention.
FIG. 5 is a diagram illustrating the extensions to an Internet Group Management Protocol (IGMP) join request in accordance with one aspect of the invention.
FIG. 6 is a flow chart of an exemplary router process for determining whether to permit or reject an IGMP join request in accordance with one aspect of the invention.
FIG. 7A shows a prior art IGMP join request.
FIG. 7B shows a prior art extension to the IGMP join request of FIG. 7 A.
FIG. 7C shows an extension to IGMP join requests in accordance with one aspect of the invention.
FIG. 8 is a flow chart of a process for setting up a private multicast in accordance with one aspect of the invention.
FIG. 9A illustrates a computer of a type suitable for carrying out the invention.
FIG. 9B illustrates a block diagram of the computer of FIG. 9 A.
FIG. 9C illustrates an exemplary memory medium containing one or more programs usable with the computer of FIG. 9 A.
NOTATIONS AND NOMENCLATURE
The detailed descriptions which follow may be presented in terms of program procedures executed on a computer or network of computers. These procedural descriptions and representations are the means used by those skilled in the art to most effectively convey the substance of their work to others skilled in the art.
A procedure is here, and generally, conceived to be a self-consistent sequence of steps leading to a desired result. These steps are those requiring physical manipulations of physical quantities. Usually, though not necessarily, these quantities take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated. It proves convenient at times, principally for reasons of common usage, to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, or the like. It should be noted, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities.
Further, the manipulations performed are often referred to in terms, such as adding or comparing, which are commonly associated with mental operations performed by a human operator. No such capability of a human operator is necessary, or desirable in most cases, in any of the operations described herein which form part of the present invention; the operations are machine operations. Useful machines for performing the operation of the present invention include general purpose digital computers or similar devices.
The present invention also relates to apparatus for performing these operations. This apparatus may be specially constructed for the required purpose or it may comprise a general purpose computer as selectively activated or reconfigured by a computer program stored in the computer. The procedures presented herein are not inherently related to a particular computer or other apparatus. Various general purpose machines may be used with programs written in accordance with the teachings herein, or it may prove more convenient to construct more specialized apparatus to perform the required method steps. The required structure for a variety of these machines will appear from the description given.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 is a block diagram of an exemplary network arrangement linking a plurality of sub-networks in accordance with one aspect of the invention. As shown in FIG. 1, a plurality of sub-networks 100 A, 100 B, 100 C and 100 D are connected together over routers 110 A, 110 B and 110 C. In the network illustrated, domain name server 130 is resident on sub-network 100 B and a certification server or authority 150 as resident on sub-network 100 C. One or more senders 140 may be the intended source of information for the multicast to exemplary user stations 120 A and 120 B.
FIG. 2 is an illustration of how a multicast address space may be partitioned into a private multicast address sub-space and public multicast address sub-space.
The left hand side of FIG. 2 represents the total multicast address space. That space ranges from 224.0.0.0 (in Internet standard dotted decimal notation) to 239.255.255.255. Underneath the dotted decimal representation is a parenthetical showing eight binary bits (bracketed) which corresponds to the numerical value of the first component of the dotted decimal notation). Each of the other components of the dotted decimal notation represent the value of a corresponding byte in a 32-bit (4 byte) address space utilized by the Internet. The notation of a binary value 1 or 0 separated by dots from another representation of the same binary value represents an indication that the remaining bits of the 32-bit address word have only those binary values contained therein. One of the important extensions to the multicast address space provided in accordance with the invention is a separation of the multicast address space into two components, the first of which is a public multicast address space and the second of which is a private multicast address space. As shown in FIG. 2, the public multicast address space ranges from 224.0.0.0 to 231.255.255.255. Similarly the private multicast address space ranges from 232.0.0.0 to 239.255.255.255. By this partitioning of the address space, one can tell immediately from a multicast address whether a private multicast is undertaken or a public multicast is undertaken.
FIG. 3 is a database schema showing a typical domain named server (DNS) record in accordance with the prior art. As shown in FIG. 3, a dotted decimal address 300 is mapped against an alias for that address 310 in respective columns of the database table.
FIG. 4 is a database schema of a domain name server modified in accordance with one aspect of the invention. Columns 400 and 410 correspond to approximately to the columns in which entries 300 and 310 of FIG. 3 occur. However, in column 410 , instead of a fixed station address, an IP Multicast address is included. Column 420 contains entries which describe the owner of the multicast address. Typically this would be the person setting up the multicast. Column 430 contains a public key for each private multicast address. Column 440 contains an optional public or private flag which can be used to distinguish public and private multicasts if the address space is not partitioned.
When using a domain name server of the prior art, a query using either the network address or its alias will result in return of the other value shown in FIG. 3 . When a domain name server is extended in accordance with the arrangement shown in FIG. 4, it is convenient that a query submitted with data from either column 400 or column 410 will result in return of the entire record matching the submitted value. Thus, if one were to search on the alias shown in column 410 of FIG. 4, one would retrieve not only the network address shown in column 400 , the owner information shown in 420 but also the public key shown in column 430 for the multicast session. This ability to retrieve public keys is useful as described more in after.
FIG. 5 is a diagram of extension to an Internet Group Management Protocol (IGMP) join request in accordance with one aspect of the invention. A header 500 , and packet type shown in Field 1 together with a requester IP address shown in Field 2 would typically be part of prior art IGMP join request. In the extensions shown in accordance with one aspect of the invention, an optional timestamp may be placed in Field 1 and a random key, placed in Field 3 , is generated by the requester. The contents of Field 1 , Field 2 and Field 3 are encrypted or digested and the digest encrypted and placed into Field 4 . The Cyclic Redundancy Check 510 (CRC) encompasses the full IGMP join request. How this extended join request is utilized is discussed more hereinafter.
FIG. 6 is a flow chart of an exemplary routing element process for determining whether to permit or reject an IGMP join request in accordance with one aspect of the invention. When an extended IGMP join request is received at a router ( 600 ) determination is made from the address whether or not the multicast is public or private ( 605 ). If it is public ( 605 -public), the join is permitted and the join request forwarded to the next routing element along the path, if any ( 640 ). If the multicast is private ( 605 -private) a check is made to determine whether the join request submitted is a duplicate of a previous request. One way an unauthorized user may attempt to gain access to a multicast would be to duplicate a join request submitted by a previous user. If the submitted join request is a duplicate ( 610 - y ), the request is rejected. If it is not, a determination is made whether the join request is timely ( 615 ). This a simple check to see that the join request is appropriate for the day and time of the current multicast session. This would prevent a user from copying an earlier join request from an authorized user in an attempt to gain access to the current session. If the join request is not timely ( 615 -N), the request to join is rejected. If it is timely, a check is made to determine whether the join request came from a proper link. If it did not ( 620 -N), the join request is rejected. However, if it did, the routing element will obtain the public key dual corresponding to the private key utilized to encrypt the IGMP extended join request ( 625 ). Preferably, the public key is obtained from a domain name server, such as DNS 130 shown in FIG. 1 . Alternatively, the public key could be obtained from a certification authority 150 shown in FIG. 1 . Using the acquired public key, Field 4 of the extended IGMP join request is decrypted using the public key ( 630 ). The resulting information decrypted from Field 4 should agree with Fields 1 - 3 . If it does, the join is permitted and the join request is forwarded to the next routing element. If it does not ( 635 - n ), the join request is rejected and the user will be denied access to the multicast by the router.
A third aspect of the invention is illustrated in FIG. 7A, FIG. 7 B and FIG. 7 C. FIG. 7A shows a prior art IGMP join request.
FIG. 7B shows a prior art extension to the IGMP join request of FIG. 7 A. The extension of the IGMP join request of FIG. 7B permits a lists of senders to be specified which are permitted to send to the address requesting the join. Similarly, it includes an list of senders prohibited from sending to the address requesting the join. This permits a participant in the multicast to inform routers to selectively prohibit packets from undesirable or disruptive sources from reaching the participant. It also permits the user to specify the list of senders from which the requesting station desires to receive information. This allows the filtering out of packets that the user does not desire to see.
FIG. 7C shows an extension to prior art IGMP join requests in accordance with one aspect of the invention. Field 760 and Field 770 permit the use of a list of 32-bit masks instead of a list of senders or receivers. Thus, by tailoring a mask, groups of addresses may be permitted to send to the address or barred from sending to the address, merely by specifying the bit-mask appropriate for the group and the property desired. For example, the property may be “permitted to send to this address” or “prohibited from sending to this address”.
FIG. 8 is a flow chart of a process for setting up a private multicast in accordance with one aspect of the invention. A user desiring to set up a private multicast first creates a private/public key pair for the multicast ( 800 ). The sponsor or owner of the multicast obtains a private multicast address ( 810 ) for use during the multicast. This can either be a permanent assignment or a temporary assignment depending on need. The owner of the multicast or other designated party may install the public key for the multicast in the DNS information for the multicast address or in a certification server ( 820 ). The private key for the multicast is distributed to authorized participants in any of several known ways, but preferably over the network ( 830 ). At that time, the multicast is ready to begin ( 840 ). The receivers that desire to participate in the multicast then formulate an extended join request such as described in FIG. 5 . If the user is authorized, the routing element will make that determination using the public key installed on the domain named server or on the certification server. When the routing element is satisfied that the request for joining the private multicast is genuine, the routing element will begin directing packets addressed to the multicast address to the user who submitted in the extended IGMP join request. However, if the user is not authorized (as discussed in conjunction with FIG. 6 ), the user will not be permitted to join the multicast and the routing element will not forward packets to the user.
FIG. 9A illustrates a computer of a type suitable for carrying out the invention. Viewed externally in FIG. 9A, a computer system has a central processing unit 900 having disk drives 910 A and 910 B. Disk drive indications 910 A and 910 B are merely symbolic of a number of disk drives which might be accommodated by the computer system. Typically, these would include a floppy disk drive such as 910 A, a hard disk drive (not shown externally) and a CD ROM drive indicated by slot 910 B. The number and type of drives varies, typically, with different computer configurations. The computer has the display 920 upon which information is displayed. A keyboard 930 and a mouse 940 are typically also available as input devices. Preferably, the computer illustrated in FIG. 9A is a SPARC workstation from Sun Microsystems, Inc.
FIG. 9B illustrates a block diagram of the internal hardware of the computer of FIG. 9A. A bus 950 serves as the main information highway interconnecting the other components of the computer. CPU 955 is the central processing unit of the system, performing calculations and logic operations required to execute programs. Read only memory ( 960 ) and random access memory ( 965 ) constitute the main memory of the computer. Disk controller 970 interfaces one or more disk drives to the system bus 950 . These disk drives may be floppy disk drives, such as 973 , internal or external hard drives, such as 972 , or CD ROM or DVD (Digital Video Disks) drives such as 971 . A display interface 925 interfaces a display 920 and permits information from the bus to be viewed on the display. Communications with external devices can occur over communications port 985 .
Computer 900 includes a communications interface 985 coupled to bus 950 . Communications interface 985 provides a two-way data communications coupling to a network link to a local network such as 100 D of FIG. 1 . For example, if communications interface 985 is an integrated services digital network (ISDN) card or a modem, communications interface 985 provides a data communications connection to the corresponding type of telephone line. If communications interface 985 is a local area network (LAN) card, communications interface 985 provides a data communications connection to a compatible LAN. Wireless links are also possible. In any such implementation, communications interface 985 sends and receives electrical, electromagnetic or optical signals which carry digital data streams representing various types of information.
The network link typically provides data communications through one or more networks such as 100 A- 110 D of FIG. 1, to other data devices. For example, the network link may provide a connection through local network to a host computer or to data equipment operated by an Internet Service Provider (ISP). An ISP may in turn provide data communications services through the world wide packet data communications network now commonly referred to as the “Internet”. The local network and Internet both use electrical, electromagnetic or optical signals which carry digital data streams. The signals through the various networks and the signals on the network link and through communications interface 985 , which carry the digital data to and from computer 900 are exemplary forms of carrier waves transporting the information.
Computer 900 can send messages and receive data, including program code, through the network(s), network link and communications interface 985 . In the Internet example, a server might transmit requested code for an application program through Internet, ISP, local network and communications interface 986 . In accordance with the invention, one such download application may include software implementing the techniques described herein.
The received code may be executed by processor 955 as it is received, and/or stored in storage devices 960 and/or 971 - 973 , or other non-volatile storage for later execution. In this manner computer 900 may obtain application code in the form of a carrier wave.
FIG. 9 shows an architecture which is suited for either a user workstation or for a routing element. However, when configured as a routing element, I/O devices will normally only be attached during servicing. When configured as a router, a plurality of communications interfaces 985 will normally be provided, one for each port. When configured as a controller for a switch at a switching node, a hardware interface will be provided to link the bus 950 with a switching matrix.
FIG. 9C illustrates an exemplary memory medium which can be used with drives such as 973 in FIG. 9B or 910 A in FIG. 9 A. Typically, memory media such as a floppy disk, or a CD ROM, or a Digital Video Disk will contain the program information for controlling the computer to enable the computer to perform its functions in accordance with the invention.
The approach discussed above provides a simple general purpose interface that works across a spectrum of varying user needs. It does not unreasonability increase the overhead for setting up and operating the multicast for users who would like to continue to set up simple open meetings. The systems provides security even if outsiders know the IP address and/or port number which might otherwise enable them to misbehave or behave maliciously. The system is flexible in that it does not require the multicast sessions organizers to know the identity of all the senders and/or listeners in advance. It also permits users to dynamically join the discussions.
Even if the system is compromised, it is possible to reasonably limit the damage caused by excluding that user or group of users from the conference. The approach described here is also compatible with current and proposed mechanism and protocols for multicasting.
Although the present invention has been described and illustrated in detail, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, the spirit and scope of the present invention being limited only by the terms of the appended claims and their equivalents.
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Multicast communications are expanded to include the concept of private multicasts. An address space dedicated to multicast is partitioned into a subspace for public multicasts and a subspace for private multicasts. A public key/private key encryption pair is used for private multicasts and installed on domain name servers or on certification authorities. Portions of a multicast join request are sent together with a corresponding encrypted version. Private multicast equipped routers receive the multicast join request, retrieve the public key from a domain name server or from a certification authority and decrypt the encrypted portion of the join request to determine if the requester is authorized. Group specific multicast joins are also permitted by sending a bit-mask identifying a group of senders which are authorized or prohibited from sending to a user joining a multicast.
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This is a continuation-in-part of my copending application, Ser. No. 356,074 filed May 24, 1989, itself a continuation-in-part of my prior application, Ser. No. 103,398 filed Oct. 1, 1987 and now U.S. Pat. No. 4,849,685 granted July 18, 1989.
TECHNICAL FIELD
This invention relates to means and methods for reduction of electromagnetic interference (EMI), such as may be generated in electrical equipment and be conducted back to input power lines. It relates particularly to a selectable mode rejection network (SMRN).
BACKGROUND OF THE INVENTION
Just as electrical power lines may transmit transient surges or other voltage irregularities to electrical equipment intended to be powered therefrom, so equipment in line of such power transmission may cause interfering electrical signals or noise to be conducted back to an intervening electrical bus and even to the power lines.
Such conducted emissions (CE) may degrade computer performance, television picture quality, and the functioning of other electrical equipment powered from such lines. CE types of interference may be generated by computers, radio and TV receivers, motors, switching apparatus, or almost any electrical equipment having (or causing) a varying or random emission, whether as intended output or otherwise.
Filters are useful in reducing such interference, and it is conventional--in determining the desirability and effectiveness of filters--to measure conducted emissions with an instrument often called an EMI meter or spectrum analyzer. Such a meter has a logarithmic (dB) scale and is responsive via a voltage probe or current loop throughout a frequency range up to 30 MHz or higher.
Plotting the results of such measurements reveals whatever interference peaks and bands may exist, so that adequate filters can be designed and be connected to (or be installed in) the equipment under test (EUT) to limit such interference to a tolerable level at all frequencies. Designing such filters may fairly be viewed now as principally an art rather than a science. A need exists for methods and means of empirically determining, with greater facility, filters most suitable to combat both such types of conducted emissions.
Lon M. Schneider and Alphonse A. Toppetto, as well as the present inventor, are well known workers and writers in this field. Their published articles, some listed in my aforementioned patent, are of more interest than are most EMI patents, but Toppetto U.S. Pat. No. 4,263,549 discloses apparatus for determining "differential mode" and "common" mode noise. Common mode (CM) current flows from phase and neutral lines to ground, whereas "differential mode" (DM) current flows from a phase line to a neutral line.
SUMMARY OF THE INVENTION
Whereas my aforesaid patented invention provides an excellent method and means for measuring both CM and DM noise and utilizing such measurements in reducing EMI to a desirably acceptable level, it may be more demanding than some designers need or wish to handle. My present invention is directed toward a more simplified method and means for approximating a similarly desirable result.
A primary object of the present invention also is to facilitate desired reduction of electromagnetic interference from electrical equipment that in its operation is a generator of unintended EMI.
Another object of this invention is to systematize further the designing of filters for limiting EMI to tolerable levels.
A further object of the invention is to provide a sequence of steps for measuring and limiting respective components of EMI.
Yet another object is to provide a specific circuitry of a mode selection device useful during the performance of such steps.
A still further object of the invention is to provide a technique for measuring source impedance.
In general, the objects of this invention are accomplished by interposing a selectable mode rejection network between LISN-terminated phase and neutral power lines and their output to equipment under test (EUT), to enable either the common mode (CM) or the differential mode (DM) outputs to add in phase--and the other to cancel out--depending upon selectable mode switch setting.
When DM contributions from the respective phases are out of phase (as they normally are) they cancel one another out, and the common mode (CM) contributions add together. In the opposite setting of the phase-reversing selectable mode switch, CM contributions cancel one another because then they are out of phase, and the DM contributions add together.
A filter designer can design a filter to exclude whichever type of noise is measured in the one position and then exclude the other type as measured in the other position. A resulting combined filter should exclude both types well enough to comply with EMI limits.
Other object of this invention, together with methods and means for accomplishing the various objects, will become apparent from the following description and the accompanying drawings, presented here by way of example rather than limitation.
SUMMARY OF THE DRAWINGS
FIG. 1 is a schematic electrical diagram of the interconnection of an A.C. power source to an electrical load, here equipment to be put under test (EUT) for electromagnetic interference (EMI);
FIG. 2A is a similar schematic view of a power line impedance stabilization network (LISN) interposed between the power source and the EUT--only one of the power lines to the EUT being shown, for the sake of simplicity; and
FIGS. 2B and 2C are views showing the equivalent electrical circuits of the apparatus of FIG. 2 at, respectively, conventional power frequency and a much higher frequency characterized by EMI;
FIG. 3 is a schematic view of the same apparatus connected conventionally to an EMI receiver for measurement of its EMI;
FIGS. 4A and 4B are schematic diagrams of "common mode" (CM) and "differential mode" (DM) conducted emissions (CE) from the EUT, especially part thereof acting to generate noise.
FIG. 5 is a schematic electrical diagram of the connection of the EUT and the EMI receiver as in FIG. 3, with the addition of a selectable mode rejection network (SMRN) interposed between the line impedance stabilization networks (LISNs) and the EMI receiver (REC), in accordance with this invention;
FIG. 6A is a schematic block diagram of such SMRN electrical circuitry for use with single-phase input power sources;
FIG. 6B is a circuit diagram of such SMRN for like use;
FIG. 7 is a block diagram of a method of limiting EMI from an EUT according to this invention, using an SMRN as in FIG. 5; and
FIGS. 8A, 8B, and 8C are schematic representations of an EUT with, respectively, a CM filter, a DM filter, and a composite or resulting filter interposed between it and the input power lines.
DESCRIPTION OF THE INVENTION
FIG. 1 shows, in conventional schematic manner, circuitry 10 wherein A.C. electrical power source 11 has ungrounded phase line 12 and grounded neutral line 14 leading to electrical load EUT 19. It will be understood, of course, that the same power lines have numerous other electrical loads (not shown) on them and that any one or more of such loads may generate EMI and propagate it as conducted emissions via the power transmission lines to other connected loads. Filters are needed between the power lines and the load equipment of such a conventional hookup to limit conduction of such emissions back to the power lines and, thus, to other equipment so powered.
FIG. 2A shows in similar manner circuitry 20, wherein LISN 13 is interposed between line 12 and ground. The LISN is intended to provide a stabilized impedance to emissions conducted from the EUT to the power lines, without interference with the normal supply of power to the EUT. Grounded neutral line 14 (not shown here) is also provided with a like LISN. LISN 13 is made up of first impedance element Z1 (largely inductive) in series in the line and second impedance element Z2 (largely capacitive) in series between the inductive impedance and ground. Impedance Z of the EUT is also shown as connected to ground (through parasitics) and to neutral line 14 (through the operational load).
FIGS. 2B and 2C are simplified schematic views to show DM and CM effective source impedances at ordinary power frequency (FIG. 2B) and at much higher or "noise" frequencies (FIG. 2C).
FIG. 2B shows effective circuitry 20' of the apparatus of FIG. 2A at power frequency, say 50 to 60 Hz, whereby inductive Z1 is low in impedance, and capacitive Z2 is so high in impedance as to be practically and open circuit--and, therefore, is omitted from view.
FIG. 2C shows effective circuitry 20" of the apparatus of FIG. 2A at high or noise frequency, whereby inductive Z1 is so high in impedance as to be practically an open circuit and, thus, is omitted from this view--along with the power source--whereas capacitive Z2 is very low in impedance. EMI source 25 (DM) is indicated in series between impedance element Z within the EUT (now designated 19') and neutral line 14, and EMI source 26 (CM) is indicated in series between the same impedance element and ground.
FIG. 3 shows schematically conventional circuitry 30, wherein LISN 13 is interposed in phase line 12, and LISN 15 is interposed in neutral line 14 leading to EUT 19, and wherein EMI receiver 18 and equivalent termination impedance ZT are connectable alternately via double-pole double-throw switch S1 to the respective LISNs. Here upper switch arm 27 connects the phase line LISN (via lead 23) to EMI receiver (REC) lead 29, while lower switch arm 28 connects the neutral line LISN (via lead 24) to the ZT unnumbered lead. Such switch setting leaves unconnected alternative LISN leads 23' and 24' which interchange the LISN connections to REC and ZT.
Such a conventional measuring arrangement fails to distinguish between "common mode" conducted emissions and "differential mode" conducted emissions, leaving filter design quite experimental and uncertain--even when the desirability of distinguishing between CM CE and DM CE is appreciated. The next views further emphasize that customary failure to cope with the practical problem.
FIG. 4A shows schematically effective circuitry 40' of CM CE at high or noise frequencies. Impedance elements Z2 between ground and respective phase and neutral power lines 12 and 14 receive currents from indicated source 25'--denoting whatever component(s) of the EUT act(s) as a source of such EMI. As CM CE currents (arrows) flow in the same direction at any given time in each of the power lines, source 26 is shown between both lines and ground. The EUT itself is marked 19A to distinguish it from its previous simpler representation, and load Z is omitted.
FIG. 4B shows similarly the effective circuitry 40" of DM CE at high or noise frequencies. Pair of impedance elements Z2 between respective phase and neutral power lines 12 and 14 and ground receive currents from source 25 of the EUT (now 19B) and circulate or flow in opposite directions in the two lines.
FIG. 5 shows schematically circuitry 50 for use in practicing the method of the present invention. This arrangement resembles FIG. 3 except that "selectable mode rejection network" (SMRN) 55 is interposed between EMI receiver 18 and respective leads 23 and 24 to the LISNs. The utility of such SMRN will become apparent in the description of how and when to use it in measurements of EMI.
FIG. 6A shows in block or similar schematic form positive (+1) amplifier AMP A in a shielded line from LISN A and shows positive amplifier AMP B and negative (-1) amplifier AMPB, in parallel with one another in line from LISN B . The amplifier outputs are summed (as A+B) algebraically at junction 70 and go via a shielded lead to EMI receiver REC. Switch SW B enables either the positive or the negative amplifier in the LISN B line to be connected at will. Thus, when both amplifiers have positive output, the output of in-phase (CM) noise (halved by the voltage dividers), will add together, and the output of exactly out-of-phase (DM) noise will be nullified; whereas when the amplifiers have opposite outputs, the net output is out-of-phase (DM) noise, and the in-phase (CM) noise becomes nil.
FIG. 6B is an equivalent of 6A in which AMP A is specifically provided as transformer L A , and AMP B is provided as transformer L B . Resistors R A1 and R B1 are across the primary windings of the respective transformers, each with one end grounded. Switch SW B shown connectable to either end of the ungrounded secondary of the second transformer simultaneously grounds the other end of its winding. The outputs from the respective transformers pass through respective resistors R A2 and R AB2 to junction 70, and the combined output goes from there through resistor R AB2 to EMI receiver REC.
In view of standard (in the U.S.) termination requirement of 50 ohms for LISNs and for an EMI receiver, each R 1 resistor (whether A or B) has a value of 50 ohms, and each R 2 resistor (A, B, or AB) has a value of 16 2/3 ohms. European countries may prefer a higher LISN impedance (say, 100 or 150 ohms), but the respective resistor values can be scaled readily from the 50-ohm termination.
Such SMRN is used in only a part of an EMI measuring process, but its use is critical to success of the measurement and to the effectiveness of consequent filter design, as will be understood from the next diagram and from description of it and subsequent views.
FIG. 7 shows in block form successive steps of the present invention, which inherently provides alternative ways of proceeding, corresponding to beginning with either CM (preferably) or DM as net output depending upon the initial setting of the phase switch. In generality, the method is characterizable succinctly as a preliminary step of (i) setting the phase switch and thereby excluding by cancellation one mode of conductive emissions (CE), followed by the steps of (ii) measuring the unexcluded mode of CE, (iii) reversing the setting of the phase switch and (iv) measuring the previously excluded but now unexcluded other mode of CE.
After either or both of the measuring steps, the measurement(s) is (are) used in conventional manner to design a filter adapted to filter one (both) of the modes of CE out. Two individual filters or a single combined filter so designed (and connected to or included in the equipment) are effective to reduce EMI very substantially, if not entirely. Care should be taken to recheck both types of emissions to ensure that nothing occurred in adding or combining filters to disturb effective filtration of either mode of CE.
FIGS. 8A, 8B, and 8C illustrate circuitry generally, whether in the prior art (as marked) or according to this invention when this teaching is followed therein. Whereas prior art methodology at best only approximates effective values, in the practice of this invention the specified values of the various circuit elements provide highly effective filtering out of EMI. These last three views are described here principally from this improved perspective with reference to the foregoing sequence of steps, notwithstanding application of the illustrations generally to attempts of the prior art to accomplish effective EMI filtering. In other words, to the extent they incorporate the means or methods of the present invention, these FIGS. are not merely prior art though they are properly so considered (and designated) when not enhanced by this invention.
FIG. 8A shows schematically the apparatus upon interposition of CM filter 60 between the power lines and the EUT after step (b); FIG. 8B shows additionally interposed DM filter 65 after step (d); and FIG. 8C shows filter 69, a composite of 60 and 65 so interposed. Producing such a composite filter from two individually determined filters is well known and can be accomplished by persons of ordinary skill, once values of the respective filter components are known.
Notwithstanding the specificity of the foregoing description, variants have been suggested, and other modification may be made, as by adding, combining, deleting, or subdividing parts or steps, while retaining at least part of the advantages and benefits of the present invention--which itself is defined in the following claims.
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Selectable mode rejection network (SMRN) for electromagnetic interference (EMI) excludes common mode (CM) and, alternatively, differential mode (DM) conducted emissions (CE) from entering power transmission lines from electrical equipment powered from such lines and producing such unwanted electrical noise. Phase-switching the SMRN determines whether CM or DM is so excluded, thereby facilitating measurement of the unexcluded type of CE. So used in measuring EMI, such SMRN enables improved filter design for the respective types of CE and composite filters for limiting both CM and DM CE.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The field of the present invention relates to attachments to spectacles or sunglasses which further enhances their usefulness. The present invention also relates to apparatus which are designed to carry writing instruments such as pens and pencils.
2. Description of the Prior Art
In general, writing instruments such as a pen or pencil are carried in the pocket of a garment. When wearing a suit jacket or sports coat, the writing instrument is traditionally carried in an inside pocket. When wearing only a shirt, the writing instrument is carried in a breast pocket of the shirt.
In the construction industry, workers frequently wear polo shirts or T-shirts which do not have any breast pockets. It is frequently necessary for workers to have the use of a writing instrument such as pen or pencil in order to mark measurements on one or more surfaces of a particular item such as a beam, rod, etc. Traditionally, workers carry such pen or pencil behind their ear. While the technique for placing a pen or pencil behind an ear and permitting it to rest between an ear and the user's head or hair has become commonplace, it also creates many problems. The writing instrument is placed in an unstable position. Since the worker is physically active in moving around a construction project, the writing instrument frequently falls off and is lost. While some workers do wear shirts with pockets, placing a writing instrument, especially a lead pencil, in a breast pocket, also creates problems. Since the worker frequently bends over, it is easy for the writing instrument to fall out of the pocket and get lost. In addition, if a worker wears spectacles or sunglasses, the temples of the spectacles or sunglasses take up the place behind the wearer's ear where the writing instrument would be placed. Therefore, there really is no room to place the writing instrument behind the wearer's ear if he or she is also wearing spectacles or sunglasses.
Therefore, a significant need exists for an apparatus which permits a writing instrument to be easily carried by a construction worker such as a carpenter, electrician, plumber, etc. who is physically active and must constantly have a pencil readily available. In addition, there is a need for an apparatus which enables such a construction worker who wears spectacles or sunglasses to easily carry such a writing instrument in a location where it is readily accessible and where it will not accidentally fall off and get lost.
SUMMARY OF THE PRESENT INVENTION
The present invention is an apparatus to be attached to a pair of spectacles or sunglasses and which provides a means for carrying a writing instrument in a manner from which it can be readily removed for use and subsequently replaced on the apparatus for subsequent reuse.
It has been discovered, according to the present invention, that the combination of a partially opened generally cylindrical hollow clip and an attachment means by which the partially opened hollow generally cylindrical clip can be either permanently or removably attached to a pair of spectacles or sunglasses provides an apparatus for removably retaining a writing instrument such as a pen or pencil in a manner from which the writing instrument can be easily removed from the hollow retaining clip for use and subsequently replaced in the hollow retaining clip for subsequent reuse.
It has also been discovered, according to the present invention, that a hollow retaining clip which is generally elongated and generally circular or oval in cross-section, which is open at both ends, and which has a diameter that is slightly larger than the diameter of a conventional lead pencil; when provided with a longitudinal slot which extends along its entire length for a portion of its circumference no wider than just smaller than the diameter of a conventional lead pencil, provides an efficient means for retaining such a lead pencil.
It has further been discovered, according to the present invention, that if the hollow retaining clip is made of flexible material such as thin plastic, the writing instrument such as a pencil can be easily placed through the elongated slot whose width is slightly smaller than the diameter of the pencil and can be retained within the retaining clip whose diameter is slightly larger than the diameter of the lead pencil.
It has also been discovered, according to the present invention, that if the retaining means further comprises an elongated flat bar which is bent to extend from its point of attachment to the hollow retaining clip toward the body of the hollow retaining clip, then the elongated flat bar can be inserted within a sleeve that has been placed on the temples of a pair of glasses to thereby retain the hollow retaining clip thereon. More particularly, if the sleeve or jacket which is slidably placed on the temples of a pair of spectacles or sunglasses is a conventional item known as Croakies, the elongated flat bar can be removably slid between a temple of the spectacles or sunglasses, and a portion of the sleeve or jacket of the Croakies to thereby retain the hollow retaining clip thereon. Preferably, the orientation of the retaining means is such that the longitudinal opening in the surface of the hollow retaining clip upon upwardly when the spectacles or sunglasses are worn.
It has further been discovered, according to the present invention, that if a portion of the exterior surface of the hollow retaining clip comprises one portion of a mating velcro type fastener and a portion of a temple from a pair of spectacles or sunglasses comprises the opposite mating velcro type fastener, then the retaining means can comprise the pair of mating Velcro fasteners.
It is therefore an object of the present invention to provide an apparatus which can be moveable and removably attached to a portion of a pair of spectacles or sunglasses, and preferably the temple portion thereof, and which further provides a means for removably retaining a writing instrument.
It is a further object of the present invention to provide an apparatus which is light weight and flexible so that it will not be cumbersome when attached on a temple of a pair of spectacles or sunglasses.
It is an additional object of the present invention to provide an apparatus which can be attached to a temple of a pair of spectacles or sunglasses and retain a writing instrument therein such that the writing instrument can be carried between an ear and the side of the user's head when the user is wearing the spectacles or sunglasses.
It is also an object of the present invention to provide an apparatus which can be attached adjacent a temple of a pair of spectacles or sunglasses and retain a writing instrument therein such that the writing instrument can be carried between an ear and the side of the user's head when the user is wearing the spectacles or sunglasses.
It is another object of the present invention to provide an apparatus for retaining a writing instrument either on or adjacent a pair of spectacles or sunglasses which apparatus is inexpensive and can be easily replaced if it becomes worn or broken.
Further novel features and other objects of the present invention will become apparent from the following detailed description, discussion and the appended claims, taken in conjunction with the drawings.
DRAWING SUMMARY
Referring particularly to the drawings for the purpose of illustration only and not limitation, there is illustrated:
FIG. 1 is a perspective view of the preferred embodiment of the present invention apparatus for retaining a writing instrument.
FIG. 2 is an end view of the preferred embodiment of the present invention apparatus for retaining a writing instrument.
FIG. 3 is a perspective view of the present invention apparatus for retaining a writing instrument attached adjacent to a pair of spectacles or sunglasses.
FIG. 4 is a side elevational view of an alternative embodiment of the present invention apparatus for retaining a writing instrument attached to a temple of a pair of spectacles or sunglasses.
FIG. 5 is a cross-sectional view taken along line 5-5 of FIG. 4.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Although specific embodiments of the invention will now be described with reference to the drawings, it should be understood that such embodiments are by way of example only and merely illustrative of but a small number of the many specific embodiments which can represent applications of the principles of the invention. Various changes and modifications obvious to one skilled in the art to which the invention pertains are deemed to be within the spirit, scope and contemplation of the invention as further defined in the appended claims.
Referring particularly to FIG. 1, ther is shown at 10 the preferred embodiment of the present invention apparatus for retaining a writing instrument on a pair of spectacles or sunglasses. The retaining apparatus 10 comprises a writing instrument retaining means 20 and an attachment means 40. The retaining means 20 further comprises an elongated hollow member 22 which is open at its front end 24 and its rear end 26 to thereby define an interior chamber 28 which runs for the entire length of the elongated hollow member 22. In the preferred embodiment, the elongated hollow member 22 is generally cylindrical. The wall 30 of the elongated hollow member 22 further comprises a longitudinal slot 32 which runs the entire length of the wall 30. The longitudinal slot opens into the interior chamber 28 and also intersects the front opening 25 at the front end 24 and the rear opening 27 at the rear end 26. Therefore, the slot 32 provides a means by which a cylindrical object which may be longer than the retaining means 22 may be inserted into the retaining means and protrude through the front opening 25 and or rear opening 27. Referring to FIG. 3, it can be seen that a conventional lead pencil 100 can be inserted through slot 32 since the pencil is placed transversely through slot 32 such that its longitudinal axis corresponds to the longitudinal orientation of the retaining means 20. While the pencil 100 is shown with its eraser end protruding through front opening 25 and its point end protruding through rear ending 27, it will be appreciated that the pencil can be reversed and the tip can protrude through front opening 25 while the eraser protrudes through rear opening 27. The retaining apparatus 10 can be configurated such that its interior chamber diameter D is just slightly larger than the diameter of a conventional pencil such that there is a press snug fit. In this way, the pencil 100 will not fall out. It will also be appreciated that the slot width "W" is preferably smaller than the diameter of the conventional pencil by a small amount. In this way, the pencil will have to be squeezed through the slot 32 to further enhance the tight fit. The retaining means 20 is preferably made of flexible material such as plastic so that the writing instrument 100 can be squeezed through the slot and be press fit into the interior chamber 28. The length "L" of retaining means 20 need only be sufficiently long to provide a balanced fit for the writing instrument 100. By way of example, the length "L" may be from one-half inch to two inches. If the retaining means 20 is designed to hold a conventional pencil, the interior diameter "D" is approximately one-quarter of an inch. The slot width "W" can be approximately three-sixteenths of an inch. It will be appreciated that the retaining means 20 can be designed to retain any type of writing instrument. Accordingly, the diameter "D" and width "W" can be adjusted to accommodate the particular type of writing instrument for which the particular retaining apparatus is intended. For example, a Scripto mechanical lead pencil is fatter than a conventional wooden lead pencil and so the interior diameter "D" should be approximately five-sixteenths of an inch while the slot width "W" can be one-quarter of an inch.
The attachment means 40 by which the retaining means 20 is retained on a pair of spectacles or sunglasses by being attached adjacent a temple or to a temple is illustrated in FIGS. 3 through 5. Referring to FIG. 3, a conventional pair of spectacles or sunglasses is shown at 110. Such optical wear comprises a rim 112 retaining a pair of lenses 114 and 116, a pair of oppositely disposed temples 120 and 126 which terminate in pair of bows respectively, 122 and 128. For the intended purpose of the present invention retaining apparatus 10, it is best that the retaining apparatus be in the proximity of a temple.
In the preferred embodiment as illustrated in FIGS. 1 through 3, the attachment means 40 is comprised of a flat elongated bar 42 which is attached to a portion of the wall 30 of retaining means 20 by cross-bar 44. Elongated bar 42 and cross-bar 44 may be of one piece construction. Preferably, elongated bar is pre-sprung so that it tapers toward the wall 30 as its distance from cross-bar 44 increases, however, an elongated bar which does straight back and does not taper is also within the spirit and scope of the present invention. A small gap 46 exists between the free end of elongated bar 42 and wall 30. In this embodiment, it is necessary to have a tight sleeve fit around a portion of a temple of the spectacles or sunglasses so that the elongated bar may be slid between the sleeve and the temple and retained thereon adjacent the temple. One type of tight sleeve arrangement is provided by a conventional spectacle retaining apparatus commonly known as a Croakie. The Croakie 140 is shown in FIG. 3 and comprises a pair of sleeves 142 and 144 which slidably fit onto temples 120 and 126 respectively and a joining strap 150 which joins the two sleeves. When worn by a user, the strap goes around the back of the user's head. Each sleeve 142 and 144 is made of stretch fabric and can be slid onto each respectively temple so there is a tight press fit between the sleeve and the temple. Anything slid between the sleeve and the temple is retained thereon by the tight press fit. As illustrated in FIG. 3, sleeve 144 from Croakie 140 is slid onto temple 126 and elongated bar 40 is slid between the temple 126 and sleeve portion 144 of Croakie 140. The retaining means 20 extends above the temple 126. It will be appreciated that the present invention writing instrument retaining apparatus 10 can also be designed such that the retaining means 20 is adjacent the outside of temple 126 instead of being above temple 126. It will be appreciated that the retaining apparatus 10 retaining means need not be an entire Croakie 140 but instead can merely be a tight fitting sleeve which fits around a portion of the temple 126. When worn in this manner, the temple 126 with the sleeve thereon rests on an ear and the retaining means 20 sits above the ear between the user's head and/or hair and the ear.
An alternative attachment means is illustrated in FIGS. 4 and 5. In this attaching means 60, one half of a mating Velcro member 70 is attached to a portion of wall 30 and the opposite half of mating Velcro member 72 is attached to a portion of a temple. In the illustration shown in FIG. 5, a sleeve 80 is slid around temple 126 and mating Velcro member 72 is attached to sleeve 80. It is also within the spirit and scope of the present invention for the mating Velcro member 72 to be attached directly to the temple 126. In the illustration shown in FIG. 4, the mating Velcro members 70 and 72 are coupled side by side so that the writing instrument retaining means 62 is off to the side of the temple 126. It will be appreciated that the mating Velcro members 70 and 72 can be located so that their attachment is top to bottom, in the orientation illustrated in FIG. 3.
While it is possible for the slot 32 in the preferred embodiment and slot 64 in the alternative embodiment to be oriented at any location, it is preferred that the orientation be such that the slot is at the top most position of the retaining means when the writing instrument retaining apparatus is worn on the spectacles or sunglasses.
Defined in broad terms, the present invention is an apparatus for retaining a writing instrument on a temple of a pair of spectacles or sunglasses, comprising:
a. a writing instrument retaining means;
b. said writing instrument retaining means further comprising:
(i) an elongated hollow member having a side wall which is open at its front end and its rear end to thereby define an interior chamber which runs for the entire length of the retaining means and is open at both ends,
(ii) the side wall having a longitudinal slot which runs the entire length of the elongated hollow member and which opens into the interior chamber and intersects the front opening and the rear opening of the elongated hollow member; and
c. an attachment means connected to said elongated hollow member by which said writing instrument retaining means is retained on a temple of a pair of spectacles or sunglasses.
The attachment means may comprise a flat elongated bar which is attached to a portion of the wall of said elongated hollow member by a cross-bar such that the flat elongated bar extends for at least a portion of the distance adjacent the wall, whereby the temple of said pair of spectacles or sunglasses is fitted with a tight flexible sleeve and the flat elongated bar is inserted between the temple and the tight flexible sleeve. In the preferred embodiment, the elongated bar is pre-sprung so that it tapers toward the wall as its distance from the cross-bar increases.
In an alternative embodiment, the attachment means may comprise a mating Velcro member attached to a portion of the wall of said elongated hollow member for mating engagement with a Velcro member attached to portion of a temple of said pair of spectacles or sunglasses.
In the preferred embodiment, said elongated hollow member is generally cylindrical. Other possible cross-sections for the elongated hollow member beside circular include oval.
For its most common use with a lead pencil, the interior hollow chamber of said elongated hollow member is slightly larger than the diameter of a standard lead pencil. For this embodiment, the width of said slot is slightly smaller than the diameter of a standard lead pencil.
In the preferred embodiment, said elongated hollow member is made of flexible plastic.
Of course the present invention is not intended to be restricted to any particular form or arrangement, or any specific embodiment disclosed herein, or any specific use, since the same may be modified in various particulars or relations without departing from the spirit or scope of the claimed invention hereinabove shown and described of which the apparatus shown is intended only for illustration and for disclosure of an operative embodiment and not to show all of the various forms or modification in which the invention might be embodied or operated.
The invention has been described in considerable detail in order to comply with the patent laws by providing full public disclosure of at least one of its forms. However, such detailed description is not intended in any way to limit the broad features or principles of the invention, or the scope of patent monopoly to be granted.
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An apparatus to be attached to a pair of spectacles or sunglasses and which provides a means for carrying a writing instrument in a manner from which it can be readily removed for use and subsequently replaced on the apparatus for subsequent reuse. The apparatus includes the combination of a partially opened hollow clip and an attachment means by which the partially opened hollow clip can be either permanently or removably attached to a pair of spectacles or sunglasses.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation of application Ser. No. 398,255, filed Aug. 24, 1989, now U.S. Pat. No. 5,112,558, which in turn is a continuation-in-part of application Ser. No. 150,157, filed Jan. 29, 1988, now U.S. Pat. No. 4,867,938.
BACKGROUND OF THE INVENTION
The present invention relates to injection molding machines and relates in particular to such machines having the capability of operating a plurality of molds arranged in series.
The prior art shows injection molding machines having the capability of operating a plurality of molds arranged in series. For example, U.S. Pat. No. 3,707,342, issued to A. Lohman on Dec. 26, 1972 shows two molds spaced apart in tandem with a dual nozzle injection unit positioned therebetween to fill the two molds alternately. No provision is made for separate means to stuff the molds.
An additional prior art patent pertinent to the present invention is U.S. Pat. No. 3,898,030, issued Aug. 5, 1975 to T. G. Bishop entitled Injection-Mold Clamping Unit Having Alternately Ejecting Die Assemblies.
In this disclosure latches 80A and 80B are used to couple separable mold halves 56A and 58A whereby single clamping and ejection units are used for both molds.
A further prior art patent is U.S. Pat. No. Re 28,721 reissued to J. J. Farrell on Feb. 24, 1976 entitled Time Saver Plastic Draw-Back Valve Assembly. This patent discloses a primary reciprocating-screw injection unit 12 and an auxiliary injection piston 50 with a valve 52 for diverting molten plastic flow from the primary unit to the secondary unit thereby isolating the primary unit and permitting the secondary unit to "stuff" mold 32.
Other pertinent machine patents include PCT Publication No. WO 86/01146, dated Feb. 26, 1986 and West German Patent No. 3428780, dated Mar. 13, 1986.
In addition, the prior art shows stack and sandwich mold arrangements wherein the mold cavity plates are disposed back to back separated by an integral hot runner. Representative of stack mold arrangements are U.S. Pat. Nos. 3,723,040, 3,973,892 and 4,400,341. Stack or sandwich mold arrangements are well known in the art; however, their draw backs include a less than optimum operating cycle and lack of versatility in components. Moreover, there is a disadvantage to combining a hot runner and the cavity plates, for example: this necessitates replacement of a complete multiple mold assembly rather than to replace one cavity plate at a time.
SUMMARY OF THE INVENTION
In contrast to the above prior art disclosures, the present invention relates to an injection molding machine having a plurality of molding stations with a plurality of machine accessories arranged in various combinations developing a sequence of operations calculated to reduce molding cycle time per part particularly when molding large parts such as large containers or auto body parts.
It is a primary feature of the present invention to provide an injection molding machine which enables the mold assemblies to be operable independently of each other and to be readily separable from the machine.
A further feature of the invention is the provision of a plurality of mold stations arranged in series and separated by a discrete, central, movable machine platen.
A further feature of the invention is the incorporation in the central platen of a distributor communicating with whatever mold halves may be attached to said central platen.
It is a further feature of the invention to provide a primary clamping system operable to clamp all mold stations simultaneously.
It is a further feature of the invention to provide an independent secondary clamping system operable to clamp platens of a given mold station directly and selectively or, in the alternative, operable to clamp mold halves of said given station directly and selectively.
It is a further feature of the invention to mount secondary clamps directly upon the mold platens.
It is a still further feature of the invention to feed molten plastic into a plurality of individual mold cavities at different, serially arranged mold stations utilizing a single primary injection means and one or more secondary injection means to fill and pack (stuff) each said mold cavity in sequence thereby increasing overall productivity of individual molds.
It is a further feature of the present invention to use the primary injection means dually as a mold cavity "filler" and a mold cavity "stuffer".
It is a further feature of the present invention to provide a novel sequencing system for utilizing primary and secondary injection means to inject molten plastic into a plurality of mold stations clamped by a single, primary clamping means, where the primary injection means performs both, a mold filling and a stuffing function at one station.
For purposes of claiming this invention the language "single primary clamp" is intended to denote a molding cycle in which the primary clamping means is applied only once during the molding of at least one part at each of at least two individual molding stations.
This language is intended to distinguish from the prior art situation in which at least one part is molded at each of two individual molding stations and the primary clamping means is applied and released at each station independently. A further feature of the invention is that the primary clamp means may be used solely as a means for moving platens and the secondary clamp means may be the sole mold clamping means.
A further feature of this novel molding sequence is that a part molded at a station A, for example, which is serviced by a primary and a secondary injection means may be of entirely different size and structural complexity than another part molded at a Station B. In accordance with this feature, filling and stuffing of the mold therein may be accomplished sequentially by a single injection means.
A still further feature of the invention is that two parts requiring generally equal cooling periods may be molded with the use of a single primary clamp means. The single primary clamp may act upon two stations in the same time that it would take for a single part to be molded as if the parts were molded successively at two mold stations utilizing primary and secondary clamp means.
A further feature of the invention is the provision of an injection molding machine in which one or more primary injection means are mounted on a fixed or movable platen with track means facilitating motion of the units, to and fro, along the longitudinal axis (x axis) of the machine.
A still further feature of this invention is the incorporation, into an injection molding machine, of a parts removal device or robot which is operable to remove parts molded in reverse or in identical orientation.
A further feature of the invention is the provision of a secondary injection means mounted on a movable platen whose design lends itself to a wide variety of mounting locations on said movable platen.
A further feature of the invention is the provision of an injection molding machine on a single frame means comprising at least two injection means and at least four mold stations arranged in series.
An injection molding machine embracing features of the present invention includes, in one combination or another, a main frame, fixed and movable platens to support mold halves and primary and secondary clamp means. The secondary clamp means are usually attached to the mold platens; however, if necessary they may also be mounted directly on mold halves that are attached to the platens.
A distributing manifold is incorporated in a central movable platen including valve means for directing molten plastic to opposed mold stations. The manifold includes a connection to a primary injection means and to a secondary injection means with appropriate valve means for controlling flow from the primary injection means.
In an alternative embodiment of the machine, the primary injection means is programmed to melt sufficient plastic to fill two molds. A first mold is then filled by the primary injection means and stuffed by a secondary injection means. Next, molten plastic flow is directed to a second mold station where the filling of the mold as well as the stuffing step is performed solely by the primary injection means. In this embodiment the clamping function may be solely by the primary clamp means or by the primary clamp means in combination with secondary clamps, depending upon size, configuration and relative cooling rates of the respective molded parts.
Further, the machine includes ejection means and a parts remover (robot) which operates on rectilinear coordinates to move from molding station to molding station along a first axis and into and out of an open mold along a second axis.
Product may be molded in the same or in reverse orientation with appropriate modification of the parts remover and the flow path of the molten plastic.
In reverse orientation the remover head carries dual "pick up" elements, while product molded in same orientation is grasped by a remover head with a single pick up.
In certain situations, the size and complexity of the molded parts require the use of a plurality of primary injection means adapted to cooperate with a plurality of secondary injection means to insure complete filling and stuffing the corresponding mold cavity in a given mold station.
A further embodiment of the machine takes the form of a double capacity unit. In this arrangement there are four molding stations, two primary injection means and two central platens, each incorporating a distributor.
Other features and advantages of the present invention will become more apparent from an examination of the succeeding specification when read in conjunction with the appended drawings, in which;
DETAILED DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a side view of a typical lay out of the sequential molding machine of the present invention with the distributor block broken away for clarity;
FIG. 2 is a view similar to FIG. 1 showing the opposite molding station open with the molded part poised for removal;
FIG. 3 is an additional side view showing both mold stations in the closed condition with primary and secondary clamp means in operation;
FIG. 4 is a side of the machine with the molded parts remover or robot in an open mold retrieving a part;
FIG. 5 is a top plan view of the illustration of FIG. 4;
FIG. 6 is similar to FIG. 5 showing the robot in the opposite molding station;
FIG. 7 is a plot of the machine sequence of operation charting the position of the various machine accessories against the step by step generation of the molded parts;
FIGS. 8, 9 and 10 show an alternative arrangement of primary and secondary injection meals serving two molding stations;
FIG. 11 is a plan view of an injection molding machine with an alternative secondary or parting line clamp structure;
FIG. 12 is a schematic illustration of details of the structure and mounting means of the alternative secondary clamp of FIG. 11;
FIG. 13 is a plan view of a machine modification in which a plurality of primary injection means are utilized in combination with a plurality of distributor blocks and corresponding secondary injection means;
FIG. 14 is a side view of an additional machine modification showing double sets of primary and secondary injection means and robots servicing four mold stations;
FIG. 15 is a chart detailing the operating sequence of the machine of FIG. 14;
FIG. 16 is a side view of an alternative machine arrangement facilitating molding piece parts in the same physical orientation using a single primary injection means;
FIG. 17 is similar to FIG. 16 modified to use two primary injection units, and;
FIG. 18 is a cycle chart for the FIG. 17 modification.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 1, 2 and 3, a basic embodiment of the injection molding machine of the present invention is disclosed comprising molding stations A and B having essential accessories defining a primary clamp section 11, a secondary clamp section 12, a primary molten plastic injection section 13 and a secondary injection section 14. Either the primary and/or secondary injection unit may be of the reciprocating screw type or piston type.
Molds 16 and 17, frequently of different configurations, comprise mold halves 18 and 19 and 21 and 22, respectively.
Mold halves 19 and 21 are mounted on central movable platen 26 and halves 18 and 22 are mounted on movable platen 24 and fixed platen 27, respectively.
Platens 23 and 27, fixed to the machine frame 31, support tie bars 28 and 29 in the usual and customary fashion.
Platen 24 is connected to primary clamping piston 32 and is reciprocated thereby sliding on tie bars 28 and 29.
Central platen 26 is also movable on tie bars 28 and 29 and is releasably connected to movable platen 24 and fixed platen 27 by secondary clamping means 12 in a manner which will be explained in greater detail as this specification proceeds.
Machine section 14 includes a distribution block 33 incorporated in platen 26, with heating elements 34, molten plastic supply channel 36 and selector valve 37 for diverting compound flow from station A to station B and vice versa.
The distributor block 33 terminates in a cylinder 38 having a piston 39 and a reservoir 41.
A second channel 42, adapted to make a connection with a reciprocating primary injection section 13, as is most apparent in FIG. 2, includes a shut off valve 43 for cutting off molten plastic flow from the primary injection means.
With the piston 39 in the retracted position, as shown in FIG. 1, the molten plastic advanced by the injection section 13 operates to fill the mold cavity to which selector valve 37 is set (station B in FIG. 1) and simultaneously fills reservoir or accumulator 41. Upon closure of shut off valve 43, isolating the injection section 13, actuation of the piston 39 is operable to "stuff" the mold cavity to which molten plastic was initially directed.
Obviously the reservoir can be reestablished and recharged upon retraction of the piston 39 in preparation to charge the opposite mold cavity.
Typically, the injection section 13 includes a plasticizing-injection unit referred to in the art as a reciprocating-screw extruder.
FIGS. 4, 5 and 6 are similar to FIGS. 1, 2 and 3 and show details of one embodiment of the secondary clamp means and the structure and operation of the molded parts removal unit or robot.
Referring to FIG. 4, the parts removal unit operates automatically in timed sequence, in robot fashion, and includes a first leg 44 which reciprocates under control of power unit 46 along the longitudinal axis (x axis) of the machine guided by a track (not shown). The power unit 46 is supported by fixed platen 27.
When the part removal head 48 is in register with an open mold, such as the open mold at station A in FIG. 4, a second leg 49 is actuated by suitable power means to advance the head along a second axis (z axis) into register with finished part P. The part is then ejected from core 51 by ejector pins 52, in well known fashion, and picked up by the head.
The head 48 is provided with a source of vacuum and a valve operable to direct vacuum to the part side of the head whereupon the part P is grasped and drawn away from the core by the head. The head is retracted automatically and the part P released to an appropriate container (not shown) for packaging or further processing, as the case may be.
FIGS. 5 and 6 are top plan views of the illustration of FIG. 4 and show details and operation of one embodiment of the secondary clamp section indicated generally by the reference numeral 12.
Pairs of opposed arms 53 and 54, fixed to central platen 26, are formed with notches 56 and 57 and cam faces 58 and 59. The notches are engaged by dogs or lugs 61 and 62 having mating cam faces 63 and 64. The lugs 61 and 62, operable to reciprocate in timed sequence under the control of piston-cylinder assemblies 66 and 67, are mounted on the movable platen 24 and fixed platen 27, respectively.
As mold halves of a given mold station approach their closed position, the lugs move into mating notches and the mating cam faces engage one another to drive the mold halves into tight face to face contact holding the mold halves sealed during cavity stuffing and subsequent cooling period independently of the primary clamp means in a manner and according to an operating sequence set forth in the cycle chart of FIG. 7.
FIG. 6 shows the part removal head 48 in place in the open mold at station B poised to retract from the mold to transfer part P out of the machine.
In this position the vacuum of the head 48 has been diverted from the right side of the head to the left side of the head as viewed in FIG. 6 to accomplish the part pick up at station B.
Referring in detail to FIG. 7, a plot showing a typical molding cycle of the machine of FIGS. 1 through 6 is laid out coordinately where the y axis is a schedule of sequential positions of the various machine components or accessories for stations A and B, and the x axis is a schedule of the progress of the part through the molding steps.
The chart is read in the following fashion: starting at the upper left hand corner at the point indicated by the letter S, one "picks up" the molding cycle by noting the small circles extending along the y axis which indicate that primary clamp 11 is open, injection section 13 is back (to the right in FIG. 4), the injection section 13 is plasticizing, shut off valve 43 is closed, secondary injection section 14 (stuffer piston 38) is retracted, selector valve 37 is open to station A, secondary clamp section 12 is clamping station A, secondary clamp 12 at station B is free (open), ejector pins 52 are retracted at station A, ejector pins 52 are forward (ejecting) at station B, robot or pick up head 48 has moved along machine x axis to station B and along the z axis into the mold at station B.
Referring to the point x at the lower left corner of the chart of FIG. 7, it is apparent when the various machine elements are in the positions just indicated by "reading" the chart a molded part is cooling in its mold at station A and the robot or pick up head 48 is positioned in the open mold at station B.
The chart is read in the manner described incrementally from left to right, the machine having produced two parts P upon arriving at end E of a complete cycle.
Referring now to FIGS. 8, 9 and 10, an alternative embodiment of the primary and secondary injection means is disclosed schematically. In this arrangement molding stations A and B are serviced by an injection unit 68 and secondary injection unit 69. A selector valve 71, (shown as a two way valve but which may be a three way valve) disposed in distributor block 72 within platen 70, is operable to divert the flow of molten plastic from injection unit 68 to the mold at station B as indicated schematically in FIG. 9 or to the mold at station A as indicated schematically in FIG. 10. Thus, operation of the injection unit in the FIG. 9 arrangement delivers molten plastic simultaneously to the mold of station B and to the secondary injection unit 69. At the appropriate interval selector valve 71 directs the molten plastic to mold station A while injection continues into station B from the secondary injection unit. The significance of this arrangement is that (1) the primary injection unit is programmed to prepare sufficient plastic to satisfy the molds of both mold stations A and B; (2) the secondary injection unit 69 completes injection into the mold at station B after selector valve 71 shifts the flow of plastic to station A; (3) molten plastic is delivered directly to station A from the primary injection unit to complete the injection, whereby either the primary and/or secondary unit may serve as a stuffer. For example, as a variation of this embodiment one may also stuff station A with secondary injection unit 69 with appropriate valving.
Either the primary or secondary injection units may be of the reciprocating screw type or the piston type.
Injection pressure of molten plastic into a mold cavity to fill a mold cavity is frequently of a level ranging from 15,000 to 21,000 psi and injection pressure to "hold or stuff" the cavity to compensate for shrinkage is frequently of the order of 6,000 psi.
These pressure levels can be developed by primary and/or secondary injection means.
When piece parts molded at stations A and B have substantially uniform or equal cooling periods, secondary clamping means (parting line clamps) can be eliminated and the molds of station A and B are held clamped by the primary clamping unit and both molds are opened simultaneously.
In situations where the cooling periods are unequal it is necessary to use parting line clamps in addition to primary clamp.
Referring now to FIGS. 11 and 12, an alternative design for a secondary clamping unit is disclosed wherein parting line clamp elements 73 and 74 are shown mounted on mold halves 75 as at 76 shown in FIGS. 11 and 12. The units at station A and station B are of identical structure. Therefore, only one modified secondary clamping unit will be described.
The clamp elements 73 and 74 are operated by a piston-cylinder arrangement 77 on opposite sides of a mold station such as is shown at stations A and B in FIG. 11. Mating mold halves are formed with cut outs or recesses 81 and 82 fitted with hardened inserts 83 and 84 secured to mold halves by bolts 87 and 88. Each insert is formed with a taper mating with a corresponding taper on the complementary clamps 73-74. Actuation of the cylinder unit 77 moves the clamps on opposite sides of the molds along a piston rod 86 (fixed to a mold half as at 76) from a retracted position of FIG. 12 to an operating position shown in FIG. 11 driving the mold halves into face to face contact under very high compressive stress.
Note that the parting line clamp structure of FIGS. 11 and 12 is mounted directly on the mold halves and operates directly on the mold halves, in contrast to the secondary clamp structure described previously which is mounted on the mold platens and operates directly on the mold platens.
Obviously, any of a number of arrangements may be devised in mounting the secondary clamping arrangement on the mold halves as engineering and other design considerations dictate.
Referring to FIG. 13, a further alternative embodiment of the injection molding machine is disclosed wherein the open mold configuration at station B represents a large, complex part. In order to insure adequate filling and stuffing, a machine modification is arranged wherein a plurality of primary injection units 91, 92 and 93 are mounted on the top of fixed platen 94. Suitable tracks 96 are provided for advancing the injection units to and fro to make appropriate connection with mating secondary injection units or stuffers 97, 98 and 99 incorporated in a central movable platen 101. Thus, in operation the primary injection units and cooperating stuffer units are operable individually or collectively in various combinations and permutations as design complexity of the molded parts dictate.
Obviously, the position and number of the primary injection and cooperating stuffer units is a matter of choice consistent with part retrieval, overall length of machine, floor space and so forth.
FIG. 14 illustrates a double capacity machine in which there are four molding stations A, B, C and D, two opposed primary injection extruders 102 and 103 with two central mold platens 104 and 106 each incorporating a secondary extrusion units or stuffers 107 and 108, in the fashion and for the purpose previously described, for servicing mold stations D and C on the left and mold stations B and A on the right, respectively. The reference numerals 109 and 111 designate mold part removal units or robots. Naturally, each mold station could have a plurality of molds as required.
Hereagain, the location of primary injecting units is a matter of design choice based on machine size limitations and available operating space.
The machine configuration of FIG. 14 shows the molds open at stations A and D while the molds at stations B and C are closed.
This configuration is developed in the following fashion:
Assume that the primary clamping means actuated by piston 32 has moved all movable platens 24, 104, 25 and 106 to the right against stationary platen 27 closing all molds at stations A, B, C and D with all secondary clamps 12--12 latched.
Upon an appropriate signal from the clamp control (FIG. 5), the secondary clamp 12 at station A is released while the secondary clamps 12 at stations B, C and D remain latched.
The piston 32 is ordered to move to the left. This occurrence opens the mold at station A and dog 117 secured to movable platen 25 moves from the dashed line position to the solid line position to abut stop 118.
Contact between the dog 117 and stop 118 stops movable platen 106 in the position shown in FIG. 14 and blocks further separation of mold halves at station A.
Upon the occurrence of the above noted abutment and in timed sequence, the secondary clamp at station D is unlatched so that upon continued motion of the piston 32 to the left the mold at station D opens to complete development of the mold layout shown in FIG. 14, i.e. molds at stations A and D are open and molds at stations B and C remain closed and clamped.
Again starting from a closed mold position at stations A, B, C and D, the molds at stations B and C are opened in similar fashion in response to the appropriate signals from the clamp control unit.
FIG. 15 is an operating schedule showing the sequential positions of the various machine accessories as the double capacity unit of FIG. 14 operates to produce four molded parts per cycle.
FIG. 16 shows a machine arrangement in which a single primary injection unit is utilized to mold parts at stations A and B where each part is molded in the same physical and spatial orientation. Significantly, in this arrangement, the robot head requires only a single pick up unit in that each mold part is grasped while disposed in the same orientation.
In this machine configuration a segment Of the molten plastic flow channel leading to station B is carried by and reciprocates with the central platen 104 and is separable from the flow channel serving station A as shown by the reference numeral 100. The flow channels operate to supply the mold at station B when valves 112 and 113 are open and valve 114 is closed. After injection and suitable holding at station B valves 112 and 113 are closed, valve 114 is opened and molten plastic is injected into the mold at station A at the appropriate time in the molding cycle. In order to facilitate this arrangement, a conical cut out 116 is formed in the stationary platen 117.
Depending, for example, upon the similarity of molded parts and cooling time required, use of a secondary injection unit or stuffer is optional. Correspondingly, use of secondary clamp units is also an optional accessory. The necessity for secondary clamping units depends primarily on the relative cooling rates of the parts molded at each station.
FIG. 17 shows a modification of the arrangement of FIG. 16 in which two primary injection units are utilized, one servicing molding station A and the another servicing station B. In this arrangement, stuffer units are unnecessary in that the primary injection units act dually to perform the mold filling and mold stuffing function.
FIG. 18 is a chart of the molding cycle of FIG. 17 indicating the various positions of machine accessories during the course of molding, cooling and ejecting piece parts from stations A and B sequentially.
When using more than one injection means, different resins may be injected into different mold cavities or different resins may be coinjected in the same mold cavity to gain a layered wall structure.
It is to be understood that the invention is not limited to the illustrations described and shown herein, which are deemed to be merely illustrative of the best modes of carrying out the invention, and which are susceptible of modification of form, size, arrangement of parts and details of operation. The invention rather is intended to encompass all such modifications which are within its spirit and scope as defined by the claims.
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An injection molding machine and method of operation having a plurality of accessory arrangements for molding a plurality of piece parts in efficient overlapping time cycle using primary and secondary molten plastic injection units, primary and secondary clamping units, a plurality of injection units in various arrays including molding piece parts in reverse or uniform orientation.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a continuation of copending U.S. application Ser. No. 11/020,193, filed Dec. 27, 2004, itself a continuation of U.S. application Ser. No. 10/773,247, filed on Feb. 9, 2004, which is itself a continuation of U.S. application Ser. No. 09/357,379, filed on Jul. 20, 1999, now U.S. Pat. No. 6,690,677, all of which are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to the field of wired communication systems, and, more specifically, to the networking of devices using telephone lines.
BACKGROUND OF THE INVENTION
[0003] FIG. 1 shows the wiring configuration for a prior-art telephone system 10 for a residence or other building, wired with a telephone line 5 . Residence telephone line 5 consists of single wire pair which connects to a junction-box 16 , which in turn connects to a Public Switched Telephone Network (PSTN) 18 via a cable 17 , terminating in a public switch 19 , apparatus which establishes and enables telephony from one telephone to another. The term “analog telephony” herein denotes traditional analog low-frequency audio voice signals typically under 3 KHz, sometimes referred to as “POTS” (“plain old telephone service”), whereas the term “telephony” in general denotes any kind of telephone service, including digital service such as Integrated Services Digital Network (ISDN). The term “high-frequency” herein denotes any frequency substantially above such analog telephony audio frequencies, such as that used for data. ISDN typically uses frequencies not exceeding 100 KHz (typically the energy is concentrated around 40 KHz). The term “telephone device” herein denotes, without limitation, any apparatus for telephony (including both analog telephony and ISDN), as well as any device using telephony signals, such as fax, voice-modem, and so forth.
[0004] Junction box 16 is used to separate the in-home circuitry from the PSTN and is used as a test facility for troubleshooting as well as for wiring new telephone outlets in the home. A plurality of telephones 13 a , 13 b , and 13 c connects to telephone line 5 via a plurality of outlets 11 a , 11 b , 11 c , and 11 d . Each outlet has a connector (often referred to as a “jack”), denoted in FIG. 1 as 12 a , 12 b , 12 c , and 12 d , respectively. Each outlet may be connected to a telephone via a connector (often referred to as a “plug”), denoted in FIG. 1 (for the three telephone illustrated) as 14 a , 14 b , and 14 c , respectively. It is also important to note that lines 5 a , 5 b , 5 c , 5 d , and 5 e are electrically the same paired conductors.
[0005] There is a requirement for using the existing telephone infrastructure for both telephone and data networking. This would simplify the task of establishing a new local area network in a home or other building, because there would be no additional wires and outlets to install. U.S. Pat. No. 4,766,402 to Crane (hereinafter referred to as “Crane”) teaches a way to form a LAN over two wire telephone lines, but without the telephone service.
[0006] The concept of frequency domain/division multiplexing (FDM) is well-known in the art, and provides a means of splitting the bandwidth carried by a wire into a low-frequency band capable of carrying an analog telephony signal and a high-frequency band capable of carrying data communication or other signals. Such a mechanism is described for example in U.S. Pat. No. 4,785,448 to Reichert et al (hereinafter referred to as “Reichert”). Also is widely used are xDSL systems, primarily Asymmetric Digital Subscriber Loop (ADSL) systems.
[0007] Relevant prior art in this field is also disclosed in U.S. Pat. No. 5,896,443 to Dichter (hereinafter referred to as “Dichter”). Dichter is the first to suggest a method and apparatus for applying such a technique for residence telephone wiring, enabling simultaneously carrying telephone and data communication signals. The Dichter network is illustrated in FIG. 2 , which shows a network 20 serving both telephones and a local area network. Data Terminal Equipment (DTE) units 24 a , 24 b and 24 c are connected to the local area network via Data Communication Equipment (DCE) units 23 a , 23 b and 23 c , respectively. Examples of Data Communication Equipment include modems, line drivers, line receivers, and transceivers. DCE units 23 a , 23 b and 23 c are respectively connected to high pass filters (HPF) 22 a , 22 b and 22 c . The HPF's allow the DCE units access to the high-frequency band carried by telephone line 5 . In a first embodiment (not shown in FIG. 2 ), telephones 13 a , 13 b and 13 c are directly connected to telephone line 5 via connectors 14 a , 14 b and 14 c , respectively. However, in order to avoid interference to the data network caused by the telephones, a second embodiment is suggested (shown in FIG. 2 ), wherein low pass filters (LPF's) 21 a , 21 b and 21 c are added to isolate telephones 13 a , 13 b and 13 c from telephone line 5 . Furthermore, a low pass filter must also be connected to Junction-Box 16 , in order to filter noises induced from or to the PSTN wiring 17 . As is the case in FIG. 1 , it is important to note that lines 5 a , 5 b , 5 c , 5 d and 5 e are electrically the same paired conductors.
[0008] The Dichter network suffers from degraded data communication performance, because of the following drawbacks:
[0009] 1. Induced noise in the band used by the data communication network is distributed throughout the network. The telephone line within a building serves as a long antenna, receiving electromagnetic noise produced from outside the building or by local equipment such as air-conditioning systems, appliances, and so forth. Electrical noise in the frequency band used by the data communication network can be induced in the extremities of the telephone line 5 (line 5 e or 5 a in FIG. 2 ) and propagated via the telephone line 5 throughout the whole system. This is liable to cause errors in the data transportation.
[0010] 2. The wiring media consists of a single long wire (telephone line 5 ). In order to ensure a proper impedance match to this transmission-line, it is necessary to install terminators at each end of the telephone line 5 . One of the advantages of using the telephone infrastructure for a data network, however, is to avoid replacing the internal wiring. Thus, either such terminators must be installed at additional cost, or suffer the performance problems associated with an impedance mismatch.
[0011] 3. In the case where LPF 21 is not fitted to the telephones 13 , each connected telephone appears as a non-terminated stub, and this is liable to cause undesirable signal reflections.
[0012] 4. In one embodiment, an LPF 21 is to be attached to each telephone 13 . In such a configuration, an additional modification to the telephone itself is required. This further makes the implementation of such system complex and costly, and defeats the purpose of using an existing telephone line and telephone sets ‘as is’ for a data network.
[0013] 5. The data communication network used in the Dichter network supports only the ‘bus’ type of data communication network, wherein all devices share the same physical media. Such topology suffers from a number of drawbacks, as described in U.S. Pat. No. 5,841,360 to the present inventor, which is incorporated by reference for all purposes as if fully set forth herein. Dichter also discloses drawbacks of the bus topology, including the need for bus mastering and logic to contend with the data packet collision problem. Topologies that are preferable to the bus topology include the Token-Ring (IEEE 803), the PSIC network according to U.S. Pat. No. 5,841,360, and other point-to-point networks known in the art (such as a serial point-to-point ‘daisy chain’ network). Such networks are in most cases superior to ‘bus’ topology systems.
[0014] The above drawbacks affect the data communication performance of the Dichter network, and therefore limit the total distance and the maximum data rate such a network can support. In addition, the Dichter network typically requires a complex and therefore costly transceiver to support the data communication system. While the Reichert network relies on a star topology and does not suffer from these drawbacks of the bus topology, the star topology also has disadvantages. First, the star topology requires a complex and costly hub module, whose capacity limits the capacity of the network. Furthermore, the star configuration requires that there exist wiring from every device on the network to a central location, where the hub module is situated. This may be impractical and/or expensive to achieve, especially in the case where the wiring of an existing telephone system is to be utilized. The Reichert network is intended for use only in offices where a central telephone connection point already exists. Moreover, the Reichert network requires a separate telephone line for each separate telephone device, and this, too, may be impractical and/or expensive to achieve.
[0015] There is thus a widely-recognized need for, and it would be highly advantageous to have, a means for implementing a data communication network using existing telephone lines of arbitrary topology, which continues to support analog telephony while also allowing for improved communication characteristics by supporting a point-to-point topology network.
SUMMARY OF THE INVENTION
[0016] The present invention provides a method and apparatus for using the telephone line wiring system within residence or other building for both analog telephony service and a local area data network featuring a serial “daisy chained” or other arbitrary topology. First, the regular outlets are modified or substituted to allow splitting of the telephone line having two wires into segments such that each segment connecting two outlets is fully separated from all other segments. Each segment has two ends, to which various devices, other segments, and so forth, may be connected. A low pass filter is connected in series to each end of the segment, thereby forming a low-frequency path between the external ports of the low pass filters, utilizing the low-frequency band. Similarly, a high pass filter is connected in series to each end of the segment, thereby forming a high-frequency path between the external ports of the high pass filters, utilizing the high-frequency band. The bandwidth carried by the segments is thereby split into non-overlapping frequency bands, and the distinct paths can be interconnected via the high pass filters and low pass filters as coupling and isolating devices to form different paths. Depending on how the devices and paths are selectively connected, these paths may be simultaneously different for different frequencies. A low-frequency band is allocated to regular telephone service (analog telephony), while a high-frequency band is allocated to the data communication network. In the low-frequency (analog telephony) band, the wiring composed of the coupled low-frequency paths appears as a normal telephone line, in such a way that the low-frequency (analog telephony) band is coupled among all the segments and is accessible to telephone devices at any outlet, whereas the segments may remain individually isolated in the high-frequency (data) band, so that in this data band the communication media, if desired, can appear to be point-to-point (such as a serialized “daisy chain”) from one outlet to the next. The term “low pass filter” herein denotes any device that passes signals in the low-frequency (analog telephony) band but blocks signals in the high-frequency (data) band. Conversely, the term “high pass filter” herein denotes any device that passes signals in the high-frequency (data) band but blocks signals in the low-frequency (analog telephony) band. The term “data device” herein denotes any apparatus that handles digital data, including without limitation modems, transceivers, Data Communication Equipment, and Data Terminal Equipment.
[0017] A network according to the present invention allows the telephone devices to be connected as in a normal telephone installation (i.e., in parallel over the telephone lines), but can be configured to virtually any desired topology for data transport and distribution, as determined by the available existing telephone line wiring and without being constrained to any predetermined data network topology. Moreover, such a network offers the potential for the improved data transport and distribution performance of a point-to-point network topology, while still allowing a bus-type data network topology in all or part of the network if desired. This is in contrast to the prior art, which constrains the network topology to a predetermined type.
[0018] A network according to the present invention may be used advantageously when connected to external systems and networks, such as xDSL, ADSL, as well as the Internet.
[0019] In a first embodiment, the high pass filters are connected in such a way to create a virtual ‘bus’ topology for the high-frequency band, allowing for a local area network based on DCE units or transceivers connected to the segments via the high pass filters. In a second embodiment, each segment end is connected to a dedicated modem, hence offering a serial point-to-point daisy chain network. In all embodiments of the present invention, DTE units or other devices connected to the DCE units can communicate over the telephone line without interfering with, or being affected by, simultaneous analog telephony service. Unlike prior-art networks, the topology of a network according to the present invention is not constrained to a particular network topology determined in advance, but can be adapted to the configuration of an existing telephone line installation. Moreover, embodiments of the present invention that feature point-to-point data network topologies exhibit the superior performance characteristics that such topologies offer over the bus network topologies of the prior art, such as the Dichter network and the Crane network.
[0020] Therefore, according to the present invention there is provided a network for telephony and data communication including: (a) at least one electrically-conductive segment containing at least two distinct electrical conductors operative to conducting a low-frequency telephony band and at least one high-frequency data band, each of the segments having a respective first end and a respective second end; (b) a first low pass filter connected in series to the respective first end of each of the segments, for establishing a low-frequency path for the low-frequency telephony band; (c) a second low pass filter connected in series to the respective second end of each of the segments, for establishing a low-frequency path for the low-frequency telephony band; (d) a first high pass filter connected in series to the respective first end of each of the segments, for establishing a high-frequency path for the at least one high-frequency data band; (e) a second high pass filter connected in series to the respective second end of each of the segments, for establishing a high-frequency path for the at least one high-frequency data band; and (f) at least two outlets each operative to connecting at least one telephone device to at least one of the low-frequency paths, and at least two of the at least two outlets being operative to connecting at least one data device to at least one of the high-frequency paths; wherein each of the segments electrically connects two of the outlets; and each of the outlets that is connected to more than one of the segments couples the low-frequency telephony band among each of the connected segments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] In order to understand the invention and to see how the same may be carried out in practice, some preferred embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, wherein:
[0022] FIG. 1 shows a common prior art telephone line wiring configuration for a residence or other building.
[0023] FIG. 2 shows a prior art local area network based on telephone line wiring for a residence or other building.
[0024] FIG. 3 shows modifications to telephone line wiring according to the present invention for a local area network.
[0025] FIG. 4 shows modifications to telephone line wiring according to the present invention, to support regular telephone service operation.
[0026] FIG. 5 shows a splitter according to the present invention.
[0027] FIG. 6 shows a local area network based on telephone lines according to the present invention, wherein the network supports two devices at adjacent outlets.
[0028] FIG. 7 shows a first embodiment of a local area network based on telephone lines according to the present invention, wherein the network supports two devices at non-adjacent outlets.
[0029] FIG. 8 shows a second embodiment of a local area network based on telephone lines according to the present invention, wherein the network supports three devices at adjacent outlets.
[0030] FIG. 9 shows third embodiment of a local area network based on telephone lines according to the present invention, wherein the network is a bus type network.
[0031] FIG. 10 shows a node of local area network based on telephone lines according to the present invention.
[0032] FIG. 11 shows a fourth embodiment of a local area network based on telephone lines according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0033] The principles and operation of a network according to the present invention may be understood with reference to the drawings and the accompanying description. The drawings and descriptions are conceptual only. In actual practice, a single component can implement one or more functions; alternatively, each function can be implemented by a plurality of components and circuits. In the drawings and descriptions, identical reference numerals indicate those components which are common to different embodiments or configurations.
[0034] The basic concept of the invention is shown in FIG. 3 . A network 30 is based on modified telephone outlets 31 a , 31 b , 31 c and 31 d . The modification relates to wiring changes at the outlets and substituting the telephone connectors, shown as connectors 32 a , 32 b , 32 c and 32 d in outlets 31 a , 31 b , 31 c and 31 d respectively. No changes are required in the overall telephone line layout or configuration. The wiring is changed by separating the wires at each outlet into distinct segments of electrically-conducting media. Thus, each segment connecting two outlets can be individually accessed from either end. In the prior art Dichter network, the telephone wiring is not changed, and is continuously conductive from junction box 16 throughout the system. According to the present invention, the telephone line is broken into electrically distinct isolated segments 15 a , 15 b , 15 c , 15 d and 15 e , each of which connects two outlets. In order to fully access the media, each of connectors 32 a , 32 b , 32 c and 32 d must support four connections, two in each segment. This modification to the telephone line can be carried out by replacing each of the outlets 31 a , 31 b , 31 c and 31 d , replacing only the connectors 32 a , 32 b , 32 c and 32 d , or simply by cutting the telephone line wiring at the outlet. As will be explained later, these modifications need be performed only to those outlets which connect to data network devices, but are recommended at all other outlets. A minimum of two outlets must be modified, enabling data communication between those outlets only.
[0035] FIG. 4 shows how a network 40 of the present invention continues to support the regular telephone service, by the installation of jumpers 41 a , 41 b , 41 c and 41 d in modified outlets 31 a , 31 b , 31 c and 31 d respectively. At each outlet where they are installed, the jumpers connect both segment ends and allow telephone connection to the combined segment. Installation of a jumper effects a re-connection of the split telephone line at the point of installation. Installation of jumpers at all outlets would reconstruct the prior art telephone line configuration as shown in FIG. 1 . Such jumpers can be add-ons to the outlets, integrated within the outlets, or integrated into a separate module. Alternately, a jumper can be integrated within a telephone set, as part of connector 14 . The term “jumper” herein denotes any device for selectively coupling or isolating the distinct segments in a way that is not specific to the frequency band of the coupled or isolated signals. Jumper 41 can be implemented with a simple electrical connection between the connection points of connector 32 and the external connection of the telephone.
[0036] As described above, jumpers 41 are to be installed in all outlets which are not required for connection to the data communication network. Those outlets which are required to support data communication connections, however, will not use jumper 41 but rather a splitter 50 , shown in FIG. 5 . Such a splitter connects to both segments in each modified outlet 31 via connector 32 , using a port 54 for a first connection and a port 55 for a second connection. Splitter 50 has two LPF's for maintaining the continuity of the audio/telephone low-frequency band. After low pass filtering by LPF 51 a for the port 54 and LPF 51 b for port 55 , the analog telephony signals are connected together and connected to a telephone connector 53 . Hence, from the point of view of the telephone signal, the splitter 50 provides the same continuity and telephone access provided by the jumper 41 . On the other hand, the data communication network employs the high-frequency band, access to which is made via HPF's 52 a and 52 b . HPF 52 a is connected to port 54 and HPF 52 b is connected to port 55 . The high pass filtered signals are not passed from port 54 to port 55 , but are kept separate, and are routed to a connector 56 and a connector 57 , respectively. The term “splitter” herein denotes any device for selectively coupling or isolating the distinct segments that is specific to the frequency band of the coupled or isolated signals.
[0037] Therefore, when installed in an outlet, the splitter 50 serves two functions. With respect to the low-frequency analog telephony band, splitter 50 establishes a coupling to effect the prior-art configuration shown in FIG. 1 , wherein all telephone devices in the premises are connected virtually in parallel via the telephone line, as if the telephone line were not broken into segments. On the other hand, with respect to the high-frequency data communication network, splitter 50 establishes electrical isolation to effect the configuration shown in FIG. 3 , wherein the segments are separated, and access to each segment end is provided by the outlets. With the use of splitters, the telephone system and the data communication network are actually decoupled, with each supporting a different topology.
[0038] FIG. 6 shows a first embodiment of a data communication network 60 between two DTE units 24 a and 24 b , connected to adjacent outlets 31 b and 31 c , which are connected together via a single segment 15 c . Splitters 50 a and 50 b are connected to outlets 31 b and 31 c via connectors 32 b and 32 c , respectively. As explained above, the splitters allow transparent audio/telephone signal connection. Thus, for analog telephony, the telephone line remains virtually unchanged, allowing access to telephone external connection 17 via junction box 16 for telephones 13 a and 13 c . Likewise, telephone 13 b connected via connector 14 b to a connector 53 a on splitter 50 a , is also connected to the telephone line. In a similar way, an additional telephone can be added to outlet 31 c by connecting the telephone to connector 53 b on splitter 50 b . It should be clear that connecting a telephone to an outlet, either via jumper 41 or via splitter 50 does not affect the data communication network.
[0039] Network 60 ( FIG. 6 ) supports data communication by providing a communication path between port 57 a of splitter 50 a and port 56 b of splitter 50 b . Between these ports there exists a point-to-point connection for the high-frequency portion of the signal spectrum, as determined by HPF 52 a and 52 b within splitters 50 ( FIG. 5 ). This path can be used to establish a communication link between DTE units 24 a and 24 b , by means of DCE units 23 a and 23 b , which are respectively connected to ports 57 a and 56 b . The communication between DTE units 24 a and 24 b can be unidirectional, half-duplex, or full-duplex. The only limitation imposed on the communication system is the capability to use the high-frequency portion of the spectrum of segment 15 c . As an example, the implementation of data transmission over a telephone line point-to-point system described in Reichert can also be used in network 60 . Reichert implements both LPF and HPF by means of a transformer with a capacitor connected in the center-tap, as is well known in the art. Similarly, splitter 50 can be easily implemented by two such circuits, one for each side.
[0040] It should also be apparent that HPF 52 a in splitter 50 a and HPF 52 b in splitter 50 b can be omitted, because neither port 56 a in splitter 50 a nor port 57 b in splitter 50 b is connected.
[0041] Network 60 provides clear advantages over the networks described in hitherto-proposed networks. First, the communication media supports point-to-point connections, which are known to be superior to multi-tap (bus) connections for communication performance. In addition, terminators can be used within each splitter or DCE unit, providing a superior match to the transmission line characteristics. Furthermore, no taps (drops) exists in the media, thereby avoiding impedance matching problems and the reflections that result therefrom.
[0042] Moreover, the data communication system in network 60 is isolated from noises from both the network and the ‘left’ part of the telephone network (Segments 15 a and 15 b ), as well as noises induced from the ‘right’ portion of the network (Segments 15 d and 15 e ). Such isolation is not provided in any prior-art implementation. Dichter suggests installation of a low pass filter in the junction box, which is not a satisfactory solution since the junction box is usually owned by the telephone service provider and cannot always be accessed. Furthermore, safety issues such as isolation, lightning protection, power-cross and other issues are involved in such a modification.
[0043] Implementing splitter 50 by passive components only, such as two transformers and two center-tap capacitors, is also advantageous, since the reliability of the telephone service will not be degraded, even in the case of failure in any DCE unit, and furthermore requires no external power. This accommodates a ‘life-line’ function, which provides for continuous telephone service even in the event of other system malfunction (e.g. electrical failures).
[0044] The splitter 50 can be integrated into outlet 31 . In such a case, outlets equipped with splitter 50 will have two types of connectors: One regular telephone connector based on port 53 , and one or two connectors providing access to ports 56 and 57 (a single quadruple-circuit connector or two double-circuit connectors). Alternatively, splitter 50 can be an independent module attached as an add-on to outlet 31 . In another embodiment, the splitter is included as part of DCE 23 . However, in order for network 60 to operate properly, either jumper 41 or splitter 50 must be employed in outlet 31 as modified in order to split connector 32 according to the present invention, allowing the retaining of regular telephone service.
[0045] FIG. 7 also shows data communication between two DTE units 24 a and 24 b in a network 70 . However, in the case of network 70 , DTE units 24 a and 24 b are located at outlets 31 b and 31 d , which are not directly connected, but have an additional outlet 31 c interposed therebetween. Outlet 31 c is connected to outlet 31 b via a segment 15 c , and to outlet 31 d via a segment 15 d.
[0046] In one embodiment of network 70 , a jumper (not shown, but similar to jumper 41 in FIG. 4 ) is connected to a connector 32 c in outlet 31 c . The previous discussion regarding the splitting of the signal spectrum also applies here, and allows for data transport between DTE units 24 a and 24 b via the high-frequency portion of the spectrum across segments 15 c and 15 d . When only jumper 41 is connected at outlet 31 c , the same point-to-point performance as previously discussed can be expected; the only influence on communication performance is from the addition of segment 15 d , which extends the length of the media and hence leads to increased signal attenuation. Some degradation, however, can also be expected when a telephone is connected to jumper 41 at outlet 31 c . Such degradation can be the result of noise produced by the telephone in the high-frequency data communication band, as well as the result of the addition of a tap caused by the telephone connection, which usually has a non-matched termination. Those problems can be overcome by installing a low pass filter in the telephone.
[0047] In a preferred embodiment of network 70 , a splitter 50 b is installed in outlet 31 c . Splitter 50 b provides the LPF functionality, and allows for connecting a telephone via connector 53 b . However, in order to allow for continuity in data communication, there must be a connection between the circuits in connectors 56 b and 57 b . Such a connection is obtained by a jumper 71 , as shown in FIG. 7 . Installation of splitter 50 b and jumper 71 provides good communication performance, similar to network 60 ( FIG. 6 ). From this discussion of a system wherein there is only one unused outlet between the outlets to which the DTE units are connected, it should be clear that the any number of unused outlets between the outlets to which the DTE units are connected can be handled in the same manner.
[0048] For the purpose of the foregoing discussions, only two communicating DTE units have been described. However, the present invention can be easily applied to any number of DTE units. FIG. 8 illustrates a network 80 supporting three DTE units 24 a , 24 b and 24 c , connected thereto via DCE units 23 a , 23 b and 23 c , respectively. The structure of network 80 is the same as that of network 70 ( FIG. 7 ), with the exception of the substitution of jumper 71 with a jumper 81 . Jumper 81 makes a connection between ports 56 b and 57 b in the same way as does jumper 71 . However, in a manner similar to that of jumper 41 ( FIG. 4 ), jumper 81 further allows for an external connection to the joined circuits, allowing the connection of external unit, such as a DCE unit 23 c . In this way, segments 15 c and 15 d appear electrically-connected for high-frequency signals, and constitute media for a data communication network connecting DTE units 24 a , 24 b and 24 c . Obviously, this configuration can be adapted to any number of outlets and DTE units. In fact, any data communication network which supports a ‘bus’ or multi-point connection over two-conductor media, and which also makes use of the higher-frequency part of the spectrum can be used. In addition, the discussion and techniques explained in the Dichter patent are equally applicable here. Some networks, such as Ethernet IEEE 802.3 interface 10BaseT and 100BaseTX, require a four-conductor connection, two conductors (usually single twisted-wire pair) for transmitting, and two conductors (usually another twisted-wire pair) for receiving. As is known in the art, a four-to-two wires converter (commonly known as hybrid) can be used to convert the four wires required into two, thereby allowing network data transport over telephone lines according to the present invention.
[0049] As with jumper 41 ( FIG. 4 ), jumper 81 can be an integral part of splitter 50 , an integral part of DCE 23 , or a separate component.
[0050] In order to simplify the installation and operation of a network, it is beneficial to use the same equipment in all parts of the network. One such embodiment supporting this approach is shown in for a set of three similar outlets in FIG. 8 , illustrating network 80 . In network 80 , outlets 31 b , 31 c , and 31 d are similar and are all used as part of the data communication network. Therefore for uniformity, these outlets are all coupled to splitters 50 a , 50 b , and 50 c respectively, to which jumpers are attached, such as a jumper 81 attached to splitter 50 b (the corresponding jumpers attached to splitter 50 a and splitter 50 c have been omitted from FIG. 8 for clarity), and thus provide connections to local DCE units 23 a , 23 c , and 23 b , respectively. In a preferred embodiment of the present invention, all outlets in the building will be modified to include both splitter 50 and jumper 81 functionalities. Each such outlet will provide two connectors: one connector coupled to port 53 for a telephone connection, and the other connector coupled to jumper 81 for a DCE connection.
[0051] In yet another embodiment, DCE 23 and splitter 50 are integrated into the housing of outlet 31 , thereby offering a direct DTE connection. In a preferred embodiment, a standard DTE interface is employed.
[0052] In most ‘bus’ type networks, it is occasionally required to split the network into sections, and connect the sections via repeaters (to compensate for long cabling), via bridges (to decouple each section from the others), or via routers. This may also be done according to the present invention, as illustrated in FIG. 9 for a network 90 , which employs a repeater/bridge/router unit 91 . Unit 91 can perform repeating, bridging, routing, or any other function associated with a split between two or more networks. As illustrated, a splitter 50 b is coupled to an outlet 31 c , in a manner similar to the other outlets and splitters of network 90 . However, at splitter 50 b , no jumper is employed. Instead, a repeater/bridge/router unit 91 is connected between port 56 b and port 57 b , thereby providing a connection between separate parts of network 90 . Optionally, unit 91 can also provide an interface to DTE 24 c for access to network 90 .
[0053] FIG. 9 also demonstrates the capability of connecting to external DTE units or networks, via a high pass filter 92 connected to a line 15 a . Alternatively, HPF 92 can be installed in junction box 16 . HPF 92 allows for additional external units to access network 90 . As shown in FIG. 9 , HPF 92 is coupled to a DCE unit 93 , which in turn is connected to a network 94 . In this configuration, the local data communication network in the building becomes part of network 94 . In one embodiment, network 94 offers ADSL service, thereby allowing the DTE units 24 d , 24 a , 24 c and 24 b within the building to communicate with the ADSL network. The capability of communicating with external DTE units or networks is equally applicable to all other embodiments of the present invention, but for clarity is omitted from the other drawings.
[0054] While the foregoing relates to data communication networks employing bus topology, the present invention can also support networks where the physical layer is distinct within each communication link. Such a network can be a Token-Passing or Token-Ring network according to IEEE 802, or preferably a PSIC network as described in U.S. Pat. No. 5,841,360 to the present inventor, which details the advantages of such a topology. FIG. 10 illustrates a node 100 for implementing such a network. Node 100 employs two modems 103 a and 103 b , which handle the communication physical layer. Modems 103 a and 103 b are independent, and couple to dedicated communication links 104 a and 104 b , respectively. Node 100 also features a DTE interface 101 for connecting to a DTE unit (not shown). A control and logic unit 102 manages the higher OSI layers of the data communication above the physical layer, processing the data to and from a connected DTE and handling the network control. Detailed discussion about such node 100 and the functioning thereof can be found in U.S. Pat. No. 5,841,360 and other sources known in the art.
[0055] FIG. 11 describes a network 110 containing nodes 100 d , 100 a , 100 b and 100 c coupled directly to splitters 50 d , 50 a , 50 b and 50 c , which in turn are coupled to outlets 31 a , 31 b , 31 c and 31 d respectively. Each node 100 has access to the corresponding splitter 50 via two pairs of contacts, one of which is to connector 56 and the other of which is to connector 57 . In this way, for example, node 100 a has independent access to both segment 15 b and segment 15 c . This arrangement allows building a network connecting DTE units 24 d , 24 a , 24 b and 24 c via nodes 100 d , 100 a , 100 b and 100 c , respectively.
[0056] For clarity, telephones are omitted from FIGS. 9 and 11 , but it will be clear that telephones can be connected or removed without affecting the data communication network. Telephones can be connected as required via connectors 53 of splitters 50 . In general, according to the present invention, a telephone can be connected without any modifications either to a splitter 50 (as in FIG. 8 ) or to a jumper 41 (as in FIG. 4 ).
[0057] Furthermore, although the present invention has so far been described with a single DTE connected to a single outlet, multiple DTE units can be connected to an outlet, as long as the corresponding node or DCE supports the requisite number of connections. Moreover, access to the communication media can be available for plurality of users using multiplexing techniques known in the art. In the case of time domain/division multiplexing (TDM) the whole bandwidth is dedicated to a specific user during a given time interval. In the case of frequency domain/division multiplexing (FDM), a number of users can share the media simultaneously, each using different non-overlapping portions of the frequency spectrum.
[0058] In addition to the described data communication purposes, a network according to the present invention can be used for control (e.g. home automation), sensing, audio, or video applications, and the communication can also utilize analog signals (herein denoted by the term “analog communication”). For example, a video signal can be transmitted in analog form via the network.
[0059] While the present invention has been described in terms of outlets which have only two connections and therefore can connect only to two other outlets (i.e., in a serial, or “daisy chain” configuration), the concept can also be extended to three or more connections. In such a case, each additional connecting telephone line must be broken at the outlet, with connections made to the conductors thereof, in the same manner as has been described and illustrated for two segments. A splitter for such a multi-segment application should use one low pass filter and one high pass filter for each segment connection.
[0060] The present invention has also been described in terms of media having a single pair of wires, but can also be applied for more conductors. For example, ISDN employs two pairs for communication. Each pair can be used individually for a data communication network as described above.
[0061] Also as explained above, an outlet 31 according to the invention ( FIG. 3 ) has a connector 32 having at least four connection points. As an option, jumper 41 ( FIG. 4 ), splitter 50 ( FIG. 5 ), or splitter 50 with jumper 81 ( FIG. 8 ), low pass filters, high pass filters, or other additional hardware may also be integrated or housed internally within outlet 31 . Alternatively, these devices may be external to the outlet. Moreover, the outlet may contain standard connectors for devices, such as DTE units. In one embodiment, only passive components are included within the outlet. For example, splitter 50 can have two transformers and two capacitors (or an alternative implementation consisting of passive components). In another embodiment, the outlet may contain active, power-consuming components. Three options can be used for providing power to such circuits:
[0062] 1. Local powering: In this option, supply power is fed locally to each power-consuming outlet. Such outlets must be modified to support connection for input power.
[0063] 2. Telephone power: In both POTS and ISDN telephone networks, power is carried in the lines with the telephone signals. This power can also be used for powering the outlet circuits, as long as the total power consumption does not exceed the POTS/ISDN system specifications. Furthermore, in some POTS systems the power consumption is used for OFF-HOOK/ON-HOOK signaling. In such a case, the network power consumption must not interfere with the telephone logic.
[0064] 3. Dedicated power carried in the media: In this option, power for the data communication related components is carried in the communication media. For example, power can be distributed using 5 kHz signal. This frequency is beyond the telephone signal bandwidth, and thus does not interfere with the telephone service. The data communication bandwidth, however, be above this 5 kHz frequency, again ensuring that there is no interference between power and signals.
[0065] While the invention has been described with respect to a limited number of embodiments, it will be appreciated that many variations, modifications and other applications of the invention may be made.
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A service outlet for coupling a data unit to a wired digital data signal and for coupling a service unit to an analog service signal, for use with a service wire pair installed in walls of a building, the service wire pair concurrently carrying a wired bi-directional digital data signal and an analog service signal carried over a service signal frequency band, using frequency division multiplexing, wherein the wired digital data signal is carried over a frequency band distinct from the service signal frequency band. The outlet has a single enclosure and, within the enclosure: a wiring connector; first and second filters coupled to the wiring connector; a service connector coupled to the first filter and connectable to the service unit for coupling the service unit to the analog service signal; a service wiring modem coupled to the second filter; and a power supply coupled to the service wiring modem.
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FIELD OF THE INVENTION
This invention relates to the reclamation of plastics which have been used or rejected in the job for which they were formed. This invention relates more particularly to the comminution of scrap so that these so-called "post-consumer" plastics may be more easily utilized again or be more easily degraded biologically. Still more particularly, this invention relates to a method for refining plastic scrap rapidly to a size suitable for use as a partial or total replacement of cellulosic pulp as a filler.
BACKGROUND OF THE INVENTION
The recycling of post-consumer plastics is expected to expand as much as ten-fold beyond the current 200 million pound per year business in less than a decade. Industrial waste recycling is and will be an even bigger business.
Accordingly, there have been many different approaches to the problem of what to do with the scrap. Some merely melt down mixtures of the plastics and mold it into useful shapes. Others classify and separate them before melting or dissolving them. Still others change the nature of the mixed plastics by chemical reaction.
An older and larger business is the recycling of newspaper and other waste paper. One problem in this business is that plastic scraps are often mixed in with the paper. Re-pulping of the paper is hampered by such scraps and their removal and disposal costs threaten the profitability of the business.
A reduction in the size of the scrap pieces facilitates melting, dissolution, and reaction. In the re-pulping of paper, some end uses of the product would permit or even benefit from the presence of comminuted plastic. One process for grinding polyethylene terephthalate (PET) bottles is limited to specific bottle designs. Another process, invented before the need for recycling became apparent and directed to the comminution of virgin plastics for use in certain applications, is taught in U.S. Pat. No. 3,150,834. There, a suspension of the plastic in water or some other non-solvating liquid that is inert to the plastic is fed between a pair of grinding surfaces, at least one of which is rotating.
In U.S. Pat. No. 2,412,586, the wet grinding of scrap rubber is taught but the use of an excessive amount of water is taught against because the formation of a slurry would reduce the grinding efficiency.
The intensive milling of a poly (arylene sulfide) in water containing a non-ionic surface active agent such as Rohm & Haas' Triton X-100 wetting agent to form a dispersion is taught in U.S. Pat. No. 3,799,454. The particle size of the plastic before being milled in a ball mill is about 30 mesh (about 24 mils) or smaller. The milling time in a ball mill is from 5 to 40 hours; use of a vibratory ball mill may reduce the time tenfold.
It is an object of this invention, therefore, to provide a quick, low-cost method for comminuting thin films or sheets of plastic.
It is a related object to provide a method for comminuting macro-sized scraps of such thin film.
It is a further related object to provide a method for comminuting a mixture of different plastics.
It is another object to provide a comminuted plastic for use as a filler.
It is another object of this invention to provide a pulp of cellulose and plastic.
BRIEF SUMMARY OF THE INVENTION
These and other objects which will become apparent from the following description are achieved by circulating a suspension of plastic scraps in water containing at least one antifoam agent selected from the class consisting of a defoamer having an HLB value of from about 0.5 to about 10 and a polypropylene glycol having an average molecular weight of from about 900 to about 1500 through a cutting machine.
DETAILED DESCRIPTION OF THE INVENTION
Plastic, as used herein, means a molded or extruded solid resin. The resin may be thermoplastic or thermosetting or elastomeric. Polyvinyl chloride, cellophane, polyethylene, polypropylene, polystyrene, polyethylene terephthalate, polycarbonate, ABS and neoprene rubber are a few examples of the plastic which may be cut up by the method of this invention. Macro-sized scraps, i.e. those having a length of about 0.5 inch or more, are suitable. Thin films or sheets, i.e. those having a thickness of about 60 mils (1.6 mils) or less, are particularly suitable. It will be evident that this invention is not limited to used plastic; it is described here with reference to plastic scraps because of its being particularly advantageous in the reclamation of such scraps. Virgin plastic may chopped up by this method for some special reason.
The cutting machine is exemplified by the Valley beater and the disc refiner, both of which are used conventionally in the wood pulp and paper industries. In both, the suspended plastic must pass between a plurality of knife edges which are in intermittent sliding contact. A short batch time of up to about 10 minutes is sufficient in the beater and average residence times of about 1 minute or less are employed in the continuous operation of a disc refiner according to this invention.
It is not understood how or why the plastic scraps are so quickly cut up by the method of this invention in contrast to the absence of any noticeable comminution of such scraps when they are circulated through a Valley beater as a suspension in plain tap water for eight hours. Within a short time after the addition of one of the above-defined antifoam agents to a fresh suspension, the scraps are reduced to a powder. The agent is exemplified by the tetramethylated decyne diol and certain ethyoxylated derivatives thereof sold by Air Products & Chemicals, Inc. under the trademark Surfynol. The effective Surfynol surfactants have a hydrophile-lipophile balance (HLB) number of about 8 or less. Other examples of the effective agents for this invention include two non-silicone-based defoamers: one is sold under the trademark Foam Blast 327 by Ross Chem, Inc. and has an HLB number between 5 and 10; the other is sold under the Nopco NXZ trademark by Henkel Corporation. A silicone emulsion sold under the trademark Dow Corning H-10 as a defoamer is also effective. A preferred antifoam agent for the purposes of this invention is a polypropylene glycol having a molecular weight of from about 900 to about 1500. This material is almost totally hydrophobic despite a hydroxyl group content of from about 2 to about 4% by weight. Nevertheless, it is sufficiently polar to affect the surface tension of water in foams and, we have discovered, to affect the surface of a plastic so that the plastic can no longer slip unscathed through a cutting machine.
A small amount of the defoamer, suitably from about 0.05% to about 1% by weight of the total aqueous suspension, is sufficient to promote the comminution of the water-wetted plastic scraps. When the plastic scraps are comminuted along with paper to form a pulp, the surfactant amounts to from about 1% to about 5% of the total weight of the suspended plastic and paper.
Waste paper such as old newspapers, kraft wrapping paper, cardboard, paper mill rejects and the like is a good source of the paper.
The following examples illustrate the invention in greater detail but are not to be taken as limitative thereof in any way. All parts and percentages are by weight unless otherwise indicated.
EXAMPLE 1
A 15% aqueous slurry of assorted waste materials consisting principally of plastic films and paper was circulated in a Valley beater and a sufficient amount of polypropylene glycol having an average molecular weight of 1200 (sold by Permethyl Corporation) was added to equal 5 parts per 100 parts of the waste material. The plastic film along with the other waste material was comminuted to fine sized particles in a short time.
EXAMPLE 2
To a suspension of 700 parts of waste material similar to that of Example 1 in 13,300 parts of water there was added 21 parts of the polypropylene glycol of Example 1. The suspension was then passed through a Beloit-Jones Double Disc #4000 refiner having 20 inch plates. A total of three passes were made in about two minutes. The slurry of finely comminuted particles was drained and pressed to remove water. The mean particle size of the product was 9 microns (0.009 mm).
EXAMPLES 3-10
Seven different defoamers were tested in an aqueous slurry containing 5% of the starting waste material of Example 2 and 3% of the defoamer, based on the weight of the waste material. The procedure of Example 1 was followed. Each of the following defoamers caused a satisfactory comminution of the plastic scraps to occur:
Ethoxylated acetylenic diol (Surfynol 440; 40% oxyethylene, HLB=8)
2,4,7,9-tetramethyl-5-decyne-4,7 diol (Surfynol 104, HLB=5)
Silicone emulsion (Dow Corning H-10)
Silicone emulsion (Dow Corning 59)
Non-silicone, non-mineral oil defoamer (Foam Blast 327, Ross Chem, Inc.)
NOPCO NXZ defoamer (Henkel Corporation)
EXAMPLE 11
Another fresh suspension like that of Comparative Example A was charged into the Valley beater and a small amount of the polypropylene glycol of Examples 1 and 2 was added. The suspension was circulated in the Valley beater for about 5 to 10 minutes and all of the plastic scraps and other waste were comminuted to a fine particle size.
EXAMPLE 12
The product of Example 2 was charged into a hydropulper along with water to give a slurry containing 3% by weight solids. The slurry was added to a calcined gypsum slurry in a mixer at a conventional gypsum board line at a rate of 6 pounds of comminuted solids per thousand square feet of half-inch board. The mixture was then sandwiched between two cover sheets of paper in the conventional manner. Four trial runs produced good board without any processing problems.
The compressive strength, nail pull strength and density of boards made during the trials and in a control run using standard refined kraft paper instead of the refined plastic are given in the following table:
______________________________________ Trial Trial Trial Trial Control #1 #2 #3 #4______________________________________Dry Density 41.4 40.6 41.2 42.0 42.1(lbs./ft.sup.3)Compressive 578 592 598 594 592Strength (psi)Nail Pull 81 79 79 78 --(pounds-force)______________________________________
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A method for comminuting plastic scrap material wherein the plastic scrap is suspended in water and an antifoam agent is added to the suspension which is then passed through a disc refiner or a Valley beater to comminute the plastic scrap. The antifoam agent is selected from defoamers having an HLB value of from about 0.5 to about 10 and a polypropylene glycol having an average molecular weight of from about 900 to about 1500. The comminuted plastic scrap is useful as an additive to the core material of a gypsum wallboard.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of pending U.S. application Ser. No. 915,116 filed on Oct. 3, 1986 now abandoned and entitled: "Recirculating High Velocity Hot Air Sterilization Device".
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a device and process for the sterilization and depyrogenation of dental and surgical metal instruments. The invention relates, more particularly, to an automatically controlled device for the rapid, inexpensive and non-corrosive sterilization and depyrogenation of dental and surgical metal instruments.
2. Description of the Prior Art
In every health profession, the guiding principle ". . . do good, but do no harm" is as valid today as in the ancient Greece of its author, Hippocrates. Over the years, the second part of this motto was directed at the patient while treatment-related hazards to the practitioner's health were either discounted or accepted stoically. In dentistry, the simplistic attitude that patients--not professionals acquire treatment-related diseases is giving way to the more realistic concept that operatory personnel are the main targets of viral and bacterial agents of infections.
To demonstrate the central position of dentists in the acquisition and broadcast of nosocomial infectious disease, their rate of hepatitis B infection is four-fold higher than that of the general public. If the dentist is male, he can pass the disease by sexual activity to his wife. If she, or female operatory personnel, incubate the virus during pregnancy, their newborn children have a 90% chance of becoming lifelong carriers of the virus and a 53% chance of dying from liver cancer. Male or female, dental personnel harboring hepatitis B virus can pass the disease to patients, especially via blood exiting the finger through cuts.
The recent dramatic rise in the spread of infectious diseases in the United States has resulted in an acute awareness of the potentially grave danger of transmission to health care professionals in general. As noted above, dentists and dental auxiliaries occupy a central position in the acquisition and broadcast of nosocomial infectious disease. The risk, however, extends beyond dentists and dental auxiliaries to the crossover contamination from patient to patient.
For example, it is estimated that there are 200,000 new cases of hepatitis B in the U.S. each year with nearly 1 million chronic carriers. Since 1974, there has been a 234% increase in reported cases of Herpes Simplex II and a 40,350% increase in AIDS cases. Add to these the diseases that can frequently be transmitted, such as gonorrhea, infectious mononucleosis, measles, pneumonia, tetanus, amoebic dysentery and the highly resistant organisms that are reaching the United States from foreign countries, and a frightening scenario emerges.
Recent legal decisions have placed the burden of proof of proper sterilization procedures on the dental office where the possibility of suspected transmission of infection exists. It follows that malpractice insurance carriers may soon require strict adherence to effective and accepted sterilization procedures.
The solution to the problem of contamination with infectious disease in the dental office from patient to dental personnel and from patient to patient is to ensure the complete sterilization and depyrogenation (killing all forms of microbial life: viral and bacterial pathogens including spores) of all instruments.
In the dental office environment, there are several currently accepted means of sterilization. All of the systems currently employed, as discussed below, lack the capability of rapid sterilization of instruments between patients to allow the immediate reuse of the instruments.
The first method of sterilization is known as cold solution sterilization. Cold solution sterilization requires 20 to 30 minutes to disinfect and 10 hours to sterilize (if the solution is fresh and mixed to proper strength). Procedural problems involved with cold solution sterilization are as follows: many currently available solutions will discolor the skin on contact; most available solutions have an offensive odor; dental instruments will rust if they are left in the solutions over an extended period of time; and instruments are often placed in the solution haphazardly with no record of how long they remain. Other limitations concerning the cold solution sterilization system include the fact that the required solutions are expensive and must constantly be replenished.
The second method of sterilization involves the utilization of steam heat. Steam heat sterilization requires 30 to 60 minutes to sterilize. Procedural problems involved with steam heat sterilization are as follows: a central sterilization area is required and a large piece of expensive equipment which can be hazardous to operating personnel is required. Other limitations concerning steam heat sterilization include the fact that the method corrodes, rusts and dulls instruments--particularly where such instruments are of a carbon steel construction.
The third method of sterilization involves the use of alcohol steam. Alcohol steam requires a minimum of 30 minutes to achieve sterilization. Procedural problems involved with alcohol steam sterilization are as follows: a central sterilization area is required; sterilization usually requires the use of "wrapped packs" which necessitate an increase in the number of instruments needed by an office; and the use of "wrapped packs" also lends itself to careless techniques in that packs are often broken into to retrieve one needed instrument if complete packs of all instruments are not available. Other limitations concerning alcohol steam sterilization include the fact that alcohol steam also corrodes instruments, but not to the same degree as steam heat. Additionally, alcohol steam contains formaldehyde--the presence of which constitutes a potential health hazard. Accordingly, purging systems are typically required to exhaust the alcohol steam from the sterilizer cabinet each time its access door is opened.
The fourth method of sterilization involves the use of dry heat. Dry heat sterilization conventionally requires a minimum of 60 minutes to achieve sterilization. With the exception of the purging requirements associated with the presence of formaldehyde, the problems involved with dry heat sterilization are essentially the same as discussed with regard to alcohol steam sterilization since wrapped packs are used. Additionally, however, the lack of uniform sterilizing heat distribution, and a corresponding non-uniform temperature pattern within the sterilizing cabinetry, render the validation of the sterilization process somewhat difficult.
The fifth method of sterilization involves the use of ethylene oxide gas. The size, expense and sophistication of this process and the necessary equipment, however, limit its use to commercial large volume sterilization.
The sixth method of sterilization involves the use of heat transfer with glass beads, sand, glass, ball bearings and other similar items being used as a heat-transfer medium. Heat transfer sterilization requires 10 seconds at 450° to achieve sterilization. This method has no known procedural problems. A major limitation concerning heat transfer sterilization, however, is the fact that a small unit is used which is suitable only for small endodontic files, broaches and other similar items.
Among the currently employed sterilization systems, the heat transfer system is the only one with the capability of rapid sterilization of instruments between patients and its small capacity limits its use in the dental office.
Thus, a need exists in the art for a rapid, safe, inexpensive and non-corrosive sterilization method and device that provides for the automatic sterilization and depyrogenation of procedural instruments in health care facilities and especially the dental office thereby minimizing the human error factors attending the use of known sterilization devices.
SUMMARY OF THE INVENTION
The device for the automatic sterilization and depyrogenation of dental and surgical metal instruments of the present invention avoids the above-mentioned disadvantages which are characteristic of the prior art. More specifically, the device of the present invention provides an automatically controlled means for the sterilization of dental and surgical metal instruments that is rapid, non-corrosive, clean, inexpensive and efficient. The device of the present invention is an automatically controlled dry-heat sterilizer that utilizes the speed of heat transfer principles in a unit large enough to accommodate dental instruments and other small surgical instruments. The device is also useful for the sterilization and depyrogenation of dental and surgical implants.
The sterilization device of the present invention has high heat transfer efficiency and reduces the time required to sterilize dental and surgical metal instruments over that required by conventional sterilization devices. The sterilization device of the present invention provides complete sterilization and depyrogenation, utilizing a process in which deturbulized air, moving at, preferably, 1500 to 3000 feet per minute, is heated to a sterilizing temperature of, preferably, 350° to 400° F.
The sterilization device operation is under the control of a controller. The controller includes two timed operating cycle selections. A first cycle selection provides for the operation of the device for a first preselected time, for example, three minutes, continuously at a temperature of about 375° F. for sterilizing unwrapped instruments. While a second cycle selection provides for operation of the device for a second preselected time, and temperature for sterilizing instruments requiring additional time such as, for example, wrapped instruments, excessively bulky instruments, or a large quantity load. Any interruptions of the operation of the device or a drop in temperature during operation restarts the timer.
The controller also features: a solid state display; a monitor for detecting system operating failures; a temperature reading means for continuous temperature reading; a proportional heat control means for the heating element; relays responsive to on/off switch inputs for controlling fan and heater on/off operations; an audible alarm for alerting an operator as to system operating status; a timer for providing an accurate time base; and an input means for operator input including on/off operation.
The sterilization device of the present invention provides for instrument sterilization between treatment of each patient thereby eliminating the greatest source of contamination from patient to personnel as well as cross contamination from patient to patient.
The sterilization device of the present invention and its variations may be used in dental offices, medical offices and clinics particularly where minor surgical procedures are performed; in oral surgery offices; in hospitals and other health care facilities; in emergency rooms; in Dental, Medical and Veterinary Medical Schools; in schools of Dental Hygiene; in schools of Medical Technology; in schools of Physical Therapy; in Military Health Care Facilities; and, in other environments where individuals could be subjected to contamination or cross infection including, but not limited to, ear piercing, electrolysis and skin care.
It is an object of the present invention to provide a device for the sterilization and depyrogenation of metal dental instruments that is 10 to 20 times faster than any other currently employed system of sterilization in the dental office; completely safe to operating personnel; durable and lasts the lifetime of a dental office with only the simple replacement of a fan motor or heating element; simple in operation; more inexpensive than other types of sterilization devices; less harmful to instruments than any other types of specification; small enough for use in the operatory and does not require a central sterilization area; inexpensive enough to allow for use of multiple units placed at convenient locations where instruments are used; maintenance free; preferably insulated to protect the outside of the unit from becoming hot; and preferably constructed with external stainless steel to provide a lifetime non-corrosive surface that can be disinfected with a wipe solution.
It is another object of the present invention to provide a device that reliably provides total sterilization and depyrogenation of dental and surgical metal instruments.
It is an additional object of the present invention to provide a device for the sterilization and depyrogenation of dental and surgical metal instruments that releases no heat or odor and does not require the use or addition of chemicals.
It is a further object of the invention to provide sterilization and depyrogenation device having a controller for controlling the operation of the device, monitoring the operation of the device, and signaling operational malfunctions.
It is still a further object of the invention to provide a sterilization and depyrogenation device having multimode operation cycles for operator selection.
These and other objects are achieved by the recirculating high velocity hot air sterilization device of the present invention.
The device of the present invention includes an enclosure or housing which defines a sterilization chamber and a plenum chamber with a blower disposed in the plenum chamber. A perforated jet curtain plate is disposed within the sterilization chamber and partially defines an air supply plenum. A heating element is disposed within the air supply plenum. Means are provided for fluid communication between the outlet port of the blower, the air supply plenum, the sterilization chamber, and the intake port of the blower. The blower recirculates air throughout the device at a high temperature and a high velocity and sterilizes dental and surgical metal instruments that may be placed within the device.
The blower forces heated air upwardly through the perforations in the jet curtain plate to form within the sterilization chamber a mutually spaced series of upwardly directed high velocity heated air impingement jets. A temperature sensing means is positioned within the sterilization chamber to detect the temperature within the sterilization chamber. Positioned within the sterilization chamber in an upwardly spaced relationship with the jet curtain plate and temperature sensor is a corrugated, nonperforated air deflector plate which extends generally parallel to the jet curtain plate. The corrugated deflector plate is positioned in the path of the upwardly directed impingement jets and serves to intercept, laterally offset and rearwardly deflect such jets toward the jet curtain plate. The instruments to be sterilized are supported within a wire mesh tray which is removably positioned within the sterilization chamber between and spaced apart from the corrugated deflector plate and jet curtain plate.
Some of the upwardly directed impingement jets strike lower surface portions of the supported instruments, while other impingement jets bypass the supported instruments and impinge upon the upper deflector plate. These jets which bypass the supported instruments impinge upon the deflector plate, are laterally offset, and then are rearwardly deflected toward the supported instruments. The deflected jets impinge upon upper surface portions of the supported instruments and create a high degree of heated air turbulence adjacent thereto. The combination of high velocity heated air impinging on both sides of the instruments, and the resulting high degree of heated air turbulence, sterilizes and depyrogenates the instruments in a small fraction of the time normally required in conventional sterilizing apparatus. In addition to their jet-forming and deflecting functions, the corrugated jet curtain plate and air deflector plate additionally function in a unique manner to facilitate an extremely uniform air distribution flow within the sterilizing chamber of both the originally formed impingements jets and the rearwardly deflected impingement jets. A controller having a timer and an input/output switch means for operation cycle selection and device turn on, and a display for displaying the temperature and time remaining for completion of the selected cycle, controls the operation of the heating element and blower during the selected sterilizing cycle. The controller also monitors the temperature for restarting the timing of the cycle whenever the temperature is below the required (set) temperature. The display shows the temperature of the sterilization chamber continuously and the time remaining for completion of the selected cycle.
BRIEF DESCRIPTION OF THE DRAWINGS
In describing the invention, reference will be made to the accompanying drawings in which:
FIG. 1 is an isometric view of a preferred embodiment of the recirculating high velocity hot air sterilization device of the present invention;
FIG. 2 is a cross-sectional view of the recirculating high velocity, hot air sterilization device of the present invention; and
FIGS. 3a-3e constitute a schematic view of the controller for the recirculating high velocity hot air sterilization device of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings and, in particular, FIG. 1, a preferred recirculating high velocity hot air sterilization device generally indicated at 10 is defined by an enclosure or housing 12. As shown more clearly in FIG. 2, the enclosure 12 includes a plurality of walls 14. Walls 14 are preferably insulated. A partition 16 divides the enclosure 12 into a sterilization chamber 18 and a plenum chamber. A blower 20 is disposed within the plenum chamber of enclosure 12. The intake port 22 of blower 20 is in fluid communication with sterilization chamber 18. The outlet port 24 of blower 20 is in fluid communication with a duct chamber 26. A wall 27 separates the duct chamber 26 from the sterilization chamber 18. An airflow opening 28 is provided within wall 27 to allow for fluid communication between duct chamber 26 and sterilization chamber 18.
As shown in FIG. 2, a perforated jet curtain plate 34 is provided within enclosure 12. The perforated jet curtain plate 34 partially defines an air supply plenum 32 within sterilization chamber 14. A heating element 30 is provided within plenum 32 to heat the air entering the plenum through air flow opening 28. An upper non-perforated jet curtain or air deflector plate 36 may preferably be disposed within sterilization chamber 18. The perforated jet curtain plate 34 and non-perforated jet curtain plate 36 are rigidly supported within enclosure 12 by a plurality of support flanges 38. A plurality of support flanges 40 are provided between perforated jet curtain plate 34 and non-perforated jet curtain plate 36 to removably support an open wire mesh tray 44 containing metal dental or surgical metal instruments 45. A door 42 (FIG. 1) is openable to provide access to sterilization chamber 18. Door 42 provides an air-tight seal and serves to seal the sterilization chamber 18 from the outside environment.
The perforated jet curtain plate 34 (FIG. 2) is mounted within housing 10 and is spaced apart from and above the heating element 30, and downwardly from the upper plate 36. The perforated jet curtain plate 34 contains an array of elongated, generally rectangular slots 35 through which turbulized air from the air supply plenum 32 is unturbulized and directed in a series of heated air impingement jets toward the dental or surgical metal instruments 45 supported in tray 44. The rectangular slots 35 of the perforated jet curtain plate 34 vary in width, length and number in relation to the horsepower of the blower to yield jets of air emanating from the slots 35 at a velocity of from 1500 to 3000 feet/minute. The velocity of air emanating from the slots 35 may be measured by a Dwyer Air Velocity Calculator: #460 Air Meter made by Dwyer Instruments, Inc., Michigan City, Ind. under U.S. Pat. No. 2,993,374. The velocity of the air emanating from the slots 35 depends upon the ratio of the area of the output port 24 of the blower 20 to the area of the slots 35. The velocity of the air emanating from the slots 35 also depends upon the horsepower and speed of the blower 20. Those skilled in the art will recognize that these variables may be adjusted through routine experimentation to achieve a desired velocity of air emanating from the slots 35.
The perforated jet curtain plate 34 distributes heat uniformly and efficiently to the instruments 45 being supported and sterilized in the tray 44. The deturbulized air emanating from the slots 35 of the perforated jet curtain plate 34 travels through the sterilization chamber 18, past a thermocouple 46 for sensing the temperature of the hot air to the corrugated, non-perforated jet curtain plate 36. The curtain plate 36 reflects the hot air rearwardly to the blower. The air is then circulated back through the blower 20 to again enter the duct chamber 26, the air supply plenum 32 and the sterilization chamber 18, in sequence. When the blower 20 is operating, a continuous stream of air flows through the entire system. Turbulized air from the blower 20 scrubs the heating element 30 and picks up heat which is then delivered to the instruments by the high velocity jets of air emanating from the slots 35 of the perforated jet curtain plate 34.
The perforated jet curtain plate 34 is uniquely corrugated in a pattern of rounded v-shaped corrugations alternately v-shaped and inverted v-shaped. The slots 35 of the perforated jet curtain plate 34 are disposed in the crests rather than the troughs of the v-shaped corrugations.
The extreme efficiency of jets of high velocity heated air emanating from the slots 35 of the perforated jet curtain plate 34 speeds the sterilization and depyrogenation of the dental or surgical metal instruments supported in the tray 44 without requiring an extreme differential between the temperature of the heating element 30 and the temperature of the air. Unused heat contained in the recirculating air is conserved by the device of the present invention which, as noted previously, may be insulated to reduce heat loss. It is therefore possible to provide quick efficient sterilization and depyrogenation of dental or surgical metal instruments with air heated to about 350° to 400° F., and preferably about 375° F., without requiring the heating element 30 to run at full capacity, which conserves energy and increases the life of the instruments. It is well known by those skilled in the art that the alloy arrangements in dental and surgical metal instruments are disrupted when exposed to temperatures in excess of 400° F.
A control chamber 48 (FIG. 1) is located above the sterilization chamber 18 for housing the controller system circuitry hereinafter described in detail. A control panel 50 is disposed on the external portion of the control chamber 48. The control panel 50 includes an on/off switch 52, a temperature display 54, a timer display 56, and cycle 1 and cycle 2 selection switches 58 and 60.
Referring now to FIGS. 3a-3e, the controller system includes a processor means (FIG. 3a). The processor means 62 includes a microprocessor 64 such as, for example, an 8-bit HD63B03 microprocessor sold by Hitachi, Ltd. The microprocessor 64 has a plurality of input terminals and address and data output terminals for providing an interface to circuits hereinafter described, a test console port, a small amount of random access memory (RAM) for data storage, and a very accurate crystal based timing circuit 65 for checking the natural timer hereinafter described. A typical address decoder which includes a demultiplexer decoder 66 (FIG. 3b) and a latch 68, is attached to the address and data output terminals by a data and address bus 70 for processing 16 bit addresses and 8 bit data words. And an electrically programmable read only memory (EPROM) 72, which contains the operating instruction software, is connected by the data and address bus 70 to the microprocessor for controlling the operation of the microprocessor. The display 56 completes the processor means 62.
The on/off switch 52 (FIG. 3a) is connected by leads 73 to an encoder 74 (FIG. 3b). The encoder 74 is connected by the data and address bus 70 to the microprocessor 64 (FIG. 3a). The microprocessor monitors the position of the on/off switch and outputs coded signals on data and address bus 70 to a decoder 76. The decoder 76 has output terminals connected respectively to three light emitting diodes 78, 80, and 82 for indicating, respectively, the on/off switch status and cycle 1 or cycle 2 selection, and by leads 84 and 86 to a blower power control circuit (FIG. 3c) and to a heating element power control circuit for controlling the connection of ac power to the blower 20 and heating element 30 (FIG. 2).
The blower circuit includes a bias resistor 88 (FIG. 3c) having one end connected by lead 86 to the decoder 76 and a second end connected to the base of a power transistor 90. When a switch on indicating signal is applied to the base of the transistor 90, the transistor turns on to close a relay switch 92 and supply working power from a source thereof to the blower 20 and to a TRIAC 94 or other suitable thyristor of the heating element circuit.
The heating element circuit includes a TRIAC driver 96 having an input connected by lead 84 to the decoder 76 and an output connected to the gate of the TRIAC 94. The TRIAC when triggered on supplies power to the heating element 30. The relay switch 92 provides on/off control of the blower as well as safety control of the heater, and the TRIAC provides proportional control of the heater with an opto-coupler to isolate the logic control from the ac power.
A power supply circuit includes a power connector 98 for connection to a typical 50 or 60 Hertz power line. A thermal fuse 100 is connected between the connector 98 and junction of the blower circuit relay 92 and a transformer 102. The transformer output, which is for example, a 12Vac output is connected to the junction of lead 106 to a 12Vac zero detector circuit (FIG. 3b) and a full wave rectifier 110 (FIG. 3c). The full wave rectifier is connected to the transformer for converting the ac transformer output to dc of a first voltage (12V). The 12V output of the full wave rectifier is connected to the junction of terminal 112 to power the relays and an audible alarm hereinafter described, and a voltage regulator 112. The voltage regulator converts the +12Vdc to a second voltage (+5V Vcc) for output at terminal 114 to the microprocessor, display and temperature sensing electronics.
The zero detection circuit 108 (FIG. 3b) includes a filter 115 connected by lead 106 to the output of transformer 102 for removing any dc component and to voltage dropping resistor 116. The dropping resistor 116 is connected to the negative terminal of comparator 118. The positive terminal of comparator 118 is connected to the junction of a resistor 120 and diode 122 connected to the Vcc source for receiving a voltage stabilized Vcc. The output of the comparator 118 is connected by lead 124 to the junction of pin 15 of the microprocessor 64 (FIG. 3a) and first terminal of a NAND gate 126. The second terminal of NAND gate 126 is connected to output pin 16 of the microprocessor. A second NAND gate 128 has its input terminals connected to the output of NAND gate 126 and its output connected to the nonmaskable interrupt pin 4 of the microprocessor. Thus, the zero crossing detector provides basic timing to the processor based on the 50 or 60 Hz cycle of the ac line for synchronizing the TRIAC operation.
A temperature sensor electronic circuit 130 (FIG. 3a) includes a thermocouple amplifier 132 with cold junction compensation having input terminals connected to the temperature sensing thermocouple 46 mounted in the sterilization chamber 18. A suitable thermocouple amplifier with cold junction compensation is an AD 595 device manufactured by Analog Devices, Inc. The output of the thermocouple amplifier is connected by lead 134 to the junction of a feedback line 136 to the negative temperature terminal of the amplifier and to an analog to digital converter (ADC) 138. The thermocouple amplifier receives the output feedback and provides an offset adjustment to allow for re-calibration to the dynamics of the sterilizer's chamber. If the thermocouple is disconnected or out of limits the microprocessor generates an alarm signal back through lead 140 to the encoder 74 (FIG. 3b) and alarm speaker 142 (FIG. 3a). The ADC 138 converts the temperature indicating analog signals to digital signals for input to the microprocessor or 64.
The display (FIGS. 3d-3e) includes in addition to the three LED indicators 78, 80, and 82 (FIG. 3a), twelve seven segment displays and seven logic inputs. Of the twelve seven segment displays three are used to display temperature and three are used to display time remaining for either cycle 1 or cycle 2 operation hereinafter described, and the remaining displays are not used. The time displays are also used to show the last cycle completed and any error codes. For a timing cycle longer than 9 minutes and 59 seconds, additional displays can be installed. Of the seven logic inputs, three are used for front panel switches and four are used for on-board jumper options. The display is connected directly to the microprocessor 64 and provides no action on its own. The functionality of the switches and displays are under the sole control of the microprocessor.
The display includes display drivers 140 and 142 having their clock terminals connected to the latch clock signal line 144 of the microprocessor 64, and their data input terminals connected to the microprocessor 64 through the data bus 70. A decoder 146, is connected to the microprocessor decode control line 148 of the microprocessor. The display drivers 140 and 142 have their output terminals connected to the input terminals of six of the twelve seven segment display modules (FIGS. 3d and 3e), and the decoder 146 has its outputs connected respectively to the bases of transistor switches 150 for the display elements. Each output of the decoder is connected to bases of the transistors 150 for two displays and act as switches for connecting Vcc to the displays.
Returning to the microprocessor 64 (FIG. 3a), a speaker circuit includes a transistor 152 having its base connected to output pin 17 through a bias resistor 154. The transistor 152 is biased on to supply the positive operating voltage (+12V) to a speaker 142 for purposes hereinafter described.
In operation the unit 10 is connected to a power source by connector 98 and the microprocessor 64 is powered up with instructions to scan the on/off switch. Turning the on/off switch on is detected by the microprocessor. The microprocessor then receives instructions to activate the blower, heater, display and enable the two cycle select switches. If the unit was on and no cycle activated, the unit receives instructions to shut off the display, cycle switches and heater immediately, and to shut off the blower after the temperature sensed has dropped below a preset value for a pre-set time. Activation of the cycle switches enables the microprocessor to cycle through the prescribed temperature and time instructions, sound the alarm and display the cycle that has been completed. During the on time the microprocessor receives instructions to continuously display the updated temperature, and during a cycle to display the time remaining in the cycle.
The processor ensures that a cycle is completed only if the temperatures were maintained continuously for the prescribed times. If during the cycle the temperature drops below the minimum sterilization temperature preferably 375 degrees Fahrenheit, the microprocessor receives instructions to automatically restart the cycle. The operator sees a continuous display of full time remaining as long as the sterilizer is below temperature. The time remaining display would start decrementing as soon as the operating temperature is reached.
The microprocessor instructions are broken up into a main program loop, an NMI interrupt based on the ac cycle, a quadrature interrupt from the crystal based timer and service routines based on a one second timing tick.
The main program loop provides a self check and initialization when it is plugged in. The display indicators and beeper are tested at turn on. All indicators and the beeper are turned on for a few seconds to allow the operator to verify their working. The operator must note if any segment has burned out. The main program loop also times the zero crossing to determine if it is on a 50 or 60 Hz system and sets up accordingly. The unit then sits idle scanning only the on/off switch. The unit again does a self check when the on/off switch is pressed. This includes a check sum verification of the operating software, exercise check, and clearing of the local data store RAM and in addition to the original power up tests turns on all indicators and displays for a few (five) seconds as a check for burned out elements.
The main loop then turns the fans and the heaters fully on, enables the heater control software and the display software, and scans for keyboard inputs and alarms. The main loop reads the processed temperature value and converts it to display format, sets the cycle times according to switch activation and the interlock of cycles. The main loop also provides warble generation, switch debounce and shut down sequence including either holding the blower on until the oven temperature is below a preset value or holding the blower on for a preset time.
The nonmaskable interrupt (NMI) routine provides a timing reference point for each ac cycle of the 50 Hz or 60 Hz ac power going to the heaters. This is required as the proportional control of the heaters is achieved by turning on the TRIAC for a preselected fraction of the ac cycle. The TRIAC naturally turns off at every zero crossing in the cycle; thus, the reference of the turn on pulse to the cycle zero crossing is very important. The interrupt for triggering the TRIAC on handler resets the time interrupt for triggering the TRIAC on so the quadrature interrupts must be tied to the cycle zero crossing. A phase relationship between these two (NMI and TI) interrupts is established at this point based on the duty cycle requested by the heater control software. That is, the switch 92 after initialization is continuously supplying an ac working current to the blower and TRIAC. A TRIAC is a semiconductor device that snaps to a completely on state for working current when a momentary pulse of control current is received and can be turned off only by interrupting the working current elsewhere in the circuit. As the working current is ac it goes off twice each ac cycle (at the 180 and 360 degree zero current crossing points) or for 60 Hz ac 120 times a second. The zero crossing detector is detecting the 120 zero current crossings each second and its logic is applying an outside pulse to the nonmaskable interrupt (NMI) terminal of the programmable controller.
The NMI interrupts the main program of the programmable controller 120 times a second and each time calls up the interrupt handler program. The interrupt handler program during heat up to the sterilization temperature pulses the TRIAC back on each time it goes off to provide working current to the heater element substantially continuously to provide a 100% duty cycle. After heat up, the interrupt handler computes a duty cycle for the heater for use during each second of heater operation.
The duty cycle is sufficient to maintain substantially constant the sterilization temperature during this time. The interrupt handler using the duty cycle information determines the quadrant and time to issue a turn on pulse to the TRIAC in order that the duty cycle will terminate on the 360 degree zero crossing of each ac cycle. After pulsing on the TRIAC to start a duty cycle the interrupt handler issues an instruction to pulse the TRIAC back on for any 180 degree crossing occurring during the duty cycle and an instruction not to send a turn on pulse to the TRIAC at the 360 degree crossing. Thus, the TRIAC remains off until triggered on again at the beginning of the next duty cycle.
The NMI is also used to provide real-time counters for all timing functions since the 50/60 Hz timing is very accurate. The thermocouple is also read during this ac cycle and accumulated in an average.
The quadrature interrupts are actually initiated by the zero crossing of the ac cycle, and break the ac cycle into four evenly timed quadrants.
The quadrant when the TRIAC is triggered by the time interrupt provides a coarse control of the heater power and the phase relationship to the NMI zero crossing interrupt provides the fine adjustment. The TRIAC is fired on entering this routine if it is the right quadrant and the heaters are enabled. This routine also provides a predictor function for the NMI zero crossing that blocks spurious interrupts and inserts missing cycles.
The one second based timing service routines are implemented as a cycle count of the zero crossing NMI interrupt. They decrement any timers that have been activated by the main loop software. They also update the current oven temperature by averaging the accumulated 50 or 60 readings and clearing an accumulator to form the next average. This current oven temperature is used for the temperature display as well as the proportional heater control. The proportional heater control software calculates the quadrant and the phase relationship to be used by the quadrature interrupt handlers in driving the TRIAC for the next second.
A short history is also kept of the temperature to be used in calculating the first and second derivatives of temperature with respect to time. The control equation is based on a straight forward second order equation using the difference between current and required temperatures and its derivatives. There are some discontinuities in the control function to try to compensate for previous history of abnormalities. The processor receives instructions to turn off the complete system should the temperatures exceed a certain level based on the assumption that the TRIAC has failed. The processor also looks at the history of temperatures and duty cycles to determine if the door has been open for a long time or that the heater chamber may be super heated. The microprocessor receives instructions to either cut back or step up the duty cycle according to the past history. These discontinuities are intended to speed up the rise to operating temperature and reduce overshoots by predicting abnormalities. Assuming there are no abnormal temperature jumps, the second order equation alone provides a smooth control of the heaters at operating temperatures.
The display is multiplexed in the sense that only two digits are displayed at any one time. This saves hardware and power. The illusion that there is a steady display of up to twelve digits is achieved by quickly displaying the six pairs that form the twelve digits, each in turn. The quadrature interrupt initiates the display of the next pair. This interrupt is running at, for example, 4×60=240 or 4×50=200 times a second thereby making the display look stationary. If the ac cycle were not broken up in this way, the display update of 60 times a second would be too slow and the display would appear to flicker.
Four basic error code groups are implemented by the processor. The error codes are displayed in the time window and have the following general format `E-XY` where `E` is a fixed format to identify this as an error display, the `X` identifies the error group and the `Y` identifies the error within the group. All errors will cause the microprocessor to turn off the TRIAC control to the heater and the relay controlling all ac power devices. Thus, the blower as well as the heater will be shut off. The error code flashes and the beeper sounds in time to the flashing display. The temperature will continue to show the current temperature; however, this reading may be false depending on the error type. The unit will remain in this state until the operator turns off the unit with the on/off switch or disconnects the power cord.
The on/off switch disables the beeper and the error code is displayed continuously instead of flashing. Unplugging the unit resets the error detect logic and the unit will start as if there were no error when it is plugged back in. Should the error code be detected again then it will go into the error state again as described above. The error codes are as follows:
Processor Failures:
E-10--EPROM Checksum failure (verifies program code not changed)
E-11--RAM failure (verifies variable space working)
E-12--Switch failure (verifies switches not shorted)
E-13--Timing failure (verifies 50-60 Hz line timing against on-board crystal)
Temperature Probe:
E-20--OPEN probe (check for broken leads)
E-21--REASONABLENESS check (check for rapidly changing or erratic temperature readings)
Heat Drive:
E-30--OVER heat (check for blower failure or shorted TRIAC)
E-31--UNDER heat (check for burnt out heater element).
The software program for accomplishing the above described features of the invention is contained in the file wrapper for those persons skilled in the art desiring more detailed information as to how to implement these features.
Although only a single embodiment of the invention has been described, it will be apparent to those persons skilled in the art that various modifications to the details of construction shown and described can be made without departing from the scope of the invention.
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An automatically controlled recirculating high velocity hot air sterilization device includes a housing having a sterilization chamber with a temperature sensor mounted therein, a hot air plenum including a blower in fluid communication with a heating element and sterilization chamber for inputting hor air into and receiving hot air from the sterilization chamber for recirculation, and a control chamber having a temperature sensing circuit connected to the temperature circuit for producing electrical inputs representative of the sterilization chamber temperature, power circuits connected to the heating element and blower, a controller connected to the temperature sensing circuit for monitoring the temperature, and to the heating element and blower circuits for controlling their operation, and a control panel including cycle selection switches for operation, an on/off switch, and temperature and timer/error displays. The controller is designed for monitoring the cycle selection switches and on/off switch, for controlling operation of the heating element, blower and timer for the cycle selected, for monitoring the temperature, for starting the timer when the temperature rises to the required temperature, for restarting the timer should the temperature fall below the required temperature during a cycle, for shutting down the device when a catastrophic failure occurs and for outputting an error signal together with problem information for display.
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This is a division of application Ser. No. 954,533, filed Oct. 25, 1978 and now U.S. Pat. No. 4,269,482.
BACKGROUND OF THE INVENTION
The present invention relates to a simultaneous multi-beam light modulation system, which can be employed in a laser printing apparatus.
In a well-known simultaneous multi-beam light modulation system, a plurality of image signals are assigned to carriers, respectively and the amplitude of each carrier is modulated, whereby a plurality of modulated signals are produced, and at the same time, by the modulated signals, an acoustic optical element is actuated, so that a laser beam is divided and modulated by the acoustic optical element. This system is employed in a laser printing apparatus and is practical for use in lowering the deflection speed of a scanning optical deflection apparatus. However, in this system, since the acoustic optical element is actuated simultaneously by a plurality of modulated signals, the light modulation intensity by each image signal is changed under the influence of other image signals, so that cross modulation occurs between the multiple beams from the acoustic optical element.
Under the circumstances, a system as shown in FIG. 1 is proposed for the purpose of obviating such cross modulation. In this system, a plurality of image signals from a signal source 1 respectively modulate the amplitude of the carriers assigned to the respective image signals, from high-frequency oscillators 5 to 7 in AM modulators 2 to 4. The polarities of the respective image signals from the signal source 1 are inverted in inverters 8 to 10 and summed up by an adder 11. The output signals from the adder 11 modulates the amplitude of an assigned carrier from a high-frequency oscillator 13 in an AM modulator 12. The output signals from the AM modulators 2 to 4 and 12 are mixed by a mixer 14 and are then amplified by an amplifier 15 so that the amplified signal is applied to an acoustic optical element 16. The acoustic optical element 16 diffracts a laser beam 17 by Bragg diffraction and produces diffracted lights of first order 18 to 21 corresponding to the output signals from the AM modulators 2 to 4 and 12, and a light of zero order 22. Of the multiple diffracted light beams 18 to 21, the light beam 21 which corresponds to an output signal of the AM modulator 12 is cut out by a light cut plate 23, so that only the light beam 18 to 20 corresponding to the image signals are taken out.
In this system, the output signals modulated by the image signals and the output signals modulated by the image signals whose polarities are inversed are applied to the acoustic optical element 16. Therefore, the light modulation intensity by each image signals becomes constant, without being influenced by other image signals, so that cross modulation between the respective beams less occurs. However, since the respective polarities of a plurality of image signals from the signal source 1 are first inversed by the inverters 8 to 10 and are then added by the adder 11, the necessary electric circuits become complicated. Furthermore, there exist as many image signals as the corresponding multiple beams 18 to 20, and the dynamic range of each beam is equal, but the AM modulators 2 to 4, the amplifier 15 and the acoustic optical element 16 have their own frequency bands which are not flat, and the respective beams more or less influence each other. Therefore, the characteristics of image signal: light output are not always identical.
SUMMARY OF THE INVENTION
For the foregoing reason, a principal object of the present invention is to provide a simultaneous multi-beam light modulation system capable of removing cross modulation of beams and correcting the characteristics of image signal: light output, so that the above-mentioned shortcomings of the conventional simultaneous multi-beam light modulation system are eliminated.
According to the present invention, a dummy signal is produced in such a manner that the sum of a plurality of signals and the dummy signal is constant, and the amplitude of carriers assigned to the signals and the dummy signal are respectively modulated by the signals and the dummy signal, so that a modulated output produced by the above-mentioned procedure is applied to an acoustic optical element. Therefore, cross modulation of beams is minimized. Furthermore, since the dummy signal is produced by addition and inversion of a plurality of signals and a setting signal, the dummy signal can be produced by one circuit. Therefore, an electric circuit necessary for producing the dummy signal is very simple. Furthermore, the gain of each modulated output can be controlled by a gain control means so that the input and output characteristics can be controlled with respect to each beam.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of the invention as well as the object and other features, reference will be had to the following detailed descsription which is to be read in conjunction with the drawings wherein:
FIG. 1 is a blcok diagram of a conventional simultaneous multi-beam light modulation system;
FIG. 2 is a block diagram of an embodiment of a simultaneous multi-beam light modulation system according to the present invention;
FIG. 3 is a timing chart of the embodiment according to the present invention.
FIG. 4 is a graph showing the characteristics of image signal input voltage: intensity of refraction of first order;
FIG. 5 shows schematically an example of multi-beam simultaneous scanning apparatus that can be employed in conjunction with the simultaneous multi-beam light modulation system according to the present invention;
FIG. 6 shows schematically another example of multi-beam simultaneous scanning apparatus that can be employed in conjuction with the simultaneous multi-beam light modulation system according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Minimizing cross modulation between beams in the simultaneous multi-beam light modulation system can be attained by use of an acoustic optical element having a broad frequency band with intensity of the overall deflection of light of first order kept constant, irrespective of input of image signals, and when an employed frequency band is broad, since the characteristics of image signal input: deflection of light of first order do not differ so much in each beam, a system capable of reducing cross modulation can be conceivable by keeping the sum of the input of image signals constant. In an embodiment of a simultaneous multi-beam light modulation system according to the present invention, a design is such that the sum of output beams I 11 to I 1m and a dummy beam I 1n , namely ΣI 1 =I 11 +I 12 + . . . I 1m +I 1n is kept constant. In order to accomplish this, a dummy signal voltage f sn is produced in such a manner as to make the sum of image signal input voltages f s1 to f sm and dummy signal voltage f sn , namely Σf s3 =f s1 +f s2 +f sm . . . +f sn , constant. To be more specific, referring to FIG. 2, an addition-reduction inverting amplifier 24 comprising resistors R 0 to R n (where R 0 =R 1 =R 2 =R 3 = . . . R n ), a diode D 1 and a direct current amplifier A performs addition of the image signal input voltages f s1 to f sm and reduction of a setting voltage f sn ' and inverse amplification of the image signal input voltages f s1 to f sm and the setting voltage f sn '. The setting voltage f sn ' is a voltage for setting the overall deflection efficiency of an acoustic optical element 25 and is produced by dividing a power source whose polarity is opposite to that of the image signal input voltages f s1 to f sm by use of a resistor VR 1 . In other words, the addition-reduction inverting amplifier 24 produces the dummy signal f sn by addition of the image signal input voltages f s1 to f sm and the setting voltage -f sn ', followed by inversion thereof, namely f sn =-{(f s1 +f s2 + . . . +f sm )-f sn '}.
Referring to FIG. 3 (a) to (d), there are shown the image signal input voltages f s1 to f sm . In FIG. 3 (e), the dot lines indicate f s1 +f s2 + . . . +f sm , and the solid line indicates f sn '. FIG. 3 (f) shows the dummy signal f sn . Thus, in the present invention, addition of the image signal input voltages f si to f sm and the setting voltage -f sn ' and their inversion can be performed by one element 24. Furthermore, even if the number of beams or the number of image signals increases, such addition or inversion can be performed by increasing only the number of the resistors R 1 to R m . Therefore, the necessary circuits do not become complicated. The diode D 1 constitutes a protective circuit for prohibiting generation of a negative output.
By modulators M 1 to M m and M n , the thus produced dummy signal f sn and the image signals f s1 and f s2 modulates the amplitude of the carriers f c1 to f cm and f en , which are respectively assigned by high-frequency oscillators 26 1 to 26 m and 26 n . The output signals of the modulators M 1 to M n are summed up into one signal by a mixer respectively through gain control amplifiers GC 1 to GC n . The summed signal is amplified by a power amplifier 28 and is then applied to an acoustic optical element 25. The acoustic optical element 25 divides and modulates a laser beam 29 from a laser generating apparatus and produces deflected light beams of first order I 11 to I 1m and I 1n which respectively correspond to the image signals f s1 to f sm and the dummy signal f sn , and a light beam of zero under I 0 . Of the deflected light beams of first order I 11 to I 1n , the deflected light beam I 1n corresponding to the dummy signal f sn is unnecessary. Thus, it is cut out by a light cutting plate 31.
When the dynamic ranges of the image signals f s1 to f sm are made equal, the characteristics of image signal: first order deflected light or intensity of refraction of first order are scattered as shown in FIG. 4 with respect to each beam by the employed electric circuits, the frequency band of the acoustic optical element 25 and cross modulation between the beams. Since the scattering of the characteristics of image signal: first order deflected light is caused by the difference of the gain or the gradient of the input and output characteristics, the gain control amplifiers GC 1 to GC n are adjusted so that the input and output characteristics of the respective beams are in agreement. By such adjustment, the first order deflected lights I 11 to I 1n having an equal intensity are obtained from the image signals f sl to f sm having an equal intensity. As a resistor VR 1 for setting the overall first order deflected light in FIG. 2, a variable resistor is employed so that the overall first order deflected light can be changed in accordance with the dynamic range of each image signal when the dynamic range is changed. When the first order deflected lights I 11 to I 1n are recorded on a photoconductive material for the purpose of reading by a computer output apparatus, a facsimile apparatus or a copying apparatus, a multi-beam simultaneous scanning apparatus as shown in FIG. 5 can be employed. In FIG. 5, the laser beam 29 from a laser source 41 is focussed by a focussing lens system 44 and is injected into the acoustic optical element 25 which is located in a focussing point of the laser beam 29. In the figure, reference numerals 42 and 43 indicate plane reflectors. A plurality of image signals, namely four image signals in FIG. 5, are applied to a transducer 25a of the acoustic optical element 25.
Supposing that high-frequency carriers for the respective image signals are, for instance, cos 2πf 1 t, cos 2πf 2 t, cos 2πf 3 t, cos 2πf 4 t and that information signals for performing amplitude modulation of these high-frequency carriers are a 1 (t), a 2 (t), a 3 (t), and a 4 (t), the image signals are applied to the transducer 25a in the form of ##EQU1##
Then, the first order deflected light beams I 11 , I 12 , I 13 , I 14 come out in the respective directions in accordance with the respective frequencies f 1 to f 4 . These first order deflected lights I 1i (i=1 to 4) are modulated in their intensities by their corresponding information signals a i (t)(i=1 to 4).
The zero order light beam I 0 which comes out of the acoustic optical element 25 is cut out by a stopper 46.
The first order deflected light beams I 11 to I 14 enter a focussing lens system 47 and are focussed near a point q on a photoconductive recording material 48. In practice, a deflecting means such as a galvanormittor, is placed between the acoustic optical element 25 and the recording material 48, so that the abovementioned deflected light beams I 1i (i=1 to 4) are deflected for scanning the recording material 48 in the direction normal to FIG. 5.
Referring to FIG. 6, there is shown another example of multi-beam simultaneous scanning apparatus for use with the present invention. In the figure, reference numeral indicates a laser source and reference numerals 52 and 53 indicate plane reflectors. Reference numeral 54 indicates a focussing lens system and reference numeral 25 indicates an acoustic optical element. The above-mentioned members are substantially identical with those in the apparatus shown in FIG. 5.
The multi-beam simultaneous scanning apparatus in FIG. 6 is for writing six lines by a simultaneous scanning. As the laser source 5, He-Ne laser is employed, and as a crystal for use in the acoustic optical element 25, PbM 0 O 4 is employed. As the focussing lens system 54, a focussing lens system with a 120 mm focal length is employed. High-frequency carriers with frequencies f 1 =150 MHz, f 2 =167 MHz, f 3 =184 MHz, f 4 =201 MHz, f 5 =218 MHz, and f 6 =235 MHz are employed. Six first order deflected light beams I 11 , I 12 , . . . I 16 come out of the acoustic optical element 25 which is positioned, 80 mm apart from the focussing lens system 54, on the optical axis of the focussing lens system 54, and are focussed on a plane S 0 with a 60 μm space therebetween. For simplification, only the deflected light beams I 11 , I 13 and I 16 are shown in FIG. 6.
Reference numeral 59 indicates a beam expander. The diameter of the laser beam from the laser source 51 is enlarged by the beam expander 59 and is then caused to enter the focussing lens system 54.
Reference numeral 71 indicates a lens system, and reference numeral 72 indicates a f-θ lens system. These two lens systems 71 and 72 constitute another focussing lens system.
As a deflecting means, a rotary multi-mirror device (not shown) is placed between the lens system 71 and f-θ lens system.
In order that the first order deflected light beams I 1i (i=1 to 6) are focussed, with a 83 μm space therebetween, on a recording material 58, by the focussing lens system comprising the lens system 71 and the f-θ lens system 72, the synthesizing magnification ratio in the focussing lens system has to be 1.33.
In the case where the lens system 71 with a 184 focal length and the f-θ lens system 72 with a 245.8 mm focal length and with a 33 mm distance between its lens surface and its second principal point are employed, in order to satisfy the above-mentioned condition, the object focal plane of the lens system 71 is caused to coincide with the surface S 0 and the distance between the lens system 71 and the image side principal point of the f-θ lens system 72 is set at 200 mm and the position of the recording material is determined in such a manner that the scanning surface of the recording material 58 is caused to coincide with the image side focal plane of the f-θ lens system 72.
The rotary multi-mirror as the deflecting means is positioned in such a manner that its beam deflection center comes to a position apart from the object side lens surface of the f-θ lens system by 30 mm.
The recording material 58 is a photoconductive drum. The surface of the photoconductive drum is charged uniformly and the scanning of six lines is performed simultaneously on the charged surface in the direction normal to FIG. 6 under the rotation of the photoconductive drum in the direction of the arrow, whereby a latent electrostatic image corresponding to an image signal is formed on the surface of the photoconductive drum.
The thus formed latent image is visualized by toner. The visible toner image is transferred and then fixed to a recording sheet, whereby a recording image corresponding to the image signal can be obtained.
By adjusting the beam diameter magnification of the beam expander 59, fine adjustment of the spot diameter of the focal point of the beam can be performed. Furthermore, by adjusting the frequency of carrier applied to the acoustic optical element or by moving minutely the position of the f-θ lens system along its optical axis, fine adjustment of the line space for writing-out scanning can be performed.
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The simultaneous multi-beam optical modulation system comprises the steps of producing a dummy signal in such a manner that the sum of a plurality of signals and the dummy signal is kept constant, modulating the amplitudes of assigned carriers by the dummy signal and the plurality of the signals so as to produce a modulated output and applying the modulated output to an acoustic optical element.
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This application is a continuation of application Ser. No. 641,412, filed Aug. 16, 1984, now abandoned, which is a continuation of application Ser. No. 532,939, filed Sept. 16, 1983, now abandoned, which is a continuation of application Ser. No. 232,800, filed Feb. 9, 1981, now abandoned, which is a continuation of application Ser. No. 121,759, filed Feb. 15, 1980, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a process for producing alkyl tert-alkyl ethers useful, among other things, as octane improvers in gasoline compositions.
2. Description of the Prior Art
It is known that alkyl tert-alkyl ethers can be prepared by reacting a primary alcohol with an olefin having a double bond on a tertiary carbon atom, thus methanol reacts with isobutylene and isopentenes (2 methyl 1-butene or 2 methyl 2-butene) to form respectively methyl tert-butyl ether (MTBE) and methyl tert-amyl ether (MTAE).
The reaction is selective for tertiary olefins so that it constitutes a valid process for their removal from olefinic streams in which they are contained together with linear unreactive olefins.
The reaction has an equilibrium which is the more favorable to the synthesis of the ether the lower the reaction temperature in accordance with its negative enthalpy.
It is known that the reaction is catalyzed by Lewis acids (aluminium trichloride, boron trifluoride), mineral acids (sulphuric acid) and organic acids (alkyl and aryl sulphonic acids, ion exchange resins).
Particularly suitable for the task are ion exchange resins in their acid form and it is known that the best results are obtained by means of macroreticular resins of the type "Amberlyst 15".
By means of such last named catalysts it is possible to reach thermodynamic equilibrium within industrially acceptable contact times in the temperature range of 50°-60° C.
At lower temperatures, thermodynamically more favorable, the kinetics are not sufficiently favorable to permit reaching equilibrium in practice.
This fact limits conversions.
Obviously the conversion of a reagent can be increased by increasing in the feed the content of the other reagent but this involves a lowering of the conversion of the excess reagent.
This can cause some drawbacks, as for instance in the synthesis of MTBE starting from methanol and isobutylene contained in an olefinic stream, the use of excess isobutylene involves the fact that the olefinic stream after separation of MTBE still contains 5-10% isobutylene and this constitutes a drawback when such stream has to be utilized for the production of maleic anhydride or butadiene. On the other hand an excess of methanol renders the purification of MTBE very expensive because of the formation of azeotropes.
It is to overcome the foregoing drawbacks in the production of tert-alkyl ethers that this invention is directed by employing a zeolitic catalyst material instead of an ion-exchange resin. Not only are the zeolitic catalysts substantially perfectly stable (which ion-exchange resins are not) but they also suppress formation of diisobutylene during the conversion to tert-alkyl ethers.
Unable to meet the demand for unleaded gasoline, petroleum refiners are turning to other chemicals to extend available supplies and obtain more usable fuel out of a barrel of oil. The chemicals, compounds of carbon, hydrogen and oxygen, contain no metal and avoid the environmental problems associated with tetraethyl lead and MMT (methylcyclopentadienyl manganese tricarbonyl).
Currently much of the interest in these blending agents centers on methyl tert-butyl ether, MTBE, which has been approved for use in motor fuels in concentrations of up to 7 percent by the Environmental Protection Agency.
Since MTBE is derived from crude oil fractions unsuitable by themselves for use in gasoline, simply adding it to the mixture called gasoline adds to gasoline supplies; but MTBE has another useful property; it enhances the octane rating of gasoline.
SUMMARY OF THE INVENTION
In accord with the invention there has now been found a process for the preparation of alkyl tert-alkyl ethers by a method which comprises reacting primary alcohols with an olefin having a double bond on a tertiary carbon atom in the presence of an acidic zeolite catalyst characterized by having a constraint index of from about 1 to 12, and a silica/alumina ratio of at least about 5. Removal of any excess alcohol from the reaction product is accomplished by adsorption on a small pore zeolite.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a block-flow diagram illustrating how the invention process fits into a refinery set up.
FIG. 2 is a block-flow diagram illustrating a self-contained MTBE plant.
DESCRIPTION OF PREFERRED EMBODIMENTS
The zeolite catalysts useful in this invention are characterized by a constraint index of from about 1 to 12, and preferably a SiO 2 /Al 2 O 3 mole ratio of at least about 5, non-limiting examples of which include zeolites ZSM-5, 11, 12, 23, dealuminized zeolite Y, and REALY. RE=Rare Earth.
Zeolite ZSM-5 is taught by U.S. Pat. No. 3,702,886. In a preferred synthesized form, the zeolite ZSM-5 for use in the catalyst composition useful in this invention has a formula, in terms of mole ratios of oxides in anhydrous state, as follows:
(0.9±0.2)M.sub.2 O/n:Al.sub.2 O.sub.3 :xSiO.sub.2
wherein M is selected from the group consisting of a mixture of alkali metal cations, especially sodium, and tetraalkylammonium cations, the alkyl groups of which preferably contain 1 to 5 carbon atoms, and x is at least 5.
Zeolite ZSM-11 is taught by U.S. Pat. No. 3,709,979. In the as synthesized form, the zeolite ZSM-11 for use in the catalyst composition useful in this invention has a formula, in terms of mole ratios of oxides in the anhydrous state, as follows:
(0.9±0.3)M.sub.2 O/n:Al.sub.2 O.sub.3 :zSiO.sub.2
wherein M is a mixture of at least one of the quaternary cations of a Group V-A element of the Periodic Table and alkali metal cations, especially sodium and z is at least 10.
Zeolite ZSM-12 is taught by U.S. Pat. No. 3,832,449. In the as synthesized form, the zeolite ZSM-12 for use in the catalyst composition useful in this invention has a formula, in terms of mole ratios of oxides in the anhydrous state, as follows:
(0.9±0.3)M.sub.2 O/n:Al.sub.2 O.sub.3 :wSiO.sub.2
wherein M is a mixture of at least one quaternary ammonium cation having the valence n, and alkali metal cations, especially sodium, and w is at least 20.
Zeolite ZSM-23 is described in U.S. Pat. No. 4,076,842.
In the as synthesized form, zeolite ZSM-23 for use in the catalyst composition useful in this invention, has a formula, in terms of mole ratios of oxides and in the anhydrous state, as follows:
(0.5-3.0)R.sub.2 O:(0.08-0.4)M.sub.2 O:Al.sub.2 O.sub.3 :(40-250)SiO.sub.2
wherein R is a nitrogen-containing organic cation and M is an alkali metal cation.
Dealuminized zeolite Y may be prepared by a method described in U.S. Pat. No. 3,442,795 in which the SiO 2 /Al 2 O 3 ratio of crystalline aluminosilicates is increased by treating such aluminosilicates to remove part of the aluminum atoms in their anionic structure. Such removal is effected by a combined solvolysis-chelation technique, using ethylenediaminetetraacetic acid (EDTA).
An important characteristic of the crystal structure of the zeolites for use herein is that they provide constrained access to, and egress from, the intracrystalline free space by virtue of having a pore dimension greater than about 5 Angstroms and pore windows of about a size such as wound be provided by 10-membered rings of oxygen atoms. It is to be understood, of course, that these rings are those formed by the regular disposition of the tetrahedra making up the anionic framework of the crystalline aluminosilicate, the oxygen atoms themselves being bonded to the silicon or aluminum atoms at the centers of the tetrahedra. Briefly, the preferred type catalysts useful in this invention possess, in combination: a silica to alumina ratio of at least about 5; and a structure providing constrained access to the intracrystalline free space.
The type zeolites useful in this invention freely sorb normal hexane and have a pore dimension greater than about 5 Angstroms. In addition, the structure must provide constrained access to large molecules. It is sometimes possible to judge from a known crystal structure whether such constrained access exists. For example, if the only pore windows in a crystal are formed by 8-membered rings of oxygen atoms, then access to molecules of larger cross-section than normal hexane is excluded and the zeolite is not of the desired type. Windows of 10-membered rings are preferred, although, in some instances, excessive puckering or pore blockage may render these catalysts ineffective. Twelve-membered rings do not generally appear to offer sufficient constraint to produce the advantageous conversions. But structures can be conceived due to pore blockage e.g. by cations, or other cause, they may be operative.
Rather than attempt to judge from crystal structure whether or not a catalyst possesses the necessary constrained access, a simple determination of the "constraint index" may be made by passing continuously a mixture of an equal weight of normal hexane and 3-methylpentane over a small sample, approximately 1 gram or less, of catalyst at atmospheric pressure according to the following procedure. A sample of the catalyst, in the form of pellets or extrudate, is crushed to a particle size about that of coarse sand and mounted in a glass tube. Prior to testing, the catalyst is treated with a stream of air at 1000° F. for at least 15 minutes. The catalyst is then flushed with helium and the temperature adjusted between 550° F. and 950° F. to give an overall conversion between 10% and 60%. The mixture of hydrocarbons is passed at 1 liquid hourly space velocity (i.e., 1 volume of liquid hydrocarbon per volume of catalyst per hour) over the catalyst with a helium dilution to give a helium to total hydrocarbon mole ratio of 4:1. After 20 minutes on stream, a sample of the effluent is taken and analyzed, most conveniently by gas chromatography, to determine the fraction remaining unchanged for each of the two hydrocarbons.
The "constrained index" is calculated as follows: ##EQU1##
The constraint index approximates the ratio of the cracking rate constants for the two hydrocarbons. Catalysts suitable for the present invention are those having a constraint index in the approximate range of 1 to 12. Constraint Index (CI) values for some typical catalysts, including those useful herein, are
______________________________________Crystalline Aluminosilicate CI______________________________________ZSM-5 8.3ZSM-11 8.7Clinoptilolite 3.4ZSM-12 2ZSM-23 9.1ZSM-35 2ZSM-38 2Beta 0.6ZSM-4 0.5Erionite 38______________________________________
It is to be realized that the above constraint index values typically characterize the specified zeolites but that such are the cumulative result of several variables used in determination and calculation thereof. Thus, for a given zeolite depending on the temperature employed within the aforenoted range of 550° F. to 950° F., with accompanying conversion between 10% and 60%, the constraint index may vary within the indicated approximate range of 1 to 12. Likewise, over variables such as the crystal size of the zeolite, the presence of possibly occluded contaminants and binders intimately combined with the zeolite may affect the constraint index. It will accordingly be understood by those skilled in the art that the constraint index, as utilized herein, while affording a highly useful means for characterizing the zeolites of interest is approximate, taking into consideration the manner of its determination, with the probability, in some instances, of compounding variable extremes. However, in all instances, at a temperature within the above-specified range of 550° F. to 950° F., the constraint index will have a value for any given zeolite of interest herein within the approximate range of 1 to 12.
Members of the above group of zeolites for use in the catalyst composition of the present invention possess definite distinguishing crystalline structures as evidenced by the above U.S. Patents incorporated herein by reference.
In one preferred embodiment, methanol is reacted with isobutylene (i-C 4 H 8 ) over an acid catalyst falling within the definition of the invention, such as HZSM-5, HZSM-12, and dealuminized zeolite Y at atmospheric pressure and a temperature range of between about 150° and 350° F., to produce methyl tert-butyl ether. It is known that the conversion of isobutylene increases with decreasing temperatures. It has been found that optimum temperature for most zeolites at atmospheric pressure is at about 180° F. As will be seen hereinbelow conversion of isobutylene is expected to increase significantly when carried out in liquid phase under a pressure required to keep the feed mixture liquid, e.g. of about 150-300 psig.
As described above, in a process for the production of methyl tertiary butyl ether (MTBE) or methyl tertiary amyl ether (MTAE), methanol is reacted with isobutylene or isopentene, respectively. In the prior art, a slight excess of methanol is required to suppress oligomerization of the olefin. The liquid product of the reaction is a mixture of MTBE (MTAE) with unreacted methanol and isobutene (isopentene) and inert C 4 's. Whereas the isobutene (isopentene) can be distilled off, the methanol forms an azeotrope with MTBE containing about 14 wt % (38.5 mol %) methanol. Therefore, with a molar ratio of CH 3 OH/i-C 4 H 8 in the charge of 1.2, half of the MTBE has to be recycled. The amount of MTBE to be recycled can be cut in half by applying pressure in the rectification.
Rather than performing a complicated rectification involving an azeotrope, it has been found in accord with another embodiment of the invention that the methanol can be removed from the reaction product by adsorption on a small-pore zeolite, e.g., zeolites 3A, 4A, 5A, or chabazite, and preferably 4A. Only methanol, which can be desorbed at higher temperature or lower pressure or a combination of both, is recycled. Instead of desorbing at reduced pressure, desorbing of the methanol in the C 4 feed stream is conducted at elevated temperature with the hydrocarbon feed as a purge. Thus the preheating of the reactor feed is combined with the desorption cycle of the adsorbers.
If MTBE is to be used as a gasoline octane booster, some oligomerization product, mainly diisobutene, as found in the prior art, can be tolerated. In such a case a smaller or no excess of methanol can be applied resulting in a product that consists mainly of MTBE and small amounts of isobutene, diisobutene and methanol. Again, if desired, the methanol can be removed from the mixture by adsorption on a small-pore zeolite. The same desorption schemes can be applied.
If highly pure MTBE is to be obtained, in the prior art, either an excess of methanol, e.g., 1.2:1, is applied in the catalytic reaction thus causing a large amount of MTBE to be recycled in the rectification. If adsorbers are employed, a higher load on the adsorbers is caused by the large excess of methanol. Oligomerized impurities, mainly diisobutene, can be removed only by distilling the MTBE.
With reference to the accompanying FIG. 1, the process which is the subject of the present invention will now be illustrated for the particular case of the preparation of MTBE, even though as noted above, the process is valid for the preparation of other alkyl tertiary alkyl ethers, the drawing being intended as not restrictive of the invention itself.
A C 4 fraction 10 is mixed with methanol 12, preheated and introduced into the reactor 14. The effluent 16 flows to a stripper 18 in which the unreacted C 4 hydrocarbons 20 are removed and led 24 to the alkylation unit. Methanol is removed from the bottom fraction 26 by adsorption on, e.g., 4A zeolite in a dual column adsorption-desorption unit 28. The effluent 30 from the adsorber 28 is essentially pure MTBE, containing <0.5% of TBA and no methanol; it can be blended directly with gasoline to obtain a higher octane rating. The adsorbed methanol is desorbed with a combination of heat and reduced pressure. The heat can be supplied with a preheated C 4 feed stream 11. The desorbed methanol, together with the C 4 feed, is recycled 32 to the reactor 14.
FIG. 2 is a block-flow diagram showing a self-contained MTBE plant. Isobutylene is produced in an isobutylene generator 10, which is not part of this invention, by charging a light hydrocarbon feed 12. A C 4 -stream 14 from this unit, after removal of by-products, contains isobutylene and inert C 4 hydrocarbons. This stream is heated and passed through an adsorption column 18 containing zeolite 4A loaded with methanol. The methanol is desorbed 18 and the mixed methanol-C 4 stream is charged, together with fresh methanol feed, to the MTBE reactor 20. Unreacted C 4 's are removed from the MTBE product in a C 4 stripper 22 and returned to the isobutylene generator. The stripper bottoms consist of MTBE with some unreacted methanol. This stream is passed to an adsorber 16 filled with, e.g. zeolite 4A which removes the methanol by adsorption. The effluent of the adsorber is pure MTBE 30. The adsorbed methanol is then again desorbed in the desorption cycle with the preheated C 4 stream, as described above.
The invention will be further described in conjunction with the following non-limitative examples.
Examples 1 (a-b), 2 (a-d), 3 (a-c), 4, 5 (a-b), 6 (a-c), 7 (a-d), 8 (a-b) and 9 (a-c) compiled in tabular form as Table I shows the manufacture of methyl tert-butyl ether over various zeolite catalysts in the vapor phase.
TABLE 1__________________________________________________________________________Formation of MTBE Over Zeolite Catalyst__________________________________________________________________________ Example 1 Example 2 Example 3 Example 4 Example 5 (a) (b) (a) (b) (c) (d) (a) (b) (c) (a) (b) (a) (b)__________________________________________________________________________CatalystZeolite Type H-Mordenite H-Beta → → → REHY → → REA1Y → HZSM-35 →SiO.sub.2 /Al.sub.2 O.sub.3 26 → 22 → → → 5.3 → → 5.1 → 23 →Wt of Zeolite, g 1.0 → → → → → → → → → → 0.65 →Wt of Al.sub.2 O.sub.3 Binder, g 0 → → → → → → → → → → 0.35 →ChargeMethanol, cc/hour 1.6 → → → → → → → → → → → →Isobutene, cc/min 15 → → → → → → → → → → → →Molar Ratio, CH.sub.3 OH/i-C.sub.4.sup.= 1.0 → → → → → → → → → → → →WHSV, total charge.sup.(1) 3.44 → → → → → → → → → → 5.29 →Pressure, PSIG 0 → → → → → → → → → → → →Temperature, set, °F. 150 180 200 150 180 200 150 180 200 180 200 180 200Temperature, peak, °F. 168 192 212 165 196 216 155 193 210 181 209 181 202Product Analysis 1.25 1.07 1.14 1.25 1.46 1.53 1.16 1.20 1.18 1.06 1.04 1.15 1.23CH.sub.3 OH/i-C.sub.4 H.sub.8 of chargeConversion of i-C.sub.4 H.sub.8to MTBE, % 4.8 8.4 7.1 20.8 13.9 9.1 0.8 11.3 10.6 25.3 23.4 0.13 0.41to C.sub.8 Olefin, % 1.15 6.0 14.1 13.2 23.0 27.3 0 0.47 1.88 0.3 1.25 0 0Selectivity to MTBE, % 80.7 58.3 33.5 61.2 37.7 25.0 100 96.0 85.0 98.8 94.9 100 100__________________________________________________________________________ Example 6 Example 7 Example 8 Example 9 (a) (b) (c) (a) (b) (c) (d) (a) (b) (a) (b) (c)__________________________________________________________________________CatalystZeolite Type HZSM-5 → → HZSM-5 → → → HZSM-5 → HZSM-11 → →SiO.sub.2 /Al.sub.2 O.sub.3 70 → → 70 → → → 40 → 20 → →Wt of Zeolite, g 1.0 → → 0.65 → → → → → 1.0 → →Wt of Al.sub.2 O.sub.3 Binder, g 0 → → 0.35 → → → → → 0 → →ChargeMethanol, cc/hour 1.6 → → → → → → → → → → →Isobutene, cc/min 15 → → → → → → → → → → →Molar Ratio, CH.sub.3 OH/i-C.sub.4.sup.= 1.0 → → → → → → → → → → →WHSV, total charge.sup.(1) 3.44 → → 5.29 → → → → → 3.44 → →Pressure, PSIG 0 → → → → → → → → → → →Temperature, set, °F. 180 200 220 170 180 200 220 180 200 170 180 200Temperature, peak, °F. 195 209 226 185 197 211 228 196 211 188 200 212Product Analysis 1.06 1.05 1.09 1.10 1.20 1.12 1.06 1.08 0.98 1.05 0.98 0.98CH.sub.3 OH/i-C.sub.4 H.sub.8 of chargeConversion of i-C.sub.4 H.sub.8to MTBE, % 30.5 25.3 18.6 23.6 27.6 25.9 18.7 26.2 21.8 24.6 25.1 21.0to C.sub.8 Olefin, % 0 0.1 0.15 0 0 0 0 0 0 0 0.14 0.21Selectivity to MTBE, % 100 99.6 99.2 100 100 100 100 100 100 100 99.4 99.0__________________________________________________________________________ .sup.(1) per g of zeolite
The conversion of i-C 4 H 8 increased with decreasing temperature; however, HZSM-12 gave no conversion at 150° F. It appears that the optimum temperature for most zeolites at atmospheric pressure, is in the vicinity of 180° F. The selectivity to MTBE increases also with decreasing temperature, ie., the olefin oligomerization reaction is reduced at lower temperature.
The following examples compiled in tabular form illustrated the conversion of i-C 4 H 8 in liquid phase under pressure of 150-200 psig in the presence of HZSM-5 and HZSM-11, respectively.
TABLE 2______________________________________Reaction of i-C.sub.4 H.sub.8 with CH.sub.3 OH over HZSM-5 ExtrudateTemperature Conver- Conver-Ex- Reactor sion of sion ofam- Peak Bottom CH.sub.3 OH i-C.sub.4 H.sub.8 CH.sub.3 OH,ple °F. °F. WHSV.sup.(1) i-C.sub.4 H.sub.8 % %______________________________________ 6 221 175 1.85 0.88 91.6 7 222 174 1.82 0.92 90.6 8 226 173 1.75 0.97 89.6 9 228 174 1.46 1.31 93.010 230 174 1.40 1.43 94.211 229 174 1.38 1.50 94.312 228 184 1.62 1.21 91.313 227 163 1.51 1.36 93.114 249 184 1.28 1.17 89.0______________________________________ .sup.(1) Based on zeolite
The catalyst used for the Examples listed in Table 2 was hydrogen ZSM-5, having a SiO 2 /Al 2 O 3 molar ratio of 40. The results show 90-94% conversion of the stoichiometrically minor component in the feed mixture. Formation of diisobutylene by oligomerization of isobutylene was not observed except for a very minor amount in Example 6, having the highest excess of isobutylene; less than 0.05% of isobutylene was converted to diisobutylene in this run. The suppression of the oligomerization side reaction is one of the advantages of this catalyst. As Example 14 indicates, higher reaction temperature was deleterious to the conversion, as the equilibrium
i-C.sub.4 H.sub.8 +CH.sub.3 OH⃡(CH.sub.3).sub.3 C--O--CH.sub.3
shifts to the left with increasing temperature. The catalyst showed no loss in activity or selectivity in seven days.
TABLE 3______________________________________Reaction of i-C.sub.4 H.sub.8 with CH.sub.3 OH over HZSM-11Temperature Bottom Conversion Peak Reactor CH.sub.3 OH ofExample °F. °F. WHSV i-C.sub.4 H.sub.8 i-C.sub.4 H.sub.8,______________________________________ %15 186 173 1.41 1.05 88.716 199 174 1.39 1.13 90.917 192 163 1.36 1.16 91.418 199 167 1.06 1.66 95.6______________________________________
Another zeolite useful as catalyst in this reaction is hydrogen ZSM-11. The material used had a SiO 2 /Al 2 O 3 molar ratio of 25. The results listed in Table 3 showed the same conversion levels as with ZSM-5 with this more active catalyst at a lower temperature.
The percentage of i-C 4 H 8 converted to tert.butyl alcohol can be reduced considerably by passing the methanol feed stream through a drying column containing 3A zeolite. In this manner we have been able to reduce the conversion of i-C 4 H 8 to TBA from about 1.0% to about 0.25%.
The following example illustrated the removal of methanol from a mixture containing the same with tertbutyl alcohol and MTBE.
EXAMPLE 19
Dehydrated zeolite 4A extrudate, 10.0 g. was placed in a column, and a liquid mixture containing 8.2 wt % of methanol, 5.3 wt % tert.butyl alcohol and 86.5 wt % MTBE was passed through the bed. The effluent was divided into three fractions. None of these fractions contained any methanol, whereas tert.butyl alcohol and MTBE were not sorbed.
The following examples illustrated adsorption vs. desorption at increasing temperatures.
EXAMPLE 20
Zeolite 4A containing 12.5 g of adsorbed methanol per 100 g. of zeolite, was calcined in an inert gas stream at a heating rate of 20° C. min. The fastest desorption rate was achieved at about 175° C., and all methanol was desorbed at 250° C.
EXAMPLE 21
Zeolite 4A containing adsorbed methanol was calcined in an inert gas stream at 175° C. All methanol was removed at this temperature. Analysis of the gas stream showed methanol being desorbed without forming by-products.
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Process for the preparation of alkyl tert-alkyl ethers which comprises reacting a primary alcohol with an olefin having a double bond on a tertiary carbon atom in the presence of an acidic zeolite catalyst. Removal of any excess alcohol from the reaction product is accomplished by passing the reaction product through a bed of small pore zeolite.
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This is a continuation-in-part of co-pending U.S. patent application entitled "UV Transparent Oxynitride Deposition in Single Wafer", Ser. No. 07/711,935, filed on Jun. 7, 1991, now abandoned.
FIELD OF THE INVENTION
The present invention relates to the field of semi-conductor fabrication; particularly to the deposition of a passivation layer on an integrated circuit wafer.
BACKGROUND OF THE INVENTION
An erasable and programmable read-only memory (EPROM) is erased by exposing it to ultraviolet (UV) light. To allow for such erasure, the EPROM must utilize a passivation layer which is sufficiently transparent to allow passage of the UV light. A number of EPROMs use oxynitride films for their passivation layer. These films are often deposited using a chemical vapor deposition (CVD) process wherein solid films are formed on an integrated circuit wafer by the chemical reaction of vapor phase chemicals (reactants) that contain the required constituent gases. Three major CVD processes exist: atmospheric pressure CVD (APCVD), low pressure CVD (LPCVD), and plasma-enhanced CVD (PECVD). APCVD and LPCVD systems are characterized by the requisite pressure for the deposition. Typically, these system use thermal energy to promote chemical reactions responsible for the film deposition. PECVD systems, however, are categorized by pressure and by its method of energy input. PECVD systems do not rely solely on thermal energy, but instead use a radio-frequency (RF) induced glow discharge plasma to transfer energy into the reactant gases, allowing the integrated circuit wafer to remain at a lower temperature than in APCVD or LPCVD processes.
Typically, in PECVD systems, the films are deposited in low frequency, lower power density batch reactors. Batch reactors accommodate a large number of wafers at the same time. In low power density processes, the RF power is distributed over large numbers of wafers, wherein each wafer is subjected to a low power density plasma. Under these conditions, the deposition time is long. Low frequency processes also have drawbacks. In low frequency processes, the films tend to be very sensitive to device pattern. In other words, a different process is required to fabricate each different type of devices, where each wafer contains different devices. Secondly, low frequency processes tend to produce films which are non-uniform across the wafer. The question of uniformity also arises where the wafer has a variety of devices on it with a varying structure density. Batch systems also have a higher wafer-to-wafer thickness nonuniformity as compared to single-wafer systems.
The present invention avoids these drawbacks by using a high frequency, high RF power density single wafer PECVD process to fabricate a passivation layer of oxynitride on EPROMs. The present invention operates on single wafers, irrespective of device type, to produce a uniform passivation film. Moreover, the present invention has the advantage of being a low particulate process.
SUMMARY OF THE INVENTION
A high density, high frequency, single wafer, plasma-enhanced chemical vapor deposition (PECVD) process for depositing a passivation layer on an integrated circuit semi-conductor wafer is described. In one embodiment, the wafer is placed on a first electrode, a grounded succeptor, in a vacuum chamber. The wafer is then heated to a process temperature. In the currently preferred embodiment, the process temperature ranges from 350°-430° C. Next, the vacuum chamber is pumped to a low pressure. The pressure range for the currently preferred embodiment is 4-6 torr.
After low pressure has been achieved, a gas mixture consisting of nitrogen, silane, ammonia and nitrous oxide is introduced to the vacuum chamber through a second electrode which is designed like a showerhead. The gas mixture flows directly on top of the wafer. A radio-frequency (RF) potential is then applied to the showerhead electrode, causing excitation and ionization of the gas mixture leading to chemical reaction and the formation of a passivation film on the wafer.
The films formed with the described process simultaneously exhibit low particle densities, high UV transparency, low within-wafer and wafer-to-wafer thickness variations, low pattern sensitivity, high moisture resistance, no pinholes, low stress, good step coverage, and low bound hydrogen content. The gas mixture flows through the showerhead electrode from a gas manifold. Each gas enters the gas manifold from a separate gas line. Each gas line utilizes two control valves which operate to minimize particle production in the vacuum chamber.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be understood more fully from the detailed description given below and from the accompanying drawings of the preferred embodiments of the invention, which, however, should not be taken to limit the invention to the specific embodiments, but are for explanation and understanding only.
FIG. 1 illustrates a single wafer plasma-enhanced chemical vapor deposition (PECVD) system.
FIG. 2 illustrates a flow diagram of the passivation layer deposition process using a PECVD system.
DETAILED DESCRIPTION OF THE INVENTION
A process for depositing a passivation layer on an integrated circuit is described. In the following description, numerous specific details are set forth such as specific process steps, film thicknesses, etc., in order to provide a thorough understanding of the present invention. It will be obvious, however, to one skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known processing steps have not been described in detail to avoid unnecessarily obscuring the present invention.
The following detailed description depicts one portion of the backend of a fabrication process for a semiconductor integrated circuit. Passivation films are deposited on electrically programmable read-only memory (EPROM) devices and are utilized to erase the EPROM. Typically, an EPROM employs floating gates, that is, polysilicon members completely surrounded by an insulator. Electrical charge is transferred into the floating gate through a variety of mechanisms, such as avalanche injection, channel injection, Fowler-Nordheim tunnelling, hot electron injection from the substrate, etc. These memories are erased by exposure to ultraviolet (UV) radiation. The passivation film is deposited on top of the memory device. Therefore, the passivation film must be transparent enough to allow UV light to pass through the film so that the device may be erased. In the currently preferred embodiment, the passivation film (layer) is deposited using a plasma-enhanced chemical vapor deposition (PECVD) system 100 as shown in FIG. 1.
Referring to FIG. 1, PECVD system 100 is a single wafer load-locked system. PECVD system 100 utilizes chamber 101 as the environment for depositing a passivation film on a semiconductor wafer, such as wafer 102. The composition of the passivation film is silicon oxynitride, which is a mixture of silicon, oxygen, and nitrogen. Hydrogen is a by-product of the film deposition process. A wafer, such as wafer 102, once inside chamber 101 can be subjected to temperature and pressure variation by PECVD system 100. Temperature is varied and regulated by a heater and temperature sensor respectively (not shown). Pressure is controlled and regulated by pressure control valve 106A and vacuum pump 106B.
Wafer 102 rests on an electrode, succeptor 104. In the currently preferred embodiment, succeptor 104 is electrically grounded. Above wafer 102 is a second electrode, showerhead 103. Showerhead 103 has a special showerhead design. Showerhead 103 has holes in it and distributes gases over the top surface of wafer 102 in the same manner as a showerhead. The distance between showerhead 103 and succeptor 104 is referred to as the electrode, or gap, spacing.
Gases enter chamber 101 through showerhead 103. Showerhead 103 is supplied by gas manifold 110. Gas manifold 110 is suppled by gas lines 111, 112, 113, and 114. Nitrogen (N 2 ) flows through gas line 111 into gas manifold 110. The flow of nitrogen is controlled by control valves 121 and 131. Silane (SiH 4 ) flows through gas line 112 into gas manifold 110. The flow of silane is controlled by control valves 122 and 132. Ammonia (NH 3 ) flows through gas line 113 into gas manifold 110. The flow of ammonia is controlled by control valves 123 and 133. Nitrous Oxide (N 2 O) flows through gas line 114 into gas manifold 110. The flow of nitrous oxide is controlled by control valves 124 and 134.
As shown in FIG. 1, RF generator 105 is coupled to showerhead 103. RF generator 105 applies an RF potential to showerhead 103 which sets up a potential between the two electrodes, showerhead 103 and succeptor 104. This potential allows wafer 102 to be exposed to an RF plasma while the four reactant gases (nitrogen, silane, ammonia, and nitrous oxide) are introduced into chamber 101. The RF potential causes the four gases to react and form the passivation layer.
Hence, FIG. 1 discloses a plasma-enhanced chemical vapor deposition system, PECVD system 100, which produces a silicon oxynitride passivation film on a semiconductor wafer. The properties of this passivation film are critical. Namely, the UV transmission, where the UV wavelength equals 254 nm (nanometers), and the stress of the film are critical to the device properties. Secondarily, the refractive index, uniformity and wet etch rate (moisture permeability) which result from the process are of equal concern. Finally, the hydrogen content in the film is important. The film stress is strongly affected by RF power (increased RF power results in increased compressive stress). Increased SiH 4 flow causes a more tensile film.
The refractive index is strongly affected by SiH 4 and gap spacing--increasing SiH 4 increases refractive index, and increasing gap reduces refractive index. The wet etch rate is affected by RF, SiH 4 , gap and N 2 O. Increasing RF and/or SiH 4 decreases the wet etch rate, while increasing gap or N 2 O increases the wet etch rate. Increasing the gap also improves the thickness uniformity, while increased SiH 4 reduces the UV transmittance.
Referring to FIG. 2, the passivation film deposition process is depicted. During stage 201 of the process, wafer 102 is placed into chamber 101 face up on succeptor 104. Above wafer 102 is the second electrode, showerhead 103, through which the gases are distributed. Then chamber 101 is sealed. During stage 202, the sealed chamber 101 is pumped to the process pressure using vacuum pump 106B. In the currently preferred embodiment, the process pressure is between 4-6 Torr. The temperature is stabilized to the process, or wafer, temperature. In stage 203, wafer 102 is heated to the process temperature. In the currently preferred embodiment, the process temperature, referred to as wafer temperature, is between 350°-430° C. Once temperature and pressure parameters have been set, the electrode spacing (gap) between grounded succeptor 104 and showerhead 103 is adjusted to the correct spacing, stage 204. In the currently preferred embodiment, the electrode spacing or gap is adjusted to approximately 300-600 mils (thousands of an inch).
Once the system parameters have been set, the four gases (nitrogen, silane, ammonia and nitrous oxide) are turned on and stabilized at their individual flow rates (stage 205). In the currently preferred embodiment, the flow rates are as follows: nitrogen (N 2 ) with a flow rate of 500-4000 standard cubic centimeter/minute (sccm); silane (SiH 4 ) with range 50-150 sccm; ammonia (NH 3 ) with a flow rate of 40-150 sccm; and nitrous oxide (N 2 O) with a range 50-150 sccm. The gases are mixed into gas manifold 110 which leads into chamber 101. At stage 205, all of the parameters have been set.
The optimization of all critical film properties (UV transmissivity, stress, wet etch rate, deposition rate, and thickness uniformity) requires tight control of processing parameters, particularly the gas flows. Silane (SiH 4 ) flow strongly affects UV transmissivity and wet etch rate, while nitrous oxide (N 2 O) flow strongly affects wet etch rate. The process window required to achieve UV transmissivity greater than 90% and wet etch rate less than 800 Å/min (6:1 buffered oxide etch) consists of SiH 4 flow between 70 and 80 sccm and N 2 O flow between 40 and 50 sccm. For SiH 4 flow greater than 80 sccm, the UV transmissivity drops below 90%, and for N 2 O flow greater than 50 sccm, the wet etch rate increases to greater than 800 Å/min. For flows below the lower limits, the deposition rate drops below 5200 Å/min.
Stage 206 involves the application of the RF potential. This is accomplished by switching on the RF generator 105. RF generator 105 is a high frequency generator, operating at a frequency of 13.56 MHz. When RF generator 105 is switched on, Showerhead 103 is placed at high RF potential. In the currently preferred embodiment, the power from RF generator is between 200-500 watts. The gases flow for a few seconds until they achieve a stable flow. The RF potential creates an RF field which supplies energy to the gas mixture within chamber 101. The gases become excited and form a glow discharge or plasma (The plasma refers to the partially ionized gas, while the glow discharge refers to the plasma maintained over the specific pressure range (4-6 Torr)). The plasma, in turn, transfers energy into the reactant gases to enhance the deposition of the passivation film onto wafer 102. Since the PECVD system 100 is a high frequency system, the gases are more efficiently ionized once the plasma is struck. Using silane (SiH 4 ), nitrous oxide (N 2 O), ammonia (NH 3 ) and nitrogen (N 2 ) as reactant gases, a thin film of silicon oxynitride (Si x O y N z ) is deposited on wafer 102. Thus, PECVD system 100 produces a passivation layer on wafer 102.
The process concludes stage 207 by reversing the order of steps 201-206. RF generator 105 is turned off. The gases are turned off, and wafer 102 is removed from the chamber.
Finally, stage 208 involves cleaning chamber 101. Cleaning is done by generating a plasma with certain gases in chamber 101, when it is empty. In other words, only succeptor 104 and showerhead 103 are in chamber 101. The gases that are used are those that would tend to etch or react strongly with silicon oxides or nitrides. These gases are usually flourine containing gases, such as nitrous flouride, NF 3 . It is normally mixed with nitrous oxide, N 2 O. A plasma is generated with those two gases to create pre-flourine and oxygen species. Since oxygen tends to react with silicon to form silicon dioxide. SiO 2 , the oxygen bonds to residual silicon. The flourine tends to etch off and break-up the silicon dioxide. Subsequently, these gases and their by-products are pumped away and cleaning is complete. The process depicted in FIG. 2 is a low particulate process, wherein very low particle levels are generated on wafer 102. This is an improvement over previous approaches.
Typically, many particles are generated during the process. Particles are formed during the deposition process. The majority of the deposition occurs on wafer 102. Deposition occurs also on showerhead 103 because it is exposed to the RF plasma. Hence, some film tends to be deposited on all surfaces. Even after cleaning, stage 208, some residual film remains on the walls of chamber 101. When a new wafer is placed in chamber 101 and a burst of gas flows into chamber 101, those flakes or residual deposits loosen up and fall on to the wafer. These particles, or "clumps" of material, can interfere with the operation device if one or more of them becomes part of the passivation film. For instance, these particles can impair the UV erasability due to blockage of some memory cells during the erase operation. Particles can have a wide range of detrimental effects. Thus, particle minimization is important. The effects of any of the residual background film or contamination can be reduced by reducing the amount the gas that stirs up the residual material.
Particle minimization can be accomplished by operating showerhead 103 in the proper manner. One method to combat the problem is to evacuate gas lines 111, 112, 113 and 114 before loading wafers into process chamber 101. Control of the gas flow is accomplished by valves 131, 132, 133, 134, 121, 122, 123 and 124 which adjust flow rates of their respective gases. Each gas passes through the valve and continues into gas manifold 110 where all four gas lines 111, 112, 113 and 114 meet. Gas manifold 110 outputs the gases in chamber 101. Gases are pumped out of chamber 101 by vacuum pump 106B. When PECVD system 100 is idle (i.e., no processing occurring), chamber 101 is under vacuum and gas valves 121, 122, 123, and 124 are closed. When the deposition process is to be utilized, wafer 102 will be brought into the chamber, and the process described above begins. At some point it will be necessary to open gas control valves 121, 122, 123, and 124. The gases are at fairly high pressure (5-15 psi). The pressure in chamber 101 is 4-6 Torr. This is a large pressure differential. When one valve is opened, a very large burst of gas initially flows very quickly, otherwise known as turbulence.
The burst of gas can stir up particles and deposit them on wafer 102. One method to minimize turbulence is to undertake the following procedure after circulation of the chamber clean process stage. Each mass flow controller (MFC) valve (131, 132, 133, 134) is closed, the gas shutoff valves (121, 122, 123, 124) are opened, and the section of gas line between the MFC valve and the chamber is evacuated. The shutoff valves are then closed, and the next wafer is placed in the chamber (step 201). During gas stabilization step 205, the shutoff valves are opened and the MFC valves are slowly opened in a step-wise fashion to their final setpoint valves. This allows the gases to be slowly introduced and prevents large bursts of the gases. The elimination of gas bursts minimizes the possibility of particles being loosened up and falling onto wafer 102.
Thus, a plasma-enhanced chemical vapor deposition process for depositing a passivation layer on a semiconductor wafer is described.
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A high density, high frequency, plasma-enhanced chemical vapor deposition (PECVD) process for depositing a passivation layer on a semiconductor integrated circuit wafer. The wafer rests on a grounded electrode while a second electrode disperses gases over the wafer. The second electrode disperses the gases in the same manner as a showerhead. An radio-frequency (RF) potential applied to the showerhead electrode causes the gases to react under specific temperature, pressure, and electrode spacing conditions. Furthermore, the present invention is a low particulate process. The process forms a film of high UV transparency. The chamber is cleaned after removal of the wafer, and gas lines are evacuated. This results in a low particle process. The film have low within-wafer and wafer-to-wafer variation of thickness and refractive index, low pattern sensitivity of thickness of the deposited film, high deposition rate, high moisture resistance (low wet etched rate), low density of SiH and NH bonds, no pinholes, low stress, good sidewall step average, and high resistance to film cracking.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to mounting assemblies for temporarily stowing locks, for example, bicycle U-locks and cable locks, when not in use, and for releasing the locks for ready use when needed. More particularly, the present invention relates to mounting arrangements which facilitate adjustment in the position of the lock relative to the bicycle.
[0002] Since the invention of bicycle U-locks and cable locks, a variety of holders have been proposed for removably carrying such a lock when the bicycle is in use, rather than parked. Such a U-lock typically comprises a semi-enclosure member or shackle having legs or fittings with configured feet, a straight crossbar having openings for reception of these feet, and a locking mechanism in the crossbar for retaining or releasing these feet. Such a cable lock typically comprises a cable having at one end a leg or fitting with a configured foot, a bar extending from the other end of the cable and having an opening for reception of this foot, and a locking mechanism in the bar for retaining or releasing this foot. For protection against theft, this tie lock assemblage ties a strut or the like of the bicycle to a post, rail or other station.
[0003] The objectives of a holder for such locks are to carry the a lock securely on the bicycle frame without rattling, to position the lock inconspicuously on the bicycle frame without hindering movement of the cyclist, and yet to facilitate convenient release of the lock from the holder whenever needed. Prior art holders have not completely met these objectives.
SUMMARY OF THE INVENTION
[0004] The present invention provides in one aspect a lock mounting arrangement comprising a lock and a mounting member secured to a portion of the lock such that the mounting member is rotatable relative to the portion of the lock. At least two position delineators are provided on one of the mounting member and the lock and an engagement member is provided on the other of the mounting member and the lock. The engagement member is movable between a first position in which the engagement member engages at least one of the position delineators and thereby fixes the rotative position of the mounting member relative to the portion of the lock, and a second position in which the engagement member is lockingly disengaged from the position delineators such that the mounting member is free to rotate relative to the portion of the lock.
[0005] Other aspects of the invention are shown in the accompanying drawing figures and described in the following detailed description of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 shows a cable lock incorporating a mounting arrangement in accordance with the invention, the cable lock being mounted on the bicycle.
[0007] FIG. 2 shows the bicycle of FIG. 1 parked and secured by the cable lock of FIG. 1 .
[0008] FIG. 3 is a top perspective view of an exemplary bracket in accordance with the lock mounting arrangement of the present invention.
[0009] FIG. 4 is a side plan view of a portion of a cable lock incorporating a mounting arrangement that is a first embodiment of the invention.
[0010] FIG. 5 is an isometric view showing the mounting member of the cable lock of FIG. 4 .
[0011] FIG. 6 is a top plan view of the cable lock of FIG. 4 .
[0012] FIG. 7 is a bottom plan view of the cable lock of FIG. 4 .
[0013] FIG. 8 is an end elevation view of the cable lock of FIG. 4 .
[0014] FIG. 9 is an exploded isometric view of the lock housing and mounting member of the cable lock of FIG. 4 .
[0015] FIG. 10 shows the mounting member of FIG. 9 , in partial section, assembled on the lock housing.
[0016] FIG. 11 is an isometric view of the mounting arrangement of FIG. 4 with the mounting member shown transparently.
[0017] FIG. 12 is an expanded view of the mounting arrangement illustrated in FIG. 11 , illustrating the engagement member in an engaged position.
[0018] FIG. 13 is similar to FIG. 12 and shows the engagement member in a disengaged position.
[0019] FIG. 14 is similar to FIG. 13 and illustrates rotative adjustment of the mounting member relative to the lock housing with the engagement member in a disengaged position.
[0020] FIG. 15 is a side plan view of a portion of a cable lock incorporating a mounting arrangement that is an alternate embodiment of the invention.
[0021] FIG. 16 is front elevation view of the cable lock of FIG. 15 .
[0022] FIG. 17 is rear elevation view of the cable lock of FIG. 15 .
[0023] FIG. 18 is a top plan view of the cable lock of FIG. 15 .
[0024] FIG. 19 is a bottom plan view of the cable lock of FIG. 15 .
[0025] FIG. 20 is an exploded isometric view of the lock housing and mounting member of the cable lock of FIG. 15 .
[0026] FIG. 21 is a cross sectional view of the mounting arrangement of FIG. 15 with the engagement member in an engaged position.
[0027] FIG. 22 is a cross sectional view of the mounting arrangement of FIG. 15 with the engagement member in a disengaged position.
[0028] FIG. 23 is an isometric view of the mounting arrangement of FIG. 15 illustrating rotative adjustment of the mounting member relative to the lock housing.
[0029] FIGS. 24 and 25 are isometric views of the mounting arrangement of FIG. 15 in partial section and illustrating the movement of the adjusting member during adjustment.
[0030] FIG. 26 is an elevation view of a U-lock incorporating a mounting arrangement that is an alternate embodiment of the invention.
[0031] FIG. 27 is an exploded elevation view of the mounting arrangement of the U-lock of FIG. 26 .
[0032] FIG. 28 is an elevation view of a U-lock incorporating a mounting arrangement that is an another alternate embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0033] Although the invention is illustrated and described herein with reference to specific embodiments, the invention is not intended to be limited to the details shown. Rather, various modifications may be made in the details within the scope and range of equivalents of the claims and without departing from the invention.
[0034] FIGS. 1 and 2 show a cable lock 20 held on a strut 22 of a bicycle frame by an mounting arrangement 24 , which comprises a mounting member 26 secured to the lock body 21 and a bracket 28 which is securely connected to the strut 22 of the bicycle frame. As described in more detail hereinafter, the mounting arrangement 24 allows the rotative position of the mount member 26 relative to the lock body 21 to be adjusted such that the lock 20 can be unobtrusively stowed on the bicycle frame as shown in FIG. 1 . With disengagement, the lock 20 is readily available for tying the bicycle to a secure post or other station as shown in FIG. 2 .
[0035] Referring to FIG. 3 , an exemplary bracket 28 is illustrated. The exemplary bracket 28 is substantially as described in U.S. Pat. No. 6,422,442 which is incorporated herein by reference. The bracket 28 includes a mount portion 30 and an attachment portion 34 . The attachment portion 34 in the exemplary bracket 28 includes a strap 36 which is positioned about a bicycle frame member and tightened. While the exemplary bracket 28 includes a strap as an attachment means, the invention is not limited to such. The bracket 28 may have any of a number of attachment means, for example, but not limited to, the various attachment means illustrated in U.S. Pat. No. 5,647,520, incorporated herein by reference.
[0036] The mount portion 30 includes a channel 32 or the like which is configured to receive a complementary tongue portion 52 of the mounting member 26 (see FIG. 4 ). Engagement of the tongue portion 52 in the channel 32 secures the lock 20 to the bracket 28 . While the illustrated tongue portion 52 and channel 32 are tapered, the invention is not limited to such. The complementary mating members can have any configuration, for example, a rectangular tongue and a corresponding channel. Furthermore, the complementary mating members may be reversed, i.e., the tongue portion may be provided on the bracket with the channel being defined on the mounting member. Various other configurations of mating members may be utilized without departing from the invention.
[0037] Referring to FIGS. 4-14 , a cable lock 20 incorporating a mounting arrangement 24 that is first embodiment of the present invention will be described. The mounting arrangement 24 includes a mounting member 26 rotatably secured to an end of the lock body 21 . In the present embodiment, the lock body 21 includes a key face 23 opposite the mounting member 26 and a cable head receiving opening 27 approximately midway along the body 21 . Such a configuration is not required and the lock body 21 may be otherwise configured, for example, the key opening may be provided midway along the body 21 with the cable head receiving opening 27 opposite the mounting member 26 . Other configurations may also be utilized. A lock cylinder (not shown) is positioned in the lock body 21 to lockingly engage a head (not shown) forward the shank 25 attached to end 31 of the cable. A keyway (not shown) or the like is provided on key face 23 to selectively lock and unlock the lock cylinder.
[0038] Referring to FIGS. 9-14 , the mounting member 26 has a cylindrical body 50 having a generally open end 53 and a reduced open end 51 . The body 50 does not have to be cylindrical, but may have other configurations. The reduced open end 51 is configured to receive the opposite end 33 of the cable which passes through the mounting member 26 and is secured within the lock body 21 . The generally open end 53 has an internal annular protrusion 55 configured to snap fit into an annular recess 72 provided along an end projection 70 extending from the lock body 21 . The annular protrusion 55 may be continuous or segmented and may have various configurations. Engagement of the protrusion 55 in the recess 72 secures the mounting member 26 to the lock body 21 . Sufficient clearance is provided between the protrusion 55 and the recess 72 such that the mounting member 26 is rotatable relative to the lock body 21 .
[0039] To set the position of the mounting member 26 relative to the lock body 21 , the lock body 21 includes a plurality of position delineators 73 and the mounting member 26 includes an engagement member 60 . While the present embodiment includes the position delineators 73 on the lock body 21 and the engagement member 60 on the mounting member 26 , the invention is not limited to such. Alternatively, position delineators may provided on or within the mounting member 26 and the engagement member 60 may be provided on the lock body 21 , or a combination thereof.
[0040] In the present embodiment, the position delineators 73 are defined by a series of alternating teeth 74 and openings 76 defined by the end projection 70 extending from the lock body 21 . The delineators may have other structures including, but not limited to, projections, recesses, splines, or the like. For example, the end projection 70 extending from the lock body 21 may be provided with external splines while the inside surface of the mounting member 26 is provided with complementary splines. The mounting member 26 would be axially movable relative to the locking body 21 to engage and disengage the splines.
[0041] In the present embodiment, the engagement member 60 includes a sliding block 64 with an engagement pin 66 extending from one end thereof. The opposite end of the sliding block 64 includes a spring post 67 which supports a spring 68 or other biasing member. The spring post 67 and spring 68 are received in a recess 59 within the mounting member 26 such that the spring 68 biases the sliding block 64 , and thereby the engagement pin 66 , toward the locking body 21 . The engagement pin 66 engages one of the openings 76 between the teeth 74 and thereby locks the rotative position of the mounting member 26 relative to the locking body 21 .
[0042] To adjust the position of the mounting member 26 relative to the lock body 21 , for example, to facilitate a more comfortable position of the lock 20 on the bicycle, the engagement member 60 includes a push pad 62 which extends through an opening 54 in the mounting member body 50 . In the present embodiment, the push pad 62 includes feet 63 which snap fit into an aperture 65 in the sliding block 64 . Referring to FIG. 14 , to adjust the position of the mounting member 26 , the push pad 62 is pushed away from the lock body 21 against the force of the spring 68 , as indicated by arrow A, until the engagement pin 66 disengages from the opening 76 . The mounting member 26 can then be rotated relative to the lock body 21 as indicated by arrow B. Once a desired position is reached, the push pad 62 is released and the spring 66 biases the sliding block 64 until the engagement pin 66 engages one of the openings 76 . The teeth 74 defining the openings 76 may be provided with tapered surfaces or the like to encourage the pin 66 into one of the openings 76 .
[0043] The mounting arrangement 24 allows a user to easily fine tune the position of the lock 20 on the bicycle in a secure, reliable manner without the need for any tools.
[0044] Referring to FIGS. 15-25 , a cable lock 120 incorporating a mounting arrangement 124 that is an alternate embodiment of the present invention will be described. The mounting arrangement 124 includes a mounting member 126 rotatably secured to an end of the lock body 121 . In the present embodiment, the lock body 121 includes a combination lock assembly 123 therealong and a cable head receiving opening 127 opposite the mounting member 126 . Such a configuration is not required and the lock body 121 may be otherwise configured. The combination lock assembly lockingly engages a head (not shown) forward the shank 125 attached to end 131 of the cable.
[0045] Referring to FIGS. 20-25 , the mounting member 126 has a cylindrical body 150 having a generally open end 53 and a reduced open end 51 . The body 150 does not have to be cylindrical, but may have other configurations. The reduced open end 151 is configured to receive the opposite end 133 of the cable which passes through the mounting member 126 and is secured within the lock body 121 . The generally open end 153 has an internal annular protrusion 155 configured to snap fit over radial projections 174 provided along an end projection 170 extending from the lock body 121 . Engagement of the protrusion 155 against the projections 174 secures the mounting member 126 to the lock body 121 . Sufficient clearance is provided between the protrusion 155 and the projections 174 such that the mounting member 126 is rotatable relative to the lock body 121 .
[0046] To set the position of the mounting member 126 relative to the lock body 121 , the lock body 121 includes a plurality of position delineators 173 and the mounting member 126 includes an engagement member 160 . While the present embodiment includes the position delineators 173 on the lock body 121 and the engagement member 160 on the mounting member 126 , the invention is not limited to such. Alternatively, position delineators may provided on or within the mounting member 126 and the engagement member 160 may be provided on the lock body 121 , or a combination thereof.
[0047] In the present embodiment, the position delineators 173 are defined by the radial projections 174 and the openings 176 therebetween defined about the end projection 170 extending from the lock body 121 . The delineators may have other structures including, but not limited to, projections, recesses, splines, or the like. For example, the end projection 170 extending from the lock body 121 may include a plurality of detents and the mounting member 126 may include a complementary inward projection configured to engage within a desired detent.
[0048] In the present embodiment, the engagement member 160 includes a flexible finger 164 formed integrally with the mounting member body 150 within an opening 154 through the body 150 . (see FIG. 21 ). The flexible finger 164 is configured to be biased radially inward toward the delineators 173 defined on the end projection 170 extending from the lock body 121 . As such, the flexible finger 164 positions itself within one of the openings 176 defined between the radial projections 174 and thereby locks the rotative position of the mounting member 126 relative to the locking body 121 .
[0049] To ensure the flexible finger 164 does not inadvertently disengage, the engagement member 160 further comprises an engagement pad 162 which moves along guides 163 extending outwardly from the mounting member body 150 as shown in FIG. 23 . The engagement pad 162 is moveable between a locked position shown in FIG. 21 and an unlocked position shown in FIG. 22 . A first radially outwardly extending contact 167 engages a corresponding first radially inwardly extending contact 173 on the engagement pad 162 . To move the engagement pad 162 to the unlock position, the first radially inwardly extending contact 173 is snapped past the first radially outwardly extending contact 167 . In the locked position, a second radially inwardly extending contact 171 on the engagement pad 162 is positioned above and engages a second radially outwardly extending contact 165 on the flexible finger 164 , and thereby prevents the flexible finger 164 from inadvertently disengaging from the position delineators 173 .
[0050] To adjust the position of the mounting member 126 relative to the lock body 121 , the engagement pad 162 is slid away from the lock body 121 , as indicated by arrow A in FIG. 23 , with the first radially inwardly extending contact 173 snapping past the first radially outwardly extending contact 167 . As the engagement pad 162 is slid, the second radially inwardly extending contact 171 disengages from the second radially outwardly extending contact 165 , such that the flexible finger 164 is free to flex outward, see FIG. 25 , as the mounting member 126 is rotated relative to the lock body 121 as indicated by arrow B in FIG. 23 . The flexible finger 164 sliding past the radial projections 174 provides a ratcheting effect. Once a desired position is reached, the engagement pad 162 is slid back to the locked position, with the second radially inwardly extending contact 171 engaging the second radially outwardly extending contact 165 to maintain such in place. As in the previous embodiment, the mounting arrangement 124 allows a user to easily fine tune the position of the lock 120 on the bicycle in a secure, reliable manner without the need for any tools.
[0051] Referring to FIGS. 26 and 27 , a U-lock 220 incorporating a mounting arrangement 224 that is another alternate embodiment of the present invention will be described. The mounting arrangement 224 includes a mounting member 26 which is substantially the same as in the first embodiment and like elements are numbered alike. While the mounting member 26 of the present embodiment is similar to the first embodiment, the mounting member 26 may have other configurations, including but not limited to the configuration of the mounting member 126 . The mounting member 26 is rotatably secured to a collar 270 affixed to the shackle 231 of the U-lock 220 . The collar 270 may be affixed in various manners including, but not limited to, a set screw, welding or the like. The shackle 231 is configured for locking engagement with a crossbar 221 as is known in the art.
[0052] Referring to FIG. 27 , the collar 270 of the present embodiment is similar to the projecting end 70 of the first embodiment. The collar 270 includes an annular recess 272 configured to receive the annular protrusion 55 (not shown in FIG. 27 ) on the mounting member 26 . Engagement of the protrusion 55 in the recess 272 secures the mounting member 26 to the collar 270 and thereby the shackle 231 . Other means for connecting the mounting member 26 to the collar 270 may also be utilized. Sufficient clearance is provided between the protrusion 55 and the recess 272 such that the mounting member 26 is rotatable relative to the collar 270 and shackle 231 . The collar 270 includes position delineators 273 defined by a series of alternating teeth 274 and openings 276 or any other configuration. The mounting member 26 may be adjusted relative to the collar 270 in the same manner as discussed above with respect to the first embodiment.
[0053] As in the previous embodiments, the mounting arrangement 224 allows a user to easily fine tune the position of the lock 220 on the bicycle in a secure, reliable manner without the need for any tools.
[0054] Referring to FIG. 28 , a U-lock 320 incorporating a mounting arrangement 324 that is another alternate embodiment of the present invention will be described. The mounting arrangement 324 includes a mounting member 26 which is substantially the same as in the first embodiment and like elements are numbered alike. While the mounting member 26 of the present embodiment is similar to the first embodiment, the mounting member 26 may have other configurations, including but not limited to the configuration of the mounting member 126 . The mounting member 26 is rotatably secured to an end 370 of the crossbar 321 of the U-lock 220 . A shackle 331 is configured for locking engagement with the crossbar 321 as is known in the art.
[0055] The end 370 of the crossbar 321 includes an annular recess 372 (shown in phantom) configured to receive the annular protrusion 55 (not shown in FIG. 28 ) on the mounting member 26 . Engagement of the protrusion 55 in the recess 372 secures the mounting member 26 to the end 370 of the crossbar 321 . Other means for connecting the mounting member 26 to the collar 270 may also be utilized. Sufficient clearance is provided between the protrusion 55 and the recess 372 such that the mounting member 26 is rotatable relative to the crossbar 321 . The crossbar 321 includes position delineators 373 defined by a series of alternating teeth and openings or any other configuration. The mounting member 26 may be adjusted relative to the crossbar 321 in the same manner as discussed above with respect to the first embodiment.
[0056] As in the previous embodiment, the mounting arrangement 324 allows a user to easily fine tune the position of the lock 320 on the bicycle in a secure, reliable manner without the need for any tools.
[0057] While preferred embodiments of the invention have been shown and described herein, it will be understood that such embodiments are provided by way of example only. Numerous variations, changes and substitutions will occur to those skilled in the art without departing from the spirit of the invention. Accordingly, it is intended that the appended claims cover all such variations as fall within the spirit and scope of the invention.
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A lock mounting arrangement comprising a lock and a mounting member secured to a portion of the lock such that the mounting member is rotatable relative to the portion of the lock. At least two position delineators are provided on one of the mounting member and the lock and an engagement member is provided on the other of the mounting member and the lock. The engagement member is movable between a first position in which the engagement member engages at least one of the position delineators and thereby fixes the rotative position of the mounting member relative to the portion of the lock and a second position in which the engagement member is lockingly disengaged from the position delineators such that the mounting member is free to rotate relative to the portion of the lock.
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CROSS-REFERENCE TO RELATED APPLICATION(S)
[0001] This application is a continuation application of U.S. application Ser. No. 14/309,786, filed Jun. 19, 2014, which is a continuation of U.S. patent application Ser. No. 14/059,271 (now abandoned), filed Oct. 21, 2013, which is a continuation of U.S. patent application Ser. No. 13/290,944, filed Nov. 7, 2011 (now U.S. Pat. No. 8,601,291), which is a continuation of U.S. patent application Ser. No. 11/459,011 (now abandoned), filed Jul. 20, 2006, which is a continuation of U.S. patent application Ser. No. 10/313,314, filed Dec. 6, 2002 (now U.S. Pat. No. 7,171,461), which is a continuation-in-part of U.S. patent application Ser. No. 09/930,780, filed Aug. 15, 2001, (now U.S. Pat. No. 7,043,543), which is a continuation-in-part of U.S. patent application Ser. No. 09/732,557, filed Dec. 8, 2000 (now U.S. Pat. No. 7,099,934), which is a continuation-in-part of U.S. patent application Ser. No. 09/375,471 filed Aug. 16, 1999 (now U.S. Pat. No. 6,711,613) which is a continuation-in-part of U.S. application Ser. No. 08/685,436, filed Jul. 23, 1996 (now U.S. Pat. No. 5,949,974) the entireties of all of which are incorporated herein by reference.
TECHNICAL FIELD
[0002] The technical field relates generally to power management systems, and more particularly to electrical power distribution devices and methods.
BACKGROUND
[0003] Network server “farms” and other network router equipment have settled on the use of the equipment bays in 19″ standard RETMA racks. Many of these server and router farms are located at telephone company (TelCo) central equipment offices because they need to tie into very high bandwidth telephone line trunks and backbones. So each TelCo typically rents space on their premises to the network providers, and such space is tight and very expensive.
[0004] The typical network router, server, or other appliance comes in a rack-mount chassis with a standard width and depth. Such chassis are vertically sized in whole multiples of vertical units (U). Each rented space in the TelCo premises has only so much vertical space, and so the best solution is to make best use of the vertical space by filling it with the network appliances and other mission-critical equipment.
[0005] Two kinds of operating power are supplied to such network appliances, alternating current (AC) from an uninterruptable power supply (UPS) or direct from a utility, the second kind is direct current (DC) from TelCo central office battery sets. Prior art devices have been marketed that control such AC or DC power to these network appliances. For example, Server Technology, Inc. (Reno, Nev.) provides operating-power control equipment that is specialized for use in such TelCo premises RETMA racks. Some of these power-control devices can cycle the operating power on and off to individual network appliances.
[0006] Such cycling of operating power will force a power-on reset of the network appliance, and is sometimes needed when an appliance hangs or bombs. Since the network appliance is usually located remote from the network administration center, Server Technology has been quite successful in marketing power managers that can remotely report and control network-appliance operating power over the Internet and other computer data networks.
[0007] Conventional power management equipment or bottoms of the server farm RETMA racks, and thus has consumed vertical mounting space needed by the network appliances themselves. So what is needed now is an alternative way of supplying AC or DC operating power to such network appliances without having to consume much or any RETMA rack space.
SUMMARY
[0008] Briefly, a vertical-mount network remove power management outlet strip embodiment of the present disclosure comprises a long, thin outlet strip body with several independently controllable power outlet sockets distributed along its length. A power input cord is provided at one end, and this supplies AC-operating power to relays associated with each of the power outlet sockets. The relays can each be addressably controlled by a microprocessor connected to an internal I2C-bus serial communications channel. The power-on status of each relay output to the power outlet sockets can be sensed and communicated back to the internal I2C-bus. A device-networking communications processor with an embedded operating system may translate messages, status, and controls between external networks, the internal I2C-bus, and other ports.
[0009] In alternative embodiments of the present disclosure, a power management architecture provides for building-block construction of vertical and horizontal arrangements of outlet sockets in equipment racks. The electronics used in all such variants is essentially the same in each instance. Each of a plurality of power input feeds can have a monitor that can provide current measurements and reports on the internal I2C-bus. Each of the power input feeds could be independently loaded with a plurality of addressable-controllable outlets. Each outlet can also capable of measure the respective outlet socket load current and reporting those values on the internal I2C-bus. Separate digital displays can be provided for reach monitored and measured loan and infeed current. The internal I2C-bus, logic power supply, network interfaces, power control modules and relays, etc., could be distributed amongst several enclosures that have simple plug connections between each, the infeed power source, and the equipment loads in the rack.
[0010] An advantage of certain embodiments of the present disclosure is that a network remote power management outlet strip is provided that frees up vertical rackmount space for other equipment.
[0011] Another advantage of certain embodiments of the present disclosure is that a network remote power management outlet strip is provided for controlling the operating power supplied to network appliances over computer networks, such as TCP/IP and SNMP.
[0012] A further advantage of certain embodiments of the present disclosure is that a network remote power management outlet strip is provided that allows a network console operator to control the electrical power status of a router or other network device.
[0013] A still further advantage of certain embodiments of the present disclosure is that a network remote power management outlet strip is provided for reducing the need for enterprise network operators to dispatch third party maintenance vendors to remote equipment rooms and POP locations simply to power-cycle failed network appliances.
[0014] There are other objects and advantages of the various embodiments of the present disclosure. They will no doubt become obvious those of ordinary skill in the art after having read the following detailed description of the preferred embodiments which are illustrated in the various drawing figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a functional block diagram of a network remote power management outlet strip embodiment of the present disclosure.
[0016] FIG. 2A is a front diagram of an implementation of the network remote power management outlet strip of FIG. 1 .
[0017] FIG. 2B is an assembly diagram of the network remote power management outlet strip of FIG. 2A without the sheet metal enclosure, and shows the interwiring amongst the AC-receptacles, the power input plug, and the various printed circuit board modules.
[0018] FIG. 3 is a non-component side diagram of a printed circuit board (PCB) implementation of an intelligent power module IPT-IPM, similar to those of FIGS. 1 , 2 A and 2 B, and further illustrates an insulating sheet that is fitted to the back.
[0019] FIG. 4 is a component-side diagram of a printed circuit board (PCB) implementation of an intelligent power module IPT-IPM, similar to those of FIGS. 1 , 2 A, 2 B, and 3 , and further illustrates the bus connections of the power outlet receptacles it sockets into.
[0020] FIG. 5 is functional block diagram of an IPT-NetworkPM module embodiment of the present disclosure.
[0021] FIG. 6 is a schematic diagram of a circuit that could be used in an implementation of the IPT-PS of FIGS. 1 , 2 A, and 2 B.
[0022] FIG. 7 is a functional block diagram of a network remote power management system embodiment of the present disclosure.
[0023] FIG. 8 is a functional block diagram of an expandable power management system embodiment of the present disclosure.
[0024] FIG. 9 is a functional block diagram of a power distribution unit embodiment of the present disclosure.
[0025] FIG. 10 is a schematic diagram of one way to implement the IPT-IPM's in any of FIGS. 1-9 .
DETAILED DESCRIPTION
[0026] FIG. 1 represents a network remote power management outlet strip embodiment of the present disclosure, and is referred to herein by the general reference numeral 100 . The outlet strip 100 provides independently managed power to each of sixteen AC-output receptacles 101 - 116 . A power supply (IPT-PS) module 118 senses and totalizes the combined current delivered to all the AC-output receptacles 101 - 116 from its AC-power input.
[0027] Peripheral integrated circuits (IC's) that have to communicate with each other and the outside world can use a simple bi-directional 2-wire, serial data (SDA) and serial clock (SCL) bus for inter-IC (I2C) control developed by Philips Semiconductor. The I2C-bus has become a worldwide industry-standard proprietary control bus.
[0028] The IPT-PS module 118 digitally encodes the total AC-current information onto an internal I2C-bus 119 . The IPT-PS module 118 supplies DC-operating power for the internal I2C-bus 119 which is derived from the AC-power input. Each of four intelligent power modules (IPT-IPM) 120 - 123 have four relays (K1-K4) that switch AC-power from the IPT-PS module 118 to respective ones of the sixteen AC-output receptacles 101 - 116 . Such relays K1-K4 are controlled by a single I2C transceiver daisy-chain connected to others along the internal I2C-bus 119 . Each such I2C transceiver is independently addressable on the I2C-bus 119 , and provides a digitally encoded power-on status indication for all four relays K1-K4.
[0029] An I2C-module (IPT-I2C) 124 receives digital messages on the internal I2C-bus 119 and decodes and displays the totalized combined current, e.g., in AC-amperes, on an LED-readout 126 . A user is thus able to see the effect on the total current caused by plugging or unplugging a load from any or all of the AC-output receptacles 101 - 116 .
[0030] The Philips 87LPC762 microcontroller is used as an 120 interface to a dual seven-segment display. Port-0 pins select the illuminated segments of a seven-segment display. Pin P1.7 selects which of the two seven-segment displays is being driven, and alternates between the two seven-segment displays fast enough to avoid flicker. The I2C slave address is configurable. Five commands are supported: STAT (status) RBTN (Read button), RPRB (Read probe), CRST (Clear reset), and WDSP (Write display). A checksum is used on received/sent bytes for data integrity across the I2C-bus.
[0031] The IPT-I2C microcontroller starts up with the I2C interface in idle slave mode. Main () waits in a loop until the I2C interface is flagged as non-idle. After an I2C start occurs, and the rising edge of SCL sets DRDY (and thus ATN), an I2C interrupt occurs. The I2C ISR disables the I2C interrupt and sets a global I2C non-idle flag. The main loop then proceeds to read in the first byte from the I2C-bus. When seven bits are received, the target I2C is known and is compared to the IPT-I2C microcontroller's own module address. If different, the I2C interface processing stops and waits for another start to begin again. If the same, the last bit of the first byte is read, which is the RJW bit. If a Read, then the IPT-I2C microcontroller acknowledges the byte and repeatedly sends a fixed number of response bytes: an address byte, a type byte, one or more data bytes, and a checksum. If a Write, then the IPT-I2C microcontroller acknowledges the byte, and then will read up to four more bytes: a command byte one or more data bytes, and a checksum. As received, the bytes are acknowledged and compared to expected valid commands and data. As soon as a valid command, any data parameters and a valid checksum are received and acknowledged, the command is acted upon. Without a valid checksum, the command is not acted upon. If an unexpected command or data is received, or more bytes are received than expected, then a negative acknowledge occurs after the next byte is received, and the I2C interface is stopped, and another start is needed to begin again. Throughout the I2C processing loop, a bus timeout (by Timer 1 interrupt) resets the I2C interface to idle and the I2C processing loop to the appropriate states Timer U also guards the I2C interface with a 5-millisecond inter-clock timeout and a 15 second total I2C timeout. The total I2C timeout is reset when the IPT-I2C microcontroller is addressed on the I2C with its primary address (not the secondary address).
[0032] The I1C IPT-I2C microcontroller commands include the STAT command which sets the IPT-I2C microcontroller to a read type to STAT. This means that an I2C Read will send four bytes (address, type data checksum) in which the data byte represents the status of the IPT-I2C microcontroller.
[0033] The RBTN command sets the IPT-I2C microcontroller read type to RBTN. This means that an I2C Read will send four bytes (address, type, data, checksum) in which the data byte represents the status of the button.
[0034] The RPRB command sets the IPT-I2C microcontroller read type to RPRB. This means that an I2C Read will send five bytes (address, type data, data, checksum) in which the data bytes represent the type of 1-wire bus probe and the probe data.
[0035] The CRST command clears the Reset Flag (RSTF), Power On Reset Flag (PORF), Brownout Reset Flag (BORF), and WatchDog Reset Flag (WDRF) bits of the IPT-I2C microcontroller status byte.
[0036] The WDSP command sets the values for the dual seven-segment display.
[0037] At power up, the dash-dash blinks until a valid WDSP command is received. After that, if ten seconds pass without receiving a valid WDSP command, the display reverts back to the blinking dash-dash.
[0038] A read command is started by the master addressing the slave with the RIW bit set.
[0039] A read command to the slave IPT-I2C microcontroller results in a fixed number of bytes repeatedly being transmitted by the slave (address, type, datal . . . dataN checksum). The first byte is the address of the slave. The second byte indicates the type of data in the following data byte(s). The last byte is a checksum of all the previous bytes.
[0040] A write command is started by the master addressing the slave with the RIW bit cleared. This is followed by the master transmitting multiple bytes to the slave, followed by a stop, or restart.
[0041] The internal I2C-bus 119 is terminated at a network personality module (IPT-NetworkPM) 128 . Such provides an operating system, HTTP-server, and network interface between the internal I2C-bus 119 , an external I2C-bus 130 , an Ethernet 10/100 BaseT 132 , a modem 134 , and a local operator's console 136 . The IPT-NetworkPM 128 preferably uses Internet protocols like TCP/IP and supports simple network management protocol (SNMP). In one application, the outlet strip 100 could be used in the remote power management environment described in U.S. Pat. No. 5,949,974, issued Sep. 7, 1999. Such Patent is incorporated herein by reference.
[0042] Network messages, e.g., using TCPIIP and SNMP, are communicated over the Ethernet 10/100 BaseT interface 132 . Such messages are able (a) to independently control the power on-off to each of AC-output receptacles 101 - 116 , (b) to read the power-on status of each, and (c) to report load current supplied by each outlet, or simply the total combined current measured passing through IPT-PS 118 .
[0043] In one embodiment, the power applied to AC-output receptacles 101 - 116 is not allowed by the individual IPT-IPM modules 120 - 123 to be simultaneously applied. Instead, each is allowed to turn on in succession so any instantaneous load in-rush currents cannot combine to exceed the peak capabilities of the AC-power input source.
[0044] The total input current display 126 could be used to advantage by a technician when installing or troubleshooting a RETMA equipment rack by watching how much current change is observed when each network appliance is plugged in and turned on. Unusually high or low currents can indicate particular kinds of faults to experienced technicians.
[0045] FIGS. 2A and 2B represent a network remote power management outlet strip embodiment of the present disclosure, which is referred to herein by the general reference numeral 200 . These illustrate one way the network remote power management outlet strip 100 of FIG. 1 could be physically implemented and arranged. The outlet strip 200 provides independently managed power to each of sixteen AC-output receptacles 201 - 216 . These have AC-neutral and AC-ground bussed through two sets of eight, e.g., with 12-gauge wire. A power supply (IPT-PS) module 218 is daisy-chained in an internal I2C-bus 219 to a series of four intelligent power modules (IPT-IPM) 220 - 223 . The IPT-PS module 218 has, for example, a Philips microcontroller type 87LPC762 that senses and totalizes the combined current delivered on the AC-Line leads to all of four intelligent power modules (IPT-IPM) 220 - 223 .
[0046] The Philips 87LPC762/7 microcontroller is programmed as an I2C 8-bit I/O Expander, with an 8-bit 4-channel A/D converter. Eight pins are individually selectable as either an Input (quasi-bidirectional) or Output (open drain). Four address lines determine the I2C slave address. Eight commands are supported: STAT (Status), RCFG (Read Config) RPRT (Read Port), RADC (Read ADC), CRST (Clear Reset), WCFG (Write Config), WPT (Write Port), and ADCE (ADC Enable). A checksum is used on received/sent bytes for data integrity across the I2C-bus. Without a valid checksum, a command will not be acted upon.
[0047] The microcontroller starts up with the I2C interface in idle slave mode. Main() waits in a loop until the I2C interface is flagged as non-idle. After an I2C start occurs, and the rising edge of SCL sets DRDY and thus ATN, an I2C interrupt occurs. The I2C ISR disables the I2C interrupt and sets a global I2C non-idle flag. The main loop then proceeds to read in the first byte from the I2C-bus. When seven bits are received, the target I2C is known and is compared to the I/O Expander's own module address. If different, the I2C interface processing stops and waits for another start to begin again. If the same-the last bit of the first byte is read, which is the R/W bit. If a Read, then the microcontroller acknowledges the byte, and repeatedly sends a fixed number of response bytes (an address byte, a type byte one or more data bytes, and a checksum). If a Write, then the microcontroller acknowledges the byte and then will read up to three more bytes (a command byte, a data byte, and a checksum). As received, the bytes are acknowledged and compared to expected valid commands and data. As soon as a valid command, any data parameters and a valid checksum are received and acknowledged, the command is acted upon. If an unexpected command or data is received, or more bytes are received than expected, then a negative acknowledge occurs after the next byte is received, and the I2C interface is stopped and another start is needed to begin again.
[0048] Throughout the I2C processing loop, a bus timeout by Timer 1 interrupt resets the I2C interface to idle and the I2C processing loop to the appropriate state. Timer 0 also guards the I2C interface with a 5-millisecond inter-clock timeout and a 15-second total I2C timeout. The total I2C timeout is reset when the I/O Expander is addressed on the I2C with its primary address, not the secondary address.
[0049] The I2C microcontroller commands include the STAT command, which sets the I/O Expander read type to STAT. An I2C Read will send four bytes: address, type, data, checksum. The data byte represents the status of the I/O Expander.
[0050] The RCFG command sets the I/O Expander read type to RCFG. This means that an I2C Read will send four bytes: address, type, data, checksum. The data byte represents the I/O configuration of the eight I/O pins.
[0051] The RADC command sets the microcontroller read type to RADC. This means that an I2C Read will send eight bytes (address, type, ADCE status, ADCO data, ADCI data, ADC2 data, ADC3 data, checksum) in which the data bytes represent the value of the four ADC channels. For ADC channels that are disabled, a value 0×FF is returned. For enabled ADC channels, the value represents the average of the last eight averages of 64 A/D conversions during the last four AC cycles. All four channels are converted once during each 1.042 ms, about 260 us apart. After four AC (60 Hz) cycles, each channel has been converted 64 times. For each channel these 64 conversions are averaged and stored. The most recent eight stored averages are then again averaged, making the reported value the truncated average over 64×8=512 AC cycles, which spans just over a half second.
[0052] The CRST command clears the ReSeT Flag (RSTF) Power On Reset Flag (PORF), BrownOut Reset Flag (BORF), and WatchDog Reset Flag (WDRF) bits of the I/O Expander status byte.
[0053] The WCFG command sets the microcontroller I/O configuration of the eight I/O pins. The WCFG command also sets the read type to RCFG.
[0054] The WPRT command sets the state of the eight I/O pins that are configured as outputs. The WPRT command also sets the read type to RPRT.
[0055] The ADCE command enables or disables any or all four ADC channels. The ADCE command also sets the read type to RADC.
[0056] A read command is started by the master addressing the slave with the R/W bit set. A read command to the slave IPT-I2C microcontroller results in a fixed number of bytes repeatedly being transmitted by the slave (address, type, datal .. . dataN checksum). The first byte is the address of the slave. The second byte indicates the type of data in the data bytes that follow. The last byte is a checksum of all the previous data bytes.
[0057] A write command is started by the master addressing the slave with the R/W bit cleared. This is followed by the master transmitting multiple bytes to the slave, followed by a stop or restart.
[0058] The IPT-PS module 218 digitally encodes the total AC-input current information onto the internal I2C-bus 219 . The IPT-PS module 218 derives DC-operating power from the AC-power input for modules on the internal I2C-bus 219 . Each of the IPT-IPM modules 220 - 223 have four relays (K1-K4) that switch the AC-Line from the IPT-PS module 218 to respective ones of the AC-Line connections on each of the sixteen AC-output receptacles 201 - 216 . Such relays K1-K4 are controlled by a single I2C transceiver located on each IPT-IPM 220 - 223 . For example, such I2C transceiver could be implemented with a Philips microcontroller type 87LPC762.
[0059] Each such I2C transceiver is independently addressable on the I2C-bus 219 , and provides a digitally encoded power-on status indication for all four relays K1-K4. An I2C-module (IPT-I2C) 224 receives digital messages on the internal I2C-bus 219 and decodes and displays the totalized combined current, e.g., in AC-amperes, on an LED-readout 226 . The internal I2C-bus 219 terminates at a IPT-NetworkPM 228 .
[0060] Preferably, IPT-NetworkPM 228 includes an operating system, an HTML webpage, and a network interface. Such can connect a remote user or command console with the internal I2C-bus 219 , an external I2C-bus that interconnects with other outlet strips through a RJ-11 socket 230 , an Ethernet 10/100 BaseT RJ-45 type socket 232 , etc. The IPT-NetworkPM 228 preferably uses Internet protocols like TCP/IP and supports simple network management protocol (SNMP).
[0061] The modular construction of outlet strip 200 allows a family of personality modules to be substituted for IPT-NetworkPM 228 . Each such would be able to communicate with and control the IPT-IPM's 220 - 223 via the inter al I2C-bus 219 .
[0062] The manufacturability and marketability of IPT-IPM 220 - 223 could be greatly enhanced by making the hardware and software implementation of each the same as the others. When a system that includes these is operating, it preferably sorts out for itself how many IPM's are connected in a group and how to organize their mutual handling of control and status data in and out.
[0063] FIG. 3 illustrates a printed circuit board (PCB)·implementation of an intelligent power module IPT-IPM 300 , similar to those of FIGS. 1 , 2 A, and 2 B. On the component side of the PCB, the IPT-IPM 300 has a two-position connector 302 for AC-Neutral, and on the non-component side screw connector for the AC-Line. A PCB trace 306 distributes AC-Line power input to a series of four power control relays, as shown in FIG. 4 . An insulator sheet 310 screws down over the IPT-IPM 300 and protects it from short circuits with loose wires and the sheet metal outlet strip housing.
[0064] For example, insulator sheet 310 can be made of MYLAR plastic film and may not necessarily have a set of notches 312 and 314 that provide for connector tabs 302 and 304 . Connector tabs 302 and 304 can alternatively be replaced with a two-position connector with screw fasteners.
[0065] FIG. 4 illustrates the component side of a PCB implementation of an IPT-IPM module 400 , e.g., the opposite side view of the IPT-IPM module 300 in FIG. 3 . The IPT-IPM module 400 comprises a pair of I2C daisy chain bus connectors 402 and 404 , a PCB trace 406 distributes AC-Line power input from AC-Line screw connector 304 connect at a via 408 to a series of four power control relays 410 - 413 . A microcontroller 414 processes the I2C communications on the internal I2C-bus, e.g., I2C-bus 119 in FIGS. 1 and 219 in FIGS. 2A and 2B .
[0066] FIG. 5 shows the basic construction of an IPT-NetworkPM module 500 , and is similar to the IPT-NetworkPM module 128 of FIG. 1 and 228 of FIGS. 2A and 2B . A NetSilicon (Waltham, MA type NET+50 32-bt Ethernet system-on-chip for device networking is preferably used to implement a communications processor 502 . A flash memory 504 provides program storage and a RAM memory 506 provides buffer and scratchpad storage for the communications processor operations. A local I2C-bus is implemented in part with a pair of 2N7002 transistors, for example. It connects into the I2C daisy chain with a J1-connector (CON4) 510 . An extern I2C-bus is implemented in part with a pair of 2N7002 transistors, for example. It connects into an external I2C system with an RJ12-type J7-connector 510 . Such external I2C system can expand to one additional outlet strip that shares a single IPT-NetworkPM module 500 and a single network connection.
[0067] An Ethernet 10/100 BaseT-interface with the media access controller (MAC) internal to the communications processor 502 is provided by a physical layer (PHY) device 516 . An Intel type LXT971A fast Ethernet PHY transceiver, for example, could be used together with an RJ45 connector 518 . A pair of RS-232 serial interfaces are implemented in part with an SP3243E transceiver 520 , an RJ45H connector 52 , another SP3243E transceiver 524 , and an IDC10 connector 526 .
[0068] The flash memory 504 is preferably programmed with an operating system and HTML-browser function that allow web-page type access and control over the Ethernet channel. A complete OS kernel, NET+Management simple network management protocol (SNMP) MIBII and proxy agent, NET+Protocols including TCP/IP, NET+Web HTTP server, and XML microparser, are commercially available from NetSilicon for the NET+50 32-bit Ethernet system-on-chip.
[0069] FIG. 6 represents a circuit 600 that could be used in an implementation of the IPT-PS 118 of FIG. 1 and IPT-PS 218 of FIGS. 2A and 2B . An AC-Line input 602 from the AC-power source is passed through the primary winding of an isolation transformer 604 . A set of four AC-Line outputs 606 are then connected to the four IPT-IPM's, e.g., 120 - 123 in FIG. 1 and 20 - 223 in FIGS. 2A and- 2 B. The voltage drop across the primary winding of isolation transformer 604 is relatively small and insignificant, even at full load. So the line voltage seen at the AC-Line outputs 606 is essentially the full input line voltage.
[0070] A voltage is induced into a lightly loaded secondary winding that is proportional to the total current being drawn by all the AC-loads, e.g., AC-receptacles 101 - 116 in FIG. 1 and 201 - 216 in FIGS. 2A and 2B . An op-amp 608 is configured as a precision rectifier with an output diode 610 and provides a DC-voltage proportional to the total current being drawn by all the AC-loads and passing through the primary of transformer 604 . An op-amp 612 amplifies this DC-voltage for the correct scale range for an analog-to-digital converter input (A0) of a microcontroller (uC) 616 . A Philips Semiconductor type P87LPC767 microcontroller could be used for uC 616 . Such includes a built-in four-channel 8-bit multiplexed A/D converter and an I2C communication port. When a READ ADC command is received on the I2C communication port, the AO input is read in and digitally converted into an 8-bit report value which is sent, for example, to LED display 126 in FIG. 1 .
[0071] A prototype of the devices described in connection with FIGS. 1-6 was constructed. The prototype was a combination of new hardware and software providing for a 4-outlet, 8-outlet, or 16-outlet vertical-strip power manager that could be accessed out-of-band on a single RJ45 serial port, or in-band over a 10/100Base-T Ethernet connection by Telnet or an HTML browser. An RJ12 port was connected to a second, nearly identical vertical-strip power manager that was almost entirely a slave to the first, e.g., could only be controlled by/via the first/master vertical power manager.
[0072] Vertical power manager hardware and software was used for the IPT-PS power supply board, the IPT-IPM quad-outlet boards, and IPT-I2C peripheral/display board. For the master vertical power manager, new personality module hardware and software was developed. This personality module, trademarked SENTRY3, was based upon the NetSilicon NetARM+20M microprocessor, and provided all of the control and user interface (UI). On the slave vertical power manager, a preexisting IPT-Slave personality module was modified slightly to bridge the external and internal I2C-buses. This allowed the master to control the slave vertical power manager exactly the same as the master vertical power manager, with no software or microprocessor needed on the slave. New software could be included to run in a microprocessor on the slave vertical power manager personality module to act as a backup master for load-display and power-up sequencing only.
[0073] A new SENTRY3 personality module was developed to support an HTML interface for Ethernet, and a command-line interface for Telnet and serial multiple users were supported, up to 128. One administrative user (ADMN) existed by default, and will default to having access to all ports. Outlet grouping was supported, with up to 64 groups of outlets.
[0074] There were two I2C-buses that can support up to sixteen quad-IPM (IPT-IPM) boards, across four power inputs, with at most four quad-IPM's per input, and with each input having its own load measurement and display. Each power input was required to have the same number of quad-IPM's that it powered. There was one I2C peripheral/display (IPT-I2C) board for each power input. Each bus had only one smart power supply (IPT-PS) board at I2C address 0×5 E. Each bus had at least one I2C peripheral/display (IPT-I2C) board at I2C address 0×50, and at least one quad-IPM (IPT-IPM) board at I2C address 0×60 (or 0×40).
[0075] Determining what was present on an I2C-bus, and at what address, was done by reading the 8-bit I/O port of the power supply. The eight bits were configured as,
Bit 0=→Undefined
[0076] Bit 1=→Display orientation (1=Upside-Up, 0+Upside-Down)
Bit 2=→Number of quad-IPM's per power input
Bit 3=→Number of quad-IPM's per power input
Bit four=→Overload point (1=30.5 A [244 ADC], 0=16.5 A [132 ADC])
Bit 5=→Undefined
[0077] Bit 6=→Number of power inputs
Bit 7=→Number of power inputs
[0078] Bits 2 and 3 together determine how many quad-IPM's there were per power input. Bits 6 and 7 together determine how many power input feeds there were.
[0079] The I2C address of the quad-IMP's were determined by the version of the LPC code on the IPT-PS board, as determined by a read of the STATus byte of the IPT-PS.
[0000] Version 3+→quad-IPM's start @-×60 and were 0×60, 0×62, 0×64, 0×66, 0×68, 0×6 A, 0×6 C, 0×6 E, 0×70, 0×72, 0×74, 0×76, 0×78, 0×7 A, 0×7 C, 0×7 E.
Version 2−→quad-IPM's start @0×40 and were 0×40, 0×42, 0×44, 0×46, 0×48, 0×4 A, 0×4 C, 0×4 E, 0×50, 0×52, 0×54, 0×56, 0×58, 0×5 A, 0×5 C 0×5 E.
[0080] Up to four IPT-I2C peripheral/display boards were supported at I2C addresses: 0×50, 0×52, 0×54 and 0×56.
[0081] There was a direct mapping relationship between power inputs, IPT-I2C peripheral/display boards I2C addresses, and the IPT-IPM boards I2C addresses:
[0000]
IPT-I2C
IPT-IPM v3+ Addresses
Power Input
Address
(subtract 0x20 for v2−)
A
0x50
0x60, 0x62, 0x64, 0x66
B
0x52
0x68, 0x6A, 0x6C, 0x6E
C
0x54
0x70, 0x72, 0x74, 0x76
D
0x56
0x78, 0x7A, 0x7C, 0x7E
[0082] Considering that each input power feed can support up to four quad-IPM's (sixteen ports), and that each bus can have four input feeds, and that there were two I2c-busses, an addressing scheme for a port must include three fields (a) Bus ID, (b) Input Feed ID, and (c) Relay ID.
[0083] The Bus ID could be regarded as vertical-strip power manager/enclosure ID, since one I2C-bus were for the internal/local I2C vertical power manager components and the other I2C-bus were for the external/remote vertical power manager. Other implementations could use a CAN bus in place of the external I2C-bus. Each enclosure had an address on the bus, e.g., an Enclosure ID. Thus the three address fields needed were (a) Enclosure ID, (b) Input Feed ID, and (c) Relay ID.
[0084] The Enclosure ID was represented by a letter, starting with “A”, with a currently undefined maximum ultimately limited to “Z”. Only “A” and “B” existed for the prototype. The Input Feed ID was represented by a letter, with a range of “A” to “D”. The Relay ID was represented by a decimal number, with a range of “1” to “16”.
[0085] An absolute identifier as needed for the user to enter commands. A combination of Enclosure ID, Input Feed ID, and Relay ID must be expressed in the absolute ID. This were done with a period followed by two alphabet characters and then one or two numeric characters, e.g., “{enclosure_id}[input_feed_id]{#}[#]”.
[0086] The first alphabet character represented the Enclosure ID (“A” to “Z”). The second alphabet character represented the Input Feed ID (“A” to “D”). The third and fourth number characters represented the Relay ID (“1” to “16”), e.g., “.{A-Z}[A-D]{1-16}”. The input feed ID was optional. If not specified, “A” was assumed. With an absolute ID scheme, a period, letter, and number must always be entered, making it very similar to our current scheme, but allowing for future multiple input feeds. For displaying IDs, the optional input feed ID should only be shown when the port was in an enclosure with 2 or more input feeds. A vertical power manager ID could be specified with just a period and letter. An input feed ID could be specified with a period and two letters.
[0087] Existing outlets were determined by reading the power supply I/O port of the master and slave vertical power manager. One administrative user exists by default, and has access to all outlets and groups. This administrator (ADMN) could be removed, but only if one or more other users with administrative privileges exist. Additional users could be created or removed. Administrative privileges could be given to or removed from added users.
[0088] The administrative privilege allows access to all currently-detected outlets and groups without those outlets or groups actually being in the user's outlet or group tables. Lists of outlets or groups for administrative users should include all currently-detected outlets and groups. This allowed administrative privileges to be given or taken away without affecting the users outlet and group tables.
[0089] Groups of outlets could be created or removed. Outlets could be added or removed from groups. Outlets or groups of outlets, could be added or removed from users. An outlet may belong to multiple groups. All user-defined outlet and groups names were unique. This were enforced at the time names were defined by the user. All user-defined names also cannot be the same any KEYWORDS. For example, they cannot be “GROUP”, “OUTLET”, or “ALL”. This were enforced at the time names were defined by the user. Usernames were uppercased when stored and displayed, and were compared case-insensitive. Passwords were stored and compared case-sensitive. Separate tables existed for each user's outlet access and group access.
[0090] When an ADMN user specifies “ALL” it means all currently detected outlets. For non-ADMN users, the “ALL” parameter refers to all of the outlets in the current user's outlet access table. There was no “all” to refer to all groups.
[0091] All commands that specify. outlet IDs need to be bounds-checked against the currently detected number of enclosures, number of input feeds on the target enclosure, and the number of relays on the target enclosure. Power actions could be applied to only one target at a time. The target could be an outlet or a group of outlet.
[0092] A wakeup state determined the default power-up state of each outlet. Power-on sequencing occurred independently on each vertical power manager and power feed, with each outlet being initialized to its wakeup state two seconds after the previous outlet, e.g., starting with outlet-1. Outlet names could be up to 24-characters. These were stored and displayed case-sensitive, but were compared case-insensitive as command parameters. Group names could be up to 24-characters. These were stored and displayed case-sensitive, but were compared case-insensitive as command parameters. A 24-character vertical power manager/enclosure name could be user-defined. This were stored and displayed case-sensitive, but was compared case-insensitive as a command parameter. A 32-character location name could be user-defined. This were stored and displayed case-sensitive. Username could be 1-16 characters, and were case-insensitive. Passwords also could be 1-16 characters, and were case-sensitive. Variable length command parameters were length-checked for validity. An error was displayed if too short or too long, as opposed to and automatic behavior, such as truncating a string that was too long.
[0000]
Prototype I2C Address Map
I2C Address
I2C .Address
Device
(binary)
(hex)
I2C-01
0101-000x
0x50
I2C-02
0101-001x
0x52
I2C-03
0101-010x
0x54
I2C-04
0101-011x
0x56
IPT-PS
0101-111X
0X5E
IPM-01
0101-000x
0x60
IPM-02
0101-001x
0x62
IPM-03
0101-010x
0x64
IPM-04
0101-011x
0x66
IPM-05
0101-100x
0x68
IPM-06
0101-101x
0x6A
IPM-07
0101-110x
0x6C
IPM-08
0101-111x
0x6E
IPM-09
0101-000x
0x70
IPM-10
0101-001x
0x72
IPM-12
0101-010x
0x74
IPM-13
0101-011x
0x76
IPM-14
0101-100x
0x78
IPM-15
0101-101x
0x7A
IPM-16
0101-110x
0x7C
IPM-17
0101-111x
0x7E
[0093] The prototype required several major software components to be constructed for use with the NetSilicon NET+50 device. The configuration and operational control blocks used in the prototype were described in the following tables. All of the control blocks were readable by all components in the system. The configuration control blocks were written by the user interface tasks. When the configuration control blocks were modified, the modifications were mirrored in EEPROM where copies of these control blocks were stored. The operational control blocks were also accessible to all components for read access, but each operational control block has an “owner” that performs all writes to the operational control blocks. If a non “owner” wishes to change an operational control block, a signal or message was used to let the “owner” know the control block should be updated.
[0094] The major design tasks for the prototype included designing and documenting the external I2C protocol that was used to communicate to “chained” SENTRY boxes, and the new command line interface commands to support features that were previously available only via the SENTRY SHOW Screen interface. The HTML code was developed for the prototype, as well as the “slave” SENTRY code to run in a personality module of a “chained” SENTRY. Further discrete design efforts were required to code the system initialization, the local I2C task, the external I2C task, the serial port. control task, the telnet control task, the user interface task, the power coordination task, the extern user interface (button/LED) control task, and the WEB control task.
[0095] The major software components developed for the prototype are listed in the following Tables.
[0000] SeniNIT—SENTRY initialization procedure. This software was the first SENTRY software that executes. It performs hardware, software (builds the Configuration and Operational global control blocks), and OS initialization. This code spawns the SENTRY operational tasks that provide the system services.
TskSER—One instance of this task was spawned for each active serial port. In the initial product there was one instance of this task. This task spawns TskUSR when a logon was detected. This task owns the serial port operational array control block in global memory. This control block was updated to reflect the status of the serial port. Once a TskUSR was spawned, this task performs serial port monitoring functions and if modem status signal indicate a lost connection, this task will signal TskUSR (via an OS interface) of this event.
TskTELNET—One instance of this task was spawned to listen for telnet connections. When a connection was detected, the task spawns TskUSR for the connection.
TskFTP—One instance of this task was spawned to listen for FTP connections. The function of this task was to provide field software updates for the system. The mechanism used was determined based on the developer kit capabilities.
TskWEB—This task was to provide WEB access via the system provided WEB server. The mechanism and number of instances of this task was determined based on the developer kit capabilities.
TskI2C—There were two versions of this task; the local version that controls internal I2C connections and the global version that controls external I2C connections. For the first implementation there were two instances of this task, one to control the single I2C internal connection and one to control the single I2C external connection. These tasks implement the protocol for communicating control requests from the system to the I2C connected devices. Control requests were received via system signals or messages (depending on the OS capabilities) from the power control coordinating task (TskPCntl) for power control requests and from the external user interface task (TskEUI) for LED control requests. This task communicates power control status updates received from the IPM's to TskPCntl and external button status updates to TskEUI using system signals or messages as necessary.
TskPCntl—This was the power control coordinating task. There was one instance of this task. This task receives power control request from the user interface tasks (TskUSR and TskWEB) via system provided signals messages and passes them to the correct I2C task (internal or external) using signals or messages. This task receives status updates from the I2C tasks via signals or messages. TskPCntl “owns” the IPMO and PCRO arrays and it updates the status fields in entries in these arrays as necessary.
TskEUI—This was the external user interface task that handles the push button functions and the LED display functions for the system. This task communicates with the local TskI2C via signals or messages to update the LED. TskI2C sends signals or messages to this task when the state of the external push button changes.
TskUSR—This command line user interface task was spawned by TskSER and TskTELNET when a user connection was detected. This task verifies the user login and then implements the command line interface. This routine communicates power-control commands via signals or messages to TskPCntl. This routine “owns” the active command line user array. Because there were multiple instances of this task, locks were used to serialize access to the active user array.
TskSYS—This was the general system task. Specific functions for this task were defined as development progressed.
[0096] The control blocks were globally addressable by all software in the system. Such data structures exist in RAM and were mirrored in EEPROM memory. They were constructed during system initialization using the nonvolatile versions in EEPROM memory. If the EEPROM memory was empty, the control blocks were built using defaults and the EEPROM memory was initialized using defaults as well. All software has read access to all of the data structures. The data in these control blocks was configuration data and was only changed as a result of configuration updates. The data was mostly static and was written during initialization and when configuration changes occur during an authorized user session. All write access to this data consists of a two-step process where the Global RAM copy of the data was updated followed by an update of the EEPROM copy of the data. There were seven global configuration control blocks as illustrated below. The following Tables describe each control block structure used in the prototype.
[0000] SENTRY Configuration Table (SCT)—This control block contains global configuration information. There was a single instance of this control block.
Username/Password Array (UNP)—This was an array of control blocks with each entry representing a user defined to the system. System locks were used to serialize access to this array when adding/deleting users. There was room for sixty-four entries in this array.
Intelligent Power Module (IPM) Array—This was an array of control blocks with each entry representing an IPM defined to the system. There was room for 32 entries in this array.
Power Control Relay (PCR) Array—This was an array of control blocks with each entry representing an PCR defined to the system. There was room for 128 entries in this array.
Group Power Control Relay (GRP) Array—This was an array of control blocs with each entry representing an Group of PCRs. There was room for 64 entries in this array.
Serial Port (SER) Array—This was an array of control blocks with each entry representing a serial port that can be used to access the system There was room for two entries in this array.
I2C Array—This was an array of control blocks with each entry representing an I2C connection. There was room for two entries in this array.
[0097] The Global RAM Operational Control Block Structures were globally addressable by all software in the system. These data structures exist only in RAM and are lost during a system restart. They were constructed during system initialization using current operational values. All software has read access to all of the data structures. The data in these control blocks was operational data and was changed to reflect the current operational status of devices in the system. Each of these control blocks has an “owner” task that performs updates by writing to the control block. There were six global operational control blocks as illustrated below. Complete descriptions of each control block structure follows.
[0000] Intelligent Power Module (IPMO) Array—This was an array of control blocks with each entry representing an IPM defined to the system. There was room for 32 entries in this array. The entries in this array correspond directly to the IPM configuration control block. These control blocks contain dynamic information that changes regularly. The relay coordination task (TskPCntl) “owns” this array.
Power Control Relay (PCRO) Array—This was an array of control blocks with each entry representing an PCR defined to the system. There was room for 128 entries in this array. The entries in this array correspond directly to the PCR configuration control block. These control blocks contain dynamic information that changes regularly. The relay coordination task (TskPCntl) “owns” this array.
I2C (I2CO) Array—This was an array of control blocks with each entry representing an I2C connection. There was room for 2 entries in this array. The entric/8 in this array correspond directly to the I2C configuration control block. These control blocks contain dynamic information that changes regularly. The I2C task (Tski2C) “owns” this array.
Serial Port (SERO) Array—This was an array of control blocks with each entry representing a serial port that can be used by the system. There was room for two entries in this array. The entries in this array correspond direct to the serial port configuration control block. These control blocks contain dynamic information that changes regularly. The serial port task (TskSER) “owns” this array.
Active Command Line User (UCLI) Array—This was an array of control blocks with each entry representing a current active command line user of the system. The SCT was room for 5 entries in this array. These control blocks contain dynamic information that changes regularly. The user interface task (TskUSR) “owns” this array. There were multiple instances of TskUSR so locks were used for this array.
Active HTTP Interface User (UHTP) Array—This was an array of control blocks with each entry representing. a WEB user. There was room for 5 entries in this array. These control blocks contain dynamic information that changes regularly. The WEB task (TskWEB) “owns” this array.
[0098] In FIG. 7 , a network remote power management system 700 includes a host system 702 connected over a network 704 to a remote system 706 . A power manager 708 , e.g., like outlet strips 100 and 200 of FIGS. 1 , 2 A, and 2 B, is used to monitor and control the operating power supplied to a plurality of computer-based appliances 714 associated with a network interface controller (NIC) 716 .
[0099] Such computer-based appliances 714 are subject to software freezing or crashing, and as such can become unresponsive and effectively dead. It is also some mission-critical assignment that suffers during such down time. It is therefore the role and purpose of the network remote power management system 700 to monitor the power and environmental operating conditions in which the computer-based appliance 714 operates, and to afford management personnel the ability to turn the computer-based appliance 714 on and off from the host system 702 . Such power cycling allows a power-on rebooting of software in the computer-based appliance 714 to be forced without it actually having to visit the site. The operating conditions and environment are preferably reported to the host 702 on request and when alarms occur.
[0100] The power manager 708 further includes a network interface controller (NIC) 718 , and this may be connected to a security device 720 . If the network 704 is the Internet, or otherwise insecure, it is important to provide protection of a protocol stack 72 from accidental and/or malicious attacks that could disrupt the operation or control of the computer-based appliance 714 . At a minimum, the security device 720 can be a user password mechanism. Better than that, it could include a discrete network-firewall and data encryption.
[0101] The protocol stack 722 interfaces to a remote power manager 724 , and it converts software commands communicated in the form of TCP/IP datapackets 726 into signals the remote power manager can use. For example, messages can be sent from the host 702 that will cause the remote power manager 724 to operate the relay-switch 712 . In reverse, voltage, current, and temperature readings collected by the sensor 710 are collected by the remote power manager 724 and encoded by the protocol stack 722 into appropriate datapackets 726 . Locally, a keyboard 728 can be used to select a variety of readouts on a display 730 , and also to control the relay-switch 712 .
[0102] The display 730 and keyboard 728 can be connected as a terminal through a serial connection to the power manager 724 . Such serial connection can have a set of intervening modems that allow the terminal to be remotely located. The display 730 and keyboard 728 can also be virtual, in the sense that they are both emulated by a Telnet connection over the network 704 .
[0103] The host 702 typically comprises a network interface controller (NIC) 732 connected to a computer platform and its operating system 734 . Such operating system can include Microsoft WINDOWS-NT, or any other similar commercial product. Such preferably supports or includes a Telnet application 736 , a network browser 738 , and/or an SNMP application 740 with an appropriate MIB 742 . A terminal emulation program or user terminal 744 is provided so a user can manage the system 700 from a single console.
[0104] If the computer-based appliance 714 is a conventional piece of network equipment, e.g., as supplied by Cisco Systems (San Jose, Calif.), there will usually be a great; deal of pre-existing SNMP management software already installed, e.g., in host 702 and especially in the form of SNMP 740 . In such case it is usually preferable to communicate with the protocol stack 722 using SNMP protocols and procedures. Alternatively, the Telnet application 736 can be used to control the remote site 706 .
[0105] An ordinary browser application 738 can be implemented with MSN Explorer, Microsoft Internet Explorer, or Netscape NAVIGATOR or COMMUNICATOR. The protocol stack 722 preferably includes the ability to send hypertext transfer protocol (HTTP) messages to the host 702 in datapackets 726 . In essence, the protocol stack 722 would include an embedded website that exists at the IP-address of the remote site 706 . An exemplary embodiment of similar technology is represented by the MASTERSWITCH-PLUS marketed by American Power Conversion (West Kingston, R.I.).
[0106] Many commercial network devices provide a contact or logic-level input port that can be usurped for the “tickle” signal. Cisco Systems routers, for example, provide an input that can be supported in software to issue the necessary message and identifier to the system administrator. A device interrupt has been described here because it demands immediate system attention, but a polled input port could also be used.
[0107] Network information is generally exchanged with protocol data unit (PDU) messages, which are objects that contain variables and have both titles and values. SNMP uses five types of PDU's to monitor a network. Two deal with reading terminal data, two deal with setting terminal data, and one, the trap, is used for monitoring network events such as terminal start-ups or shut-downs. When a user wants to see if a terminal is attached to the network, for example, SNMP is used to send out a read PDU to that terminal. If the terminal is attached, a user receives back a PDU with a value “yes, the terminal is attached”. If the terminal was shut off, a user would receive a packet informing them of the shutdown with a trap PDU.
[0108] In alternative embodiments of the present disclosure, it may be advantageous to include the power manager and intelligent power module functions internally as intrinsic components of an uninterruptable power supply (UPS). In applications where it is too late to incorporate such functionally, external plug-in assemblies are preferred such that off-the-self UPS systems can be used.
[0109] Once a user has installed and configured the power manager 7u08, a serial communications connection is established. For example, with a terminal or terminal emulation program. Commercial embodiments of the present disclosure that have been constructed use a variety of communications access methods.
[0110] For modem access, the communication software is launched that supports ANSI or VT100 terminal emulation to dial the phone number of the external modem attached to the power manager. When the modems connect, a user should see a “CONNECT” message. A user then presses the enter key to send a carriage return.
[0111] For direct RS-232C access, a user preferably starts any serial communication software that supports ANSI or VT100 terminal emulation. The program configures a serial port to one of the supported data rates (38400, 79200, 9600, 4800, 7400, 7200, and 300 BPS), along with no parity, eight data bits, and one stop bit, and must assert its Device Ready signal (DTR or DSR). A user then presses the enter key to send a carriage return.
[0112] For Ethernet network connections, the user typically connects to a power manager 708 through a modem or console serial port, a TELNET program, or TCP/IP interface. The power manager 708 preferably automatically detects the data rate of the carriage return and sends a username login prompt back to a user, starting a session. After the carriage return, a user will receive a banner that consists of the word “power manager” followed by the current power manager version string and a blank line and then a “Username:” prompt.
[0113] A user logged in with an administrative username can control power and make configuration changes. A user logged in with a general username can control power on/off cycling. Users logged in administrative username can control power to all intelligent power modules, a user logged in with a general username may be restricted to controlling power to a specific intelligent power module or set of intelligent power modules, as configured by the administrator.
[0114] A parent case, U.S. Pat. No. 7,099,934, issued Aug. 29, 2006, titled NETWORK-CONNECTING POWER MANAGER FOR REMOTE APPLIANCES, includes many details on the connection and command structure used for configuration management of power manager embodiments of the present disclosure. Such patent application is incorporated herein by reference and the reader will find many useful implementation details there. Such then need not be repeated here.
[0115] Referring again to FIG. 7 , a user at the user terminal 744 is able to send a command to the power manager 724 to have the power manager configuration file uploaded. The power manager 724 concentrates the configuration data it is currently operating with into a file. The user at user terminal 744 is also able to send a command to the power manager 724 to have it accept a power manager configuration file download. The download file then follows. Once downloaded, the power manager 724 begins operating with that configuration if there were no transfer or format errors detected. These commands to upload and download configuration files are preferably implemented as an extension to an already existing repertoire of commands, and behind some preexisting password protection mechanism. HyperTerminal, and other terminal emulation programs al low users to send and receive files.
[0116] In a minimal implementation, the power manager configuration files are not directly editable because they are in a concentrated format. It would, however be possible to implement specialized disassemblers, editors, and assemblers to manipulate these files off-line.
[0117] FIG. 8 is a diagram of an expandable power management system 800 that could be implemented in the style of the outlet strip 100 ( FIG. 1 ). In one commercial embodiment of the present disclosure, a first power controller board 802 is daisy-chain connected through a serial cable 803 to a second power controller board 804 . In turn, the second power controller board 804 is connected through a serial cable 805 to a third power controller board 806 . All the power controller boards can communicate with a user terminal 808 connected by a cable 809 , but such communication must pass through the top power controller board 802 first.
[0118] Alternatively, the user terminal could be replaced by an IP-address interface that provided a web presence and interactive webpages. If then connected to the Internet, ordinary browsers could be used to upload and download user configurations.
[0119] Each power controller board is preferably identical in its hardware and software construction, and yet the one placed at the top of the serial daisy-chain is able to detect that situation and take on a unique role as gateway. Each power controller board is similar to power controller 208 ( FIG. 2 ). Each power controller board communicates with the others to coordinate actions. Each power controller board independently stores user configuration data for each of its power control ports. A typical implementation had four relay-operated power control ports. Part of the user configuration can include a user-assigned name for each control port.
[0120] A resynchronization program is executed in each microprocessor of each power controller board 802 , 804 , and 806 , that detects where in the order of the daisy-chain that the particular power controller board is located. The appropriate main program control loop is selected from a collection of firmware programs that are copied to every power controller board. In such way, power controller boards may be freely added, replaced, or removed, and the resulting group will resynchronize itself with whatever is present.
[0121] The top power controller board 802 uniquely handles interactive user login, user-name tables, its private port names, and transfer acknowledgements from the other power controller boards. All the other power controller boards concern themselves only with their private resources, e.g., port names.
[0122] During a user configuration file upload, power controller board 802 begins a complete message for all the power controller boards in the string with the user-table. Such is followed by the first outlets configuration block from power controller board 802 k , and the other outlet configuration blocks from power controller boards 804 and 806 . The power controller board 802 tells each when to chime in. Each block carries a checksum so transmission errors could be detected. Each block begins with a header that identifies the source or destination, then the data, then the checksum.
[0123] During a user configuration file download, power controller board 802 receives a command from a user that says a configuration file is next. The user-name table and the serial-name table is received by power controller board 802 along with its private outlets configuration block and checksum. The next section is steered to power controller board 804 and it receives its outlets configuration block and checksum. If good, an acknowledgement is sent to the top power controller board 802 . The power controller boards further down the string do the same until the whole download has been received. If all power controller boards returned an acknowledgement, the power controller board 802 acknowledges the whole download. Operation then commences with the configuration. Otherwise a fault is generated and the old configuration is retained.
[0124] In general, embodiments of the present disclosure provide power-on sequencing of its complement of power-outlet sockets so that power loading is brought on gradually and not all at once. For example, power comes up on the power outlet sockets 2-4 seconds apart. An exaggerated power-up in rush could otherwise trip alarms and circuit breakers. Embodiments display otherwise report the total current being delivered to all loads, and some embodiments monitor individual power outlet sockets. Further embodiments of the present disclosure provide individual remote power control of independent power outlet sockets, e.g., for network operations center reboot of a crashed network server in the field.
[0125] The power-on sequencing of the power-outlet sockets preferably allows users to design the embodiments to be loaded at 80% of full capacity, versus 60% of full capacity for prior art units with no sequencing. In some situations, the number of power drops required in a Data Center can thus be reduced with substantial savings in monthly costs.
[0126] FIG. 9 represents a power distribution unit (PDU) embodiment of the present disclosure, and is referred to herein by the general reference numeral 900 . The PDU 900 allows a personality module 902 to be installed for various kinds of control input/output communication. For an Ethernet interface, a NetSilicon type NET+50 system-on-a-chip is preferred, otherwise a Philips Semiconductor type P89C644 microcontroller could be used in personality module 902 .
[0127] The PDU 900 further comprises an I2C peripheral board 904 , and a set of four IPM's 906 , 908 , 910 , and 912 . Such provide sixteen power outlets altogether. A power supply 914 provides +5-volt logic operating power, and a microcontroller with a serial connection to an inter-IC control (I2C) bus 917 . Such I2C bus 917 preferably conforms to industry standards published by Philips Semiconductor (The Netherlands). See, www.semiconductor.philips.com. Philips Semiconductor type microcontrollers are preferably used throughout PDU 900 because I2C-bus interfaces are included.
[0128] A SENTRY-slave personality module 916 could be substituted for personality module 902 and typically includes a Server Technology, Inc. (Reno, NV) SENTRY-type interface and functionality through a standard RJ12 jack. See, e.g., website at www.servertech.com. A slave personality module 918 could be substituted for personality module 902 and provides a daisy-chain I2C interface and functionality through a standard RJ12 jack. A terminal-server personality module 920 could be substituted for personality module 902 and provides a display terminal interface, e.g., via IC through a standard RJ12 jack, or RS-232 serial on a DIN connector. A network personality module 922 preferably provides a hypertext transfer protocol (http) browser interface, e.g. via 100Base-T network interface and a CAT-5 connector. The on-board microcontroller provides all these basic personalities through changes in its programming, e.g., stored in EEPROM or Flash memory devices. All of PDU 900 is preferably fully integrated, e.g., within power distribution outlet strip 100 , in FIG. 1 .
[0129] FIG. 10 illustrates an intelligent power module (IPT-IPM) 1000 and represents one way to implement IPT-IPM's 120 - 123 of FIG. 1 ; IPT-IPM's 220 - 223 of FIGS. 2A and 2B ; IPT-IPM 300 of FIG. 3 ; IPT-IPM 400 of FIG. 4 ; power controller boards 802 , 804 , and 806 of FIG. 8 ; and, 4-port IPM's 906 , 908 , 910 , and 912 of FIG. 9 . The IPT-IPM 1QOO comprises an I2C microcontroller 1002 connected to communicate on a daisy-chain I2C serial bus with in and out connectors 1004 and 1006 . An AC-Line input 1008 , e.g., from IPT-PS 118 in FIG. 1 , is independently switched under microcontroller command to AC-Line output-1 1010 , AC-Line output-2 1011 , AC-Line output-3 1012 , and AC-Line output-4 1013 . A set of four relays (K1-K4) 1014 - 1017 provide normally open (NO) contacts 1018 - 1021 . DC-power to operate the relays is respectively provided by relay power supplies 1024 - 1025 . Optical-isolators 1026 - 1029 allow logic level outputs from the microcontroller 1002 to operate the relays in response to I2C commands received from the I2C-bus.
[0130] Similarly, optical-isolators 1030 - 1033 allow the presence of AC-Line voltages at AC-Line output-1 1010 , AC-Line output-2 1011 , AC-Line output-3 1012 , and AC-Line output-4 1013 , to be sensed by logic level digital inputs to microcontroller 1002 . These are read as status and encoded onto the I2C-bus in response to read commands. A local user is also provided with a LED indication 1034 - 1037 of the AC-Line outputs. A set of load sensors 1038 - 1041 sense any current flowing through the primaries of respective isolation transformers 1042 - 1045 . A logic level LS1-LS4 is respectively provided to microcontroller 1002 to indicate if current is flowing to the load.
[0131] In general, remote power management embodiments of the present disclosure are configurable and scalable. Such provides for maximum fabricator flexibility in quickly configuring modular components to meet specific customer requests without overly burdening the manufacturing process. The following list of various customer requirements can all be met with minimal hardware, and no software changes: Vertical or Horizontal enclosure mounting; Variable controllable outlet configurations (4, 8, 12 ,16 outlets/enclosure); Variable number of power input feed configurations to support redundant power to critical network equipment (up to 4 input feeds); Option of displaying one or more input load currents on a dual 7-segment LED display(s); Ability to reorient the enclosure without having to invert the 7-segment LED display(s); Measuring per outlet load current for individual appliance load reporting; and a Variety of user interfaces that can be substituted at final product configuration time.
[0132] A modular component concept allows for communications and automated detection of any included modular components over a common communications channel so a multi-drop, addressable, and extensible bus architecture is used. The Inter-IC (I2C) bus developed by Philips semiconductor is preferred. Each modular component contains a microprocessor capable of interpreting and responding to commands over I2C-bus. An application layer enhancement on top of the standard I2C protocol allows for data integrity checking. A-checksum is appended to all commands and responses. Such checksum is validated before commands are acted upon, and data responses are acknowledged. Each module on the I2C power control bus has either a hard-coded or configurable address to enable multiple components to communicate over the same two wires that comprise the bus. Configuration jumpers on the power supply module are used to select operational items, e.g., #Power input feeds, #four port Intelligent Power Modules (IPM) attached to each input feed, Input feed overload current threshold, and Display inversion.
[0133] The main components used in most instances are the power supply boar (IPT-PS) that supplies DC voltage on the interconnection bus, and monitors and reports input feed load and enclosure configuration information; the intelligent power module IPM (IPT-IPM) which controls the source of power to each outlet based on I2C commands from the master controller personality module (PM), and that reports whether the outlet is in the requested state and the outlet load current back to the master controller; the display board (IPT-I2C) used to display load current as supplied by the master controller and to monitor user-requested resets, and that can communicate with sensors attached to its Dallas Semiconductor-type “1-wire” bus to the master controller; and, the personality modules that act as an I2C-bus master, e.g., IPT-Serial PM, IPT-Slave PM, and IPT-Network PM.
[0134] Such personality module can initialize, issue commands to, and receive responses from the various components on the bus. It also is responsible for executing user power control and configuration requests, by issuing commands on the bus to the various modules that perform these functions. These personality modules support several user interfaces and can be swapped to provide this functionality. The IPT-Serial PM is used for serial only communications. The IPT-Slave PM is used to connect to an earlier model controllers, and allows for a variety of user interfaces, e.g., Telnet, Http, SNMP, serial, modem. The IPT-Network PM has much of the same functionality as a previous model controller, but has all that functionality contained on the personality module itself and requires no external enclosure.
[0135] By combining and configuring these components, a variety of power control products can be constructed in many different enclosure forms, each with a variety of power input feed and outlet arrangements.
[0136] Lower-cost power control products can be linked to a more expensive master controller using an IPT-Network PM to configure a large-scale power control network that needs only a single IP-address and user interface. Such would require a high level, high bandwidth, multi-drop communications protocol such as industry-standard Controller Area Network (CAN). The CAN bus supports 1-Mbit/sec data transfers over a distance of 40 meters. This would enable serial sessions from a user to serial ports on the device being controlled to be virtualized and thus avoid needing costly analog switching circuitry and control logic.
[0137] Although the present disclosure has been described in terms of the present embodiment, it is to be understood that the disclosure is not to be interpreted as limiting. Various alterations and modifications will no doubt become apparent to those skilled in the art after having read the above disclosure. Accordingly, it is intended that the appended claims be interpreted as covering all alterations and modifications as fall within the true spirit and scope of the disclosure.
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A power management device can include a housing, a power input associated with the housing, and a plurality of power outputs associated with the housing. At least certain power outputs can be connectable to one or more electrical loads external to the housing and to the power input. In some embodiments, a communications bus and one or more power control sections can be associated with the housing. In some embodiments, one or more power control sections can communicate with the communications bus and with one or more corresponding power outputs among the plurality of power outputs. In some embodiments, a power information display can communicate with the communications bus. If desired, a power information determining section can be associated with the housing and in communication with the communications bus. The power information determining section may communicate power-related information to the power information display.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application is related to and claims priority from the U.S. provisional application No. 60/228,907 entitled “OPTIMIZED DISTORTION CORRECTION FOR REAL TIME GRAPHICS” filed Aug. 29, 2000, and application No. 60/311,301, entitled “METHOD AND APPARATUS FOR DISTORTION CORRECTION AND DISPLAYING ADD-ON GRAPHICS FOR REAL TIME GRAPHICS” filed Aug. 10, 2001 by the same inventors, and incorporated herein by reference.
FIELD OF INVENTION
[0002] The present invention relates generally to graphics production techniques and more particularly to an optimized technique for correcting for the effects due to lens distortion.
BACKGROUND OF THE INVENTION
[0003] Previous techniques developed for inserting registered (aligned with the content of the video) graphics into a streaming video feed is based on rendering and processing the add-on graphics on the broadcaster's side. These techniques are typically targeted towards sports broadcasts and use a combination of camera tracking and object tracking technologies. In order to insert add-graphics registered to the content of a streaming video feed, the effects due lens distortion have to be accounted for. Large amounts of data manipulation is required for such registered add-on graphic insertion, and this amount of computation is prohibitively large for processing downstream on the consumer-level hardware. There is a need for an optimized technique for distortion correction required for registered add-on graphics that can be implemented on the consumer-level hardware.
SUMMARY OF THE PRESENT INVENTION
[0004] Briefly, one aspect of the present invention is embodied in an optimized method and apparatus for correcting for distortions in rendering add-on graphics within a streaming video feed comprising receiving a streaming video feed captured using a real camera, including an image frame capturing an image of a real asset having a size and a position within the image frame, the image frame being captured from a particular view point and having a particular field of view, the real camera introducing a plurality of measurable image distortions into the image frame, receiving set of camera instrumentation sensors data corresponding to the view point, the field of view, distortion parameters of the real camera, creating a virtual camera, generating add-on graphics having a size and an insertion position within the image frame, creating a first distortion grid having a first set of coordinate values, creating a second distortion grid having a second set of coordinate values wherein the second set of coordinate values are derived from the first set of coordinate values, using the second grid to distort the add-on graphics for image distortion, and compositing the distorted add-on graphics with the image frame.
[0005] The advantages of the present invention will become apparent to those skilled in the art upon a reading of the following descriptions and study of the various figures of the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] [0006]FIG. 1 illustrates a data flow diagram of the data processing by typical STB receiver as disclosed by the present invention;
[0007] [0007]FIG. 2 illustrates a patch grid within the lattice of a full size distortion grid;
[0008] [0008]FIG. 3 illustrates a data flow diagram within the presentation engine;
[0009] [0009]FIG. 4 illustrates a detailed flow diagram of the process of using the optimized distortion correction technique in rendering add-on graphics
[0010] [0010]FIG. 5 an illustration of the use of interpolation in determining the coordinates of a patch grid.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0011] The current generation of Digital Television (DTV) receivers, primarily cable and satellite Set-Top Boxes (STB), generally offer limited resources to applications. From a manufacturer's perspective, the goal has been building low-cost receivers comprised of dedicated hardware for handling the incoming MPEG-2 transport stream: tuning and demodulating the broadcast signal, demultiplexing and possibly decrypting the transport stream, and decoding the Audio Video (AV) elementary streams. Within the software found on a DTV receiver, often called middleware, one of the main components is the presentation engine. These presentation engines perform the function of processing the elementary AV stream as well as rendering and compositing add-on graphics to be inserted into the streaming video feed. The processing performed by the presentation engine may include distortion correction necessary for inserting add-on graphics registered to a real asset in a streaming video feed.
[0012] [0012]FIG. 1 illustrates a data flow diagram of the data processing by a typical STB receiver as disclosed by the present invention. The video feed and a corresponding data stream is collected and transmitted to the receiver's input stage 11 . In the processing stage 12 of the presentation engine 10 , data is processed by a presentation engine 10 using a declarative markup language. At the output stage 14 , data is processed and a rendered graphics are composited with a frame of streaming video feed as shown in the composite scene 16 .
[0013] Looking at the input stage 11 of the presentation engine 10 , the video feed 18 generated by real cameras at the event site represented here by the camera 20 , and the corresponding camera instrumentation data 22 are received and demultiplexed by the modules of the Set Top Box (STB) receiver not shown here. Prior to entering the input stage 11 of the presentation engine 10 , the video feed 18 generated by the cameras 20 at the event site and the corresponding camera instrumentation data 22 are received, tuned by a tuner module, demultiplexed by a demux module and decoded by a MPEG-2 decoder module.
[0014] Most digital television broadcast services, whether satellite, cable, or terrestrial, are bases on the MPEG-2 standard. In addition to specifying audio/video encoding, MPEG-2 defines a transport stream format consisting of a multiplex of elementary streams. The elementary streams can contain compressed audio or video content, “program specific information: describing the structure of the transport stream, and arbitrary data. Standards such as DSM-CC and the more recent ATSC data broadcast standard give ways of placing IP datagrams in elementary data streams. Although the present invention is implemented on a MPEG-2 platform partially because it is the more prominent standard currently used digital television signal transmission, it would be apparent to on skilled in the art that the present invention may be used with standards other than MPEG-2.
[0015] After demultiplexing and decoding of the video feed 18 and the camera instrumentation data 22 , at the input stage 11 of the presentation engine 10 , appropriate parameters are collected and corresponding values are passed to a cameraViewpoint 24 node and a gridnode 26 node, or alternatively to the dataReader and viewpoint nodes, and a gridnode 26 node. The video feed 18 is accepted and processed by the videoSurface node 28 .
[0016] In practicing the present invention, a declarative markup language such as the Virtual Reality Markup Language (VRML) may be used to implement the concepts of the present invention. It would be apparent to one skilled in the art that any number of declarative markup languages including but not limited to languages such as HTML and XML may be used to practice the present invention. VRML is a web-oriented declarative markup language well suited for 2D/3D graphics generation and thus it is a suitable platform for implementing the teaching of the present invention.
[0017] In a declarative markup language such as the VRML, nodes describe shapes and their properties in the “world” being rendered. Individual nodes describe shapes, colors, lights, viewpoints, how to orient shapes, animation timers, sensors interpolators and so on. Nodes generally contain the node type, and a set of fields. Fields define the attributes of a node such as height, and color of the object to be rendered.
[0018] Enhancements that are registered to real assets within a video feed require placement that is correlated with objects in the video. Since current camera and object tracking systems may provide the data necessary for accurate graphical insertions of add-on graphics registered to the content of the video feed, in the present invention new nodes have been developed that include data fields for accepting camera instrumentation data allowing a declarative representation of the parameters used in rendering camera-aligned overlay graphics or add-on graphics. The camera tracking equipment may use encoders to read parameters such as the current pan, tilt and twist of the real camera 20 as well as the zoom level (camera tracking data 22 ) corresponding to a particular frame of the streaming video feed 18 . Additionally, if the real camera 20 is mobile, GPS tracking may be used to supply data on the physical location of the real camera at each point in time. The add-on graphics 36 are rendered at the appropriate position and size using a virtual camera 35 , and thereafter composited with the real scene.
[0019] However, geometric correction that accounts for lens distortion and optical center shift is often not applied due to the increased processing cost. The correction becomes necessary if graphical insertion of objects that are aligned with the content of the video feed 18 is desired. This correction becomes especially important if one has, for example, real objects sitting on virtual objects. Without lens distortion correction, real objects can appear to slide over the virtual set as the camera pans or zooms.
[0020] Looking at the processing stage 57 of the presentation engine 10 , the values of the camera instrumentation (sensor) data 22 are used by the CameraViewpoint node 24 to drive a virtual camera 35 . The virtual camera 35 renders a virtual scene 37 and graphics 36 of the appropriate size and at the appropriate position corresponding to the real camera's view point for that frame. The values corresponding to the viewpoint of the real camera 20 and the lens distortion values of the real camera 20 are passed as parameters to the corresponding fields of the CameraViewpoint node and drive the virtual camera's 35 viewpoint to correspond to that of the real camera 20 . Alternatively, a dataReader node accepts the real camera sensor data 22 and passes the appropriate parameters to the viewpoint node which in turn drives the virtual camera's 35 viewpoint to correspond to that of the real camera 20 . A viewpoint is a predefined viewing position and orientation in a virtual or real world, like a recommended photograph location at a tourist attraction. The location and viewing direction for the viewpoint is specified by the parameters of the viewpoint node or the CameraViewpoint node 24 . These parameters are used to correspond the virtual camera's 35 view point to that of the real camera 20 .
[0021] The video feed 18 is used by the VideoSurface node 28 to render the real scene as texture for that particular frame, as shown in video surface scene 30 . Some declarative markup languages including VRML supports a MovieTexture primitive for presenting video clips, but streaming video feed from a broadcast is not directly supported. In one embodiment of the present invention a new level of abstraction to support video synthesis, called surfaces has been introduced. By using this abstraction, the presentation engine 10 architecture enables arbitrary marking engines (e.g., video, HTML, Flash™) to render into a scene at appropriate frame rate without burdening other elements (e.g., a 5 frames/sec animation on one surface would not prevent video on another surface from playing at 30 fps). In the example of the present embodiment, a MovieSurface node is introduced and used to control and display video. A subclass of the MovieSurface node named VideoSurface is used to implement the processing of live or streaming video feed such as the DTV broadcast of the racing event of present example. The VideoSurface node includes a videoSource field and a VideoResolution field used to support a broadcast or live video feed as opposed to a locally stored video.
[0022] The VideoSource field indicates where the presentation engine browser is receiving video input. The possible values of the field are hardware dependent. For the particular platform illustrated in the example of the present embodiment, there are three possibilities: ATSC, COMPOSITE, and SDI (Serial Digital Interface). In the case of ATSC, the decoded video is extracted directly from a receiver/tuner card and displayed onto the surface. In this configuration it is assumed that the presentation engine's 10 browser and the DTV receiver reside in the same machine or set top box. Alternatively, one can envision a two-box setup, where the first box is a DTV receiver and the second box holds the presentation engine 10 . The decoded video stream is sent from the DTV receiver to the compositor via either the COMPOSITE video port or the SDI video port.
[0023] The VideoResolution field specifies the dimensions of the extracted video. In the example of present embodiment, the presentation engine has the capability of handling full-sized NTSC video of 720×480 at 30 fps. The ATSC tuner card is able to down filter any of the ATSC video resolutions to 720×480.
[0024] In a preferred embodiment of the present invention, a node named Gridnode 54 is used to correct distortions introduced by the real camera lens. The Gridnode 54 uses camera instrumentation data 22 to correct for the radial lens distortion and optical center shift of the real camera lens. This correction is needed because in order to do frame aligned graphics insertion, it is necessary to correct for the effects of radial lens distortion and optical center shift inherent in every real camera 20 . Otherwise, the inserted graphics would not accurately register to the to the real object and would appear to shift with respect to it.
[0025] In the example of the present invention, the camera instrumentation data 22 is used by the Gridnode node 26 to correct for the real camera's 20 lens distortion corresponding to the patch grid 34 . The coordinate values of the patch grid 34 may be derived by interpolation from the coordinate values of the full frame or whole grid 32 . The processing of the related data and pixels for each full frame of the video feed 18 requires a large amount of manipulation and data computation. The present invention teaches an optimized method of distortion correction based on using a patch grid 34 instead of a the whole grid 32 .
[0026] Looking at the output stage 14 of the presentation engine 10 , the CameraViewpoint node 24 drives the virtual camera 35 to produces a virtual scene 37 and add-on graphics 36 within it. The add-on graphics 36 are to be inserted into the streaming video feed as shown in 16 . The Gridnode node 26 uses parameters corresponding to the values of the real camera's lens distortion from the camera sensor data feed 22 and creates the full frame distortion grid 32 and the patch grid 34 . The distortion grid 32 and the patch grid 34 are then used to modify the rendered graphics 36 by adjusting them, so that the rendered graphics 36 are distorted in the same way as the real scene 30 . The rendered graphics are laid on the distortion grid 32 and distorted in the appropriate amount corresponding to the distortion parameters of the real camera lens. In the present example, the distortion grid 32 is adjusted for changes in the distortion parameters by correspondingly adjusting its coordinates. The distortion grid 32 introduces appropriate distortion of the virtual scene surface 37 and the add-on graphics 36 when the virtual scene 37 and the add-on graphics 36 within it are laid on it. The distortion grid 32 is used as geometry to distort the virtual scene 37 and the rendered graphics 37 in it.
[0027] The presentation engine 10 then composites the corrected add-on graphics 36 with the real scene 30 to form the composite scene 16 which is then displayed on the DTV screen. Once the rendered graphics 36 is corrected for the radial lens distortions by using the whole grid 32 and the patch grid 34 , the corrected graphics is composited with the real scene frame 30 to form the composite frame 16 with the inserted graphics 40 .
[0028] Some classes of enhancements require placement of graphics that is correlated with objects in the video. Since current camera and object tracking systems provide the data required for accurate graphical insertions registered with the video, new nodes to be used in a declarative representation language such as VRML have been developed that can support these data fields to allow a declarative representation for camera-aligned overlay graphics The camera tracking equipment, well known in the art, typically uses encoders to read the current pan, tilt, and twist of the camera, as well as, the zoom level, i.e., the field of view. Furthermore, the position of the camera is tracked in order to reproduce a virtual camera that corresponds to the real camera.
[0029] The next step is to render the graphics at the appropriate position and size using the virtual camera shot. However, geometric correction that accounts for lens distortion and optical center shift is often not applied because of the increased processing cost. When graphical objects that are aligned with the content of the video feed are inserted, the correction becomes necessary. The present invention applies a correction technique that is related the well-known techniques of rectification and geometric correction, which are normally applied on a per-image basis. The present invention introduces a two-pass rendering technique that renders the scene that is to be used as a texture in the second pass. This texture is then corrected for distortion parameters (radial distortion and optical center shift) and finally composited with the current video image. Some current virtual set systems perform this correction since it becomes especially important if one has, for example, real objects sitting on virtual objects. Without lens distortion correction, real objects can appear to slide over the virtual set as the camera pans or zooms.
[0030] [0030]FIG. 2 illustrates a patch grid 34 within the lattice of the full size Gridenode 32 . The gridnode is used as the geometry upon which the add-on graphics and the video frame scene are composited as shown in scene 16 in FIG. 1. Consumer level hardware lack the needed processing power to do things such as hardware-acceleration for graphics like alpha-blending, and still leave enough CPU cycles for other interactivity. Since in the typical case, the graphics or assets to be added are smaller in size than the video feed, i.e. the ratio of the pixels necessary to represent the assets within the video to the pixels necessary to represent the full frame of the video is less than one, the computation time required for distortion correction can be reduced considerably by applying an optimization technique. To overcome the bottleneck caused by the large amount of computation required to blend the video layer with the add-on graphics, a technique to limit the actual rendering to single patches or region of interest around the graphics to be added is taught by the present invention. A Region Of Interest (ROI) is first determined, and the distortion calculations are limited to the ROI areas only. The Gridnode defines a regular grid of vertices that can be used as control points in a generic way, i.e. independent from geometry. Gridnode, itself, uses an attached IndexedFaceSet node, so that the control points of the base node can be used to modify the geometry. This modification is repeated for the patch grid based on the location of the patch grid with respect to the whole grid.
[0031] In a declarative representation language such as VRML, primitive geometry nodes can be used to create a variety of simple shapes, but they are insufficient when your goal is to create more complex shapes. A face is a flat shape whose perimeter traces a closed path through a series of coordinates in your 3-D world. A face set is a group of these faces specified by an IndexedFaceSet node. By arranging many adjacent sets of faces in an IndexedFaceSet node, you can construct complex faceted surfaces.
[0032] As shown in FIG. 2, the full frame distortion grid 32 is created using the gridnode node 26 . The distortion grid's 32 coordinates are adjusted based on the distortion parameters from the camera sensor data 22 . In one embodiment of the present invention, within the full frame distortion grid 32 , the gridnode node 26 creates patch grids whose size and position are based on the size and position of the assets within the video frame, as well as the size and position of insertion of the add-on graphics 36 . The coordinates of the patch grid 34 are at least partially derived by interpolation from the coordinates of the full frame distortion grid 32 . Depending on the position of insertion of the add-on graphics 36 , the coordinates of the patch grid 34 change.
[0033] [0033]FIG. 3 illustrates a data flow diagram within the presentation engine 10 . In operation 38 , the next frame of the streaming video feed 18 is obtained. In operation 40 , the camera instrumentation data 22 is read. In one embodiment of the present invention, a dataReader node is used to read the camera sensor data 22 . In an alternative embodiment, the CameraViewpoint node 24 reads the distortion parameters of the real camera from the camera sensor data 22 . In operation 44 , the CameraViewpoint node 24 or in an alternative embodiment, the VRML viewpoint node sets the virtual camera's view point or field of view of corresponding to the field of view of the real camera. In operation 46 , the virtual camera 35 renders the virtual scene 37 and the add-on graphics 36 (virtual assets). In operation 48 , the patch grid 34 of the optimized gridnode patch is corrected based on the location of the patch grid within the whole grid. In operation 50 , the gridnode patch 34 is used as geometry with the appropriate distortion corresponding to the real camera lens distortion. The add-on graphics 36 is laid on the patch grid 34 as texture and distorted in the appropriate way so that the add-on graphics' 36 distortions match that of the video feed 20 . The distorted add-on graphics 36 is added to the real scene 30 to form the composite scene 16 in step 52 .
[0034] [0034]FIG. 4 illustrates a detailed flow diagram of the process of using the optimized distortion correction technique in rendering add-on graphics 36 . In operation 53 , the next frame of the streaming video feed is retrieved. In operation 54 , the presentation engine 10 compares the new distortion parameters obtained from the camera sensor data 22 to the values of the distortion parameters for the current frame. If distortion parameters of from the camera sensors data 22 have changed for the new frame, a new distortion patch grid 34 and possibly a new full distortion grid 32 may have to be created. The distortion parameters may include at least one of distortion coefficient, optical center shift in the x direction and the y direction as well as the distortion coefficient. Each real camera lens has unique distortion parameters. Furthermore, the values of the distortion parameters change based on changes in the focus and field of view of the lens. In operation 58 , a Region Of Interest (ROI) for the add-on graphics 36 to be rendered is determined. The ROI determination is based on the size of the graphics to be added and its insertion position within the video frame 30 . The ROI determination operation involves gathering data and does not adjust the patch location to correspond to the ROI. In an alternative embodiment, the patch grid 34 position may be adjusted in the same operation as determining the ROI region. Once the ROI is determined, in step 60 the patch grid 34 lattice and texture size is adjusted to correspond to the size of the add-on graphics 36 (virtual asset) to be rendered.
[0035] In operation 62 , the new distortion parameters are applied to the full frame grid (the original grid) 32 . The texture coordinates of the gridnode get adjusted so that any image that gets mapped onto it will get distorted. The distortion parameters su, sv and k drive this process. Su an sv are optical center shifts in the x and y directions respectively, i.e. they offset all grid points (texture coordinates). K does a radial distortion so that it then looks like the composite graphic scene 16 has been taken by the real camera 20 . Finally, the texture coordinates adjustment make sure the image is stretched in the appropriate way to match what is recorded by the real camera 20 .
[0036] In operation 64 the patch grid's 34 position is adjusted. The patch moves to wherever the asset is. And lastly, in step 66 the new patch grid is adjusted by interpolating from the coordinates of the full grid 32 with respect to the position of the patch on the original grid and the distortion parameters 56 of the original grid 32 .
[0037] [0037]FIG. 5 is an illustration of the application of the interpolation techniques on the grid patch 34 . The Gridnode texture coordinates are adjusted based on the location of the grid patch 34 within the full grid 32 (original grid). The Gridnode class gets derived from a base grid node (GrideBaseNode) which defines a regular grid of vertices that can be used as control points in a generic way, i.e. independent form geometry. The Gridnode, itself, uses an attached IndexedFaceSet, so that the control points of the base node can be used to modify the geometry. The patch grid 34 distortion is adjusted in respect to it's position within the full grid 32 (gridnode). The patch grid 34 has a rectangular grid like the full grid 32 . However, the patch grid's lattice is adjusted (by interpolation of the original gridnode control points), so that it reflects the part of the original grid it is covering. The values of its coordinates may be interpolated using a standard technique, such as bilinear interpolation. It will be apparent to those skilled in the art, that any interpolation techniques other than the bilinear method may be used to calculate the patch grid coordinates. For example, in looking at FIG. 5, the value of the coordinate for the abscissa 68 may be interpolated from the values of the original grid abscissa such as 70 and 72 and 74 and other abscissa. Similarly, the coordinate values of the vertices 76 may be calculated from the values of the full frame (original) grid vertices such as 80 , 82 , 84 , 86 , 88 and so on.
[0038] The following is an illustrative algorithm for the optimized distortion correction method:
[0039] FOR each frame DO
[0040] Step 0: adjust grid patch lattice and texture pixel to best represent asset to be rendered (only needed once per asset, and when asset size changes considerably);
[0041] tex_width=asset_width/grid_width * video_width+factor;
[0042] tex_height=asset_height/grid_height * video_height+factor;
[0043] patch_subdivision=min (5, grid_subdivision * asset_size/grid_size);
[0044] Step 1: adjust lattice of abstract gridnode to correct for distortion and optical center shift
[0045] FOR ALL control points with coordinates (x, y) DO
[0046] x=kappa * x+0.5−opticalCenterX;
[0047] y=kappa * y+0.5−opticalCenterY;
[0048] Step 2: adjust position of small patch to asset position being rendered;
[0049] Step 3: adjust patch grid with respect to it's position on the gridnode
[0050] FOR all patch grid texture control points with coordinates (xp, yp) DO
[0051] Find nearest n grid coordinates (xi, yi)
[0052] xp=interpolation (x1, x2, . . . , xn);
[0053] yp=interpolation (y1, y2, . . . , yn);
[0054] Step 4: render grid patch and composite with current frame.
[0055] The present invention's optimized method of distortion correction allows the instrumented camera information to be processed downstream on the user side hardware, with limited capabilities. Downstream processing allows flexibility and possibility of user interactivity. However, the method of the present invention is equally applicable integration of graphics on the broadcaster side.
[0056] [0056]FIG. 6 shows the functional block diagram for a transmission and reception systems for a Digital Television (DTV). On the transmission side 97 , the DTV production system 90 is composed of AV Production module 92 corresponding to the television cameras 20 of FIG. 1 and the AV equipment processing the raw image. The AV signals from the AV production unit 90 (broadcaster) are fed into an MPEG-2 encoder 92 which compresses the AV data based on an MPEG-2 standard. Digital television broadcast services, whether satellite, cable or terrestrial transmission are based on the MPEG-2 standard. In addition to specifying audio and video encoding, MPEG-2 defines a transport stream format consisting of a multiplex of elementary streams. The elementary streams can contain compressed audio or video content, program specific information describing the structure of the transport stream, and arbitrary data. It will be appreciated by one skilled in the art that the teachings of the present invention is not limited to an implementation based on an MPEG-2 standard. Alternatively, the present invention may be implemented using any standard such as MPEG-4, DSM-CC or the Advanced Television System Committee (ATSC) data broadcast standard that allows for ways of placing IP datagrams in elementary streams. The generated and compressed AV data is inputted into a data injector 94 , which combines the AV signals with the corresponding instrumentation data 22 of FIG. 1, coming from the data acquisition unit 95 . The data acquisition module 95 handles the various real-time data sources made available to the broadcaster. In the example used with the present embodiment, the data acquisition module 95 obtains the camera tracking, car tracking, car telemetry and standings data feeds and converts these into Internet Protocol (IP) based packets which are then sent to the data injector 94 . The data injector 94 receives the IP packets and encapsulates them in an elementary stream that is multiplexed with the AV elementary streams. The resulting transport stream is then modulated by the modulator 96 and transmitted to the receiver device via cable, satellite or terrestrial broadcast.
[0057] On the receiver side, a receiver 98 receives the transmitted combined AV/data signal. The presentation engine 10 resides on the receiver 98 . Alternatively, the receiver 98 may be incorporated into a Digital television or a Personal Computer with a DTV card or be a part of Set Top Box (STB) receiver capable of interfacing with other such devices. Furthermore, the presentation engine 10 may include an integrated application module or use a stand alone application module to interface with a gaming engine.
[0058] The digital television signals may be delivered via cable or satellite or terrestrial broadcast. The receiving antenna delivers the signals to a receiver 98 . As disclosed in the preferred embodiment of the present invention, the receiver 98 , includes a tuner 100 , a demultiplexer (Demux) 102 to demultiplex the incoming signal, a MPEG-2 Decoder 104 to decode the incoming signal, and a presentation engine 10 . The presentation engine 10 may include an application module that interfaces with a gaming platform not shown here. Alternatively, the application module may be a stand alone gaming platform interfacing with the presentation engine 10 through a network. The presentation engine 10 processes the incoming AV signals and the corresponding data, and renders a composite image on the digital television.
[0059] Although the present invention has been described above with respect to presently preferred embodiments illustrated in simple schematic form, it is to be understood that various alterations and modifications thereof will become apparent to those skilled in the art. It is therefore intended that the appended claims to be interpreted as covering all such alterations and modifications as fall within the true spirit and scope of the invention.
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An optimized method and apparatus for correcting for distortions in rendering add-on graphics within a streaming video feed comprising receiving a streaming video feed captured using a real camera, including an image frame capturing an image of a real asset having a size and a position within the image frame, the image frame being captured from a particular view point and having a particular field of view, the real camera introducing a plurality of measurable image distortions into the image frame, receiving set of camera instrumentation sensors data corresponding to the view point, the field of view, distortion parameters of the real camera, creating a virtual camera, generating add-on graphics having a size and an insertion position within the image frame, creating a first distortion grid having a first set of coordinate values, creating a second distortion grid having a second set of coordinate values wherein the second set of coordinate values are derived from the first set of coordinate values, using the second grid to distort the add-on graphics for image distortion, and compositing the distorted add-on graphics with the image frame.
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TECHNICAL FIELD OF THE INVENTION
This invention relates generally to the field of preparing and processing specimens as for microscopy and particularly relates to a method and apparatus for both securing a grid and transferring it between workstations.
BACKGROUND OF THE INVENTION
Small biological specimens are prepared for examination under the electron microscope by placing them on a reticulate specimen grid. Specimen grids are used particularly in the field of Cryoultramicrotomy, where specimens are examined at extreme high power under supercooled (-196° C.) conditions.
Conventional specimen preparation practices for Cryoultramicrotomy are illustrated by the following articles: D. Parsons, D. J. Bellotto, W. W. Schulz, M. Buja and H. K. Hagler, "Towards Routine Cryoultramicrotomy", and H. K. Hagler and L. M. Buja, "New Techniques for the Preparation of Thin Freeze Dried Cryosections For X-Ray Microanalysis", Science of Biological Specimen Preparation, pp. 161-166, both available from H. K. Hagler, University of Texas, Department of Pathology, Health Science Center at Dallas, 5323 Harry Hines Blvd., Dallas, Tex. 75235.
In conventional practice, a grid on which the microscope specimens will be mounted is coated with a formvar solution that dries to form a transparent film across the grid. The grid is then chilled to -130° C. by placing it within a block inside of a cryochamber. The cryochamber is conventionally made out of stryofoam and is filled with gaseous nitrogen at -130° C. Inside the cryochamber, a grid transfer arm is provided in order to move the specimen grid (which is preferably a 50 to 400 mesh copper grid) from one location to another. The transfer arm conventionally has a pair of forceps on one of its ends in order to grip the grid. At a first location, sections of tissue are placed on the grid and the transfer arm then moves the grid over to a second location. During transfer, the specimens on the open, single grid are subject to being inadvertently jarred from their ideal locations or even swept off the grid.
The grid is then placed in a formvar-coated beryllium capsule in order to retain the specimens between two films of formvar. The capsule is assembled and loaded into a coldstage, which is used to protect the cold specimen as it is transferred to the electron microscope.
Recently, a holder comprising two grids hinged to each other has been used for containing tissue specimens. Both copper mesh parts of the double grid are coated with formvar, the tissue specimens are placed on the grid and the double grid is manually folded upon itself. The use of a double grid obviates the need for an expensive beryllium capsule, as the grid itself retains the specimen between two transparent formvar films. It also protects the specimens in transfer between workstations in the cryochamber.
However, the conventional forceps and grid transfer arm are less than ideal for the transfer of the double grid from one location to another. In conventional practice, the arm forceps must grip the lower grid of the double grid, and the upper grid must be folded onto the lower grid by using a pre-cooled second pair of manual forceps. After the upper grid has been folded onto the lower grid, one of the transfer arm forceps will be wedged between the upper grid and the lower grid. The arm grid must thus be subsequently disengaged by opening the transfer arm forceps and removing the grid with another pair of manual forceps.
Either of the steps of manually folding the grid over onto the loaded lower grid or extracting the transfer arm forceps from the folded grid may disturb the location of the specimens, as these manual functions can be controlled only to the extent permitted by the motor skills of the operator.
Thus, a need has arisen for a grid securement and transfer arm which will provide a more automatic grid folding function and make the task of transferring the specimen grid from a first location to a second location surer and easier.
SUMMARY OF THE INVENTION
The present invention provides a new method and apparatus for securing a tissue specimen in a folding specimen holder. A specimen holder is provided in an open position, and the holder is releasably secured to a transfer arm having a holder folding device. The specimen is loaded into the holder, and the holder is folded on itself with the aid of the folding device. The transfer arm transfers the grid from a first workstation to a second workstation and releases the holder from the transfer arm.
In a preferred embodiment, a specimen grid is secured to an upper surface of the transfer arm by means of a spring clip. The spring clip is spring-biased against the upper surface of the transfer arm. In order to release the clip to allow the admittance of a specimen grid, the operator presses downward on the transfer arm on a workstation block, pushing the spring clip upward in relation to the transfer arm. The lower portion of the double grid is then placed on the upper surface beneath the clip, and the operator raises the transfer arm to secure the lower grid between the clip and the upper surface. The specimens are then secured into the grid with the use of a slidable folding device at a first workstation. The grid is transferred to a second workstation and the operator presses the arm down on a block in order to release the folded specimen grid from the transfer arm.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention and the advantages thereof, reference is now made to the following description taken in conjunction with the accompanying Drawings in which:
FIG. 1 is a perspective view of the grid transfer arm of the invention;
FIG. 2 is a partial elevation of the grid transfer arm shown in FIG. 1, illustrating the spring clip and the slider mechanism of the invention;
FIG. 3 is a perspective view of a cryobox employing the specimen grid transfer arm of the invention, showing an alternate location of the grid transfer arm in phantom; and
FIGS. 4a-4f are perspective views of the free end of the transfer arm shown in FIG. 1, showing various steps in the grid securing and transferring process.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, the transfer arm 10 of the present invention has an arm blade 12 that is preferably fabricated of a metal such as stainless steel. For the illustrated application, arm blade 12 is conveniently sized to be about 75 millimeters long. An upstanding handle 14 is affixed to an upper surface 16 of blade 12 at a pivot end 18 thereof. A pivot 20 is affixed to a lower arm surface 21 at end 18 and extends downwardly from arm blade 12. Pivot 20 is preferably coaxial with handle 14. A sliding grid folder or slider 22 is slidably mounted on arm blade 12 and is movable toward a free end 24 of arm 12 or toward pivot end 18. Slider 22 can be fashioned of stainless steel.
A spring clip 26 is mounted on arm blade 12. Spring clip 26 includes upstanding side portions 28 joined by a bottom member 29. Clip portions 30 extend inwardly from the top of side portions 28 and, when spring clip 26 is empty, are spring loaded against upper surface 16. For ultramicrotomic work, the distance between inwardly extending clip portions 30 should be about from 1.9 to 2.5 millimeters in order to be correctly sized to receive the specimen grid (later shown).
Referring to FIG. 2, an elevation of transfer arm 10 shows the relationship of upstanding handle 14 and depending pivot 20 to arm blade 12. Pivot 20 is affixed as by welding to lower surface 21. Blade 12 forms a slight downward angle from the handle pivot axis in order to aid the pressing action of blade 12 on a block (later described).
Slider 22 has side portions 32 (only one shown) which extend over the edges of blade arm 12 from upper surface 16 and fold inwardly to parallel lower surface 21. The fitting of slider 22 to blade arm 12 is loose enough to allow movement of slider 22 toward and away from end 24 when operated by a pair of forceps or the like. Slider 22 includes a push arm 34 that extends forwardly on upper surface 16 toward end 24. Push arm 34 ends in an upstanding contact member 36 to provide a pushing surface for contacting a grid. Preferably, push arm 34 is slightly sprung toward upper surface 16 in order to slightly tension slider 22 against blade arm 12 so that contact member 36 may be pushed forward in a low position.
Spring clip 26 includes a spring 40 which is attached as by welding to lower surface 21 at a point 38. Bottom member 29, shown in FIG. 2 in phantom and better shown in FIGS. 4b-4e, extends laterally from spring member 40 at least as far as the width of arm blade 12. Side portions 28 extend upwardly from the ends of bottom member 29 past sides 44 (one shown) of arm blade 12. Clip 26 may be integrally formed from a sheet of stainless steel, or may be formed of several stainless steel elements welded together. Alternately, clip 26 may be fabricated of tungsten wire, in which case clip members 30, bottom 29 and spring member 40 would be formed of wire segments instead of the flat sheet segments shown.
Push arm 34 is long enough to extend approximately to the position of side portions 28 from a position behind attachment point 38. This prevents any possibility of physical interference between spring member 40 and slider side members 32. Slider 22, spring clip 26 and arm blade 12 may be fabricated of other materials such as other metals, so long as they can withstand a -130° C. environment. For other uses outside of cold environments entailing the handling of larger specimens, transfer arm 10 could be formed of plastics.
FIG. 3 shows the positioning of transfer arm 10 inside a cryobox 46. The interior of cryobox 46 is filled with nitrogen gas at -130° C. in order to keep the biological specimens well frozen. Cryobox 46 commonly has a lid (not shown). At a first location or workstation 48 in box 46, a frozen biological specimen has been secured in a Tormey vise 50. Vise 50 is mounted in a guide block 52 and is movable in a vertical direction. A block 54 has an associated knife edge 56. The biological specimen (not shown) is mounted in the end of the Tormey vice 50, and sections of it are made by drawing the Tormey vice 50 downward past knife edge 56. Individual grid specimens are thereby formed on knife edge 56 and are subsequently transferred to a specimen grid 58 on arm blade 12.
Pivot 20 fits within a receptacle 60. Handle 14 may be rotated in order to rotate arm blade 12 from location 48 to a second location or workstation 62. It also may be raised up and down in order to raise or depress arm blade 12. At workstation 62, further processing of the specimen grid is performed. A block 64 is provided at second location 62. Handle 14 may be provided with a frictional surface 66 to provide a better manual grip.
Transfer arm 10 may be employed in other situations where it is desirable to transfer a small specimen in a holder from a first location to a second location. Arm 10 could be used in situations requiring the transfer of a specimen grid among three or more locations, instead of just two locations shown in the illustrated embodiment.
FIGS. 4a-4f illustrate sequential steps of the method of securing biological specimens in the double grid 58, and subsequently transferring the specimens from first location 48 to second location 62. In FIG. 4a, arm 12 is located at location 62 in FIG. 3. Bottom 29 of spring clip 26 is pressed upwardly in order to space clip members 30 from upper surface 16. Preferably, this is done by the operator pressing downward on handle 14, causing arm blade 12 to press downwardly on second location block 64. Spring clip 26 could also be manually squeezed upwardly toward blade 12 by a pair of forceps. Pressing blade arm 12 down on block 64 causes contact to be made between block 64 and bottom 29, pressing spring clip 26 upward against the spring force exerted by spring member 40 (FIG. 2). This spaces clip members 30 from upper surface 16. Blade 12 is made thick enough to substantially withstand any bending deformation. Alternately, blade 12 could be reinforced with upstanding or depending rib or channel members. In the illustrated embodiment, blade 12 is slanted slightly downward in order to compensate for any upward bending that does occur when blade 12 is pressed downwardly on block 64.
The double grid 58 shown is made out of number 50 copper mesh, lightly coated with carbon and coated with a formvar film. Grid 58 could be any mesh from 50 to 400 mesh. Another transparent plastic film such as Parlodian could be employed in the place of formvar. Grid 58 is generally sized between 2 mm and slightly over 3 mm for microscope applicatons. Grid 58 is retrieved from storage where it has been cooled to approximately -130° C. This storage can be provided by a suitable receptacle (not shown) in block 64 or elsewhere in cryobox 46 in order to protect it from any warming currents.
A lower grid portion 70 of double grid 58 is inserted between upper surface 16 and clip members 30 by means such as pre-cooled forceps or vacuum forceps. Grid 58 is originally provided in an open, unfolded position, with lower grid 70 being angularly separated from an upper grid portion 72.
In FIG. 4b, the operator has raised handle 14, releasing clip members 30 to exert spring force downwardly in the direction of the upper surface 16. Clip members 30 then grip lower grid 70 between themselves and upper surface 16. An upper grid 72 is hinged to an end of lower grid 70 by a hinge 74. Double grid 58 should be oriented on arm blade 12 such that hinge 74 is located about 90° from clip portions 30. In this way, upper grid 72 may be folded down onto lower grid portion 70 without interference from clip members 30. After grid 58 has been secured to arm 10, arm 10 is rotated from workstation 62 to workstation 48 (FIG. 3).
Referring to FIG. 4c, specimens S are removed from knife edge 56 (FIG. 3) and are loaded onto lower grid 70 with the aid of a hair (not shown). Each specimen is preferably entered on a separate interstice. A formvar coating forms a transparent film across the interstices to support specimens S.
After specimens S have been loaded onto lower grid 70, slider 22 is moved forwardly with forceps. Using the forceps to slide slider 22 forward is much easier than using the forceps to fold over upper grid 72. All manual movement is channeled by slider 22 in the desired forward direction, reducing the possibility that specimens S will be misaligned or even knocked off through hand-eye coordination error. As slider 22 moves forward, contact member 36 contacts upper grid 72 and pushes it forward to fold over on lower grid 70. The folding takes place at hinge 74.
FIG. 4d shows the completion of the folding of upper grid 72 onto lower grid 70. Like lower grid 70, upper grid 72 is coated with formvar to form a transparent film in between the interstices of its copper mesh. Therefore, specimens S are not completely enclosed in a transparent formvar film and are secured within double grid 58. Clip members 30 are now between upper grid 72 and lower grid 70 at locations spaced about 90° from hinge 74. In this position, double grid 58 can later be disengaged from clip members 30 by sliding grid 58 horizontally toward end 24.
In FIG. 4e, slider 22 is shown to be withdrawn, which can again be accomplished with the aid of precooled forceps. Grid 58 may be provided with a locking tab 76, which is preferably hinged to lower grid 70 at a point opposite hinge 74. If tab 76 is provided, it is folded upwardly with the aid of forceps over upper grid 72 in order to lock upper grid 72 to lower grid 70. Upper grid 72 and lower grid 70 will tend to bow slightly around clip members 30.
Locked grid 58 is now ready for transport between workstation 48 back to workstation 62. The invention provides an advantage over the conventional, single-grid method, as specimens S are secured in between two formvar surfaces during their transfer from one location to another. Previously, specimens S were often merely deposited on a plate, and thus were subject to being inadvertently swept off the grid surface.
In FIG. 4f, arm blade 12 has arrived back at workstation 62. The operator preferably presses down on handle 14 in order to exert upward pressure on bottom 29 of spring clip 26. Up to this point, inwardly extending clip portions 30 have been situated between lower grid 70 and upper grid 72. By using forceps, grid 58 is removed in a forward, horizontal direction, so that clip portions 30 merely slide out from between upper grid 72 and lower grid 70. Grid 58 is then further processed or may be protectively stored in block 64 by placement in a cold storage cylinder 68 (FIG. 3.)
The illustrated embodiment shows the invention as employed in a cryobox for securing and transferring grid specimens during preparation of the specimens for ultramicrotomy. However, the invention may also be employed in any situation where very small specimens are required to be secured in a hinged holder and then transferred from one location to the next. The invention may be employed with special advantage where the operating environment surrounding the specimen is different from the ambient environment. Thus, the present invention could be employed in a chamber having an evacuated atmosphere, or within a "hotbox" in which a radioactive shield means has to be erected between the specimens and the operator. The means to operate the apparatus of the invention may either be by hand and forceps as in the illustrated embodiment, or also could be by mechanical means.
In summary, the present invention provides a small specimen securement and transfer means which is easier to manipulate than the specimen securement and transfer means of the prior art. The invention provides a means to fold a specimen holder over onto itself, thus securing the specimens during their transfer from one workstation to another. A clip means secures the specimen holder during loading the holder and during transfer.
Although the preferred embodiment of the invention has been described in detail, it should be understood that various changes, substitutions and alterations can be made therein without departing from the spirit and the scope of the invention as defined by the appended claims.
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An apparatus (10) for use in securing a specimen (S) in a folding specimen holder (58) having an arm blade (12). A spring clip (26) releasably secures the grid (58) to the arm blade (12) so that one or more specimens may be loaded into the holder (58). A slider (22) mounted on the arm blade (12) operates to fold the holder (58) upon itself in order to secure the specimens (S) in the holder (58). The spring clip (26) is thereafter operated to release the holder (58) after the holder (58) has been transferred from a first workstation (48) to a second workstation (62).
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[0001] This is a regular application filed under 35 U.S.C. §111(a) claiming priority under 35 U.S.C. §119(e) (1), of provisional application Ser. No. 60/417,491, having a filing date of Oct. 10, 2002.
TECHNICAL FIELD
[0002] The present invention generally relates to safety devices for firearms, more particularly, to a barrel latch locking mechanism for a grenade launcher barrel latch.
BACKGROUND OF THE INVENTION
[0003] Modular weapon systems are well know, perhaps best exemplified by the tactile or assault weapon wherein a host weapon, most commonly a rifle, is readily modified to receive, among other things, a supplemental device, for instance, a grenade launcher. In the context of multi-functional modular weapon systems incorporating grenade launchers, and typified by a variety of assemblies and subassemblies, safe, reliable weapon operation is especially paramount.
[0004] An exemplary launcher for discussion is the Colt® M203 grenade launcher, a lightweight, single-shot, breech-loaded 40 mm weapon designed especially for attachment to the M4 carbine and the M16A2/A4 rifle. It creates a versatile combination weapon system capable of single round firing both 5.56 mm rifle ammunition as well as the complete range of 40 mm high explosive and special purpose ammunition. This launcher, as well as other commercially available launchers, is readily adapted, for instance via use of a variety of known rail attachment systems and the like, for receipt by various host weapons, e.g., submachine gun, shotgun or folding-stock pistol frame as a mounting platform, in addition to the M4 and M16A2/A4.
[0005] Launchers generally include a barrel, a receiver, a modified hand guard, a site (e.g., a leaf or quadrant site), and a rail, interbar or pistol frame. A complete self-cocking firing mechanism, including a barrel latch, a trigger and positive safety lever, is integral to the receiver, allowing the launcher to be operated, not only as a supplemental device, but as a completely independent weapon.
[0006] As may be readily appreciated, the barrel latch of the launcher is optimally positioned upon the receiver so as to be within ready reach when gripping the launcher barrel about the handguard (i.e., while supporting the launcher, or entire weapon system as the case may be, as by cradling same with the familiar palm-up hand cupping posture). Upon actuation of the barrel latch, the barrel is free to slide forward upon the receiver so as to accept a round of ammunition, or discharge a casing, and thereafter return to a closed, auto-locking position, ready to fire.
[0007] Heretofore, common inadvertent (i.e., unintended) manipulation of the barrel latch of the barrel latch mechanism would disengage the barrel from the remaining portion of the subassembly. Launchers have been known to be retrofitted with a barrel latch guard, more particularly, a shield type obstructing structure which minimizes the potential of barrel disengagement via inadvertent hand placement on, about, or across said barrel latch. Although arguably an improvement, the reliability of such shield has proved less than desirable, being, among other things, cumbersome to manipulate in furtherance of loading a round, and/or ejecting a casing. Thus, there remains a need for a barrel latch safety which is of subtle, reliable design, and is advantageously capable of being easily retrofitted to existing grenade launchers.
SUMMARY OF THE INVENTION
[0008] A barrel latch locking device for a grenade launcher barrel latch is provided. The locking device includes a body having opposing end portions, a first opposing end portion of the body including a locking plate. The locking device is adapted to be secured to a grenade launcher receiver proximal to the grenade launcher barrel latch for translation with respect thereto. The arrangement is such that a portion of the locking plate intercepts a travel path for the grenade launcher barrel latch, thereby preventing disengagement of a grenade launcher barrel from the grenade launcher receiver via unintentional actuation of the grenade launcher barrel latch.
[0009] More specific features and advantages obtained in view of those features will become apparent with reference to the drawing figures and DETAILED DESCRIPTION OF THE INVENTION.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 generally illustrates a weapon system, namely an M16 rifle equipped with a grenade launcher, the barrel latch locking device of the subject invention affixed to a receiver of the launcher and in operative engagement with the barrel latch thereof (i.e., “lock-on”);
[0011] FIG. 2 is a sectional view taken along line 2 - 2 of FIG. 1 illustrating the interrelationships between components of the subject barrel latch locking device and the barrel latch;
[0012] FIG. 3 is a detailed view of the circumscribed area of FIG. 1 illustrating a portion of the barrel latch received upon a latch receiving surface of the subject device; and,
[0013] FIG. 4 is a view similar to that of FIG. 2 , the subject barrel latch locking device disengaged from the barrel latch (i.e., “lock-off”).
DETAILED DESCRIPTION OF THE INVENTION
[0014] With general reference to FIG. 1 , there is shown a Colt®M203 grenade launcher 10 , operatively integrated with an M16 rifle 12 , equipped with the barrel latch locking device 14 of the subject invention. The barrel latch locking device 14 is shown affixed to a receiver 16 of the launcher 10 , and in operative engagement with a barrel latch 18 thereof (i.e., a “lock-on” condition). It is to be understood that the barrel latch locking device of the subject invention is not limited to operative engagement with the launcher of FIG. 1 .
[0015] As shown, the grenade launcher 10 generally includes a barrel 20 supported, suspended, or otherwise engaged with the receiver 16 thereof. A handguard 22 substantially extends about a portion of the exterior surface 24 of the barrel 20 . The launcher 10 , more particularly the receiver 16 , further includes, a firing mechanism 26 comprising the barrel latch 18 , trigger 28 , and trigger safety 30 . As is well known, the barrel 20 of the launcher 10 is disengagable from the receiver 16 , more particularly a breech end 32 thereof, for translation with respect thereto, in furtherance of loading a munition, and/or discharging a casing of a munition.
[0016] The subject barrel latch locking device 14 is adapted to be secured to the launcher receiver 16 proximal to the launcher barrel latch 18 , for translation with respect thereto, such that a latch receiving surface 34 thereof selectively intercepts a travel path for the launcher barrel latch 18 , thereby preventing disengagement of the launcher barrel 20 from the launcher receiver 16 via unintended actuation of the launcher barrel latch 18 . Prior to a detailed discussion of the structure, features and functionality of the subject barrel latch locking device, a discussion of the barrel latch structure and functionality is warranted.
[0017] With reference to FIG. 4 , the barrel latch 18 of the grenade launcher 10 generally comprises an elongate member (e.g., a bar) 40 having a latch or latching surface 42 opposite a free end 44 thereof, the latch surface 42 intended to selectively engage a portion (e.g., a stop) 46 of the launcher barrel 20 , as shown. The barrel latch 18 is pivotably secured by a shaft or pin 48 , between its ends, to the launcher receiver 16 such that a portion of the free end 44 (i.e., an actuation surface 50 ) outwardly projects from a lateral surface (e.g., a sidewall) 52 of the receiver 16 (i.e., the actuation surface 50 is accessible for manipulation of the latch 18 ). Pivoting of the barrel latch 18 about a pivot axis of the shaft 48 , as by “pushing” the actuation surface 50 of the free end 44 into closer proximity to the sidewall 52 of the launcher receiver 16 , frees the latch surface 42 from engagement with the stop 46 of the launcher barrel 20 (note ghost lines indicating a disengaged condition for the barrel latch 18 ), thereby permitting translation of the barrel 20 relative to the receiver 16 .
[0018] With general reference now to FIGS. 1-3 , the barrel latch locking device generally comprises a body 60 having opposing end portions, more particularly, first 62 and second 64 opposing end portions, for the sake of convention, muzzle and breech end portions respectively, the first opposing end portion 62 of the body 60 being “forward” of the second opposing end portion 64 . The device body 60 further, and generally, includes opposing surfaces, namely, first 66 (i.e., visible) and second 68 (i.e., non-visible) surfaces, see e.g., FIG. 2 .
[0019] Each opposing end portion 62 , 64 of the device body 60 preferably includes an aperture or slot 70 to facilitate affixation and retention of the device 14 to the launcher receiver 16 , using, as shown, shouldered fasteners 72 , or the like. With such arrangement, and based upon the convention adopted herein, the second surface 68 of the device body 60 will be, or is, adjacent the sidewall 52 of the receiver 16 , more particularly, an exterior surface of same, see e.g., FIG. 2 . The apertures 70 are advantageously configured to permit translation of the locking device 14 upon the fasteners 72 , and thereby the receiver 16 , namely, between the lock-on (FIG. and lock-off configurations of FIGS. 2 & 4 respectively. One such non-limiting aperture configuration, namely an oval, is shown in FIG. 3 , a maximum dimension thereof extending between the opposing end portions 62 , 64 of the device body 60 .
[0020] With continued reference to FIGS. 1-3 , especially FIG. 3 , the first opposing end portion 62 of the device body 60 generally includes a locking plate or blade 74 having a first surface, more particularly, a visible latch receiving surface 76 adapted to operatively engage the free end 44 of the barrel latch 18 . A second, non-visible surface 78 of the locking plate 74 (see e.g., FIGS. 2 & 4 ), opposite the first surface 76 , is adapted to seat a detent 80 (e.g., a pin or ball) carried by the sidewall 52 of the receiver 16 . More particularly, the non-visible surface 78 of the locking plate 74 includes a pair of spaced apart dimples 82 for receipt and seating of the detent 80 at either a first 84 ( FIG. 2 ) or second 86 ( FIG. 4 ) position of the second surface 78 of the locking plate 74 , that is to say, the lock-on and lock-off positions respectively.
[0021] The latch receiving surface 76 , preferably, but not necessarily, includes a ramped (e.g., beveled) portion so as to provide a sure interference fit for the locking device 14 relative to the barrel latch 18 . As will later be detailed, the ramped portion of the latch receiving surface 76 may be effectively wedged between the free end 44 of the barrel latch and the sidewall 52 of the receiver 16 to prohibit actuation of the barrel latch 18 .
[0022] With reference now especially to FIGS. 1 & 2 , the second opposing end portion 64 of the device body 60 preferably, as shown, has a segment configured so as to define a finger rest or grip 88 . More generally, the second opposing end portion 64 of the device body 60 is to include a structure to facilitate translation (i.e., actuation) of the device 14 between the lock-on/lock-off conditions of FIGS. 2 & 4 respectively. The subject disclosure is in no way intended to be limiting of the means available to perform the recited function. For instance, the second opposing end portion 64 of the device body 60 may include a protuberance or the like, integral therewith (e.g., a ridge), or attachable thereto (e.g., a knob). Preferably, and advantageously, a terminal end 90 of the second opposing end portion 64 of the device body 60 is configured to include a curve, bend, fold, crease, etc. (i.e., the terminal end 90 is not planar, or alternately stated, a substantial portion of the non-visible surface of the terminal end 90 of the second opposing end portion 64 does not contact the receiver sidewall 52 ). A not insubstantial amount of force must be imparted to the second opposing end portion 64 of the device body 60 so as to overcome the detent positioning of the device 14 relative to the receiver 16 , whether in the lock-on or lock-off position/condition. Thus, a finger rest or hold 88 of large surface area is advantageous, and therefore desirable.
[0023] Operation of the subject device is best appreciated by comparison of FIGS. 2 & 4 . In the lock-on position of FIG. 2 , the latch receiving surface 76 of the locking plate 74 is interposed between a portion of the free end 44 of the elongate member 40 of the barrel latch 18 , and the sidewall 52 of the launcher receiver 16 , and operatively retained in such condition due to receipt of the receiver detent 80 in the forward most dimple 82 of the non-visible surface 78 of the locking plate 74 . Pivot motion of the barrel latch 18 , and disengagement of the barrel 20 relative to the receiver 16 thereby, is prohibited.
[0024] To attain the lock-off position of FIG. 4 from the lock-on position of FIG. 2 , an operator need only apply forward pressure to the finger hold or rest 88 of the second opposing end portion 64 of the device body 60 , so as to overcome the bias force of the detent 80 within the forward most dimple 82 of the non-visible surface 78 of the locking plate 74 . Upon such manipulation, the subject locking device 14 forwardly slides such that the latch receiving surface 76 of the locking plate 74 is “clear” of the travel path of the free end 44 of the barrel latch 18 , the detent 80 , seated in the rearward dimple 82 , retaining the device body 60 in the lock-off position. By the aforementioned structures, their interrelationship, and their relationship(s) with the launcher components, unintended, inadvertent actuation of the grenade launcher barrel latch is achieved in an efficient, reliable manner.
[0025] This invention disclosure provides preferred locking device configurations, and defines preferred relationships and interrelationships between structures of the configuration, in addition to relationships and interrelationships between the subject device and the grenade launcher. There are other variations of this invention which will become obvious to those skilled in the art. It will be understood that this disclosure, in many respects, is only illustrative. Changes may be made in details, particularly in matters of shape, size, material, and arrangement of parts without exceeding the scope of the invention. Accordingly, the scope of the invention is as defined in the language of the appended claim.
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A barrel latch safety for a grenade launcher having a barrel slidable upon a receiver via actuation of a barrel latch is provided. The barrel latch safety includes a locking plate and an elongate member extending from a portion thereof so as to define a crotch between the elongate member and a side edge of said locking plate. The subject safety is adapted to be positioned on the receiver such that a surface adjacent the side edge of the locking plate prohibits barrel latch actuation upon translation of the safety relative to the receiver.
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This application is a continuation-in-part application of "Turbine", filed Aug. 7, 1973, Ser. No. 386,273, now U.S. Pat. No. 3,879,152.
BACKGROUND OF THE INVENTION
This invention relates to devices for generating power wherein a fluid is passed from a higher energy level to lower energy level by pressurizing the fluid first in a forced vortex type pressurizer section, and then further pressurizing said fluid in a free vortex type pressurizing section, and then passing said fluid into an inward flow turbine where said high pressure fluid pressure in decreased with accompanying generation of power. The temperature of the fluid is decreased when passing through the pressurizing and power generation sections and heat is then added to said fluid from external sources.
There have been various devices for generation of power; in some of these devices a fluid is passed through an inward flow turbine and the fluid is supplied to the rotor wheel from stationary nozzles at rotor periphery. These devices require for their operation a pressurized fluid source, and can not operate by using heat directly.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross section of the power generator.
FIG. 2 is an end view of the power generator.
FIG. 3 is another end view of the power generator.
FIG. 4 is a detail of nozzles.
DESCRIPTION OF PREFERRED EMBODIMENTS
It is an object of this invention to provide for a power generator which can use heat from a suitable source to generate power. Further, it is an object of this invention to provide a power generator that is inexpensive and simple in construction and which can use ordinary materials for its construction.
In FIG. 1, a cross section parallel to the rotor shafts is shown. 10 is first rotor, 11 is second rotor, 24 are second rotor vanes, 12 are fluid nozzles discharging forward in the direction of rotation of both rotors, 13 is first rotor free vortex cavity, 14 are feeder nozzles discharging forward in the direction of rotation into said free vortex cavity, 15 are vanes in first rotor forced vortex cavity, 16 is fluid space near rotor center, 17 is first rotor shaft bearing, 18 is first rotor shaft, 19 and 20 are fluid entry and exit for passing the fluid to be heated in an external heater, 21 is support, 23 second rotor shaft bearing, 22 is second rotor shaft.
In FIG. 2, an end view of the unit is shown with sections removed to show unit interior details. 10 is first rotor, 15 are first rotor vanes, 22 is second rotor shaft, 21 is support, 11 is second rotor and 24 are second rotor vanes, and 25 indicates direction of rotation for both rotors.
In FIG. 3, another end view of the unit is shown. 10 is first rotor, 14 are fluid feeder nozzles for passing said fluid into said free vortex cavity, 22 is second rotor shaft, 21 is support, 12 are fluid nozzles for discharging said fluid from first rotor and passing said fluid into said second rotor.
In FIG. 4, a detail of the nozzles used with this device is shown. 30 indicates direction of rotation of the nozzle wall 32 around shaft 31. 33 are said nozzles, and 34 indicates fluid leaving said nozzles.
In operation, said fluid is passed from center area 16 to forced vortex cavity of said first rotor 10, and there pressurized by centrifugal action on said fluid by said first rotor with vanes 15 assuring that said fluid will rotate at the same speed as said rotor. After such pressurization, said fluid is passed through feeder nozzles 14 into said free vortex cavity 13, with said fluid being oriented to leave said nozzles 14 in a forward direction so that the tangential velocity of the fluid leaving said nozzles relative to the rotor is added to the tangential velocity of said first rotor in the area where said nozzle is located. Thus, the said fluid will have a high tangential velocity, and since said fluid is forced to move along a curved path formed by said free vortex cavity, the fluid will form a free vortex. The pressure of said fluid is then increased toward the periphery of said free vortex cavity 13 in accordance with well known rules pertaining to free vortexes. The high pressure fluid is then discharged via nozzles 12 in a forward direction that is in the direction of rotation, and the said fluid then enters said second rotor near the tip of said rotor, with the tangential velocities of said fluid and said second rotor being normally nearly the same to avoid turbulence and turbulence related work losses. The fluid is then passed inward through the said second rotor where vanes 24 will assure that the fluid will rotate at the same speed as said second rotor for recovery of the work associated with the deceleration of said fluid within said second rotor. Said fluid is then discharged into said space 16 thus completing its cycle.
The function of the free vortex cavity will be further described: It is well known that a fluid passing along a curved path will have a higher pressure along the outer periphery of said path. The pressure increase for such situation is given by
dp=ρ.V.sup.2 dr/r
and for a curved path, similar to that used in the device of this invention, the equation becomes
P.sub.2 =P.sub.1 +ln (r.sub.2 /r.sub.1) V.sup.2 w/144 g
where ρ=fluid density, r is radius, V=velocity along said curved path; P 2 =pressure at outer periphery, P 1 =pressure at inner periphery, ln=natural log., r 2 =outer periphery radius, r 1 =inner periphery radius, w=weight of fluid, 144=conversion factor, and g=acceleration of gravity. In the free vortex cavity, the fluid absolute tangential velocity would ordinarily change from a higher value to a lower value with increasing radius; but by using multiple nozzles feeding said cavity at different distances from center, the reduction in said absolute tangential velocity can be controlled or eliminated, as desired. Normally, the entry velocity of said fluid into said free vortex cavity is so controlled that the absolute tangential velocity of said fluid within said free vortex cavity 13 will remain constant, however, this is not mandatory. When said absolute tangential velocity is maintained constant within cavity 13, then the velocity V, in the second equation hereinbefore is the velocity within said cavity 13. In ordinary practice, the pressure P 1 shown in said second equation, is zero, but this is not mandatory. Normally, the exit velocities from nozzles 14 are so controlled as to obtain the desired total absolute tangential velocity for said fluid, and the absolute tangential velocity of said fluid and the tangential velocity of said rotor cavity 13 will coincide at the periphery of said cavity near entry to nozzles 12, so that turbulence losses are reduced. Thus, the differential between the tangential speeds of said fluid and said rotor is reduced with increasing radius, and finally at the cavity periphery both the fluid and the rotor will rotate at the same speed.
To improve the performance of this unit, the pressure within space 16 is increased to a higher value, above ambient air pressure. With suitable increase in operational rotor speed, the pressure P 1 can still be maintained zero, and a greater pressure increase within cavity 13 be effected. This in turn will increase the power output by the machine, by allowing the use of greater speeds for the said second rotor 11, these greater speeds having been made possible by the greater pressure differential available between nozzles 12 and the center space 16.
It should be noted that while the operation in cavities 15 and 24 are normal for centrifuges and for forced vortex flow, the operation in cavity 13 is defined by laws relating to free vortexes and this different form of operation is the basis for the workability of this power generator. In a free vortex, as operated herein, the pressure increase is much greater, than in a forced vortex rotating at similar speeds, and it is this increase in pressure within said free vortex that is employed to generate said power in the device of this invention.
It should be also noted that the temperature of the fluid is decreased while passing through the device, and to maintain the fluid temperature at a suitably constant level, heat is added to said fluid from an external source. Heat may be added in an external heat exchanger and the fluid circulated therethrough, or a heat exchanger be installed within the rotor with the heating fluid being circulated within such heat exchanger; such installation was described in my previous U.S. Pat. "Compressor with Cooling," No. 3,795,461.
The working fluid for the power generator of this invention may be a liquid or it may be a gas. Liquids such as water, or many of the halogenated hydrocarbons, or other liquids may be used. Various gases also may be used.
It should be noted that the fluid may be fed into said free vortex cavity from two sides; the unit shown in FIG. 1 has nozzles only on one side of said cavity 13. Arrangement where the feeding of fluid into cavity 13 from both sides as shown in my co-pending patent application "Turbine", filed Aug. 7, 1973, Ser. No. 386,273. Having said feed nozzles on both sides of cavity 13 will allow increase in the fluid flow within said cavity 13, and this in turn will reduce fluid friction effects on the fluid velocity within said cavity 13.
Another way that the effects of fluid friction within cavity 13 may also be reduced is by using heavy working fluid. The fluid enters said cavity 13 at a predetermined velocity, and use of heavy working fluid, such as many of the halogenated hydrocarbons, with their relatively low viscosity, will reduce the slowing down of said fluid within said cavity 13.
In normal operation, the unit requires a power transmission means for passing some of the power generated by said second rotor to drive said first rotor. Also, a means for starting the unit is required.
Applications include as a power generator for electricity generation, as a power source for portable uses, and as a power source for stationary uses.
Various controls and gauges may be required with the device of this invention; also, circulating pumps, and heat exchangers may be required. They are not a part of this invention and are not further described herein.
To further illustrate the construction of the unit of this invention, assume that the fluid is water. Assume that the angular speed of the first rotor is 250 rad/sec., and the cavity 13 inner radius is 1.1 inch and outer radius is 4.6 inch, and that the distance to first row of feeder nozzles is 1.9 inch, to second row of feeder nozzles is 2.7 inch, and the distance from center to third row of feeder nozzles is 3.6 inch. Then, the pressures due to rotation in cavity defined by vanes 15 are: At first row, 10 psi, at second row, 21 psi, at third row, 38 psi. The tangential speed at nozzles 12 is 95 fps., and the required fluid tangential total velocities are 95 fps at nozzles 12, 121 fps at third row, 127 fps at second row and 135 fps at first row of feeder nozzles. Setting flow at 10 lbs/sec from first and second row nozzles, and 14 lbs/sec from third row nozzles, the adjusted absolute fluid tangential velocities then become 141 fps first row, 166 fps at second row and 165 fps at third row nozzles within cavity 13. Cavity pressure is then 213 psia at nozzles 12, and 0 psia at inner cavity radius. Actual exit velocities for the fluid from feeder nozzles are, after corrections, 142 fps for first row, 116 fps at second row, and 79 fps at third row; the corresponding fluid absolute velocities are then 176 fps at first row, within cavity 13, and 167 fps at second row and 151 fps at third row within cavity 13. Thus, for this device, the pressure of water at entry to nozzles 12 is 213 psia; for comparison, note that for a centrifuge, the water pressure for tangential speed 95 fps is 62 psia. This is the reason for the functioning of the power generator of this invention. The work input to first rotor, relating to reaction in feeder nozzles and at nozzles 12, is 0.42 BTU/lb, and work output from second rotor is 0.45 BTU/lb, with second rotor rotating at 107 fps tip speed. The pressure at exit side of nozzles 12 is 212 psia. Work output can be increased by pressurizing the system with gas, and increasing the rotor speeds. All values shown are approximate.
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A method and apparatus for the generation of power wherein a fluid is circulated within a pressurizer wherein the fluid is pressurized by centrifugal action and then passed via nozzles to a toroidal shaped cavity for further pressurization. After passing through said circular shaped cavity, the fluid passes through nozzles oriented to discharge forward, in the direction of rotation, and then the fluid is passed through a reaction type turbine wheel with inward flow, to generate the power. Work is required to rotate the pressurizer, and work is obtained from the turbine, and the difference between the two amounts of work is the work output for the power generator. Heat is added to the working fluid of the power generator from external sources. Working fluid may be either a gas or a liquid. Normally, the working fluid is maintained within the power generator at an elevated pressure.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a divisional of U.S. patent application Ser. No. 11/191,791, filed Jul. 28, 2005, now U.S. Pat. No. 7,141,558, which in turn is a divisional of U.S. patent application Ser. No. 10/957,483 filed Oct. 1, 2004, now U.S. Pat. No. 6,992,074, which in turn is a divisional of U.S. patent application Ser. No. 09/871,227, filed May 31, 2001, now U.S. Pat. No. 6,806,262, which in turn is based on and claims priority from Provisional Patent Application Ser. No. 60/208,199 filed May 31, 2000.
BACKGROUND OF THE INVENTION
This invention relates to vitamin D compounds, and more particularly to vitamin D derivatives substituted at the carbon 2 position.
The natural hormone, 1α,25-dihydroxyvitamin D 3 and its analog in ergosterol series, i.e. 1α,25-dihydroxyvitamin D 2 are known to be highly potent regulators of calcium homeostasis in animals and humans, and more recently their activity in cellular differentiation has been established, Ostrem et al., Proc. Natl. Acad. Sci. USA, 84, 2610 (1987). Many structural analogs of these metabolites have been prepared and tested, including 1α-hydroxyvitamin D 3 , 1α-hydroxyvitamin D 2 , various side chain homologated vitamins and fluorinated analogs. Some of these compounds exhibit an interesting separation of activities in cell differentiation and calcium regulation. This difference in activity may be useful in the treatment of a variety of diseases.
Recently, a new class of vitamin D analogs has been discovered, i.e. the so called 19-nor-vitamin D compounds, which are characterized by the replacement of the A-ring exocyclic methylene group (carbon 19), typical of the vitamin D system, by two hydrogen atoms. Biological testing of such 19-nor-analogs (e.g., 1α, 25-dihydroxy-19-nor-vitamin D 3 ) revealed a selective activity profile with high potency in inducing cellular differentiation, and very low calcium mobilizing activity. Thus, these compounds are potentially useful as therapeutic agents for the treatment of malignancies, or the treatment of various skin disorders. Two different methods of synthesis of such 19-nor-vitamin D analogs have been described (Perlmnan et al., Tetrahedron Lett. 31, 1823 (1990); Perlman et al., Tetrahedron Lett. 32, 7663 (1991), and DeLuca et al., U.S. Pat. No. 5,086,191).
In U.S. Pat. No. 4,666,634, 2β-hydroxy and alkoxy (e.g., ED-71) analogs of 1α,25-dihydroxyvitamin D 3 have been described and examined by Chugai group as potential drugs for osteoporosis and as antitumor agents. See also Okano et al., Biochem. Biophys. Res. Commun. 163, 1444 (1989). Other 2-substituted (with hydroxyalkyl, e.g., ED-120, and fluoroalkyl groups) A-ring analogs of 1α,25-dihydroxyvitamin D 3 have also been prepared and tested (Miyamoto et al., Chem. Pharm. Bull. 41, 1111 (1993); Nishii et al., Osteoporosis Int. Suppl. 1, 190 (1993); Posner et al., J. Org. Chem. 59, 7855 (1994), and J. Org. Chem. 60, 4617 (1995)).
Recently, 2-substituted analogs of 1α,25-dihydroxy-19-norvitamin D 3 have also been synthesized, i.e. compounds substituted at 2-position with hydroxy or alkoxy groups (DeLuca et al., U.S. Pat. No. 5,536,713), which exhibit interesting and selective activity profiles. All these studies indicate that binding sites in vitamin D receptors can accommodate different substituents at C-2 in the synthesized vitamin D analogs.
SUMMARY OF THE INVENTION
The discovery of the hormonally active form of vitamin D 3 , 1α, 25-dihydroxyvitamin D 3 (1α,25-(OH) 2 D 3 , calcitriol, 1; FIG. 1 ), has greatly stimulated research into its physiology and chemistry. As previously noted, it has been established that 1 not only regulates the mineral metabolism in animals and humans, but also exerts potent effects upon cell proliferation and cellular differentiation. Therefore, the chemistry of vitamin D has been recently focused on-the design and synthesis of analogs that can exert selective biological actions.
In a previous investigation of the structure-activity relationship of the vitamin D molecule, an analog of the natural hormone 1, 1α,25-dihydroxy-2-methylene-19-norvitamin D 3 (2), was prepared in which the exocyclic methylene group is transposed, in comparison with 1, from C-10 to C-2. Also, 2α-methyl analog 3 was obtained by selective hydrogenation of 2. Both analogs were characterized by significant biological potency, enhanced especially in their isomers in the 20S-series.
In a continuing search for biologically active vitamin D compounds novel 19-nor analogs of 1, substituted at C-2 with ethylidene (4a,b and 5a,b) and ethyl (6a,b and 7a,b) groups, have now been synthesized and tested. Structurally the novel 2-ethylidene analogs belong to a class of 19-nor vitamin D compounds characterized by the general formula I shown below:
where Y 1 and Y 2 , which may be the same or different, are each selected from the group consisting of hydrogen and a hydroxy-protecting group, and where the group R represents any of the typical side chains known for vitamin D type compounds.
Structurally the novel 2-ethyl analogs belong to a class of 19-nor vitamin D compounds characterized by the general formula II shown below:
where Y 1 and Y 2 , which may be the same or different, are each selected from the group consisting of hydrogen and a hydroxy-protecting group, and where the group R represents any of the typical side chains known for vitamin D type compounds.
More specifically R can represent a saturated or unsaturated hydrocarbon radical of 1 to 35 carbons, that may be straight-chain, branched or cyclic and that may contain one or more additional substituents, such as hydroxy-or protected-hydroxy groups, fluoro, carbonyl, ester, epoxy, amino or other heteroatomic groups. Preferred side chains of this type are represented by the structure below:
where the stereochemical center (corresponding to C-20 in steroid numbering) may have the R or S configuration, (i.e. either the natural configuration about carbon 20 or the 20-epi configuration), and where Z is selected from Y, —OY, —CH 2 OY, —C≡CY, —QH═CHY, and —CH 2 CH 2 CH═CR 3 R 4 , where the double bond may have the cis or trans geometry, and where Y is selected from hydrogen, methyl, —COR 5 and a radical of the structure:
where m and n, independently, represent the integers from 0 to 5, where R 1 is selected from hydrogen, deuterium, hydroxy, protected hydroxy, fluoro, trifluoromethyl, and C 1-5 -alkyl, which may be straight chain or branched and, optionally, bear a hydroxy or protected-hydroxy substituent, and where each of R 2 , R 3 , and R 4 , independently, is selected from deuterium, deuteroalkyl, hydrogen, fluoro, trifluoromethyl and C 1-5 alkyl, which may be straight-chain or branched, and optionally, bear a hydroxy or protected-hydroxy substituent, and where R 1 and R 2 , taken together, represent an oxo group, or an alkylidene group, ═CR 2 R 3 , or the group —(CH 2 ) p —, where p is an integer from 2 to 5, and where R 3 and R 4 , taken together, represent an oxo group, or the group —(CH 2 ) q —, where q is an integer from 2 to 5, and where R 5 represents hydrogen, hydroxy, protected hydroxy, C 1-5 alkyl or —OR 7 where R 7 represents C 1-5 alkyl, and wherein any of the CH-groups at positions 20, 22, or 23 in the side chain may be replaced by a nitrogen atom, or where any of the groups —CH(CH 3 )—, —CH(R 3 )—, or —CH(R 2 )— at positions 20, 22, and 23, respectively, may be replaced by an oxygen or sulfur atom.
The wavy lines, e.g. to the substituents at C-2 and at C-20 indicate that those substituents may have either the R or S configuration.
Specific important examples of side chains with natural 20R-configuration are the structures represented by formulas (a), b), (c), (d) and (e) below. i.e. the side chain as it occurs in 25-hydroxyvitamin D 3 (a); vitamin D 3 (b); 25-hydroxvvitamin D 2 (c); vitamin D 2 (d); and the C-24 epimer of 25-hydroxyvitamin D 2 (e):
Specific important examples of side chains with the unnatural 20S (also referred to as the 20-epi) configuration are the structures presented by formulas (f), (g), (h), (i) and (j) below:
The above novel compounds exhibit a desired, and highly advantageous, pattern of biological activity. The synthesized vitamins were tested for their ability to bind the porcine intestinal vitamin D receptor. The presented results ( FIG. 5 ) indicate that 2-ethylidene-19-norvitamins, possessing methyl group from ethylidene moiety directed toward C-3, i.e., trans in relation to C(6)-C(7) bond (isomers E), are more active than 1α,25-(OH) 2 D 3 in binding to VDR, whereas their counterparts with cis relationship between ethylidene methyl substituent and C(7)-H group (isomers Z) exhibit significantly reduced affinity for the receptor. The competitive binding analysis showed also that 2α-ethyl-19-norvitamins bind to the receptor better than their isomers with 2β-ethyl substituents ( FIG. 6 ). In the next assay, the cellular activity of the synthesized compounds was established by studying their ability to induce differentiation of human promyelocyte HL-60 cells into monocytes. E isomer of (20S)-2-ethylidene-19-norvitamin D 3 ( FIG. 7 ) and both 2α-ethyl-19-norvitamins ( FIG. 8 ) are more potent than 1α,25-(OH) 2 D 3 in this assay, whereas the remaining tested compounds are almost equivalent to the hormone 1. Both E isomers of 2-ethylidene-19-norvitamins, when tested in vivo in rats (Table 1) exhibited very high calcemic activity, the (20S)-compound being especially potent. On the contrary, isomeric Z compounds are significantly less active. 2-Ethyl-19-norvitamins have some ability to mobilize calcium from bone but not to the extent of the hormone 1, while being inactive in intestine. The only exception is the 2α-ethyl isomer from the 20S-series which shows strong calcium mobilization response and marked intestinal activity.
These compounds are thus highly specific in their calcemic activity. Their preferential activity on mobilizing calcium from bone and either high or normal intestinal calcium transport activity allows the in vivo administration of these compounds for the treatment of metabolic bone diseases where bone loss is a major concern. Because of their preferential calcemic activity on bone, these compounds would be preferred therapeutic agents for the treatment of diseases where bone formation is desired, such as osteoporosis, especially low bone turnover osteoporosis, steroid induced osteoporosis, senile osteoporosis or postmenopausal osteoporosis, as well as osteomalacia and renal osteodystrophy. The treatment may be transdermal, oral or parenteral. The compounds may be present in a composition in an amount from about 0.1 μg/gm to about 50 μkg/gm of the composition, and may be administered in dosages of from about 0.01 μg/day to about 50 μg/day.
The compounds of the invention are also especially suited for treatment and prophylaxis of human disorders which are characterized by an imbalance in the immune system, e.g. in autoimmune diseases, including multiple sclerosis, diabetes mellitus, host versus graft reaction, lupus, atherosclerosis, and rejection of transplants; and additionally for the treatment of inflammatory diseases, such as inflammatory bowel disease, rheumatoid arthritis and asthma, as well as the improvement of bone fracture healing and improved bone grafts. Acne, alopecia especially chemically induced alopecia (e.g. resulting from chemotherapy), skin conditions such as dermatitis, eczema, keratosis, dry skin (lack of dermal hydration), undue skin slackness (insufficient skin firmness), insufficient sebum secretion and wrinkles, as well as hypocalcemia, hypoparathyroidism and hypertension are other conditions which may be treated with the compounds of the invention.
The above compounds are also characterized by high cell differentiation activity. Thus, these compounds also provide therapeutic agents for the treatment of psoriasis, or as an anti-cancer agent, especially against leukemia, colon cancer,.breast cancer and prostate cancer. The compounds may be present in a composition to treat psoriasis, cancer, and/or the above list of diseases in an amount from about 0.01 μg/gm to about 100 μg/gm of the composition, and may be administered topically, transdermally, orally or parenterally in dosages of from about 0.01 μg/day to about 100 μg/day.
This invention also provides novel intermediate compounds formed during the synthesis of the end products.
This invention also provides a novel synthesis for the production of the end products of structures I and II. Two different synthetic paths were devised, both based on Lythgoe type Wittig-Horner coupling of the A-ring fragments, the corresponding phosphine oxides prepared from quinic acid, with the protected 25-hydroxy Grundmann's ketone. In the first method, the allylic phosphine oxides were substituted at C-4′ with the ethylidene group whereas in the alternative approach the introduction of ethylidene moiety was performed in the final step of the synthesis, by Wittig reaction of the intermediate 2-oxo-vitamin D analog. The selective catalytic hydrogenation of 2-ethylidene analogs of 1α,25-dihydroxy-19-norvitamin D 3 provided the corresponding 2α-and 2β-ethyl compounds.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates the general structural formulae for 1α,25-dihydroxyvitamin D 3 , 1α,25-dihydroxy-2-methylene-19-norvitamin D 3 , and 1α,25-dihydroxy-2α-methyl-19-norvitamin D 3 , and further illustrates the general structural formulae for the four 2-ethylidene-19-nor-vitamins and the four 2-ethyl-19-nor-vitamins of the present invention synthesized and tested herein;
FIG. 2 illustrates the -configurations and preferred conformations of the 4′-ethylidene intermediates 16 and 17 used in the synthesis disclosed herein;
FIG. 3 a illustrates the α-and β-forms of the A-ring chair conformers for vitamin D compounds in solutions;
FIG. 3 b illustrates that the presence of bulky 2-alkyl substituents, characterized by large conformational free energy A values, shifts the A-ring conformational equilibrium of the synthesized 2-ethyl-19-nor-vitamins toward the conformers with the equatorial C(2)-substituents;
FIG. 3 c illustrates that a strong interaction (designated as A (1,3) -strain) exists between the methyl group from the ethylidene moiety and equatorial hydroxyls at C-1 or C-3, and results in a strong bias toward conformers with an axial orientation of this hydroxy group to which the methyl from ethylidene fragment is directed; and
FIG. 4 illustrates the conformational equilibrium in ring A of 2-methylene-19-norvitamin 2 (a) and the preferred, energy minimized (PC MODEL 6.0, Serena Software) A-ring conformations of the synthesized analogs: 4a,b (b), 5a,b (c), 6a,b (d) and 7a,b (e).
FIG. 5 a is a graph illustrating the relative activity of a 2-ethylidene-19-nor-vitamins (isomers E and Z) and 1α,25-dihydroxyvitamin D 3 to compete for binding of [ 3 H]-1,25-(OH) 2 -D 3 to the pig intestinal nuclear vitamin D receptor;
FIG. 5 b is a graph similar to FIG. 5 a except illustrating the relative activity of individual compounds 2α and 2β-ethyl-19-nor-vitamins and 1α,25-dihydroxyvitamin D 3 to compete for binding of [ 3 H]-1,25-(OH) 2 -D 3 to the vitamin D pig intestinal nuclear receptor;
FIG. 6 a is a graph illustrating the percent HL-60 cell differentiation as a function of the concentration of the 2-ethylidene-19-nor-vitamins as compared to 1α,25-dihydroxyvitamin D3; and
FIG. 6 b is a graph illustrating the percent HL-60 cell differentiation as a function of the concentration of the 2α and 2β-ethyl-19-nor-vitamins as compared to 1α,25-dihydroxyvitamin D 3 .
DETAILED DESCRIPTION OF THE INVENTION
As used in the description and in the claims, the term “hydroxy-protecting group” signifies any group commonly used for the temporary protection of hydroxy functions, such as for example, alkoxycarbonyl, acyl, alkylsilyl or alkylarylsilyl groups (hereinafter referred to simply as “silyl” groups), and alkoxyalkyl groups. Alkoxycarbonyl protecting groups are alkyl-O—CO— groupings such as methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, isopropoxycarbonyl, butoxycarbonyl, isobutoxycarbonyl, tert-butoxycarbonyl, benzyloxycarbonyl or allyloxycarbonyl. The term “acyl” signifies an alkanoyl group of 1 to 6 carbons, in all of its isomeric forms, or a carboxyalkanoyl group of 1 to 6 carbons, such as an oxalyl, malonyl, succinyl, glutaryl group, or an aromatic acyl group such as benzoyl, or a halo, nitro or alkyl substituted benzoyl group. The word “alkyl” as used in the description or the claims, denotes a straight-chain or branched alkyl radical of 1 to 10 carbons, in all its isomeric forms. Alkoxyalkyl protecting groups are groupings such as methoxymethyl, ethoxymethyl, methoxyethoxymethyl, or tetrahydrofuranyl and tetrahydropyranyl. Preferred silyl-protecting groups are trimethylsilyl, triethylsilyl, t-butyldimethylsilyl, dibutylmethylsilyl, diphenylmethylsilyl, phenyldimethylsilyl, diphenyl-t-butylsilyl and analogous alkylated silyl radicals. The term “aryl” specifies a phenyl-, or an alkyl-, nitro-or halo-substituted phenyl group.
A “protected hydroxy” group is a hydroxy group derivatised or protected by any of the above groups commonly used for the temporary or permanent protection of hydroxy functions, e.g. the silyl, alkoxyalkyl, acyl or alkoxycarbonyl groups, as previously defined. The terms “hydroxyalkyl”, “deuteroalkyl” and “fluoroalkyl” refer to an alkyl radical substituted by one or more hydroxy, deuterium or fluoro groups respectively.
It should be noted in this description that the term “24-homo” refers to the addition of one methylene group and the term “24-dihomo” refers to the addition of two methylene groups at the carbon 24 position in the side chain. Likewise, the term “trihomo” refers to the addition of three methylene groups. Also, the term “26,27-dimethyl” refers to the addition of a methyl group at the carbon 26 and 27 positions so that for example R 3 and R 4 are ethyl groups. Likewise, the term “26,27-diethyl” refers to the addition of an ethyl group at the 26 and 27 positions so that R 3 and R 4 are propyl groups.
In the following lists of compounds, the particular isometric form of the ethylidene substituent attached at the carbon 2 position should be added to the nomenclature. For example, if the methyl group of the ethylidene substituent is in its (E) configuration, then the term “2(E)” should be included in each of the named compounds. If the methyl group of the ethylidene substituent is in its (Z) configuration, then the term “2(Z)” should be included in each of the named compounds. In addition, if the methyl group attached at the carbon 20 position is in its epi or unnatural configuration, the term “20(S)” or “20-epi” should be included in each of the following named compounds. Also, if the side chain contains an oxygen atom substituted at any of positions 20, 22 or 23, the term “20-oxa”, “22-oxa” or “23-oxa”, respectively, should be added to the named compound. The named compounds could also be of the vitamin D 2 or D 4 type if desired.
Specific and preferred examples of the 2-ethylidene-compounds of structure I when the side chain is unsaturated are:
2-ethylidene-19-nor-1,25-dihydroxy-22,23-dehydrovitamin D 3 ;
2-ethylidene-19-nor-24-homo-1,25-dihydroxy-22,23-dehydrovitamin D 3 ;
2-ethylidene-19-nor-24-dihomo-1,25-dihydroxy-22,23-dehydrovitamin D 3 ;
2-ethylidene-19-nor-24-trihomo-1,25-dihydroxy-22,23-dehydrovitamin D 3 ;
2-ethylidene-19-nor-26,27-dimethyl-24-homo-1,25-dihydroxy-22,23-dehydrovitamin D 3 ;
2-ethylidene-19-nor-26,27-dimethyl-24-dihomo-1,25-dihydroxy-22,23-dehydrovitamin D 3 ;
2-ethylidene-19-nor-26,27-dimethyl-24-trihomo-1,25-dihydroxy-22,23-dehydrovitamin D 3 ;
2-ethylidene-19-nor-26,27-diethyl-24-homo-1,25-dihydroxy-22,23-dehydrovitamin D 3 ;
2-ethylidene-19-nor-26,27-diethyl-24-dihomo-1,25-dihydroxy-22,23-dehydrovitamin D 3 ;
2-ethylidene-19-nor-26,27-diethyl-24-trihomo-1,25-dihydroxy-22,23-dehydrovitamin D 3 ;
2-ethylidene-19-nor-26,27-dipropoyl-24-homo-1,25-dihydroxy-22,23-dehydrovitamin D 3 ;
2-ethylidene-19-nor-26,27-dipropyl-24-dihomo-1,25-dihydroxy-22,23-dehydrovitamin D 3 ; and
2-ethylidene-19-nor-26,27-dipropyl-24-trihomo-1,25-dihydroxy-22,23-dehydrovitamin D 3 .
With respect to the above unsaturated compounds, it should be noted that the double bond located between the 22 and 23 carbon atoms in the side chain may be in either the (E) or (Z) configuration. Accordingly, depending upon the configuration, the term “22,23(E)” or “22,23(Z)” should be included in each of the above named compounds. Also, it is common to designate the double bond located between the 22 and 23 carbon atoms with the designation “Δ 22 ”. Thus, for example, the first named compound above could also be written as 2-ethylidene-19-nor-22,23(E)-Δ 22 -1,25-(OH) 2 D 3 where the double bond is in the (E) configuration. Similarly, if the methyl group attached at carbon 20 is in the unnatural configuration, this compound could be written as 2-ethylidene-19-nor-20(S)-22,23(E)-Δ 22 -1,25-(OH) 2 D 3 .
Specific and preferred examples of the 2-ethylidene-compounds of structure I when the side chain is saturated are:
2-ethylidene-19-nor-1,25-dihydroxyvitamin D 3 ;
2-ethylidene-19-nor-24-homo-1,25-dihydroxyvitamin D 3 ;
2-ethylidene-19-nor-24-dihomo-1,25-dihydroxyvitamin D 3 ;
2-ethylidene-19-nor-24-trihomo-1,25-dihydroxyvitamin D 3 ;
2-ethylidene-19-nor-26,27-dimethyl-24-homo-1,25-dihydroxyvitamin D 3 ;
2-ethylidene-19-nor-26,27-dimethyl-24-dihomo-1,25-dihydroxyvitamin D 3 ;
2-ethylidene-19-nor-26,27-dimethyl-24-trihomo-1,25-dihydroxyvitamin D 3 ;
2-ethylidene-19-nor-26,27-diethyl-24-homo-1,25-dihydroxyvitamin D 3 ;
2-ethylidene-19-nor-26,27-diethyl-24-dihomo-1,25-dihydroxyvitamin D 3 ;
2-ethylidene-19-nor-26,27-diethyl-24-trihomo-1,25-dihydroxyvitamin D 3 ;
2-ethylidene-19-nor-26,27-dipropyl-24-homo-1,25-dihydroxyvitamin D 3 ;
2-ethylidene-19-nor-26,27-dipropyl-24-dihomo-1,25-dihydroxyvitamin D 3 ; and
2-ethylidene-19-nor-26,27-dipropyl-24-trihomo-1,25-dihydroxyvitamin D 3 .
As noted previously, the above saturated side chain compounds should have the appropriate 2(E) or 2(Z) configuration and/or carbon 20 configuration added to the nomenclature. For example, particularly preferred compounds are:
19-nor-2(E)-ethylidene-1α,25-dihydroxyvitamin D 3 ;
19-nor-2(Z)-ethylidene-1α,25-dihydroxyvitamin D 3 ;
19-nor-2(E)-ethylidene-20(S)-1α,25-dihydroxyvitamin D 3 ; and
19-nor-2(Z)-ethylidene-20(S)-1α,25-dihydroxyvitamin D 3 .
In the following lists of compounds, the particular isometric form of the ethyl substituent attached at the carbon 2 position should be added to the nomenclature. For example, if the ethyl group is in the alpha configuration, the term “2α-methyl” should be included in each of the named compounds. If the ethyl group is in the beta configuration, the term “2β-ethyl” should be included in each of the named compounds. In addition, if the methyl group attached at the carbon 20 position is in its epi or unnatural configuration, the term “20(S)” or “20-epi” should be included in each of the following named compounds. Also, if the side chain contains an oxygen atom substituted at any of positions 20, 22 or 23, the term “20-oxa,” “22-oxa” or “23-oxa,” respectively, should be added to the named compound. The named compounds could also be of the vitamin D 2 or D 4 type if desired.
Specific and preferred examples of the 2-ethyl-compounds of structure II when the side chain is unsaturated are:
2-ethyl-19-nor-1,25-dihydroxy-22,23-dehydrovitamin D 3 ;
2-ethyl-19-nor-24-homo-1,25-dihydroxy-22,23-dehydrovitamin D 3 ;
2-ethyl-19-nor-24-dihomo-1,25-dihydroxy-22,23-dehydrovitamin D 3 ;
2-ethyl-19-nor-24-trihomo-1,25-dihydroxy-22,23-dehydrovitamin D 3 ;
2-ethyl-19-nor-26,27-dimethyl-24-homo-1,25-dihydroxy-22,23-dehydrovitamin D 3 ;
2-ethyl-19-nor-26,27-dimethyl-24-dihomo-1,25-dihydroxy-22,23-dehydrovitamin D 3 ;
2-ethyl-19-nor-26,27-dimethyl-24-trihomo-1,25-dihydroxy-22,23-dehydrovitamin D 3 ;
2-ethyl-19-nor-26,27-diethyl-24-homo-1,25-dihydroxy-22,23-dehydrovitamin D 3 ;
2-ethyl-19-nor-26,27-diethyl-24-dihomo-1,25-dihydroxy-22,23-dehydrovitamin D 3 ;
2-ethyl-19-nor-26,27-diethyl-24-trihomo-1,25-dihydroxy-22,23-dehydrovitamin D 3 ;
2-ethyl-19-nor-26,27-dipropoyl-24-homo-1,25-dihydroxy-22,23-dehydrovitamin D 3 ;
2-ethyl-19-nor-26,27-dipropyl-24-dihomo-1,25-dihydroxy-22,23-dehydrovitamin D 3 ; and
2-ethyl-19-nor-26,27-dipropyl-24-trihomo-1,25-dihydroxy-22,23-dehydrovitamin D 3 .
With respect to the above unsaturated compounds, it should be noted that the double bond located between the 22 and 23 carbon atoms in the side chain may be in either the (E) or (Z) configuration. Accordingly, depending upon the configuration, the term “22,23(E)” or “22,23(Z)” should be included in each of the above named compounds. Also, it is common to designate the double bond located between the 22 and 23 carbon atoms with the designation “Δ 22 ”. Thus, for example, the first named compound above could also be written as 2-ethyl-19-nor-22,23(E)-Δ 22 -1,25-(OH) 2 D 3 where the double bond is in the (E) configuration. Similarly, if the methyl group attached at carbon 20 is in the unnatural configuration, this compound could be written as 2-ethyl-19-nor-20(S)-22,23(E)-Δ 22 -1,25-(OH) 2 D 3 .
Specific and preferred examples of the 2-ethyl-compounds of structure II when the side chain is saturated are:
2-ethyl-19-nor-1,25-dihydroxyvitamin D 3 ;
2-ethyl-19-nor-24-homo-1,25-dihydroxyvitamin D 3 ;
2-ethyl-19-nor-24-dihomo-1,25-dihydroxyvitamin D 3 ;
2-ethyl-19-nor-24-trihomo-1,25-dihydroxyvitamin D 3 ;
2-ethyl-19-nor-26,27-dimethyl-24-homo-1,25-dihydroxyvitamin D 3 ;
2-ethyl-19-nor-26,27-dimethyl-24-dihomo-1,25-dihydroxyvitamin D 3 ;
2-ethyl-19-nor-26,27-dimethyl-24-trihomo-1,25-dihydroxyvitamin D 3 ;
2-ethyl-19-nor-26,27-diethyl-24-homo-1,25-dihydroxyvitamin D 3 ;
2-ethyl-19-nor-26,27-diethyl-24-dihomo-1,25-dihydroxyvitamin D 3 ;
2-ethyl-19-nor-26,27-diethyl-24-trihomo-1,25-dihydroxyvitamin D 3 ;
2-ethyl-19-nor-26,27-dipropyl-24-homo-1,25-dihydroxyvitamin D 3 ;
2-ethyl-19-nor-26,27-dipropyl-24-dihomo-1,25-dihydroxyvitamin D 3 ; and
2-ethyl-19-nor-26,27-dipropyl-24-trihomo-1,25-dihydroxyvitamin D 3 .
As noted previously, the above saturated side chain compounds should have the appropriate 2α-or 2β-configuration and/or carbon 20 configuration added to the nomenclature. For example, particularly preferred compounds are:
19-nor-2α-ethyl-1α,25-dihydroxyvitamin D 3 ;
19-nor-2β-ethyl-1α,25-dihydroxyvitamin D 3 ;
19-nor-20(S)-2α-ethyl-1α,25-dihydroxyvitamin D 3 ; and
19-nor-20(S)-2β-ethyl-1α,25-dihydroxyvitamin D 3 .
The preparation of 2-ethylidene-19-nor-vitamin D compounds, and the 2-ethyl-19-nor-vitamin D compounds, having the basic structure I and II can be accomplished by a common general method, i.e. the condensation of a bicyclic Windaus-Grundmann type ketone III with the allylic phosphine oxide IVa or IVb to the corresponding 2-ethylidene-19-nor-vitamin D analogs Va or Vb, respectively followed by a selective reduction of the ethylidene group at C-2 to the corresponding 2-ethyl compounds.
In the structures III, IV, and V groups Y 1 and Y 2 and R represent groups defined above; Y 1 and Y 2 are preferably hydroxy-protecting groups, it being also understood that any functionalities in R that might be sensitive, or that interfere with the condensation reaction, be suitable protected as is well-known in the art. The process shown above represents an application of the convergent synthesis concept, which has been applied effectively for the preparation of vitamin D compounds [e.g. Lythgoe et al., J. Chem. Soc. Perkin Trans. I, 590 (1978); Lythgoe, Chem. Soc. Rev. 9, 449 (1983); Toh et al., J. Org. Chem. 48, 1414 (1983); Baggiolini et al., J. Org. Chem. 51, 3098 (1986); Sardina et al., J. Org. Chem. 51, 1264 (1986); J. Org. Chem. 51 , 1269 (1986); DeLuca et al., U.S. Pat. No. 5,086,191; DeLuca et al., U.S. Pat. No. 5,536,713].
Hydrindanones of the general structure m are known, or can be prepared by known methods. Specific important examples of such known bicyclic ketones are the structures with the side chains (a), (b), (c) and (d) described above, i.e. 25-hydroxy Grundmann's ketone (f) [Baggiolini et al., J. Org. Chem, 51, 3098 (1986)]; Grundmann's ketone (g) [Inhoffen et al., Chem. Ber. 90, 664 (1957)]; 25-hydroxy Windaus ketone (h) [Baggiolini et al., J. Org. Chem., 51, 3098 (1986)] and Windaus ketone (i) [Windaus et al., Ann., 524, 297 (1936)]:
For the preparation of the required phosphine oxides of general structure IV, a new synthetic route has been developed starting from methyl quinicate derivative 9, easily obtained from commercial (1R,3R,4S,5R)-(−)-quinic acid 8 as described by Perlman et al., Tetrahedron Lett. 32, 7663 (1991) and DeLuca et al., U.S. Pat. No. 5,086,191. The overall process of transformation of the starting methyl ester 9 into the desired A-ring synthons, is summarized by the Scheme I. Reduction of the ester 9 with diisobutylaluminum hydride (DIBALH) or other suitable reducing agent (e.g. lithium aluminum hydride) provided the diol 10 which was subsequently oxidized by sodium periodate to the cyclohexanone ketone derivative 11. Then, the secondary 4-hydroxyl group of 11 was oxidized with RuO 4 (a catalytic method with RuCl 3 and NaIO 4 as co-oxidant). Use of such a strong oxidant was necessary for an effective oxidation process of this very hindered hydroxyl. However, other more commonly used oxidants can also be applied (e.g. pyridinium dichromate), although the reactions usually require much longer time for completion. The next step of the process comprises the Peterson reaction of the ketone 12 with methyl(trimethylsilyl)acetate to form ester 13.
Referring now to Scheme 2, the next step of the synthesis comprises the Wittig reaction of the sterically hindered 4-keto compound 13 with ylide prepared from ethyltriphenylphosphonium bromide and n-butyllithium leading to ethylidene compounds 14 and 15. Ethylidene compounds 14 and 15 in turn were treated with diisobutylaluminum hydride and the formed alcohols 16 and 17 were in turn transformed to the desired A-ring phosphine oxides 18 and 19. Conversion of 16 and 17, to 18 and 19, respectively involved 3 steps, namely, in situ tosylation with n-butyllithium and p-toluenesulfonyl chloride, followed by reaction with diphenylphosphine lithium salt and oxidation with hydrogen peroxide.
Several 2-ethylidene-19-nor-vitamin D compounds of the general structure V may be synthesized using the A-ring synthons 18 and 19 and the appropriate Windaus-Grundmann ketone III having the desired side chain structure. Thus, for example, Scheme 3 illustrates that Wittig-Horner coupling of the phosphinoxy 18 with the protected 25-hydroxy Grundmann's ketone 20 prepared according to published procedure [Sicinski et al., J. Med. Chem. 37, 3730 (1994)] gave the expected protected vitamin compound 21. This, after deprotection afforded 1α,25-dihydroxy-2(E)-ethylidene-19-nor-vitamin D 3 (4a). Similarly, Scheme 3 illustrates the synthesis of 1α,25-dihydroxy-2(Z)-ethylidene-19-nor-vitamin D 3 (5a) from phosphinoxy 19 and Grundmann's ketone 20.
Referring now to Scheme 6, the final step of the process was the selective homogeneous catalytic hydrogenation of the ethylidene unit at carbon 2 in the vitamins 4a and 5a performed efficiently in the presence of tris(triphenylphosphine)rhodium(I) chloride [Wilkinson's catalyst, (Ph 3 P) 3 RhCl]. Such reduction conditions allowed to reduce only C(2)═CH 2 unit leaving C(5)—C(8) butadiene moiety unaffected. The isolated material is an epimeric mixture (ca. 1:1) of 2-ethyl-19-nor-vitamins 6a and 7a differing in configuration at C-2. The mixture can be used without separation or, if desired, the individual 2α-and 2β-isomers can be separated by an efficient HPLC system.
The C-20 epimerization may be accomplished by the analogous coupling of the phosphine oxides 18 and 19 with protected 20(S)-25-hydroxy Grundmann's ketone 26 (Scheme 5) which after hydrolysis of the hydroxy-protecting groups gave 20(S)-1α,25-dihydroxy-2-ethylidene-19-nor-vitamin D 3 compounds 4b and 5b. Hydrogenation of 4b and 5b provided the expected mixture of the 2-ethyl-19-nor-vitamin D analogs 6b and 7b.
As noted above, other 2-ethylidene and 2-ethyl-19-nor-vitamin D analogs may be synthesized by the method disclosed herein. For example, 1α-hydroxy-2-ethylidene-19-nor-vitamin D 3 can be obtained by providing the Grundmann's ketone (g). Subsequent reduction of the A-ring ethylidene group in the formed compound can also give the corresponding epimeric mixture of 1α-hydroxy-2-ethyl-19-nor-vitamin D 3 compounds.
A number of oxa-analogs of vitamin D 3 and their synthesis are also known. For example, 20-oxa analogs are described in N. Kubodera at al, Chem. Pharm. Bull., 34, 2286 (1986), and Abe et al, FEBS Lett. 222,58, 1987. Several 22-oxa analogs are described in E. Murayama et al, Chem. Pharm. Bull., 34, 4410 (1986), Abe et al, FEBS Lett., 226, 58 (1987), PCT International Application No. WO 90/09991 and European Patent Application, publication number 184 112, and a 23-oxa analog is described in European Patent Application, publication number 78704, as well as U.S. Pat. No. 4,772,433.
This invention is described by the following illustrative examples. In these examples specific products identified by Arabic numerals (e.g. 1, 2, 3, etc) refer to the specific structures so identified in the preceding description and in the Schemes.
EXAMPLE 1
Chemistry
The strategy of the synthesis of 2-substituted 19-norvitamins was based on Lythgoe-type Wittig-Horner coupling. Since the corresponding C,D-ring ketones were available, attention was focused on the synthesis of the phosphine oxide A-ring synthons (Scheme 1 and 2). Configurations of the ethylidene unit at C′-4 in the isomeric compounds 16, 17 ( FIG. 2 ) and 17, 18, as well as their preferred conformations, were determined by analysis of 1 H NMR spectra, NOE measurements and spin decoupling experiments.
The Wittig-Homer reaction of the conjugate base of 20 with the protected 25-hydroxy Grundmann's ketone 20 produced 19-norvitamin D compound 21 in a very high yield, i.e. 91% (Scheme 3), but-the yield of an analogous coupling of the isomeric phosphine oxide 19 was very low, i.e. 13%. The obtained condensation products 21 and 22, following deprotection, gave 2-ethylidene-19-norvitamins 4a and 5a. Considering the low yield of the Wittig reaction of the cyclohexanone 13, leading to ethylidene compounds 14 and 15 (Scheme 2), an alternative synthetic approach was sought.
Thus, the carbonyl group in 13 was protected as O-trimethylsilyl hemimethylthioketal and the corresponding phosphine oxides 25 were efficiently synthesized (Scheme 4). Coupling of their anions with the hydrindanone 26 (Scheme 5) afforded the protected 19-norvitamin D compound 27 in a high yield. This, after deprotection of 2-oxo group, Wittig reaction and subsequent hydrolysis was converted to (20S)-2-ethylidene-19-norvitamins 4b and 5b. The selective catalytic hydrogenation of 2-ethylidene analogs 4a, b and 5a, b (Scheme 6) provided the corresponding 2-ethyl-19-norvitamins 6a, b and 7a, b, which were easily separated by HPLC.
Stereochemistry at C-2 in the synthesized vitamin D compounds was tentatively assigned on the basis of conformational analysis, molecular modeling studies, and 500 MHz 1 H NMR spectroscopy.
EXAMPLE 2
Conformational Analysis
It has been established that vitamin D compounds in solutions exist as a mixture of two rapidly equilibrating A-ring chair conformers abbreviated as α-and β-forms ( FIG. 3 a ). Presence of bulky 2-alkyl substituents, characterized by large conformational free energy A values ( FIG. 3 b ), shifts the A-ring conformational equilibrium of the synthesized 2-ethyl-19-norvitamins toward the conformers with the equatorial C(2)-substituents. In the obtained 2-ethylidene-19-norvitamin D compounds, an additional strong interaction (designated as A (1,3) -strain, FIG. 3 c ) is involved, existing between the methyl group from the ethylidene moiety and equatorial hydroxyls at C-1 or C-3. It results in the strong bias toward conformers with an axial orientation of this hydroxy group to which the methyl from ethylidene fragment is directed.
Conformational equilibrium in ring A of 2-methylene-19-norvitamin 2 (a) and-the preferred, energy minimized (PC MODEL 6.0, Serena Software) A-ring conformations of the synthesized analogs: 4a, b (b), 5a, b (c), 6a, b :(d) and 7a, b (e) are shown in FIG. 4 . The steric energy differences between the preferred conformers and their partners with the inverted chair forms (calculated for model compounds lacking side chain) are given. The corresponding percentage populations (in parentheses) of conformers are given for room temperature (25° C.).
EXAMPLE 3
Biological Evaluation
The synthesized vitamins were tested for their ability to bind the porcine intestinal vitamin D receptor. The presented results ( FIG. 5 a ) indicate that 2-ethylidene-19-norvitamins, possessing methyl group from ethylidene moiety directed toward C-3, i.e. trans in relation to C(6)—C(7) bond (isomers E), are more active than 1α,25-(OH) 2 D 3 in binding to VDR, whereas their counterparts with cis relationship between ethylidene methyl substituent and C(7)-H group (isomers Z) exhibit significantly reduced affinity for the receptor. The competitive binding analysis showed also that 2α-ethyl-19-norvitamins bind the receptor better than their isomers with 2β-ethyl substituents ( FIG. 5 b ). In the next assay, the cellular activity of the synthesized compounds was established by studying their ability to induce differentiation of human promyelocyte HL-60 cells into monocytes. E isomer of (20S)-2-ethylidene-19-norvitamin D 3 ( FIG. 6 a ) and both 2α-ethyl-19-norvitamins ( FIG. 6 b ) are more potent than 1α,25-(OH) 2 D 3 in this assay, whereas the remaining tested compounds are almost equivalent to the hormone.
Both E isomers of 2-ethylidene-19-norvitamins, when tested in vivo in rats (Table 1) exhibited very high calcemic activity, the (20S)-compound being especially potent. On the contrary, isomeric Z compounds are significantly less active. 2-ethyl-19-norvitamins have some ability to mobilize calcium from bone but not to the extent of the hormone 1, while being inactive in intestine. The only exception is 2α-ethyl isomer from 20S-series that shows strong calcium mobilization response and marked intestinal activity.
TABLE 1
Support of Intestinal Calcium Transport and Bone Calcium Mobilization
By 2-Substituted Analogs of 1α,25-Dihydroxy-19-norvitamin D 3
In Vitamin D-Deficient Rats on a Low-Calcium Diet a
compd.
amount
Ca transport S/M
Serum Ca
compound
no.
(pmol)
(mean ± SEM)
(mean ± SEM)
none (control)
0
3.0 ± 0.7
4.3 ± 0.1
1α,25-(OH) 2 D 3
1
130
5.5 ± 0.5
5.1 ± 0.3
260
5.9 ± 0.4
5.8 ± 0.3
2-ethylidene-19-nor-
4a
65
5.0 ± 0.4
4.5 ± 0.1
1α,25-(OH) 2 D 3 (E-isomer)
130
6.8 ± 0.4
5.2 ± 0.2
2-ethylidene-19-nor-1α,25-
5a
65
4.4 ± 0.4
4.4 ± 0.2
(OH) 2 D 3 (Z-isomer)
130
5.7 ± 0.9
4.2 ± 0.0
none (control)
0
4.4 ± 0.2
4.1 ± 0.2
1α,25-(OH) 2 D 3
1
130
4.9 ± 0.7
5.2 ± 0.2
260
6.0 ± 0.9
6.4 ± 0.4
2-ethylidene-19-nor-(20S)-
4b
65
9.0 ± 0.3
8.2 ± 0.3
1α,25-(OH) 2 D 3 (E-isomer)
130
5.8 ± 0.8
12.1 ± 0.6
2-ethylidene-19-nor-(20S)-1α,25-
5b
65
4.3 ± 0.7
4.0 ± 0.3
(OH) 2 D 3 (Z-isomer)
130
3.8 ± 0.3
4.0 ± 0.1
none (control)
0
3.8 ± 0.4
3.9 ± 0.1
1α,25-(OH) 2 D 3
1
260
6.5 ± 0.9
5.8 ± 0.1
2α-ethyl-19-nor-
6a
260
4.0 ± 0.4
5.1 ± 0.1
1α,25-(OH) 2 D 3
2β-ethyl-19-nor-
7a
260
3.7 ± 0.3
5.0 ± 0.1
1α,25-(OH) 2 D 3
2α-ethyl-19-nor-
6b
260
5.0 ± 0.4
7.0 ± 0.1
(20S)-1α,25-(OH) 2 D 3
2β-ethyl-19-nor-
7b
260
4.1 ± 0.3
5.6 ± 0.1
(20S)-1α,25-(OH) 2 D 3
a Weanling male rats were maintained on a 0.47% Ca diet for one week and then switched to a low-calcium diet containing 0.02% Ca for an additional three weeks. During the last week, they were dosed daily with the appropriate vitamin D compound for seven consecutive days. All doses were administered intraperitoneally in 0.1 mL propylene glycol/ethanol (95:5). Controls received the vehicle. Determinations were made 24 hours after the last dose. There were at least six rats per group.
For treatment purposes, the novel compounds of this invention defined by formula I and/or II may be formulated for pharmaceutical applications as a solution in innocuous solvents, or as an emulsion, suspension or dispersion in suitable solvents or carriers, or as pills, tablets or capsules, together with solid carriers, according to conventional methods known in the art. Any such formulations may also contain other pharmaceutically-acceptable and non-toxic excipients such as stabilizers, anti-oxidants, binders, coloring agents or emulsifying or taste-modifying agents.
The compounds may be administered orally, topically, parenterally, sublingually, intranasally, or transdermally. The compounds are advantageously administered by injection or by intravenous infusion or suitable sterile solutions, or in the form of liquid or solid doses via the alimentary canal, or in the form of creams, ointments, patches, or similar vehicles suitable for transdermal applications. Doses of from about 0.01 μg to about 100 μg per day,.preferably from 0.1 μg to 50 μg per day of the compounds are appropriate for treatment purposes, such doses being adjusted according to the disease to be treated, its severity and the response of the subject as is well understood in the art. Since the new compounds exhibit specificity of action, each may be suitably administered alone, or together with graded doses of another active vitamin D compound—e.g. 1α-hydroxyvitamin D 2 or D 3 , or 1α,25-dihydroxyvitamin D 3 —in situations where different degrees of bone mineral mobilization and calcium transport stimulation is found to be advantageous.
Compositions for use in the above-mentioned treatment of psoriasis and other malignancies comprise an effective amount of one or more 2-substituted-19-nor-vitamin D compound as defined by the above formula I and/or II as the active ingredient, and a suitable carrier. An effective amount of such compounds for use in accordance with this invention is from about 0.01 μg to about 100 μg per gm of composition, and may be administered topically, transdermally, orally, sublingually, intranasally, or parenterally in dosages of from about 0.1 μg/day to about 100 μg/day.
The compounds may be formulated as creams, lotions, ointments, topical patches, pills, capsules or tablets, or in liquid form as solutions, emulsions, dispersions, or suspensions in pharmaceutically innocuous and acceptable solvent or oils, and such preparations may contain in addition other pharmaceutically innocuous or beneficial components, such as stabilizers, antioxidants, emulsifiers, coloring agents, binders or taste-modifying agents.
The compounds are advantageously administered in amounts sufficient to effect the differentiation of promyelocytes to normal macrophages. Dosages as described above are suitable, it being understood that the amounts given are to be adjusted in accordance with the severity of the disease, and the condition and response of the subject as is well understood in the art.
The formulations of the present invention comprise an active ingredient in association with a pharmaceutically acceptable carrier therefore and optionally other therapeutic ingredients. The carrier must be “acceptable” in the sense of being compatible with the other ingredients of the formulations and not deleterious to the recipient thereof.
Formulations of the present invention suitable for oral administration may be in the form of discrete units as capsules, sachets, tablets or lozenges, each containing a predetermined amount of the active ingredient; in the form of a powder or granules; in the form of a solution or a suspension in an aqueous liquid or non-aqueous liquid; or in the form of an oil-in-water emulsion or a water-in-oil emulsion.
Formulations for rectal administration may be in the form of a suppository incorporating the active ingredient and carrier such as cocoa butter, or in the form of an enema.
Formulations suitable for parenteral administration conveniently comprise a sterile oily or aqueous preparation of the active ingredient which is preferably isotonic with the blood of the recipient.
Formulations suitable for topical administration include liquid or semi-liquid preparations such as liniments, lotions, applicants, oil-in-water or water-in-oil emulsions such as creams, ointments or pastes; or solutions or suspensions such as drops; or as sprays.
For asthma treatment, inhalation of powder, self-propelling or spray formulations, dispensed with a spray can, a nebulizer or an atomizer can be used. The formulations, when dispensed, preferably have a particle size in the range of 10 to 100μ.
The formulations may conveniently be presented in dosage unit form and may be prepared by any of the methods well known in the art of pharmacy. By the term “dosage unit” is meant a unitary, i.e. a single dose which is capable of being administered to a patient as a physically and chemically stable unit dose comprising either the active ingredient as such or a mixture of it with solid or liquid pharmaceutical diluents or carriers.
In its broadest application, the present invention relates to any 19-nor-analog of vitamin D which have the vitamin D nucleus. By vitamin D nucleus, it is meant a central part consisting of a substituted chain of five carbon atoms which correspond to positions 8, 14, 13, 17 and 20 of vitamin D, and at the ends of which are connected at position 20 a structural moiety representing any of the typical side chains known for vitamin D type compounds (such as R as previously defined herein), and at position 8 the 5,7-diene moiety connected to the A-ring of an active 1α-hydroxy vitamin D analog (as illustrated by formula I herein). Thus, various known modifications to the six-membered C-ring and the five-membered D-ring typically present in vitamin D, such as the lack of one or the other or both, are also embraced by the present invention.
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Biologically active 19-nor vitamin D analogs substituted at C-2 in the A-ring with an ethylidene or an ethyl group. These compounds have preferential activity on mobilizing calcium from bone and either high or normal intestinal calcium transport activity which allows their in vivo administration for the treatment of metabolic bone diseases where bone loss is a major concern. These compounds are also characterized by high cell differentiation activity.
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[0001] This application is a Divisional of application Ser. No. 10/044,360, filed on Jan. 11, 2002, which is a Continuation in Part of application Ser. No. 09/935,952, filed on Aug. 23, 2001.
FIELD OF THE INVENTION
[0002] This invention relates in general to novel synthetic hydrotalcites, their syntheses and uses. The synthetic hydrotalcites of the present invention can be made from organic anions longer than C 4 , and also from organic anions with functional groups including saturated carboxylates of C 6 , C 8 , C 10 , and C 18 , straight chain acids; aromatics such as benzoates, chlorobenzoates, naphthoates, and p-hydroxybenzoates; carboxylates of acrylic, methacrylic, vinylacetic acids and mixtures of these organic anions. The synthetic hydrotalcites of the present invention can also be made from carboxylates of C 2 and higher organic acids containing heteroatoms such as nitrogen, sulfur, phosphorous and halogens.
BACKGROUND OF THE INVENTION
[0003] Hydrotalcites are derivatives of brucite, a naturally-occurring, layered, magnesium hydroxide mineral. Synthetic hydrotalcites can be made by substituting a trivalent metal cation, such as aluminum, for some of the magnesium cations normally present in a layer. The magnesium cations can also be substituted by other divalent cations. This substitution will result in a net positive charge residing on the layer, which requires an intercalating anion to achieve a net neutral charge for the molecule. The following general formula has been derived for synthetic hydrotalcites:
[M 2+ 1-x M 3+ x (OH) 2 ] x+ [A n− x/n .m H 2 O] x
wherein M 2+ is magnesium and/or other divalent cation, M 3+ is aluminum and/or other trivalent cation and A n− is an anion. In addition to the anion, it will be noted that water is also a part of the lattice structure.
[0005] A group of hydrotalcites with a unique sheet-like morphology is described in U.S. Pat. No. 5,399,329, issued to Schutz, et al., and assigned to the assignee of the present invention. The entire contents of the Schutz '329 patent are incorporated herein by reference. The hydrotalcites of the Schutz '329 patent are comprised of anions derived from C 1 to C 4 saturated carboxylic acids. The general synthetic method of the Schutz '329 patent involves the reaction of an alumina source with a carboxylic acid in water followed by the reaction of the resulting mixture with a magnesium source. The approximate molar ratio of the reagents is as follows: 2 Mg: 1 Al: 1 anion; with the anion being the carboxylate of the acid used.
[0006] Although a hexagonal morphology is normally observed for non-carboxylate anion hydrotalcites, the carboxylate anion hydrotalcites of the Schutz '329 patent exhibit a unique morphology, termed therein “sheet-like”. The distance between the hydrotalcite layers, as measured by d spacing, depends on the size of the intercalating anion. For example, carboxylate hydrotalcites from the following anions produced by the method of the Schutz '329 patent have a d spacing of: formate 7.64 Å, acetate 12.3 Å, propionate 13.02 Å, and isobutyrate 15.15 Å.
[0007] In the Schutz '329 patent, sheet-like hydrotalcites are prepared in aqueous medium by reacting alumina with a carboxylic acid at about 60° C. for 30 minutes followed by the addition of magnesium oxide at a temperature of 95° C. for about 6 hours. The desired gel hydrotalcite is obtained upon drying the reaction product. Although the method of the Schutz '329 patent works rather well for most water-soluble carboxylic acids such as C 1 to C 4 carboxylic acids, it does not work well for those acids, which are water-insoluble. In fact, butyric acid, which is a C 4 acid, has only limited success in the method of the Schutz '329 patent.
[0008] Hydrotalcites have many uses, including such applications as catalysts or catalyst precursors, ion exchangers, ion absorbers, ion-scavengers, and medical uses as antacids. Hydrotalcites are also used as nanocomposites in polymers to provide various property enhancements. Hybrid composites of polymer and other inorganic components such as clays and mica have been described in the prior art as having improved mechanical properties. The term nanocomposites reflects the dispersion of nano-scale particulates of the inorganic component of the hybrid in the polymer matrix.
[0009] In Japanese Patent Application 96-189168, assigned to Mitsui Petrochem Ind. Ltd., naturally-occurring hydrotalcites containing a carbonate anion are used in polypropylene synthesis, along with other additives, and are said to give good melt flow index, flexural modulus and Izod impact strength.
[0010] In EP 0,910,131, assigned to AtoChem, Fr., naturally-occurring hydrotalcites containing a carbonate anion are used in an ethylene-vinylacetate copolymer and are said to produce a film with good adhesion and barrier properties.
[0011] In Japanese Patent Application 86-296799, assigned to Du-Pont Mitsui Polychemicals Co., Ltd., naturally-occurring hydrotalcites containing a carbonate anion are used in linear, low density polyethylene and are said to produce a film which has thermal insulating properties and good tensile strength.
[0012] Most nanocomposite polymer applications use pillared clays and/or naturally-occurring hydrotalcites. Compounded compositions of nylon-6 and 5% clay nanocomposites have been shown to exhibit a 40% higher tensile strength, 68% greater tensile modulus, 60% higher flexural strength and a 126% flexural modulus (See, Int'l. SAMLE Symp. Exhib. 1998, 43:1053-1066). Nanocomposites are believed to disperse in the polymer in one of the following two ways:
1) in a disorderly fashion, such as by intercalation; or 2) by exfoliation, in which the nanolayers are regularly spaced in the polymer. Exfoliation is believed to lead to improved polymer properties.
[0015] There are references in both the patent and scientific literature of various clays, which have been modified and combined with polar polymers such as polyamides to form nanocomposite materials.
[0016] However, the introduction of nanoparticles into nonpolar polymers such as polyolefins to form a nanocomposite is a much more difficult task due to incompatibility of the polar nano particles with the nonpolar polymer. This incompatibility often leads to non-uniform distribution of the inorganic component throughout the polymer, leading to less than optimum performance. Typically, this difficulty is overcome by combining the nonpolar polymer with a similar, but chemically modified polymer (e.g. polypropylene-g-MA), which contains polar functionality to act as a compatibilizer molecule. The polar functionality of the modified polypropylene is able to interact with the polar character of the nanoparticle, and the nonpolar portion of the modified polypropylene interacts with the polypropylene matrix. Presumably, the interaction between the two polar functionalities provides both exfoliation and compatiblization, thereby resulting in a nanocomposite with uniform distribution of the nanoparticles.
[0017] U.S. Pat. No. 5,973,053 describes a layered composite clay material wherein organic onium ions and primary and secondary organic “guest” molecules are introduced into the interlayer space to increase the interlayer distance. The introduction of the organic onium ion acts to increase the compatibility of the clay with polymer and facilitate the dispersion of the clay in the hybrid composite.
[0018] In “Factors Controlling Mechanical Properties of Clay Mineral/Polypropylene nanocomposites”, Journal of Materials Sciences 35 (2000) 1045-1050, Oya et al describe intercalating a clay with a polar monomer, diacetone acrylamide and maleic acid modified polypropylene as a compatibilizer. This organo-clay was then mixed with conventional polypropylene to prepare a nanocomposite. In “Poly(propylene)/organo-clay nanocomposite formation: Influence of compatibilizer functionality and organo-clay modification”, Macromolecular Material Engineering 275, 8-17 (2000), Reichert et al describe the use of alkyl amines as intercalating agents in silica clay with and without the use of maleic anhydride modified polypropylene.
[0019] A need exists in the art for new synthetic hydrotalcites made from organic anions longer than C 4 and also those with functional groups including saturated carboxylates of C 6 , C 8 , C 10 and C 1 -8 straight chain acids; aromatics such as benzoates, chlorobenzoates, naphthoates, and p-hydroxybenzoates; carboxylates of acrylic, methacrylic and vinylacetic acids; and mixtures of these organic anions. Such new synthetic hydrotalcites can find among their uses, that as nanocomposites in polymer applications, because these synthetic hydrotalcites are customizable according to the properties desired in the polymers made therefrom. A need also exists for modified hydrotalcites made from carboxylates of C 2 and higher organic acids containing heteroatoms such as nitrogen, sulfur, phosphorous and halogens, which can be used in polymer nanocomposites and are more easily dispersed in a non-polar polymer without the necessity of using a compatibilizer.
SUMMARY OF THE INVENTION
[0020] The present invention provides a synthetic hydrotalcite of the general formula,
[M 2+ 1-x M 3+ x (OH) 2 ] x+ [A n− x/n .m H 2 O] x−
wherein M 2+ is a divalent cation, M 3+ is a trivalent cation and A n− is an organic anion selected from straight chain carboxylates of C 5 -C 18 acids, carboxylates of aromatic acids, carboxylates of acrylic acid, unsaturated carboxylates of methacrylic acid and unsaturated carboxylates of vinylacetic acid.
[0022] The present invention also provides a synthetic hydrotalcite of the general formula
[M 2+ 1-x M 3+ x (OH) 2 ] x+ [A n− x/n .m H 2 O] x−
wherein M 2+ is a divalent cation, M 3+ is a trivalent cation and A n− is an anion comprising a mixture of at least two members of the group consisting of straight chain saturated carboxylates of C 2 -C 4 acids, carboxylates of aromatic acids, carboxylates of acrylic acid, unsaturated carboxylates of methacrylic acid and unsaturated carboxylates of vinylacetic acid.
[0024] The present invention also provides a synthetic hydrotalcite of the general formula
[M 2+ 1-x M 3+ x (OH) 2 ] x+ [A n− x/n .m H 2 O] x−
wherein M 2+ is a divalent cation, M 3+ is a trivalent cation and A n− is an organic anion comprising a carboxylate of a C 2 or higher acid containing a heteroatom such as nitrogen, sulfur, phosphorous or a halogen. According to one embodiment, the heteroatom is nitrogen in the form of an amino acid. In this embodiment, the acid end of the amino acid binds to cation sites on platelets of the hydrotalcite leaving the amine end to interact or react with solvents or polymer molecules. Additionally, where a polymer is modified with an acid, such as in maleated polypropylene, the amine is free to react with the acid moiety in the polymer to form an amide or imide. In this way, the synthetic hydrotalcite may be directly bonded to the polymer. Preferably, the amino acid is a straight chain alkyl. More preferably, the amino acid intercalated hydrotalcite is capable of self and/or reversible exfoliation. Even more preferably the amino-acid is 4-aminobutyric or 6-aminocaproic acid. Modified hydrotalcites, or organo-hydrotalcites according to the current invention can be used to for polymer nanocomposites, and do not necessarily require the use of compatibilizers to effect dispersion of the hydrotalcite through the polymer. In the embodiment where the synthetic hydrotalcite is capable of self exfoliation in a solvent, it may be maintained as a colloidal suspension after synthesis rather than being collected and dried.
[0026] The present invention further provides for a method of making a synthetic hydrotalcite of the general formula,
[M 2+ 1-x M 3+ x (OH) 2 ] x+ [A n− x/n .m H 2 O] x−
wherein M 2+ is a divalent cation source, M 3+ is a trivalent cation source and A n− is an organic anion source selected from straight chain carboxylates of C 5 -C 18 acids, carboxylates of aromatic acids, carboxylates of acrylic acid, unsaturated carboxylates of methacrylic acid, unsaturated carboxylates of vinylacetic acid and carboxylates of C 2 and higher acids containing heteroatoms such as nitrogen, phosphorous, sulfur and halogens, the method comprising: reacting the trivalent cation source with the organic anion source to produce an intermediate and reacting the intermediate with the divalent cation source to produce the synthetic hydrotalcite.
[0028] The present invention still further provides for a synthetic hydrotalcite polymer blend comprising a poly-addition polymer and a synthetic hydrotalcite of the general formula,
[M 2+ 1-x M 3+ x (OH) 2 ] x+ [A n− x/n .m H 2 O] x−
wherein M 2+ is a divalent cation, M 3+ is a trivalent cation and A n− is an organic anion selected from straight chain carboxylates of C 5 -C 18 acids, carboxylates of aromatic acids, carboxylates of acrylic acid, unsaturated carboxylates of methacrylic acid, unsaturated carboxylates of vinylacetic acid and carboxylates of C 2 and higher acids containing heteroatoms such as nitrogen, phosphorous, sulfur and halogens. In a preferred embodiment, the organic anion in the synthetic hydrotalcite is an amino acid. More preferably, the amino acid is one that promotes self and/or reversible exfoliation of the synthetic hydrotalcite. Additionally, the polymer may be modified or functionalized, such as with maleic acid. In the embodiment where the polymer is modified or functionalized with an acid, an amino acid intercalated hydrotalcite may be bonded to the polymer via an amide or imide formed by reaction of the amine function with the acid modified polymer.
[0030] The present invention yet further provides a method for making a synthetic hydrotalcite-polymer blend comprising: mixing an emulsion comprising a poly-addition polymer with a synthetic hydrotalcite of the general formula,
[M 2+ 1-x M 3+ x (OH) 2 ] x+ [A n− x/n .m H 2 O] x−
wherein M 2+ is a divalent cation source, M 3+ is a trivalent cation source and A n− is an organic anion source selected from straight chain carboxylates of C 5 -C 18 acids, carboxylates of aromatic acids, carboxylates of acrylic acid, unsaturated carboxylates of methacrylic acid and unsaturated carboxylates of vinylacetic acid, and carboxylates of C 2 and higher acids containing heteroatoms such as nitrogen, phosphorous, sulfur and halogens, to obtain the blend. In a preferred embodiment, the organic anion in the synthetic hydrotalcite is an amino acid. More preferably, the amino acid is one that promotes self and reversible exfoliation of the synthetic hydrotalcite. Additionally, the polymer may be modified or functionalized, such as with maleic acid. In the embodiment where the polymer is modified or functionalized with an acid, an amino acid intercalated hydrotalcite may be bonded to the polymer via an amide or imide formed by reaction of the amine function with the acid modified polymer.
BRIEF DESCRIPTION OF FIGURES
[0032] The present invention will be described for the purposes of illustration, but not limitation in conjunction with the following figures, wherein:
[0033] FIG. 1 is a micrograph of a synthetic hydrotalcite made in Example 1;
[0034] FIG. 2 is a micrograph of a synthetic hydrotalcite made in Example 2;
[0035] FIG. 3 is a micrograph of a benzoic acid-derived synthetic hydrotalcite;
[0036] FIG. 4 is a micrograph of a methacrylic acid-derived synthetic hydrotalcite;
[0037] FIG. 5 is a micrograph of an acrylic acid-derived synthetic hydrotalcite;
[0038] FIG. 6 illustrates the predicted relationship between interlayer distance and the number of carbon atoms in an anion;
[0039] FIG. 7 is a micrograph of a mixture of acetic, hexanoic, and stearic acids-derived synthetic hydrotalcite demonstrating a “semi cabbage” morphology;
[0040] FIG. 8 is a micrograph of a blend of about 81% hydrotalcite with polypropylene demonstrating the preferred “cabbage morphology”;
[0041] FIG. 9 is a micrograph of a blend of about 5% hydrotalcite with polypropylene demonstrating a “doughnut” morphology; and
[0042] FIG. 10 is a micrograph of a blend of methacrylic acid-derived hydrotalcite with polypropylene.
[0043] FIG. 11 shows XRD scans of an 8 wt % slurry of the hydrotalcite wet; an air-dried sample of hydrotalcite from an 8 wt % slurry; a sample of UNITE 1000; and a sample of the 50/50 UNITE/hydrotalcite mix.
[0044] FIG. 12 shows XRD scans of a 10 wt % slurry of the hydrotalcite wet; an air-dried sample of hydrotalcite from an 10 wt % slurry; a sample of the 10 wt % slurry dried at 100° C and a sample of the 10 wt % slurry dried at 150° C.
DETAILED DESCRIPTION OF INVENTION
[0045] The three general steps of synthesizing hydrotalcites of the present invention are given below. Two alternate embodiments of Step III are provided.
Step I: Trivalent Cation Source→Organic Anion Intermediate 60°-85° C., 4-8 hours Step II: Intermediate (in water)→Divalent Cation Source Synthetic Hydrotalcite gel 90°-95° C., 4-8 hours Step III: Dry (evaporate/dry under vacuum, filter/dry under vacuum or spray-dry) or Step III: Maintain Wet (colloidal suspension/evaporate to concentrate or paste).
[0050] Success in preparing the synthetic hydrotalcites of the present invention depends greatly on the complete reaction in Step I, i.e., the trivalent cation reacting with the specific carboxylic acid. The preparation of hydrotalcites from longer chain than C 4 carboxylic acids, heteroatom containing acids and water-insoluble aromatic acids is accomplished by driving the reaction of Step I closer to completion preferably by utilizing one or more of the following approaches:
1) the reaction time for Step I can be increased from 30 minutes, as in the Schutz '329 patent, to from 4 to 8 hours; 2) inert organic solvents can be used as a reaction media for water insoluble-organic carboxylic acids with the trivalent cation source; and 3) Step I can be carried out in a melt of the organic anion.
[0054] In the examples described herein, the following materials were used: Trivalent cation source, unless otherwise specified was CATAPAL® alumina which is aluminum oxide monohydroxide from Vista Chemical Corporation; divalent cation source: Martin Magnesia Specialties Inc. MAGCHEM® 200D (a high purity, highly reactive magnesium oxide powder); acids were from Aldrich Chemical Company; and maleated polypropylene emulsion with nonionic emulsifiers was from CHEMCOR containing 39-41% non-volatiles, Trade Name: POLY EMULSION 43N40® (used in the hydrotalcite-polypropylene blend preparation). For aminoacid intercalated hydrotalcite-polypropylene blend preparation, maleated polypropylene produced by Aristech, Trade Name: UNITE 1000®, was used.
[0055] The scanning electron microscopy (SEM) analyses of the synthetic hydrotalcite samples of the present invention were carried out by RJ Lee Group, Inc of Monroeville, Pa., USA. The analyses required collecting photomicrographs utilizing both secondary electron imaging (SEI) and transmission electron imaging (TED of typical particles in the samples. Three different typical particles from each sample were micrographed at magnifications ranging from 5,000× to 50,000×depending on the size of the particles.
[heading-0056] Spray-Drying Method
[0057] Spray-drying of the synthetic hydrotalcites of the present invention can preferably be performed by using a Niro-2 fluid nozzle spray-dryer with the following settings: heat at 5.5, air pressure to the nozzle at 1 bar and the inlet temperature maintained at desired set range of 200-230° C. by varying the liquid feed rate (4-5 liters/hr). Water can preferably be fed to the spray-dryer after the temperature is stabilized to estimate the required feed rate and to remove any material remaining from a previous use.
[heading-0058] Colloidal Suspension, Condensed Suspension or Paste
[0059] As an alternative to drying, the synthetic hydrotalcite may be maintained in a wet or moist state. Maintenance of the synthetic hydrotalcite in a wet or moist state is particularly desirable in embodiments of the invention where the synthetic hydrotalcite is capable or self exfoliation on contact with a solvent. In the case of a synthetic hydrotalcite that is capable of self exfoliation, the product can be isolated directly from the synthesis as a colloidal suspension of the exfoliated hydrotalcite and taken on without further processing. Alternatively, the suspension may be evaporated to form a concentrate of the suspension or a doughy paste.
[heading-0060] Synthetic Hydrotalcite Preparation
[0061] As was mentioned previously, preparation of the synthetic hydrotalcites of the present invention is carried out in three steps. In Step I, the organic anion source is reacted with a trivalent cation source, preferably Al 3+ , but as demonstrated in U.S. Pat. No. 5,518,704 incorporated herein in its entirety by reference, mixtures of Al 3+ and up to 50% of at least one of the other trivalent cations, Cr 3+ and Fe 3+ , may also be used in synthetic hydrotalcite preparation. Step II is the reaction of the mixture from Step I with a divalent cation source, preferably Mg 2+ , but as demonstrated in U.S. Pat. No. 5,518,704 incorporated herein in its entirety by reference, mixtures of Mg 2+ and at least one of the other divalent cations, Ni 2+ , Co 2+, Zn 2+ , Cu 2+ , and Mn 2+ , may also be used in synthetic hydrotalcite preparation. Step III is drying the resultant synthetic hydrotalcite. In alternative Step III, the hydrotalcite is maintained as a wet colloidal suspension, slurry or as a paste. Preferably, a synthetic hydrotalcite that is capable of self and/or reversible exfoliation is maintained in an exfoliated state as a slurry or paste. The Inventors have discovered that Step I of the preparation may be carried out in water, in an organic solvent, or in an acid melt, depending on the water solubility of the organic anion. Step II preferably is carried out in water.
[0062] By way of illustration and not limitation, preparations of a stearic acid synthetic hydrotalcite by methods utilizing each of the three approaches to improve Step I will now be described.
EXAMPLE 1
Step I Carried Out in Water Medium
[0063] CATAPAL® alumina (0.26 moles) was suspended in 500 ml deionized water in a 4-liter beaker and stearic acid (0.23 moles) was added to the stirred suspension. The beaker was fitted with a crystallizing dish filled with ice water to condense volatiles in the beaker as it was heated to 75′-85° C. and the temperature was maintained for 4 to 8 hours. At the end of this period, magnesium oxide (0.44 moles) was added, followed by 1.5 liters of deionized water. The mixture was heated to 90′-95° C. and the temperature was maintained for 4 to 8 hours. The mixture was cooled to room temperature overnight with stirring. The resulting material can preferably be dried in one of two ways:
a) in an air oven at 130° C. until a semi-dry solid is obtained, which is further dried in a vacuum oven at 80° C. overnight; or b) by spray-drying at approximately 200° C. inlet temperature and about 100° C. outlet temperature.
The powder obtained after drying the material is the intended synthetic hydrotalcite.
[0067] In water medium, a smaller than usual amount of water preferably is used, otherwise the acid may float above the alumina suspension in the water and slow the reaction rate. The product of this reaction was a greasy oil that was denser than the medium and settled to the bottom of the reaction vessel. In such a medium, some of the alumina and the free acid may be trapped and either reacts very slowly, or not at all, because mixing of the reagents becomes highly limited. The synthetic hydrotalcite made by this approach was not very homogenous as can be seen by reference to FIG. 1 , which is a scanning electron micrograph of the sample.
EXAMPLE 2
Step I Carried Out in Organic Solvent(s)
[0068] The reaction of the trivalent cation source and carboxylic acids that are water immiscible, such as stearic acid, can preferably be carried out in an organic solvent, such as refluxing hexane. CATAPAL® alumina (0.26 moles) was suspended in 200 ml hexane in a 4-liter beaker and the acid (0.23 moles) was added to the stirred suspension. The beaker was fitted with a crystallizing dish filled with ice water to condense volatiles in the beaker as it was heated to about 65° C. and the temperature was maintained for 4 to 8 hours. The solvent may preferably be removed by evaporation or filtration. Water was added to the resulting residue. Magnesium oxide (0.44 moles) was then added with vigorous stirring. The mixture was heated to about 90°-95° C. and the temperature was maintained for 4 to 8 hours. Product isolation, i.e., drying, was carried out as described in Example 1 above. Using this approach, a homogenous synthetic hydrotalcite was obtained with a larger d spacing value and with a seemingly smaller particle size as indicated by SEM, which can be seen by comparison of FIG. 1 to FIG. 2 .
[0069] When Step I is carried out in an organic solvent, a faster, exothermic reaction occurs which results in an intermediate which is soluble in the medium. A disadvantage of this approach, however, is that the solvent preferably be removed before the reaction of the intermediate with the divalent cation source, because Step H is preferably carried out in water.
EXAMPLE 3
Step I Carried Out in an Acid Melt
[0070] A beaker containing the required amount of solid stearic acid was heated on an oil bath until the acid melted. The desired stoichiometric amount of alumina was added in small portions to the melt with stirring. The temperature was maintained for about two or more hours. Water was added to the product, and the mixture was stirred to an even consistency. Magnesium oxide was added, followed by 1.5 liters of deionized water. The mixture was heated to 90′-95° C. and the temperature was maintained for 4 to 8 hours. The mixture was allowed to cool to room temperature overnight with stirring. Product isolation was carried out as in Example 1 above.
[0071] A difficulty encountered with this approach was similar to that observed in Example 1, i.e., the product was greasy. However, an advantage of using the acid melt approach is that the reaction rate in an acid melt is much faster than that observed in water. With adequate mixing in the acid melt, a more complete reaction than that in water is expected. This may provide an economical approach in preparing synthetic hydrotalcites of solid fatty acids, which have moderate melting temperatures. The acid melt approach is faster than the water approach due to a faster reaction rate and it is faster than the organic solvent approach because there is no need to remove an organic solvent before proceeding to Step II. Table I summarizes the d spacing, the interlayer distance and the particle size of synthetic hydrotalcites made by each approach.
TABLE I COMPARISON OF APPROACHES TO SYNTHESIZING STEARIC ACID HYDROTALCITE Organic Particle Example Anion Step 1 d spacing Interlayer Size No. Source Medium Å Distance Å Microns 1 Stearic acid Water 19.4 14.6 11 × 6 2 Stearic acid Organic 26.4 21.6 3 × 3 Solvent 3 Stearic acid Acid melt 24.4 19.6 5 × 3
EXAMPLES 4-20
[0072] Synthetic hydrotalcites from the following organic anion sources were prepared bye the methods of the present invention and some properties of these synthetic hydrotalcites are summarized in Table II: stearic acid; glycolic acid; acetic acid; acrylic acid; γ-butyrolactone; ethanesulfonic acid; lactic acid; hexanoic acid; octanoic acid; decanoic acid; benzoic acid; chlorobenzoic acid; cinnamic acid; naphthoic acid; methacrylic acid; acrylic acid, vinylacetic acid; a mixture of acrylic, acetic, and stearic acids; and a mixture of acetic, hexanoic, and stearic acids.
[0073] With longer reaction times for Step I, synthetic hydrotalcites of the following organic anion sources can be prepared in water: ethanesulfonic acid, lactic acid, benzoic acid, methacrylic acid, acrylic acid, and vinylacetic acid. FIGS. 3-5 are scanning electron micrographs of three representative members of this group: benzoic acid, methacrylic acid, and acrylic acid, respectively.
[0074] All of the synthetic hydrotalcites described herein were analyzed by x-ray diffraction analysis (XRD) for the x-ray peak position, intensity and d spacing. The d-spacing is indicative of the distance between the layers in the hydrotalcite, because it is dependent upon the size and the shape of the anion in the hydrotalcite and is given for each of the synthetic hydrotalcites in Table II. The assumption that synthetic hydrotalcites with larger d spacing would mix with or exfoliate in polymers led to the synthesis of those hydrotalcites with larger anions or anions with longer carbon chains.
[0075] FIG. 6 shows that as the number of carbon atoms in the anion increases, so does the hydrotalcite interlayer distance. This interlayer distance equals the d spacing minus the brucite layer thickness of 4.77 Å. In fact, there is a good correlation between the number of carbon atoms (at least up to C 10 ) in the organic anion and the interlayer distance. The highest interlayer distance obtained for the synthetic hydrotalcite made from stearic acid is 21.6 Å, which does not fit well in the prediction made from looking at FIG. 6 . A predicted fit would be 26.0 Å, suggesting perhaps that beyond a certain number of carbon atoms there is enough flexibility in the carbon chain backbone to cause a deviation from the prediction.
[0076] Synthetic hydrotalcites which had a d spacing equal to or higher than 12 Å, the d spacing for acetic acid hydrotalcite, were subjected to SEM analysis to obtain the particle size, overall dimensions of the particles and the morphology for the synthetic hydrotalcite. As in the Schutz '329 patent, the preferred morphology for hydrotalcites of the present invention is sheet-like, herein termed “cabbage”. Excellent examples of this morphology were obtained for the synthetic hydrotalcites prepared from the following anions: acetic, ethanesulfonic, octanoic, benzoic, chlorobenzoic, methacrylic, acrylic, and vinylacetic acids.
[0077] Other synthetic hydrotalcites which have a morphology herein described as “semi-cabbage” were those derived from the following anion sources: stearic acid, decanoic acid, naphthoic acid, mixed stearic, acrylic and acetic acids; mixed acetic, hexanoic and stearic acids, (See FIG. 7 ). “Semi-cabbage” as used herein means that only one or two of the three representative particles selected for micrography exhibited the cabbage morphology.
[0078] Without being limited to any specific theory, the Inventors believe that a possible explanation for this semi-cabbage morphology may be that the size and/or shape of the organic anion prevents it from conforming to the true cabbage formation within the crystal structure. Alternatively, the long carbon chain anion and the interlayer water molecules in the synthetic hydrotalcite structure may repel each other, thereby leading to a distortion in the crystal structure. It is also possible that an incomplete reaction with the trivalent cation in Step I of the hydrotalcite synthesis may lead to a semi-cabbage morphology.
[0079] Preparations carried out in water, which failed to result in synthetic hydrotalcites with the desired morphology, were from the following anion sources: glycolic acid, γ-butyrolactone and lactic acid. One possible explanation for the failure to produce synthetic hydrotalcites with the desired morphology from these water-soluble anion sources may be crosslinking between the layers due to the existence of double anions (carboxylate and hydroxylic) as indicated by solid state NMR.
[0080] The average size of the particles was measured in microns using the rulers shown in the SEM micrographs. A smaller particle size is preferred when the intended use for the synthetic hydrotalcite is in a nanocomposite. The particles of the synthetic hydrotalcites of the present invention are generally in the micron range as can be appreciated from a review of the data contained in Table II. The method of drying the synthetic hydrotalcites of the present invention did not seem to have any effect on the particle size.
COMPARATIVE EXAMPLES 22-24
[0081] Synthetic hydrotalcites made from a commercially available hydrotalcite (LaRoche, acetate anion HTC-0498-10), methacrylic, and acrylic acids with flash calcined alumina (FCA, available from LaRoche Industries) as the trivalent cation source gave a morphology that can, at best, be described as semi-cabbage. SEM indicated that more than one aluminum compound exists in FCA or that its reactivity with the acid is lower compared to CATAPAL® alumina. As can be appreciated from reference to Table II, the d spacing for HTC-0498-10 (Comparative Example 22) was 9.7 Å compared to 12.0 Å for a comparable synthetic hydrotalcite prepared in the assignee's laboratory from CATAPAL® alumina and acetic acid (Example 5).
TABLE II SOME PROPERTIES OF SYNTHETIC HYDROTALCITES Particle Organic Anion Interlayer Particle Size Example No. Source d spacing Å Distance Å Morphology microns 1 Stearic acid 19.4 14.6 semi-cabbage 11 × 6 2 Stearic acid 1 26.4 21.6 semi-cabbage 3 × 3 3 Stearic acid 2 24.4 19.6 Semi-cabbage 5 × 3 4 Glycolic acid 9.2 4.4 clump 2 × 1 5 Acetic acid 12.0 7.2 cabbage 6 × 4 6 γ-Butyrolactone 12.3 7.5 clump 2 × 2 7 Ethanesulfonic acid 14.8 10.0 cabbage 6 × 3 8 Lactic acid 15.0 10.2 Semi-cabbage 3 × 4 9 Hexanoic acid 19.2 14.4 clump 5 × 3 10 Octanoic acid 22.9 18.1 Semi-cabbage 5 × 4 11 Decanoic acid 23.9 19.1 Semi-cabbage 4 × 3 12 Benzoic acid 17.0 12.2 cabbage 4 × 3 13 Chlorobenzoic acid 16.8 12.0 cabbage 3 × 4 14 Cinnamic acid 18.4 13.6 clump 7 × 4 15 Naphthoic acid 19.2 14.4 Semi-cabbage 6 × 6 16 Methacrylic acid 13.2 8.4 cabbage 6 × 5 17 Acrylic acid 16.6 11.8 cabbage 3 × 3 18 Vinylacetic acid 17.7 12.9 cabbage 6 × 4 19 Mixed acids 3 15.5 10.7 Semi-cabbage 3 × 2 20 Mixed acids 4 16.4 11.6 Semi-cabbage 6 × 3 21 Octanoic acid 20.3 15.5 cabbage 5 × 2 Comp. Ex 22 HTC-0498-10 9.7 4.9 Semi-cabbage 11 × 5 Comp. Ex 23 Methacrylic acid 5 14.0 9.2 Semi-cabbage 11 × 8 Comp. Ex 24 Acrylic acid' 13.8 9.0 Semi-cabbage 7 × 5 1 Step I of preparation was carried out in hexane solvent. 2 Step I of preparation was carried out in stearic acid melt without a solvent. 3 Mixture molar composition: 3.76 acrylic acid: 1.14 acetic acid: 0.57 stearic acid. 4 Mixture molar composition: 1.34 acetic acid: 0.6 hexanoic acid: 0.8 stearic acid. 5 Trivalent cation source was flash calcined alumina (FCA).
[0082] Solid CP-MAS C 13 NMR analyses of some of the hydrotalcites (Examples 1, 4, 6, 8, 12, 16, 17 and 18) indicated that in the majority of cases, the acids used in the preparations are indeed present in the carboxylate form. However, in a few instances (Examples 4, 6 and 8), a very small amount of the free acid is present with the corresponding anion, indicating an incomplete reaction in Step I.
EXAMPLE 25
Synthesis with 4-Aminobutyric Acid
[0083] Aluminum oxide monohydroxide (0.26 moles) was suspended in 50 ml deionized water in a 500 ml flask equipped with a reflux condenser and a stirrer, and 4-aminobutyric acid (0.26 moles) was added to the stirred suspension. The contents were heated to 75′-85° C. and the temperature was maintained for 4 to 8 hours. At the end of this period, magnesium oxide (0.52 moles) was added, followed by 150 ml of deionized water. The mixture was heated to 90′-95° C., and the temperature was maintained for 4 to 8 hours. The reflux condenser was removed to condense the content to the nominal solid concentration of 10% by weight. The mixture was then allowed to cooled to room temperature overnight with stirring. The resulting slurry was a stable viscous suspension, and the solid component did not precipitate.
[0084] An aliquot of the resulting slurry was placed in an air oven and at 130° C. until a semi-dry solid is obtained, which was further dried in a vacuum oven at 80° C. overnight. The powder obtained after drying the material was the intended synthetic hydrotalcite. A 0.5 g portion of the dry powder was placed in a test tube and re-wetted with 4.5 ml of water. The test tube was vigorously shaken for a minute and the slurry was allowed to stand one overnight. The slurry became a stable viscous suspension again, and the solid component did not precipitate.
EXAMPLE 26
Synthesis with 6-Aminocaproic Acid
[0085] The same procedure was repeated as in Example 25 except that 6-aminocaproic acid was used in place of 4-aminobutyric acid. The resulting slurry was a stable viscous suspension, and the solid component did not precipitate. The powder obtained after drying the material was the intended synthetic hydrotalcite. The re-wetted powder made a stable suspension again.
EXAMPLE 27
Synthesis with 4-Aminobenzoic Acid
[0086] The same procedure was repeated as in Examples 25 and 26 except that 4-aminobenzoic acid was used in place of 4-aminobutyric acid. The condensed slurry showed a quick precipitation into a powder layer and a clear supernatant layer. The powder obtained after drying the material was the intended synthetic hydrotalcite. The re-wetted powder did not make a stable suspension but separated into a precipitated powder layer and clear supernatant layer.
[0087] XRD of the HT samples were taken in the wet and dry state to determine if there was any difference in the basal peak. The data are shown in Table III. For 4-aminobutyric acid, the 2-theta peak observed at 5.70° (corresponding the interlayer spacing of 15.49 Å) for the dry hydrotalcite is not observed in the wet sample, which indicates that the hydrotalcite is exfoliated in the wet state. Similar results are observed for 6-aminocaproic acid. This indicates that these organo hydrotalcites are self exfoliated on addition to a solvent. The data for 4-aminobenzoic acid indicate that this organo hydrotalcite is not self exfoliated on addition to a solvent.
TABLE III SYNTHESIS OF ORGANO-HYDROTALCITES WITH AMINOACIDS Example Organic Anion d spacing dry d spacing wet No. Source dry Å 2-theta wet Å 2-theta 25 4-aminobutyric 15.49 5.70° exfoliated non- acid existent 26 6-aminocaproic 14.02 6.30° exfoliated non- acid existent 27 4-amino 15.49 5.70° 15.63 5.65° benzoic acid
COMPARATIVE EXAMPLES 28-32
Preparation of Commercially Prepared Hydrotalcite-Polypropylene Blends
[0088] Two approaches were taken to prepare blends of commercially prepared hydrotalcite with CHEMCOR® polypropylene emulsion:
1) the dried hydrotalcite was regelled in water, mixed with the emulsion, and then spray-dried, or 2) the emulsion was added to the hydrotalcite before it was spray-dried to obtain the blend.
[0091] Blends with HTC-0498-10 (LaRoche) from 5% to 81% by weight in the solid weight of polypropylene were prepared as indicated in Table IV and analyzed by XRD, SEM, differential scanning calorimetry (DSC) and thermogravimetric analyses (TGA). Commercially prepared, HTC-0498-10 hydrotalcite had a limited regelling concentration of about 3% in warm water. This amount is much lower than the 8%-10% claimed by the manufacturer in its virgin gel before spray-drying. If this method of blend preparation were used, the low regelling concentration would require the use of large reactors.
TABLE IV BLENDS OF COMMERCIALLY PREPARED HYDROTALCITE AND POLYPROPYLENE 1 Comparative Weight Percent d spacing DSC TGA Percent Example No. Hydrotalcite Å Maxima, ° C. Residue 28 5 6.3 147, 380 9.6 29 9 6.2 147, 374 10.2 30 34 6.2 151, 329 22.4 31 38 6.2 151, 328 23.5 32 61 11.4 149, 331 46.1 1 3% hydrotalcite HTC-0498-10 (LaRoche) was regelled in water at about 50° C. then polypropylene emulsion was added to the mixture.
[0092] The XRD analysis of the blends made from the commercially prepared hydrotalcite, HTC-0498-10, indicated a substantial decrease in d spacing from about 9.7 Å to 6.3 Å as the amount polypropylene became more than 60% as can be seen by reference to Table IV, but increased when the level was about 19%. Without being limited to any specific theory, the Inventors believe that a reason for this drop may be due to possible exfoliation or dispersion of the synthetic hydrotalcite in the polymer matrix.
[0093] FIG. 8 , a SEM micrograph of Example 32, a blend containing about 81% hydrotalcite, showed a cabbage morphology that was better defined than that of the hydrotalcite from which it was obtained. The SEM, shown in FIG. 9 , of a similar blend with 5% hydrotalcite from Example 28, however, had a what the Inventors herein term a “doughnut” morphology. Without being limited to any specific theory, the Inventors believe that the doughnut morphology may result from the hydrophilic portion of the synthetic hydrotalcite forming a circular core while the hydrophobic portion, which comprises stearate or octanoate anion mixed with the polymer matrix, surrounds the circular core. The radii of the doughnut particles ranged from 2-3 microns. The blend of Example 28 may have the hydrotalcite so highly dispersed in the polymer matrix that it no longer exists in a layered form.
[0094] Thermogravimetric analyses of blends made from the commercially prepared hydrotalcite, HTC-0498-10, and polypropylene yield residue percentages that are indicative of the amount of hydrotalcite in the material. The residue percentages increased with the hydrotalcite percentage in the preparation as can be seen in Table V and represent nonvolatile materials that remained after heating the sample to elevated temperatures.
[0095] The DSC transition temperatures represent the temperature at which phase changes take place in the blend and are indicative of minimum temperature required for processing these materials in polymer applications. The first phase transition temperature occurred at approximately 150° C. for the blends. Some of these materials exhibited lower transition temperatures that can be attributed to a loss of water.
EXAMPLES 33-38
Preparation of Synthetic Hydrotalcite-Polymer Blends
[0096] Preparation method 1 described above for Comparative Examples 28-32 was also used to prepare blends from some of the synthetic hydrotalcites of the present invention, namely those from stearic acid, octanoic acid, vinylacetic acid, and a mixture of acetic, hexanoic, and stearic acids. These synthetic hydrotalcites did not exhibit the regelling problem associated with the commercially prepared hydrotalcite, HTC-0498-10, which became very difficult to stir when the hydrotalcite concentration was above 3%. The second approach of adding the polypropylene emulsion as a final step in the preparation of hydrotalcite before spray-drying was also tested with synthetic hydrotalcites prepared from methacrylic and acrylic acids.
[0097] An amount of the synthetic hydrotalcite, which will result in about 3% weight, was added to water. The temperature of this mixture was raised to about 40° to 60° C. and the required amount of polypropylene emulsion, depending on desired blend composition, was slowly added to the gel with vigorous stirring. Enough water was added to keep the mixture fluid. The mixture was heated to about 80° C. and maintained at that temperature for about one hour and cooled overnight to room temperature with continued stirring. The mixture was spray-dried at an inlet temperature of 230° C. and an outlet temperature of 90′-105° C. Each blend was subjected to XRD, SEM, TGA and DSC analyses. The results from Examples 30-35 are summarized in Table V.
[0098] Synthetic hydrotalcite-polypropylene blends of stearic acid, octanoic acid, methyl methacrylic acid and acrylic acid were also prepared in a manner that required the addition of the polypropylene emulsion to the un-isolated synthetic hydrotalcite in the preparations. The resulting blend was isolated by spray-drying in the manner described above.
TABLE V SYNTHETIC HYDROTALCITE-POLYPROPYLENE BLENDS Organic Percent Original d spacing DSC TGA Example Anion Synthetic d- percent Maxima, Percent No. Source Hydrotalcite spacing Å d spacing Å change ° C. Residue 33 Stearic acid 1 38 26.4 17.1 −35.2 149 10.0 35 Octanoic 47 20.3 23.6 +16.3 151 16.0 acid 34 Vinylacetic 41 17.7 15.5 −12.4 150 23.9 acid 36 Mixed 55 16.4 17.0 +3.7 148 26.1 acids 2 38 Methacrylic 49 13.2 15.5 +17.4 150 27.9 acid 3 37 Acrylic 57 16.6 13.7 −17.5 152 37.2 acid 3 1 Stearic acid hydrotalcite made by method of example 2, i.e., in organic solvent. 2 Mixed acids composed of the following molar ratio 1.34 acetic: 0.6 hexanoic: 0.8 stearic. 3 Polypropylene emulsion was added to un-isolated synthetic hydrotalcite in the final mixture. All others were prepared by addition of previously isolated synthetic hydrotalcite that was regelled before polypropylene emulsion was added.
[0099] With the longer carbon chain synthetic hydrotalcites, the effect of the blend composition on the d spacings was mixed. As can be seen from a review of Table V, with blends of synthetic hydrotalcites of stearic acid, vinylacetic acid and acrylic acid there were drops in the d spacing of 35.2%, 12.4%, and 17.5% respectively, even at hydrotalcite compositions ranging from 38%-57%. For octanoic acid, mixed acids (acetic, hexanoic and stearic), and methacrylic acid, the d spacing for the blends increased respectively by 16.3%, 3.7%, and 17.4% compared to the synthetic hydrotalcites from which they were derived. Without being limited to any specific theory, the inventors believe that these results may suggest a lack of uniform blending of the synthetic hydrotalcites with the polypropylene or that the structures of the organic anions have a different influence on the d spacing in the blend. The SEM micrographs of blends of polypropylene with synthetic hydrotalcites prepared from octanoic and from mixed acids (acetic, hexanoic and stearic acids) exhibited a doughnut morphology.
[0100] FIG. 10 , which is a SEM micrograph of Example 34, a methacrylic acid-derived synthetic hydrotalcite polypropylene blend, did not exhibit the doughnut morphology, nor was it what could be referred to as semi-cabbage. The particle size of the methacrylic acid-derived synthetic hydrotalcite-polypropylene blend averaged 5×3 angstroms.
[0101] As seen in Table V, the residue percentages from TGA for the synthetic hydrotalcites made from anions other than acetate correlate with the hydrotalcite percentages in the blends when corrections are made for the contribution of the weight of the anion. The DSC transition temperatures for these materials were similar to those materials derived from HTC-0498-10, as the first transition temperatures ranged from 148′-152° C. These materials can therefore be processed with polymers at normal temperatures.
[0102] Although the method of blending the hydrotalcites of the present invention with poly-addition polymers is illustrated by the example of polypropylene, it will be readily apparent to those skilled in the art that other poly-addition polymers can be used in the present invention such as polyethylene, polybutene-1, poly-4-methyl-pentene-1, polystyrene and polyvinyl chloride.
EXAMPLES 39-41
Methyl Methacrylate Polymerization in the Presence of Synthetic Methacrylic Acid-Derived Hydrotalcite
[0103] The reactions were carried in a 1-liter CHEMCO® reactor under 20 psig nitrogen at a stirring rate of 400 rpm. The amounts of methyl methacrylate, methacrylic acid-derived hydrotalcite and the reaction temperatures were as shown in Table VI. In each case, the reactor was charged with 460 ml water, 100 g methyl methacrylate and the desired amount of methacrylic acid-derived hydrotalcite. The reactor was first purged with nitrogen, then pressurized. 0.5 g AIBN (2,2-azobisisobutyronitrile) initiator and surfactant (Aerosol OT 75%, 2.5 g, available from Cytec Industries) were dissolved in 470 g methyl methacrylate and the solution was pumped (fed) at 88 ml/hr into the reactor which had been pre-heated to 70° C. The reaction continued until stirring became difficult due to the formation of solid product clumps. At that point, the methyl methacrylate feeding was stopped and the temperature was maintained for about 30 minutes to react any residual methyl methacrylate. After the reactor cooled to room temperature, polymer pieces were taken out and air-dried at room temperature, preferably in a fume hood. The amounts of polymer obtained are shown in Table VI.
TABLE VI METHYL METHACRYLATE POYMERIZATION IN THE PRESENCE OF SYNTHETIC METHACRYLIC ACID DERIVED HYDROTALCITE Methacrylic Acid- Reaction TGA Example Methyl Derived Reaction Time Polymer DSC ° C., percent No. Methacrylate g Hydrotalcite g temp. ° C. hours Produced g Maxima residue 39 364 30 72-84 4 341 122, 258 3.9 40 306 10 75-90 4 256 115, 372 1.6 41 264 30 75-85 4 229 114, 374 7.5
[0104] Co-polymerizing the synthetic hydrotalcite derived from methacrylic acid with methyl methacrylate demonstrates that master-batch materials may be prepared. Blends with poly-addition polymers, such as polypropylene, can then be prepared from these master batches. With the Aerosol OT surfactant, the copolymer was expected to be evenly slurried in the water in which the reaction was carried out. In all the examples, slurry formation occurred only at the beginning of the polymerization. As the polymer amount increased, the suspended particles coalesced into a ball or into chunks that forced the early termination of the polymerization because of difficulty with stirring. The product obtained was a tan, tough and stiff polymer.
[0105] TGA analyses of the products, as seen in Table VI, indicated varying levels of the methyl methacrylic acid-derived hydrotalcite (1.6% to 8%) based on the residue percentage. This percentage is indicative of the amount of alumina and magnesium left after all the carbon sources in the samples have been volatilized. The examples with highest starting weight percent of hydrotalcite yielded the highest residue percentage. The first DSC transition temperatures (114′-122° C.) were only small diffuse peaks and may not be indicative of the real polymer transition temperature. The second transition at 370° C. was likely due to the phase changes in the copolymer, this may indicate the need for higher processing temperatures in polymer applications. These polymers dissolved or formed a clear gel in toluene, ethyl acetate, and, to a limited extent, in methylene chloride. The copolymer with the least amount of synthetic methacrylic acid-derived hydrotalcite (1.6% residue by TGA) was the most soluble in toluene. When the solution containing this copolymer was dried, a clear film with good adhesive characteristics was obtained.
EXAMPLE 42
Compounding of Amino Acid Intercalated Hydrotalcite with Maleated Polypropylene
[0106] Amino acid intercalated synthetic hydrotalcites according to the current invention are particularly useful for preparing inorganic polymer blends according to the current invention. In a preferred embodiment, the amino acid intercalated synthetic hydrotalcite is capable of self exfoliation when introduced into a solvent. Preferably, according to this embodiment, the amino acid intercalated synthetic hydrotalcite is maintained as a slurry, suspension or paste when it is isolated from the synthesis. In this embodiment, the amino acid intercalated hydrotalcite is isolated from the synthesis and is maintained in an exfoliated state. Alternatively, the amino acid intercalated synthetic hydrotalcite is dried after isolation and may be subsequently added to a solvent to induce self exfoliation. In either embodiment, the hydrotalcite is added to the molten polymer as a slurry, suspension or paste. Because the amino acid intercalated synthetic hydrotalcite is capable of self-exfoliation it can be more easily dispersed in a polymer blend without the use of a compatiblizer. Although a compatiblizer is not required, amino acid intercalated synthetic hydrotalcites according to this embodiment of the invention can be used with compatiblizer molecules.
[0107] In one embodiment, the amino acid intercalated synthetic hydrotalcite is compounded with a modified poly-addition polymer. Preferably, the modified poly-addition polymer is an acid modified polyolefin, such as maleated polypropylene. The hydrotalcite may be compounded with either the acid modified polymer alone or with a mixture of modified and unmodified polymers. According to one preferred embodiment, the amino acid intercalated synthetic hydrotalcite is compounded with a molten acid modified polyolefin, such as maleated polypropylene, to produce a “master batch” of amino acid intercalated synthetic hydrotalcite and acid modified polyolefin. This “master batch” may then be compounded with unmodified poly-addition polymers to produce a final nanocomposite.
[0108] While not wishing to be bound by theory, it is believed that the amine function of the amino acid intercalated hydrotalcite reacts with the acid moiety in the modified polyolefin to produce an amide or imide. In this way, the hydrotalcite is actually bound to the polymer, improving the dispersion of the hydrotalcite in the nanocomposite.
[0109] 10 g of UNITE 1000® maleated polypropylene was added to 166.7 g of nominally 6 wt % (10.0 g) 6-aminocaproic acid-based hydrotalcite slurry in a 600 ml metal beaker in a heating jacket. Mixing was performed using a high speed (8000 rpm max) Gifford-Wood homo-mixer plugged into a variable transformer to allow adjustments to the mixing speed. The mixture was then heated while being stirred. Mixing/heating were continued until the mixture thickened into a thick, pasty material. This material was then removed from the beaker and allowed to air dry. A portion of this air-dried material was ground for XRD analysis.
[0110] XRD was performed on a ground sample of UNITE 1000® and the 50/50 UNITE/hydrotalcite mixed material, as well as on wet and air-dried hydrotalcite from a batch of hydrotalcite prepared in an 8 wt % slurry. The 6 wt % slurry is not viscous enough to perform XRD on in the wet state, so an 8 wt % preparation was used for this comparison. The 6 wt % and 8 wt % hydrotalcite slurries were prepared in the same manner, so no real difference would be expected between the two.
[0111] FIG. 11 shows from bottom to top XRD scans of an 8 wt % slurry of the hydrotalcite wet; an air-dried sample of hydrotalcite from an 8 wt % slurry; a sample of UNITE 1000®; and a sample of the 50/50 UNITE/hydrotalcite mix. Looking at FIG. 11 , the region of interest in each scan is at approximately 6°. The scan for the air dried sample of the hydrotalcite (second from bottom) shows a strong basal peak in this region, indicative of the un-exfoliated state. The absence of this peak in the scan for the 8 wt % slurry (bottom) is indicative of the hydrotalcite being in the exfoliated state. Referring to the scan for the 50/50 UNITE/hydrotalcite mix (top), it can be seen that the basal peak is completely absent. The small peak that does appear is due to the UNITE 1000® resin.
[0112] For comparison, FIG. 12 shows the evolution of the hydrotalcite structure from heating. FIG. 12 shows from bottom to top XRD scans of a 10 wt % slurry of the hydrotalcite wet; an air-dried sample of hydrotalcite from an 10 wt % slurry; a sample of the 10 wt % slurry dried at 100° C. and a sample of the 10 wt % slurry dried at 150° C. In the air dried sample (second from bottom), the peaks due to 6-aminocaproic acid appear in the region of about 12° to about 37°. Looking at the scans for the samples dried at 100° C. and 150° C. (second from top and top respectively) it can be seen that the peaks due to 6-aminocaproic acid eventually disappear with increasing heat treatment, leaving only peaks for the hydrotalcite structure (brucite layers+interlayer spacings) behind. Notably, the basal peak at approximately 6° continues to sharpen with increased heating until the hydrotalcite structure is destroyed.
[0113] Referring back to FIG. 11 it can be seen in the scan for the 50/50 UNITE/hydrotalcite mix (top), that the peaks indicative of 6-aminocaproic acid are still present. This indicates that the structure of the hydrotalcite was not destroyed in the preparation of the 50/50 mix. Further, the absence of the strong basal peak at approximately 6° indicates that the hydrotalcite is completely exfoliated. If the 50/50 UNITE/hydrotalcite mix was simply physical mixture of the polymer and un-exfoliated hydrotalcite the peak at approximately 6° would still be present. Thus, the 50/50 UNITE/hydrotalcite mix is a true nanocomposite.
[0114] The foregoing illustrations of embodiments of the present invention are offered for the purposes of illustration and not limitation. It will be readily apparent to those skilled in the art that the embodiments described herein may be modified or revised in various ways without departing from the spirit and scope of the invention. The scope of the invention is to be measured by the appended claims.
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Synthetic hydrotalcites of the general formula
[M 2+ 1-x M 3+ x (OH) 2 ] x+ [A n− x/n .m H 2 O] x−
where M 2+ is a divalent cation, M 3+ is a trivalent cation and A n− is an organic anion selected from straight chain carboxylates of C 16 -C 18 acids, carboxylates of aromatic acids, carboxylates of acrylic acid, unsaturated carboxylates of methacrylic acid, unsaturated carboxylates of vinylacetic acid and C 2 and higher organic acids containing heteroatoms such as nitrogen, phosphorous, sulfur and halogens are disclosed, along with methods of synthesis and uses.
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FIELD OF THE INVENTION
[0001] The present invention is generally related to a bumping process and bump structure, and more particularly, to a planarized bump structure and a bumping process therefor.
BACKGROUND OF THE INVENTION
[0002] Wire bonding, tape automated bonding (TAB) and flip chip bonding are popular packages for integrated circuits (ICs). Generally, wire bonding is used in low-density package with less than 300 inputs/outputs (I/Os). In high-density packages, up to 600 I/Os may be provided by TAB, and flip chip package provides much higher package density with more than 600 I/Os. In flip chip package, it is required to form bumps on the pads of the integrated circuit for the pressing process in chip-on-glass (COG), chip-on-board (COB), chip-on-film (COF), or other package processes. In order to reduce electrical noises and to increase adhesion and conductivity, gold is typically used for the bump material, which makes the bumping process expensive and difficult. Therefore, improving the bump structure and bumping process becomes an important issue. On the other hand, the density and performance of a package limit the size and performance of a chip. As the size of IC shrinks, the IC package becomes the bottleneck to further shrink the IC, if the density and performance of the package are not enhanced, for example the size and pitch of the bumps are limited or the conductivity of the bumps are not good enough.
[0003] FIG. 1 shows a conventional gold bump structure 10 , in which on a substrate 12 a pad 14 is partially covered by a passivation layer 16 , an under bump metallization (UBM) 18 is formed on the exposed surface of the pad 14 and the peripheral passivation layer 16 , and a gold film 20 and bump 22 are formed on the UBM 18 . Typically, the material of the pad 14 is aluminum, the passivation layer 16 comprises a layer of silicon dioxide 24 and a layer of silicon nitride 26 , and the UBM 18 is a stacked layer of titanium and tungsten. The gold film 20 is sputtered and has denser crystalline, to increase the adhesion between the gold bump 22 and UBM 18 . The gold bump 22 grows by electro-plating from the gold film 20 and has larger crystalline and higher hardness. Since the passivation layer 16 always has step 28 at the peripheral of the pad 14 , the upper surface of the bump 22 will have step 30 at its edge and therefore, only the central concave region 32 becomes an effective region during the pressing process. The roughness h of the upper surface of the bump 22 is about 2 μm. If a larger effective region 32 is required, the pad 14 has to be larger. However, if only the width of the bump 22 is increased, as shown in FIG. 2 , the effective region 32 will remain nearly the same because the increased region 34 on the upper surface of the bump 22 is useless due to the uneven upper surface of the bump 22 . FIG. 3 shows several bumps 22 on the substrate 12 , where the width of the pad 14 is w 1 , the bump gap is g, and the bump pitch is p. The width w 2 of the bump 22 is no greater than the width w 1 of the pad 14 , so the effective region 32 is small compared to the pad 14 . To increase the effective region 32 , it is required to have a larger pad 14 . However, the contact density of the chip is thus lowered and the chip size cannot be minimized. In addition, a larger pad 14 will result in a larger bump pitch p. If the bump gap g remains constant, the only way to obtain an increase in the contact density of the chip is to shrink the pad 14 . But shrinking the pad 14 causes the minimization of the effective region 32 . There's difficulty to solve this problem using conventional techniques.
[0004] A conventional bumping process is shown in FIGS. 4A to 4 E. In FIG. 4A , a passivation layer 16 with a thickness of 1.2 μm is deposited to cover pads 14 on a substrate 12 . In FIG. 4B , the passivation layer 16 is etched to form openings 36 to expose the pads 14 , and after this step, the passivation layer 16 will have steps 38 at the peripherals of the pads 14 . In particular, the thicker the passivation layer 16 is, the higher the steps 38 are and the deeper the openings 36 are. In FIG. 4C , Ti/W stack with a deposition thickness of 800 Å is used as UBM 18 , and a gold film 20 with a thickness of 800 Å is deposited thereon. In this step, due to the step 38 , step 40 formed thereon is even wider. The thicker the UBM 18 is, the narrower the concavity 42 is. FIG. 4D shows the structure after the UBM 18 and gold film 20 are patterned. In FIG. 4E , gold bumps 22 are grown up from the gold film 20 and have a thickness of about 17 μm. It is therefore shown by this process that the steps 38 are inevitable. As a result, effective regions 32 always have small areas. The thicker the UBM 18 is, the smaller the effective region 32 is. Moreover, the thicker the passivation layer 16 is, the greater the roughness h is. Even though the semiconductor process is capable to minimize the chip size, the backend package does not catch up with the IC shrinkage and thus limits the minimized size of the chip.
[0005] Further, a conventional bump structure has drawbacks during the pressing process. Referring to a COG structure 44 shown in FIG. 5 , while pressing the bump 22 to a wire 48 on a glass substrate 46 , an anisotropic conductive film (ACF) 50 is used therebetween as an interface. The ACF 50 is a polyimide (PI) with conductive particles thereof, and the conductive particles will form a conductive path in the pressing direction between the bump 22 and wire 48 during the pressing process. Since the surface roughness of the bump 22 is about 2 μm, the diameter of the conductive particles 52 within the ACF 50 has to be larger than 3 μm to construct an excellent conduction between the bump 22 and wire 48 . However, if the conductive particles 52 are larger, then there will be fewer of them to be trapped in the effective region 32 , and thus there's greater contact impedance and poor conduction quality after the pressing process. On the other hand, the conductive particles 56 with larger diameter inside the bump gap 34 will easily cause short or leakage between neighboring bumps 22 , and thus lower the yield of the pressing process. If small conductive particles 52 are used, excellent connection between the bump 22 and wire 48 cannot be reached. Therefore, there's unbeatable difficulty in conventional technology. To satisfy the requirement of smaller size and higher I/O count of an IC chip, the pad 14 on the chip is required to be shrunk, and the effective region 32 is thus minimized, which causes the drop of the yield of the pressing process and conduction quality of the product. Furthermore, an elemental drawback of flip chip package is the weak mechanical strength at the peripheral region 58 of the bump 22 , and damage happens easily due to lateral force. However, to obtain a smaller roughness h at the pressing surface of the bump 22 will have the step 28 to decrease, and a thinner passivation layer 16 could not overcome the drawbacks in weak mechanical strength.
[0006] Therefore, it is desired an improved bumping process and bump structure.
SUMMARY OF THE INVENTION
[0007] An object of the present invention is to provide a structure and process for a planarized bump to overcome the drawbacks of conventional art.
[0008] In a bumping process, according to the present invention, it is formed a passivation layer with a planarized surface to cover a pad on a substrate, the passivation layer is etched to form a hole penetrating therethrough to expose a contact surface of the pad, and a bump is formed on the contact surface and the planarized surface.
[0009] In a bump structure, according to the present invention, a passivation layer covering a portion of a pad on a substrate has a planarized surface, the pad has a contact surface, and a bump contacts the contact surface and the planarized surface.
[0010] Preferably, the passivation layer comprises several layers with different hardness in stack.
[0011] Preferably, the contact surface has a shape of stripe.
[0012] Since the passivation layer has the planarized surface to provide for larger effective region, the pad could be minimized, and the mechanical strength at the peripheral of the pad could be enhanced by increasing the thickness of the passivation layer. During the pressing process, since the bump has a larger effective area, there will be greater selection flexibility for the anisotropic conductive film, and the probabilities of short circuit and current leakage are reduced, thereby improving the yield of the pressing process and the conductive quality for the pad.
BRIEF DESCRIPTION OF DRAWINGS
[0013] These and other objects, features and advantages of the present invention will become apparent to those skilled in the art upon consideration of the following description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings, in which:
[0014] FIG. 1 is a cross-sectional view of a conventional gold bump structure;
[0015] FIG. 2 shows an enlarged conventional gold bump structure;
[0016] FIG. 3 is a schematic diagram of several conventional gold bumps on a substrate;
[0017] FIGS. 4A to 4 E show a conventional bumping process;
[0018] FIG. 5 is a schematic diagram of a conventional COG structure;
[0019] FIGS. 6A and 6B are two cross-sectional views of a gold bump structure according to the present invention;
[0020] FIGS. 7A and 7B are two top views of a gold bump according to the present invention;
[0021] FIGS. 8A to 8 G show a first bumping process according to the present invention;
[0022] FIGS. 9A to 9 D show a second bumping process according to the present invention;
[0023] FIG. 10 is a schematic diagram of a COG structure according to the present invention; and
[0024] FIG. 11 is a schematic diagram of a gold bump with a thicker passivation layer.
DETAILED DESCRIPTION OF THE INVENTION
[0025] FIGS. 6A and 6B show a gold bump structure 60 according to the present invention, and FIGS. 7A and 7B show the top views, in which FIG. 6A is a cross-sectional view along the X direction and FIG. 6B is a cross-sectional view along the Y direction. Referring to FIGS. 6A and 6B , in the gold bump structure 60 , a passivation layer 64 has a planarized surface and covers a portion of each pad 62 on a substrate 12 , a UBM 18 and a gold film 20 are stacked on the pad 62 and passivation layer 64 , and a gold bump 66 is on the gold film 20 . The pad 62 is made of aluminum, aluminum alloy, or other metal or highly conductive alloy, and the passivation layer 64 comprises one or more layers of silicon dioxide, silicon oxide, silicon nitride, silicon oxy nitride, or other superior chemical resistive materials or their combination to protect the circuits within the substrate 12 . The UBM 18 is used mainly to protect the pad 62 from being penetrated by any chemical particles during the following processes to affect the electrical characteristics of the product, and at the same time to improve the adhesion between the gold film 20 and pad 62 . In one embodiment, the pad 62 is made of aluminum, and the UBM 18 comprises titanium (Ti) and tungsten (W) layers in the manner that the titanium layer is at the bottom to have good adhesion with the aluminum pad 62 and the tungsten layer is at the top to have good adhesion with the gold film 20 . As shown in FIG. 6A , the pad 52 has a width w 1 x in the X direction that is much smaller than a conventional pad, and the width w 2 x of the bump 66 in the X direction is also smaller such that the bump pitch p can be minimized. However, in the Y direction, as shown in FIG. 6B , though the width w 1 y of the pad 62 is also smaller than a conventional pad, the width w 2 y of the bump 66 is much larger than the width w 1 y of the pad 62 . Due to the smaller pad 62 , the concave region 68 at the center of the top surface of the bump 66 is minimized. If the UBM 18 is thicker, the concave region 68 may be completely eliminated. Since the passivation layer 64 has a planarized surface, a planarized region 70 occupies most of the top surface of the bump 66 and can be used as the effective region for pressing. Being different from the conventional bump structure 10 , the effective region of the bump 66 is at the peripheral of the top surface rather the center; in other words, it is mainly at the region above the passivation layer 64 .
[0026] FIG. 7A further illustrates the relation between the bump 66 and pad 62 . For comparison, the conventional bump 22 and pad 14 are also shown at the right side of FIG. 7A . In the conventional bump structure 10 , the pad 14 is larger than the bump 22 , and thus, in order to have enough effective region on the bump 22 , the pad 14 cannot be shrunk. While in the bump structure 60 according to the present invention, the bump 66 is larger than the pad 62 , and therefore the pad 62 can be minimized. In the bump structure 60 , the exposed contact surface 72 on the pad 62 for coupling to the bump 66 has a stripe shape. In the conventional bump structure 10 , the exposed contact surface 74 on the pad 14 for coupling to the bump 22 has almost the same width in both the X and Y directions. FIG. 7B shows the high-density bump 66 on the substrate 12 . The bump 66 has a stripe shape extending in the Y direction. In the X direction, since the pad 62 can be minimized, the bump 66 can be more tightly arranged. If more planarized region 70 on the bump 62 is desired, it can be achieved by increasing the width w 1 y in the Y direction. Since the pad 62 can be minimized, more bumps 66 can be arranged on an IC of the same size to increase the I/O density and pin count.
[0027] FIGS. 8A to 8 G show a bumping process according to the present invention. In FIG. 8A , film 76 such as silicon dioxide or silicon oxide is deposited with thickness of 1000 to 1200 Å to cover pads 62 on a substrate 12 , and etching back process such as chemical mechanical polishing (CMP) is used to etch the film 76 to leave a thickness of 600 to 800 Å, which results in a planarized surface 78 as shown in FIG. 8B . In FIG. 8C , film 80 such as silicon nitride or silicon oxy nitride is deposited with a thickness of 300 to 500 Å on the films 76 . Since the film 76 has a planarized surface 78 , the film 80 also has a planarized surface 82 . The films 76 and 80 serve as the passivation layer 64 in FIG. 6A , and preferably, the film 80 is harder than the film 76 . The softer film 76 is used to protect the substrate 12 and the surface of the pad 62 , and the harder film 80 is used against force. As shown in FIG. 8D , the films 80 and 76 are etched to form an opening 84 that penetrates through the films 80 and 76 from the planarized surface 82 to the top surface of the pad 62 , to expose a contact surface 72 on the pad 62 . In FIG. 8E , a UBM 18 with a thickness of 800 Å is deposited on the contact surface 72 on the pad 62 and the planarized surface 82 of the film 80 by sputtering titanium and tungsten for example. A gold film 20 is deposited on the UBM 18 thereafter by sputtering. As shown in FIG. 8F , the gold film 20 and UBM 18 are patterned to define the bumps, and in FIG. 8G , a gold bump 66 is grown up from the gold film 20 for 15 to 20 μm by electro-plating. Since the passivation layer 76 and 80 has planarized surface, the central concavity 68 on the top surface of the bump 66 is very small or even none, and most of the top surface of the bump 66 is a planarized region 70 .
[0028] FIGS. 9A to 9 D show another bumping process according to the present invention. In FIG. 9A , deposited films 76 and 80 cover pads 62 on a substrate 12 , in which the film 80 is preferably harder than the film 76 . The softer film 76 is used to protect the surfaces of the substrate 12 and pad 62 , and the harder film 80 is used against force. For example, the film 76 comprises silicon dioxide or silicon oxide with a thickness of 200 to 800 Å, and the film 80 comprises silicon nitride or silicon oxy nitride with a thickness of 300 to 500 Å. In FIG. 9B , the films 76 and 80 are etched back by for example CMP, to leave them a total thickness of about 600 to 1000 Å, which results in a planarized surface 86 . In FIG. 9C , an opening 84 is formed to expose a contact surface 72 on the pad 62 . In FIG. 9D , sputtering is used for example to deposit titanium and tungsten to a thickness of 800 Å as a UBM 18 on the contact surface 72 and planarized surface 86 , a gold film 20 is deposited by sputtering to a thickness of 800 Å on the UBM 18 , the gold film 20 and UBM 18 are patterned to define the bumps, a gold bump 66 is grown up by electro-plating from the gold film 20 to a thickness of 15 to 20 μm. Since the planarized surface 86 is formed in previous step, the central concavity 68 on the top surface of the bump 66 is very small or even none, and most of the top surface of the bump 66 is a planarized region 70 .
[0029] In the bumping process according to the present invention, since the passivation layer 64 with a planarized surface is used, on the planarized surface the UBM 18 has an area much larger than that on the contact surface 72 to obtain a maximized effective region 70 . Thus the pad 62 is minimized.
[0030] FIG. 10 shows a structure 88 where the bump 66 is pressed to a wire 48 on a glass substrate 46 . Being different from the conventional COG structure 44 , the pressing effective region provided by the bump 66 is the planarized region 70 . Since there's no problem about surface roughness thereof, it will have more flexibility in selecting the diameter of the conductive particles 92 in the ACF 90 , for example 1 to 5 μm. Even though smaller conductive particles 92 are used, excellent conductivity can be still obtained. Since the effective region is the planarized region 70 that has larger area, the effective region 70 is capable to trap more conductive particles 92 . If the conductive particles 92 have smaller diameter, the trapped amount of them is even higher and the conductive quality is much better. On the other hand, if the conductive particles 92 have smaller diameter, it is less possible for the conductive particles 92 within the bump gap 94 to cause short circuit or current leakage during the pressing process. Moreover, since the passivation layer 64 with a planarized surface is used, the mechanical strength at the peripheral 96 of the bump 66 is improved and damage will not easily happen thereto. In the bump structure 60 , since it is used the passivation layer 64 with a planarized surface, the thickness of the passivation layer 64 is not limited. FIG. 11 shows an embodiment when a thicker passivation layer 64 is used. The passivation layer 64 comprises films 76 , 80 and 98 , in which the films 76 and 98 are silicon dioxide or silicon oxide, and the film 80 is silicon nitride or silicon oxy nitride. The total thickness of films 76 , 80 and 98 is up to more than 1.2 μm and thus increases the mechanical strength of the corresponding structure.
[0031] While the present invention has been described in conjunction with preferred embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and scope thereof as set forth in the appended claims.
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A bumping process comprises forming a passivation layer having a planarized surface covering a pad on a substrate, forming a hole penetrating through the passivation layer to expose a contact surface of the pad, and forming a bump on the contact surface and planarized surface. The planarized surface will provide a larger effective area for pressing, thereby minimizing the pad, enhancing the mechanical strength at the peripheral of the pad, providing more selection flexibility for anisotropic conductive film, reducing the possibilities of short circuit and current leakage within the bump gap, and increasing the yield of the pressing process and the conductive quality of the bump.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to and the benefit of U.S. Provisional Application No. 61/305,906 filed on Feb. 18, 2010 in the U.S. Patent and Trademark Office, the entire content of which is incorporated herein by reference.
BACKGROUND
[0002] 1. Field
[0003] Embodiments of the present invention relate to a rechargeable battery, more particularly, to a rechargeable battery with an improved vent member.
[0004] 2. Description of the Related Technology
[0005] A rechargeable battery is a battery that is chargeable and dischargeable, unlike primary batteries that cannot be recharged. A low-capacity rechargeable battery is typically been used for small portable electronic devices, such as mobile phones, laptop computers, and camcorders, and a large-capacity rechargeable battery is typically used as a power supply for driving motors, such as in hybrid vehicles, etc., or a large-capacity power storage device.
[0006] Recently, high output rechargeable batteries using non-aqueous electrolytes with high energy density have been developed and such high power rechargeable batteries are configured of large-capacity battery modules by connecting a plurality of rechargeable batteries in series so that they can be used, for example, to drive motors for electric vehicles, etc. The rechargeable battery may be formed of a cylindrical type, a square type, etc.
[0007] While the rechargeable battery repeats charging and discharging, gas can be generated in the rechargeable battery to increase the pressure therein. When the increase in pressure of the rechargeable battery is not handled properly, there is a risk that the rechargeable battery may explode.
[0008] The above information is only presented for enhancement of understanding of the background of the invention and may contain information that does not form the prior art.
SUMMARY
[0009] An embodiment of the present invention provides a rechargeable battery including: an electrode assembly; a battery case accommodating the electrode assembly; and a cap assembly comprising: a cap plate comprising a top portion and at least one opening; and a vent member comprising two or more notches and a supporting portion, wherein the vent member is configured to break at the two or more notches and bend along two or more lines adjacent to the supporting portion.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a cut perspective view showing a rechargeable battery according to a first embodiment of the present invention;
[0011] FIG. 2A is a perspective view showing a vent member of a rechargeable battery according to the first embodiment of the present invention;
[0012] FIG. 2B is a perspective view showing a state where a notch of a vent member shown in FIG. 2A is fractured and opened;
[0013] FIG. 2C is a plan view showing the relationship between a vent member and a cap plate of a rechargeable battery according to the first embodiment of the present invention;
[0014] FIG. 3 is a partial cross-sectional view of a rechargeable battery according to the first embodiment of the present invention;
[0015] FIG. 4 is a partial cross-sectional view showing a state where the notch of the vent member of FIG. 3 is fractured and opened;
[0016] FIG. 5A is a partial cross-sectional view showing a rechargeable battery according to the second exemplary embodiment of the present invention;
[0017] FIG. 5B is a partial cross-sectional view showing a state where the notch of the vent member of FIG. 5A is fractured and opened;
[0018] FIG. 6A is a perspective view showing a vent member of a rechargeable battery according to a third exemplary embodiment of the present invention;
[0019] FIG. 6B is a perspective view showing a state where the notch of the vent member shown in FIG. 6A is fractured and opened; and
[0020] FIG. 7 is a partial cross-sectional view showing a rechargeable battery according to the third exemplary embodiment of the present invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0021] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. Like reference numerals designate like elements in the specification and drawings.
[0022] FIG. 1 is a cut perspective view showing a rechargeable battery according to an embodiment of the present invention.
[0023] Referring to FIG. 1 , a rechargeable battery 100 according to an embodiment includes an electrode assembly 110 where an anode 112 and a cathode 113 are positioned, a separator 114 therebetween and a case 120 whose one end is opened so that it can receive the electrode assembly 110 with an electrolyte. The opening of the case 120 is installed with a cap assembly 140 that seals the case 120 .
[0024] In detail, case 120 may be made of a conductive metal, such as aluminum, aluminum alloy, or nickel-plated steel. A shape of the case 120 according to the present embodiment may be configured to be of a cylindrical type having an inner space in which the electrode assembly 110 is positioned. The cap assembly 140 may be inserted into the case 120 and then be clamped to fix the cap assembly 140 to the case 120 . In this process, the case 120 may be formed with a beading portion 123 and a clamping portion 125 .
[0025] The electrode assembly 110 according to the present embodiment may be configured of a cylindrical type wound like a vortex after the anode 112 , the separator 114 , and the cathode 113 are stacked, but the structure of the electrode assembly 110 is not necessarily limited thereto but can be formed to have a different structure. The anode 112 , the cathode 113 , and the separator 114 may be formed in a strip shape that is connected in one direction.
[0026] The anode 112 may include an anode active material layer that is formed on an anode current collector and both sides of the anode current collector and a cathode 113 may include a cathode current collector and a cathode active material layer that is formed on both sides of the cathode current collector. The separator 114 may be inserted between the anode 112 and the cathode 113 to insulate the anode 112 and the cathode 113 and to provide a passage through which ions move.
[0027] An upper end of the anode 112 may be formed with an anode non-coated portion 112 a on which the anode active material is not formed, and a lower end of the cathode 113 may be formed with a cathode non-coated portion 113 a on which the cathode active material layer is not formed. The present embodiment illustrates a case in which the anode non-coated portion 112 a and the cathode non-coated portion 113 a are formed on the upper end and the lower end of the electrode assembly 110 , respectively, but embodiments of the present invention are not limited thereto. The anode non-coated portion 112 a may be formed at one end of the anode 112 in the length direction and the cathode non-coated portion 113 a may be formed at the other end of the cathode 113 in the length direction.
[0028] The cap assembly 140 may include the cap plate 143 , a gasket 144 that is adjacently disposed to the case 120 and winds the vent member 160 installed below the cap plate 143 and the cap plate 143 , and a safety plate 141 disposed between the cap assembly 140 and the vent member 160 .
[0029] The cap plate 143 may be formed with an upwardly protruded protrusion 143 a and a penetrated exhaust port 143 b , and the vent member 160 may be formed with notches 161 and 163 fractured at the set pressure condition. A safety plate 141 that electrically connects the cap plate 143 and the vent member 160 may be installed between the cap plate 143 and the vent member 160 . The safety plate 141 may be configured of a positive temperature coefficient element and an element that increases the electric resistance approximately up to infinity when the positive temperature coefficient element exceeds a predetermined temperature. The safety plate 141 may perform a role of blocking the flow of charging and discharging current when the rechargeable battery 100 exceeds a temperature of the predetermined value.
[0030] The gasket 144 may be installed to the circumference of the cap plate 143 , the safety plate 141 , the vent member 160 and insulate the cap assembly 140 from the case 120 .
[0031] The anode 112 may be electrically connected to the vent member 160 via the anode current collecting tap 135 and the cathode 113 may be electrically connected to the bottom of the case 120 via the cathode current collecting tap 136 . The present embodiment illustrates the case in which the anode current collecting tap 135 is directly connected to the vent member 160 , but embodiments of the present invention are not limited thereto. The intermediate member of the vent member 160 may be installed such that the vent member 160 and the anode current collecting tap 135 may be connected via the intermediate member.
[0032] FIG. 2A is a perspective view showing the vent member according to the first illustrated embodiment of the present invention and FIG. 2B is a perspective view showing the state where the notch of the vent member shown in FIG. 2A is fractured and opened, and FIG. 2C is a plan view showing the relationship between the vent member and a cap plate of the rechargeable battery according to the first embodiment of the present invention.
[0033] Referring to FIGS. 2A , 2 B and 2 C, the vent member 160 according to the present illustrated embodiment is formed with the first notch 161 and the second notch 163 , and each of the notches 161 and 163 may be formed of a line segment having an arc shape. The present illustrated embodiment illustrates the case where the notches 161 and 163 are formed to have an arc shape but embodiments of the present invention are not limited thereto. The notch can be formed in various shapes, such as a triangle, a quadrangle, etc. The first notch 161 and the second notch 163 according to the present embodiment is formed of a semicircular type, and the first notch 161 and the second notch 163 are disposed to be spaced from each other. A supporting portion 165 may be formed between the bent lines 164 that connect both ends of each notch 161 and 163 . The supporting portion 165 may perform a role of separating an opening 162 where the notches 161 and 163 may be formed to be fractured. The first notch 161 and the second notch 163 may be symmetrical such that the supporting portion 165 is provided therebetween.
[0034] The notches 161 and 163 may be formed to be in a line that is convexly protruded toward the outside of the vent member 160 from the bent line 164 . A first fracture piece 167 that is bent and raised at the time of fracturing the first notch 161 may be positioned between the first notch 161 and the supporting portion 165 , and a second fracture piece 168 that is bent and raised at the time of fracturing the second notch 163 may be positioned between the second notch 163 and the supporting portion 165 .
[0035] The second notch may be formed of the same as the first notch and therefore, the description of the second notch will be described as the description of the first notch.
[0036] Referring to FIG. 2C , the supporting portion 165 is under the protrusion 143 a of the cap plate 143 and does not extend beyond the protrusion 143 a of the cap plate 143 . That is, when viewed in the plan view, the bent lines 164 and the supporting portion 165 are inside the protrusion 143 a.
[0037] If the bent lines 164 are not inside the protrusion 143 a , a portion of the supporting portion 165 positioned outside the protrusion 143 a blocks the passage to the exhaust port 143 b when the vent member 160 is opened. Since the bent lines 164 in the present embodiment are inside the protrusion 143 a , the supporting portion 165 does not block the passage to the exhaust port 143 b and the first and second fracture pieces 167 and 168 guide the gas discharged through the opening 162 to the exhaust port 143 b.
[0038] As shown in FIGS. 3 and 4 , when the maximum distance from the bent line 164 to the first notch 161 is referred to as a long width L 2 , the long width L 2 of the first notch 161 according to the present illustrated embodiment may be formed of the same distance as the distance L 3 from the bent line 164 to the upper end of the exhaust port 143 b that is formed in the cap plate 143 . Therefore, as shown in FIG. 4 , when the internal pressure of the rechargeable battery is raised to break the first notch 161 , the upper end of the first fracture piece 167 may contact the inside end of the exhaust port 143 b to sufficiently secure the passage through which gas moves. However, embodiments of the present invention are not limited thereto and the long width L 2 may be formed to be smaller than the distance L 3 from the bent line 164 to the upper end of the exhaust port 143 b.
[0039] In addition, since the notches 161 and 163 may be formed to have a predetermined space therebetween while positioning the supporting portion 165 therebetween, each notch 161 and 163 can be easily fractured without each of the notches 161 and 163 interfering with each other when being fractured, such that the opening 162 is formed at two places.
[0040] In addition, since the first notch 161 is convexly formed toward the outside of the vent member 160 with respect to the bent line 164 , when the first notch 161 is fractured such that the first fracture piece 167 is raised, the first fracture piece 167 is not positioned between the exhaust port 143 b and the opening 162 that is formed by the fracture of the first notch 161 and is positioned near the opening 162 and the exhaust port 143 b . In other words, in reference to the drawing, it can be appreciated that the lower end of the first fracture piece 167 may contact the inner side end of the opening 162 and the upper end of the first fracture piece 167 may also contact the inner side end of the exhaust port 143 b . At this time, the inner side may be inwardly positioned based on the center of the vent member 160 . Therefore, since gas discharged through the opening 162 can move the exhaust port 143 b using the guide of the first fracture piece 167 , gas can be discharged more rapidly. However, when the first notch 161 is positioned more inwardly than the bent line 164 and the exhaust port 143 b is spaced from the center of the cap plate 143 and is disposed in a circumferential direction, since the first fracture piece 167 is positioned between the opening 162 and the exhaust port 143 b , there may be a problem in that first fracture piece 167 prevents the progress of gas.
[0041] When the first notch 161 is determined by the rise of internal pressure, the first fracture piece 167 may be bent at an inclined angle of 30° to 90° with respect to the supporting portion 165 in the bent line 164 . When the bending inclination of the first fracture piece 167 is smaller than 30°, there may be a problem in that the gas inside the rechargeable battery cannot be discharged rapidly, and when the bending inclination of the first fracture piece 167 is larger than 90°, a vortex may be generated at an area adjacent to the upper end of the first fracture piece 167 such that the discharge speed of gas is deteriorated. In other words, when the bending inclination of the first fracture piece 167 is larger than 90°, a reflowing phenomenon can occur by the introduction of gas in a reverse direction than the direction that discharges gas. Therefore, the discharge of gas may be delayed due to the reflowing gas.
[0042] The discharge speed of gas is very important in terms of safety of the rechargeable battery, and when the discharge speed of gas is delayed, there may be a serious problem in that the rechargeable battery explodes according to the conditions. Since the discharge of gas can be performed within a short time in a sudden situation, safety can be improved only in the case where gas needs to be rapidly discharged in a short time.
[0043] An experiment in which the battery module that includes 10 rechargeable batteries exploded under a situation using fire was tested. In the rechargeable battery of a comparative example in which one notch having a large semicircle is formed, four batteries exploded and 6 batteries became inflamed, while in the rechargeable battery according to the present embodiment, all 10 rechargeable batteries became inflamed but they did not explode. Through the above experiment, even in the scene of a fire or an abnormal situation where the temperature was very high, it could be appreciated that the rechargeable battery according to the present embodiment did not explode. The reason appears to be that before the rechargeable battery was able to explode, the vent member 160 was rapidly opened, thereby making it possible to rapidly discharge the internal gas to the ambient.
[0044] FIG. 5A is a partial cross-sectional view showing a rechargeable battery according to a second embodiment of the present invention and FIG. 5B is a partial cross-sectional view showing a state where the notch of the vent member of FIG. 5A is fractured and opened. Referring to FIGS. 5A and 5B , the rechargeable battery according to the present embodiment is configured to have the same structure as the rechargeable battery of to the first described embodiment except for the structure of the vent member 170 , and thus, certain common descriptions thereof will not be repeated.
[0045] The vent member 170 may be formed with the first notch 171 and the second notch 172 having an arc type formed to be spaced, putting the supporting portion 175 therebetween, similar to the first described embodiment. The first notch 171 and the second notch 172 may be formed to be symmetrical with respect to the position of the supporting portion 175 , and the line segment that connects both ends of the first notch 171 , and the line segment that connects both ends of the second notch 172 , can become the bent line 174 . When the internal pressure of the rechargeable battery is raised, the first notch 171 may be fractured such that the first fracture piece 177 is bent and raised at the bent line 174 , and the second notch 172 may also be fractured such that the second fracture piece 178 is bent and raised at the bent line 174 .
[0046] The vent member 170 according to the present embodiment may be formed so that a long width L 4 , that is the maximum distance from the bent line 174 to the first notch, may be smaller than a distance L 5 from the bent line 174 to the inner side end of the exhaust port 143 b , and may be larger than a distance h 1 from the bent line 174 to the upper end of the cap plate 143 . Thereby, the upper ends of the fracture pieces 177 and 178 may be positioned between the inner side end of the exhaust port 143 b and the place just above the bent line 174 , such that gas discharged through the opening 173 can be rapidly guided to the exhaust port 143 b.
[0047] FIG. 6A is a perspective view showing a vent member of a rechargeable battery according to a third embodiment of the present invention and FIG. 6B is a perspective view showing a state where the notch of the vent member shown in FIG. 6A is fractured and opened.
[0048] Referring to FIGS. 6A and 6B , the rechargeable battery according to the present embodiment is configured to have the same structure as the rechargeable battery according to the first described embodiment, except for a vent member 180 and thus, certain common description thereof will not be repeated.
[0049] The vent member 180 may be formed with a first notch 181 and a second notch 182 , and a third notch 183 . The notches 181 , 182 , and 183 may be disposed along the circumferential direction of the vent member 180 in equidistance and may be formed in a curved line that is convexly curved toward the outside of the vent member 180 . A line segment that connects both ends of the notches 181 , 182 , and 183 may become a bent line 184 . The cap plate 143 may be formed with three exhaust ports 143 b and may be formed with three notches 181 , 182 , and 183 to correspond to the number of exhaust ports 143 b . At this time, the notches 181 , 182 , and 183 may be disposed at the corresponding positions below each exhaust port. When the notches 181 , 182 , and 183 are fractured due to the increase in the internal pressure of the battery, a first fracture piece 186 , a second fracture piece 187 , and a third fracture piece 188 may be bent and raised at the bent line 184 . A supporting portion 185 that supports the fracture pieces 186 , 187 , and 188 may be formed at the center of the vent member 180 among the notches 181 , 182 , and 183 .
[0050] When the fracture pieces 186 , 187 , and 188 are raised, since the vent member 180 is formed with an opening 189 , the opening may be positioned at the corresponding positions below the exhaust port. Thereby, gas discharged through each opening 189 can be rapidly discharged through the corresponding exhaust port 143 b.
[0051] Since the second notch 182 and the third notch 183 are configured to have the same structure as the first notch 181 according to an embodiment, the description of the second notch 182 and the third notch 183 will not be repeated since the description of the first notch 181 is described above.
[0052] A width L 6 that is the maximum distance from the bent line 184 to the first notch 181 may be formed to be smaller than the distance h 1 from the bent line 184 to the upper end of the cap plate 143 . Therefore, the fracture pieces 186 , 187 , and 188 can freely bend at any angle according to the fracture pressure but interfere with the adjacent fracture pieces 186 , 187 , and 188 , thereby making it possible to prevent the fracture piece 186 , 187 , and 188 from excessively bending.
[0053] While this invention has been described in connection with what is presently considered to be practical embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, 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 rechargeable battery according to an embodiment of the present invention includes: an electrode assembly; a battery case accommodating the electrode assembly; and a cap assembly comprising: a cap plate comprising a top portion and at least one opening; and a vent member comprising two or more notches and a supporting portion, wherein the vent member is configured to break at the two or more notches and bend along two or more lines adjacent to the supporting portion.
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BACKGROUND OF THE INVENTION
The present invention relates generally to a golf practice device and, more particularly, to an improved golf practice device designed to help golfers improve and maintain their driving skills by realistically reproducing for them the conditions of actual play in private areas, while measuring for them the distance and accuracy of their practice drives.
The game of golf has long been a popular sport in many countries, challenging golfers to acquire and maintain skills including good form and consistency. Practice has always been necessary for playing well, and a variety of teaching and practice aids have been available in the past, including driving ranges, plastic practice balls, and home practice devices. One known practice device has a rectangular metal base with a steel rod mounted thereon for horizontal pivoting. At its free end, the rod is formed in a loop and passes between two vertically spaced steel retainers which are bolted across the front of the base. A steel yoke and a rubber ring are formed to travel along the rod, the rubber ring going ahead of the yoke. Attached to the yoke is a nylon rope which passes through the loop on the rod and has a golf ball secured to its other end. A length of stretchy cord is positioned across the back of the base, and is bolted at its ends to the corners of the base. This cord passes through the yoke. Two lengths of the same stretchy cord are positioned across the front of the base, crossed through the loop of the rod and bolted to the corners of the base. An illustration of this device is set forth in FIG. 13.
The device just described is operated by spiking the base to the ground, placing the ball a distance behind the base and driving the ball over the base. When the ball reaches the end of the rope, it pulls the yoke and the ring along the arm, stretching the back cord. If the ball has travelled at an angle, the rod pivots toward the direction of flight against the resistance of the front and back cords. When the energy of the ball has been spent by the stretching of the cords, the back cord recoils, returning the yoke to its starting position on the rod. The rubber ring stays in the position to which it was pushed, and the arm remains pivoted off-center. Thus the distance and angle of the practice drive are respectively measured by the distance the ring has travelled and by the angle the arm has pivoted.
SUMMARY OF THE INVENTION
In a principal aspect, the present invention comprises an improved portable golf practice device for developing golf swings in private, relatively restricted areas under realistic conditions. The device includes a base and a pivotal arm mounted on the base at a pivot. A distance indicator is mounted on the arm and is slidable toward and away from the pivot. A yoke is mounted on the arm and is also slidable toward and away from the pivot. The yoke is mounted for engaging the distance indicator and pushing it away from the pivot. Attached to the yoke for biasing it toward the pivot is a spring which is coaxially aligned with the axis of the arm. A cord is attached to the yoke and a golf ball is attached to the cord. Distance markings are provided on the base. These markings convert the distance that the distance indicator travels when the ball is struck into the distance the ball would travel if it were not restrained by the device.
The present invention may also include an angle indicator member on the arm, an angle scale on the base, and a mechanism for locking or holding the arm, which includes cooperating elements on the angle indicator member and on the base. The locking mechanism locks the arm in a plurality of pivotal positions, and upon vertical movement releases to allow the arm to pivot.
It is thus an object of the present invention to provide an improved portable golf practice device which permits a golfer to improve his or her swing, by recording the distance and angle the ball would travel from each drive if the golfer's swing were made in actual play.
Another object of the present invention is to provide a golf practice device which accurately and consistently gauges the distance the ball would travel if unrestrained, and does so regardless of any hook, slice, pull or push.
A further object of the present invention is to provide a device which accurately and consistently measures angles, and does so without being affected by the distance to which the ball is driven.
Still further objects are to provide a device enjoyable to use because it includes a real ball which flies when struck, which is mechanically streamlined, which is inexpensive for the consumer, and which has a rugged construction for safety and durability.
These and other objects and advantages of the present invention will become apparent from the description of the preferred embodiment of the invention which follows.
BRIEF DESCRIPTION OF THE DRAWING
The following is a description of the preferred embodiment, which is described in connection with the accompanying drawing, wherein:
FIG. 1 is a perspective view of a preferred embodiment of the present invention shown with the ball placed behind the base on a tee ready to be struck;
FIG. 2 is a perspective view showing the ball in flight in front of the base with the cord pulled taut;
FIG. 3 is a close-up perspective view of the device as shown in FIG. 1;
FIG. 4 is a top plan view of the device shown in FIG. 1;
FIG. 5 is a vertical cross-sectional view taken along line 5--5 of FIG. 4;
FIG. 6 is a bottom plan view of the device shown in FIG. 1;
FIG. 7 is a partial horizontal cross-sectional view of the device taken along lines 7--7 of FIG. 5;
FIG. 8 is a partial vertical cross-sectional view taken along lines 8--8 of FIG. 7;
FIG. 9 is a partial vertical cross-sectional view taken along line 9--9 of FIG. 7;
FIG. 10 is a partial vertical cross-sectional view taken along line 10--10 of FIG. 7;
FIG. 11 is an enlarged partial vertical cross-sectional view taken from FIG. 5; and
FIG. 12 is a partial horizontal cross-sectional view taken along line 12 of FIG. 11.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawing, a preferred embodiment of the present invention is shown and generally designated as a golf practice device 20 in FIG. 1, and as noted above, is adapted to be utilized by golfers to practice their swings under realistic conditions and in private, somewhat restricted areas such as backyards or parks. Briefly, golf practice device 20 has components which include a body 22, a pivot pin 50, an indicator arm 60, a distance indicator 70, a yoke 80, a helical spring 90, an angle indicator 120, cord 101, and ball 105. When assembled, indicator arm 60 and helical spring 90 are pivotally secured to body 22 by pivot pin 50, distance indicator 70 and yoke 80 are slidably mounted on indicator arm 60, cord 101 is attached to yoke 80, ball 105 is attached to cord 101, and angle indicator 120 is mounted on indicator arm 60.
Referring now to the specific details of the components of device 20, body 22 is shown in detail in FIG. 3, and includes a relatively thin, substantially rectangular base 24, an integrally molded front wall 25, side walls 26 and 27, and rear wall 28. When body 22 is secured to the ground, walls 26, 27, and 28 are in direct contact with the ground, while front wall 25 is shorter than the others and defines an opening through which arm 60 passes. Base 24 has substantially flat upper and lower surfaces 30 and 32, as shown in FIGS. 4 and 6, and a plurality of apertures 34 spaced about its periphery. Each of these apertures extends through the base and is adapted so that a peg 36 shown in FIG. 3 may be driven into the ground through the aperture to secure body 22 in position for use.
Adjacent front wall 25 a slot for arm 60 is defined in base 24. The slot extends from adjacent side wall 26 to adjacent side wall 27, and is curved along arcs of circles having centers along the central longitudinal axis of post 40. Arm 60 thus may pivot freely from side to side in the slot. Front wall 25 of body 22 is also curved along an arc of a circle having its center along the central longitudinal axis of post 40, and has a plurality of rounded vertical ribs 44 spaced along at least a portion thereof, as shown in FIGS. 6 and 12. These ribs cooperate with a rib on angle indicator 120 (described below) to releasably lock indicator arm 60.
An upright post 40 is integrally molded as part of body 22 for the mounting of arm 60 and spring 90. Post 40 is disposed on body 22 so that its central longitudinal axis is equidistant from side wall 26 and side wall 27 and adjacent rear wall 28. Body 22 has a plurality of braces 38 integrally molded with post 40, which extend below lower surface 32 to a distance less than that of walls 26, 27, and 28. Braces 38 provide extra rigidity and strength to body 22.
Base 24 further includes distance markings 130 between post 40 and slot 42, and angle markings 132 adjacent front wall 25. Distance markings 130, marked in yards or meters, provide the golfer with the distance he would have driven an unrestrained ball if he had hit it just as he hit the ball which is attached to the device. Actually the distance markings measure the travel of distance indicator 70. But since the travel of distance indicator 70 is directly related to the distance spring 90 is stretched, which distance is directly related to the energy of the driven golf ball member 105, distance markings 130 also reflect the energy of golf ball member 105. Since the energy of an unrestrained ball determines the length of its flight, the travel of distance indicator 70 can be converted to the distance an unrestrained ball would travel if hit with the same energy as a golf ball member 105. Distance markings 130 are calibrated to make this conversion for the golfer. As for angle markings 132, they simply measure the turn of indicator arm 60 from a selected reference line.
Referring now to FIGS. 5 and 6, molded plastic pivot pin 50 is shown disposed within post 40 and having a generally cylindrical shank 51 and a cap 52. Pivot pin 50 secures arm 60 and spring 90 to base 20, as noted above. Shank 51 is adapted so that it fits snugly within upright post 40, and has at its end 53 a plurality of buttons 54 extending radially outward therefrom and a plurality of longitudinal channels 55 spaced between the buttons. Buttons 54 are adapted to extend beyond the inner wall of post 40 when the pivot pin is positioned in post 40, and channels 55 are adapted so that the end 53 of shank 51 may be squeezed to a diameter small enough to permit buttons 54 to pass through post 40 when pivot pin 50 is pressed into place.
Molded plastic indicator arm 60 adapted to be mounted for horizontal rotation on post 40 and held in position by pivot pin 50, is shown in FIG. 3. Specifically, indicator arm 60 has at one end 61 a substantially horizontal flat cylindrical collar 62 by which it is secured. Collar 62 has an inner diameter smaller than the outer diameter of post 40 and larger than the diameter of shank 51 of pivot pin 50. As shown in FIG. 4, indicator arm 60 also has a semi-cylindrical enclosure 63 for spring 90 adjacent collar 62, two horizontal opposed slide rails 64 for yoke 80 and distance indicator 70 adjacent enclosure 63, and a loop 65 for cord 101 at end 66. In the length of indicator arm 60 between slider rails 64 and loop 65, indicator arm 60 passes through slot 42 in body 22, as noted above, and extends beyond front wall 25 under base 24, as shown in FIG. 11. Loop 65 is a substantially vertical loop.
As shown in FIG. 7, molded plastic distance indicator 70 is adapted to fit between slide rails 64 of indicator arm 60, and has flanges 72 resting on slide rails 64. Distance indicator 70 is thus freely slidable along slide rails 64. Pointers 71, which extend outward, provide for easy reading of distance markings 130.
As shown in FIG. 8 and noted above, yoke 80 is also mounted on slide rails 64, by flanges 81. Channels 82 on the upper surface 83 thereof and vertical holes 84 receive cords 101, which are tied together under yoke 80. As shown in FIGS. 3 and 11, cords 101 are passed through loop 65 of indicator arm 60 and again tied. One of said cords 101 has a great length in comparison with the length of indicator arm 60, and as shown in FIGS. 1 and 2, golf ball member 105 is attached to its other end.
Referring now to FIGS. 9 and 10, helical spring 90, positioned within enclosure 63 of indicator arm 60, is shown. Yoke 80 has a vertical opening 87 and spring 90 has an end 91 adapted to fit in that vertical opening. Other end 92 of spring 90 is adapted to fit around shank 51 of pivot pin 50. Spring 90 thus is secured at end 92 to the base and biases yoke 80 toward post 40. Spring 90 is chosen to have a force constant suitable for the chosen length of slide rails 64 and cord 101. This is done because the length of slide rails 64 determines the range of distance within which distance indicator 70 can be pushed by the stretch of spring 90, and cord 101 determines the range of force which will be applied to spring 90, since the energy of golf ball member 105 when it pulls spring 90 depends on the distance it has travelled from the tee.
Angle indicator 120 is shown in FIG. 3 and is adapted to fit over loop 65 of arm 60. More specifically, angle indicator 120, as shown in FIGS. 11 and 12, has a generally rectangular body portion 121 and a pointer portion 122 which lies in a horizontal plane above base 24. A vertical mating rib 128 is integrally molded on the face 127 of body portion 122 which faces front wall 25. As stated above, ribs 44 and rib 128 cooperate to releasably lock arm 60. That is, rib 128 is engaged between two of ribs 44 when arm 60 is at rest. By lifting angle indicator 120, mating rib 128 can be disengaged from ribs 44 and thus arm 60 may pivot until angle indicator 120 is no longer lifted. Angle indicator 120 is held on arm 60 by cords 101, which pass through loop 65 of indicator arm 60 above angle indicator 120.
The improved golf practice device thus described may be easily and readily used by any golfer. First a circular area clear of objects which has a radius at least equal to the free length of the cord is chosen. Then the body 22 is secured to the ground by hammering pegs 36 into the ground through apertures 34. The indicator arm 60 is set at zero angle by lifting the arm to disengage mating rib 128 on angle indicator 120 from ribs 38 on body 22 and moving it to zero. Distance indicator 70 is slid along slide rails 64 to abut yoke 80, and ball 105 is placed directly behind the machine and teed up at a distance which leaves little slack in the cord. The golfer may then practice his or her swing by hitting ball 105 over the machine.
The ball is driven to the position shown in FIG. 2 where its flight is arrested. The ball pulls yoke 80 against the tension of spring 90, sliding distance indicator 70 along slide rails 64. The ball also pulls arm 60 up, disengaging the ribs, and moves it to the angle to which the ball is flying. Once the ball drops to the ground, along the path depicted by the dashed line in FIG. 2, the golfer may approach the base and read the distance and angle his or her drive would have gone if the ball were free flying. The ball may be retrieved by pulling on the cord and the golfer can then set the device for his or her next drive.
From the foregoing, it should be apparent to those having skill in the art that the improved golf practice device affords a novel and useful device by which a golfer may practice both tee and fairway shots. As noted above, all of the components of the improved golf practice device 20, except the pegs 36, the spring 90, the cord 101 and the ball 105, can be made from a plastic material of the type which can be readily molded. Polyethylene is one such material. Thus the improved device 20 may be relatively inexpensively manufactured because substantially all of its component parts can be of molded plastic construction. Not only does the use of such molded plastic components decrease the manufacturing costs, but it also greatly enhances the appearance of the device, thereby giving the device widespread customer appeal.
Finally, various modifications and changes can be made in the structure or design of my improved golf practice device 20 as described hereinabove. In other words, the improved golf practice device 10 disclosed herein may be embodied in other specific forms without departing from the spirit or central characteristics of my invention. Thus the preferred embodiment of my improved golf practice device 20 is to be considered in all respects as illustrative and not restrictive. The scope of my invention is indicated by the appended claims, rather than by the foregoing description. All changes which come within the meaning and range of equivalence of the claims are intended to be embraced therein.
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An improved portable golf practice device includes a base with a pivotably attached arm. A freely slidable distance indicator and a spring biased slidable yoke are mounted on the arm. The yoke is mounted for pushing the indicator away from the point at which the arm pivots on the base. A cord and ball are attached to the yoke. When the ball is struck, it pulls the yoke against the force of the spring which biases the yoke and causes the distance indicator to slide along the arm away from the pivot. A distance scale formed in the base indicates the distance the distance indicator travelled and thus indicates the distance the ball would travel if unattached. The device also includes an angle indicator member on the arm which cooperates with an angle scale on the base to indicate the direction of flight of the golf ball.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Priority is claimed with respect to application Ser. No. 100 07 268.2-26 filed in Germany on Feb. 17, 2000, the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The invention relates to a carding machine for the parallel arrangement of fibers by clothing guided along a carding track and having combing structures that engage in the fibers.
[0003] A carding machine of this type is used for the parallel alignment of fibers, in particular cotton fibers. The fibers are transported in bundles to a main carding cylinder in the shape of a cylindrical roller which is horizontally positioned. The fiber bundles are aligned in the circumferential direction of the main carding cylinder while positioned on the surface of the carding cylinder along the longitudinal length thereof.
[0004] Specifically, the fibers are transported in the circumferential direction on the main carding cylinder and engage in clothing fitted onto a carding track and guided over a cylinder arrangement. The clothing consists of individual flexible material strips with combing structures in the form of metal needles on the top.
[0005] The clothing extends in the longitudinal direction of the main carding cylinder, directly above its surface, so that the fibers are combed with these combing structures and are aligned in the circumferential direction of the main carding cylinder.
[0006] The clothing is fastened to respective flat bars guided along the carding track on the carding machine, wherein the dimensions of the flat bars are adapted to the dimensions of the clothing.
[0007] With known carding machines, the clothing rests on top of the flat bars. The flat bars are wider at the upper end and have a rectangular cross-sectional profile, wherein the clothing rests on the complete upper front of the profile. Parts made of sheet metal or the like are attached to the side walls of the flat bars for reinforcement. These parts project slightly over the upper edge of the profile with the clothing, as well as over the lower edge of the profile. The projecting ends of the sheet metal parts are bent through beading, so that they fit against the top and bottom side of the profiles and thus secure the respective clothing on a profile.
[0008] The individual clothing is subject to relatively high wear and thus must be exchanged within a predetermined time interval. The clothing is removed for replacement from the carding machine, along with the fixedly attached flat bars. Subsequently, the clothing assembly is mechanically treated in a machine shop or servicing station in order to separate the clothing secured with the beading on the flat bars from these flat bars. New clothing is then attached to the flat bars and secured in place through beading of the sheet metal parts affixed to the side.
[0009] The disadvantage of this type of arrangement is that the assembly for replacing the clothing is extremely involved. Particularly disadvantageous is the fact that changing the clothing requires corresponding mechanical tools, so that the replacement cannot be made at the location of the carding machine, but must be made in a machine shop or servicing station. Thus, the replacement of clothing not only requires considerable time for the assembly, but also results in a considerable expenditure due to transport time and transport costs.
SUMMARY OF THE INVENTION
[0010] It is an object of this invention to provide a carding machine of the aforementioned type in such a way that the replacement of clothing is made as simple as possible.
[0011] The above and other objects are accomplished according to the invention by the provision of an arrangement for a carding machine for parallel arrangement of fibers, including: a carding track; a plurality of flat bars arranged for being guided along the carding track; clothing positioned respectively on each flat bar, the clothing including clothing structure that engages in the fibers; and means for releaseably fastening the clothing to each flat bar.
[0012] The essential advantage of fastening the clothing in this way to the flat bars is that the clothing can be fastened and repeatedly released by using simple tools. The clothing can therefore be replaced easily and quickly at the location of the carding machine. It is particularly advantageous in this case that the fastening mechanism can be attached to the flat bars, and can be are reversibly detached or released so that the mechanism can be reused after the clothing has been replaced.
[0013] The clothing of one particularly advantageous embodiment of the invention is attached to a rigid base support, for example a sheet metal part.
[0014] The sheet metal part with attached clothing forms a stable structural unit that can be mounted flexibly and easily to a flat bar. In particular the flexible clothing is protected in that case against mechanical damage or being pulled out of shape. Furthermore, it is advantageous that the dimensionally stable structural unit, consisting of base support and clothing, can be positioned easily and safely on the flat bar, thus making it easier to attach to the flat bar.
[0015] According to one preferred embodiment, brackets are used as means for securing the clothing to a flat bar. In that case, the clothing with base support is positioned on the top front of the flat bar. The brackets are then fitted from the side onto the flat bar and the clothing that rests on top.
[0016] The fastening means for another advantageous embodiment are guides in the flat bars, into which the clothing secured on the base support can be inserted.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The invention is explained in the following with the aid of the accompanying drawings.
[0018] [0018]FIG. 1 is a schematic representation of an end view of a carding machine for the parallel arrangement of fibers.
[0019] [0019]FIG. 2 is an enlarged, detailed view of a portion of the carding machine according to FIG. 1, showing clothing attached to flat bars and engaged in fibers.
[0020] [0020]FIGS. 3 a and 3 b are schematic end views which show first and second exemplary embodiments, respectively, of a base support for the clothing.
[0021] [0021]FIG. 4 is a schematic end view of a first exemplary embodiment of the fastening mechanism for fastening clothing to a flat bar.
[0022] [0022]FIG. 5 is a schematic end view of a second exemplary embodiment of the fastening mechanism for fastening clothing to a flat bar.
DETAILED DESCRIPTION OF THE INVENTION
[0023] [0023]FIG. 1 shows an exemplary embodiment of a carding machine 1 for the parallel alignment of fibers 2 , in particular cotton fibers.
[0024] The carding machine 1 comprises a main carding cylinder 3 in the shape of a cylindrical roller, for which the longitudinal axis is positioned horizontally. The main carding cylinder 3 is positioned so as to rotate around a rotational axis that extends in the longitudinal direction and is made to rotate by means of non-depicted drives.
[0025] A carding track 4 that is driven by a system of rollers 5 adjoins the top of the surface of main carding cylinder 3 . The rollers 5 are arranged such that the carding track 4 is guided at a short distance from the surface, via an angular section of nearly 180°, wherein the carding track extends in the circumferential direction of the main carding cylinder 3 .
[0026] The fibers 2 are fed to the main carding cylinder 3 with the aid of an insertion device with insertion fitting or shoe 6 . The fibers 2 are guided as fiber bundles in the circumferential direction, while resting on the surface and in the longitudinal direction of the main carding cylinder 3 .
[0027] The sectional detail of carding machine 1 , shown in FIG. 2, shows that the fibers 2 are guided between the surface of the main carding cylinder 3 and the clothing 8 that is positioned on the fronts of flat bars 7 . The flat bars 7 are positioned on the carding machine.
[0028] The flat bars 7 are arranged as traveling flat assemblies on the carding track 4 , one after another and at a short distance to each other. The longitudinal axes of flat bars 7 extend in the longitudinal direction of the main carding cylinder 3 .
[0029] The dimensions for clothing 8 are approximately the same as for the flat bars 7 , and the clothing is composed of strip-type, elongated, web-like material layers 9 with comb structures 10 projecting from the top. The comb structures 10 are metal needle combs, which extend across nearly the complete surface of clothing 8 .
[0030] The comb structures 10 engage in the fibers 2 that are guided on the main carding cylinder 3 . As a result, the fibers are combed in the circumferential direction of the main carding cylinder 3 and are thus aligned parallel.
[0031] According to the invention, fastening means are provided for securing the clothing 8 to the flat bars 7 , which means are reversibly detachable. Thus, these means can preferably be fastened and released repeatedly from the flat bars with the aid of simple tools.
[0032] For this, the clothing 8 is not mounted directly on the flat bars 7 . Rather, the clothing 8 is secured on base supports 11 . A base support 11 with clothing 8 respectively forms a dimensionally stable structural unit, which can be positioned easily and precisely on a flat bar 7 .
[0033] [0033]FIGS. 3 a and 3 b show different embodiments for a base support 11 of this type, preferably consisting of sheet metal parts or thin metal profiles. In any case, the base support 11 is dimensionally stable and rigid, so that it can provide the flexible clothing 8 positioned thereon with a secure hold.
[0034] The exemplary embodiment shown in FIG. 3 a shows a base support 11 , for which the surface area is identical to the surface area of clothing 8 . The base support 11 in this case has a level surface upon which the clothing 8 rests.
[0035] The base support 11 shown in FIG. 3 b has a level surface, analog to the exemplary embodiment according to FIG. 3 a, on which the clothing 8 rests. In addition, the base support 11 is provided along its two longitudinal edges with edge strips 12 , which project from the top and secure the clothing 8 on the side. The height for edge strip 12 in this case is adjusted to the structural height of clothing 8 . The edge strips 12 preferably form one piece with the base body 11 a of base support 11 .
[0036] The clothing 8 is secured to the base support 11 , wherein the clothing 8 is preferably screwed on or glued to the base support.
[0037] The structural unit thus formed by securing the clothing 8 to the base support 11 is then releaseably fastened to the respective flat bar 7 .
[0038] In principal, the base support 11 can be attached to the flat bar 7 by screwing or gluing it to the top of the flat bar.
[0039] [0039]FIG. 4 shows fastening means for securing the clothing 8 with base support 11 to a flat bar 7 , thus making the assembly particularly easy, time-saving and cost-effective.
[0040] [0040]FIG. 4 shows that the flat bar 7 is provided at its upper end with a widening 7 a in the form of a rectangular cross-sectional profile, which is followed by the narrow back end 7 b of the flat bar 7 .
[0041] As a result, the flat bar 7 has two offsets 7 ′ a and 7 ′ b at the lower end of the profile, which are joined by two vertically extending side walls 7 ′ c and 7 ′ d and the level top 7 ′ e of the flat bar 7 .
[0042] For the assembly, the clothing 8 together with its base support 11 is placed on the top 7 ′ e of flat bar 7 , wherein the side walls 11 b and 11 c of base support 11 end flush with the side walls 7 ′ c and 7 ′ d of the profile for the flat bar 7 .
[0043] Brackets 13 that serve as means for fastening the flat bar 7 are snapped from the side onto the profiles. The brackets 13 consist of sheet metal parts or the like and have level support surfaces 13 a, which fit flush against the side walls 7 ′ c and 7 ′ d of the profile for flat bar 7 and the base support 11 resting thereon. A projection 14 projects from the supporting surface on the top and bottom side of each bracket 13 . The projection 14 on the top of bracket 13 rests against the top of base support 11 , or the top of projection 12 thereof, while the projection 14 on the underside of bracket 13 fits against the profile offset 7 ′ a, 7 ′ b of flat bar 7 . Thus, the brackets 13 secure the clothing 8 with base support 11 against being detached from the flat bar 7 . The brackets 13 can preferably be snapped without tools onto the base support 11 and the flat bar 7 and can also be released from these, without the brackets 13 being destroyed in the process.
[0044] The brackets 13 of one preferred embodiment are designed as rail-type elements, wherein each bracket 13 extends over the total length of flat bar 7 .
[0045] Alternatively, several individual brackets 13 can be arranged one after the other along the flat bar 7 .
[0046] [0046]FIG. 5 shows another embodiment of the means for securing the base support 11 with clothing 8 on the flat bar 7 . In this case, the fastening means consist of a guide in the flat bar 7 , wherein the guide preferably is designed as dovetail guide defining a groove 16 . The dovetail guide extends in the longitudinal direction of the flat bar 7 . The dovetail guide forms one piece together with the flat bar 7 and consists of two guide rails 15 , which respectively stop at a longitudinal edge on the top of flat bar 7 .
[0047] The heights of these guide rails 15 are adapted to the structural height of the base support 11 with clothing 8 positioned thereon.
[0048] In addition, the spacing between the guide rails 15 is adapted to the width of the base support 11 with clothing 8 positioned thereon, so that the base support 11 with clothing 8 fits tightly against the insides of the guide rails 15 .
[0049] The base support 11 with clothing 8 is inserted from the front or back end of flat bar 7 into the guide opening until the base support 11 with its total length rests on the top of flat bar 7 .
[0050] In order to secure the base support 11 on the flat bar 7 , threaded bores that are not depicted here can be provided in the side walls of guide rails 15 and the base support 11 . Screws for fastening the base support 11 to the guide rails 15 are inserted into these threaded bores.
[0051] Alternatively or in addition, the base support 11 with clothing 8 that is positioned in the guides, can be secured by closing off the end parts of the guides at the front and back end with a fastener that is not shown here. It is necessary in that case that the length of base support 11 matches exactly the length of flat bar 7 , so that the base support 11 fits tightly against the front and back end between the fasteners.
[0052] The fasteners can be plates, for example, onto which the front and back sides of the flat bar 7 are screwed. End caps or the like can also be provided alternatively as fasteners, which are attached to the flat bar 7 by snapping them in.
[0053] In a modification of the exemplary embodiment according to FIG. 5, the guides and the base body for flat bar 7 can also have a multi-part design.
[0054] For example, the base body for flat bar 7 can have a level top, on which the base support 11 with clothing 8 rests. The base support 11 again extends over the complete length of flat bar 7 . However, the top of flat bar 7 is wider than the width of the base support 11 . The edge strips that project over the clothing 8 contain bores for fastening.
[0055] Guide rails 15 are fitted onto these edge strips in order to secure the base support 11 . Screws extending through the fastening bores are used to secure the guide rails to the base body of flat bar 7 .
[0056] The invention has been described in detail with respect to preferred embodiments, and it will now be apparent from the foregoing to those skilled in the art, that changes and modifications may be made without departing from the invention in its broader aspects, and the invention, therefore, as defined in the appended claims, is intended to cover all such changes and modifications that fall within the true spirit of the invention.
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An arrangement for a carding machine for parallel arrangement of fibers, includes a carding track; a plurality of flat bars arranged for being guided along the carding track; clothing positioned respectively on each flat bar, the clothing including clothing structure that engages in the fibers; and a mechanism for releaseably fastening the clothing to each flat bar.
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The present invention relates to a rotor for an engine, in particular a rotor for a compressor of an aircraft engine or a gas turbine.
BACKGROUND
Rotors for compressors of gas turbines or aircraft engines are for the most part constructed in such a way that air is diverted at the compressor of the engine and is conducted preferably with low loss to the inside to a consumer, in particular for cooling. As the cooling air mass flow is conducted, considerable pressure losses occur as early as when the air is diverted from the compressor drum and conducted to the disk hub on which the compressor disks are mounted. Therefore, an air mass flow of the magnitude necessary for generating sufficient cooling of the turbine is not made possible.
As a rule, apertures or bore holes are provided on the outside of the rotor so that air from the compressor drum may reach the disk hub. For example, these apertures are provided on disk vanes or flanges of the disks. A radial mass flow of compressor air from the compressor drum may enter the rotor, in particular between the disks, via these apertures. Flow losses occur since conducting the air via a bore hole into a chamber formed between the disks causes a turbulence or a swirl in the flow. A system of a free vortex and Ekman layers develops after a flow through the aperture. These flow conditions cause a great pressure drop which makes it impossible to reach the required mass flow of (0.7% to 1.5%), for example.
In order to avoid this flow pattern and the resulting pressure losses, devices, which are supposed to conduct the radial flow, are used in some engines. For example, radially directed tubes are used which are also referred to as “giggle tubes.” Using these tubes, a rigid vortex which generates only a small pressure drop may be forcibly produced. Although the required flow rate for cooling may be achieved in this way, the approach of the related art has a number of disadvantages. On the one hand, mounting these tubes poses a problem. Moreover, the weight of the rotor is a disadvantage which is increased by these tubes and the mounting device. Finally, these tubes are subject to friction wear, the so-called fretting, and are exposed to vibrations.
SUMMARY OF THE INVENTION
Therefore, it is the object of the present invention to create a rotor in which a sufficient mass flow of air from the drum to the disk hub may be implemented and the further problems of the related art may be eliminated at the same time.
The present invention is based on the finding that the object may be achieved by separating the vortex, which occurs when air is conducted into the inside of the rotor, into multiple sub-vortexes.
The present invention provides a rotor for an engine, in particular an aircraft engine or a gas turbine, the rotor having at least two rotor disks connected to one another. The rotor is characterized in that an inlet aperture is provided for the entry of fluid from the area surrounding the rotor into a chamber in one rotor disk or between two adjacent rotor disks and at least one interrupting element having at least one fluid passage is situated in the chamber.
As defined in the present invention, an area surrounding the rotor is the area outside of a radius on which the outermost connection point between adjacent rotor disks is provided. In particular, this area represents the compressor drum in which the blades of the compressor disks run and which is surrounded by the compressor housing.
By providing an interrupting element which disturbs, i.e., interrupts the air flow, a vortex, which would form during entry through the inlet aperture without an interrupting element, cannot fully develop. The flow is changed by passing through the passage in the interrupting element. Two sub-vortexes occur when one single interrupting element is provided, one vortex forming downstream from the inlet aperture and one vortex forming downstream from the passage. This flow characteristic makes it possible to optimize the pressure drop and thus the air mass flow to the hub and further to the turbine.
In one specific embodiment, the rotor is designed in such a way that at least two adjacent chambers are formed by the at least one interrupting element which are connected to one another via the fluid passage.
Within the scope of this invention, a space is defined as a chamber whose dimension in the axial direction of the rotor is greater over at least part of the height of the space than the dimension of the inlet aperture and the outlet aperture.
This rotor design makes it possible that suitable flow patterns may form in the individual chambers and that overall a flow may be achieved which results in a very low pressure drop and along with it an optimum mass flow for cooling air.
If only one interrupting element is provided, only a low turbulence may develop in the flow in the first chamber due to the radial limitation by the interrupting element. The same is true for the second chamber which faces the hub of the rotor.
The rotor is made up of at least two rotor disks which are rigidly connected to one another via suitable connecting means. The connection may be established via screws or by welding, for example.
The rotor disks are preferably connected to one another in such a way that there is a gap between the individual rotor disks which form the rotor. In one specific embodiment, the at least one interrupting element is provided in this gap between two adjacent rotor disks, thereby forming two chambers in the gap. In contrast to the specific embodiment in which the at least one interrupting element is positioned in the rotor disk itself and thus forms the chambers in the disk, this specific embodiment has the advantage of simpler manufacturing. The disks do not have to be manufactured using a complex hollow casting method or subjected to a complex drilling process.
The interrupting element preferably represents a connecting element. This makes it possible to further enhance the rotor's stability. At least one connecting element is mandatory for producing a disk packet which is jointly supported. This connecting element represents a disk flange, for example. The inlet aperture may be provided in this connecting element. The connecting element lends itself to this since the wall thickness of the connecting elements, such as disk flanges, for example, is as a rule smaller than the wall thickness of the disk. Due to this fact, introducing a bore hole or another aperture into the connecting element is simpler than introducing a bore hole through the disk. The stability of the rotor packet may be further enhanced by designing the interrupting element as an additional connecting element. A passage may also be introduced into this additional connecting element in a simple manner.
Both the inlet aperture and the at least one passage are particularly preferably designed in such a way that they have a length which conducts the flow. This is achieved in particular by introducing the inlet apertures into components having a small wall thickness and thereby providing the required hydraulic conditions for generating at least two sub-vortexes with a low pressure drop.
The inlet aperture and the at least one passage are preferably positioned radially. This alignment ensures that the flow entering the outer chamber, for example, is able to exit again without extreme turbulences. The inlet aperture and the passage are particularly preferably aligned with each other. The outlet aperture of the second, inner chamber is formed by the gap between the adjacent disks at their inner radius. As a rule, the disks are reinforced at the inner radius. A taper of the inner chamber is thereby formed at its outlet via which the air exits from the chamber.
The interrupting element and the connecting element, in which the inlet aperture is provided, are preferably designed in one piece with one of the disks and represent in particular disk flanges or disk wings. This specific embodiment has the advantage that the manufacture of the disk packets may be simplified since a separate process of attaching the connecting element and the interrupting element to both adjacent disks may be omitted. In addition, the one-piece design improves the stability.
The interrupting element is provided in an area in which, due to the inlet aperture, a system of a free vortex and Ekman layers would develop. By interrupting the flow in this area, the flow pattern may be improved overall. A swirl, which is formed in the first chamber, has a certain vortex circumferential velocity which is reduced by passing through the passage. A pressure drop occurring due to an angular flow toward the passage is low compared to a pressure drop which occurs during further development of the vortex.
The rotor according to the present invention is preferably used in the high pressure compressor of the engine.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is explained in greater detail in the following with reference to the appended figures.
FIG. 1 shows a section of a rotor according to the related art in a schematic sectional view;
FIG. 2 shows a section of an additional rotor according to the related art in a schematic sectional view, and
FIG. 3 shows a section of a specific embodiment of a rotor according to the present invention.
The approaches and problems of the related art are explained in the following with reference to FIGS. 1 and 2 .
DETAILED DESCRIPTION
FIG. 1 shows a section of a rotor 10 . Depicted are two rotor disks 12 and 14 in whose bore hole there is a shaft 16 . Disks 12 and 14 have grooves on their outer circumference in which root 18 of a blade 20 is fixed. Blades 20 are compressor blades in the depicted embodiment. In the depicted specific embodiment, rotor disk 12 has disk flanges 22 which extend on a radius Ra in the axial direction from disk 12 . These disk flanges 22 , also referred to as disk wings, are provided at a distance to the outer circumference of disk 12 . This means that the disk flanges are provided on a radius Ra which is smaller than the radius on which the grooves for receiving blade roots 18 are provided. Disk flanges 22 are connected at their free ends to an additional rotor disk 14 . The connection is implemented via a screw construction 24 in the depicted embodiment.
A chamber 26 is formed by the sidewalls of disks 12 and 14 , shaft 16 and disk flange 22 . A bore hole 30 is provided in disk flange 22 as the inlet for air from compressor drum 28 in which blades 20 are situated. The outlet of chamber 26 is formed by the gap between both disks 12 and 14 in the area of shaft 16 .
Air, which enters chamber 26 via bore holes 30 , which act as inlet apertures, is going to form a system of a free vortex and Ekman layers as schematically indicated in the drawing by the rectangles. The ratio of radius Ra, on which disk flanges 22 are situated, to radius Ri on shaft 16 , on which the air is conveyed to the turbine, is relevant for the vortex formation. At given edge pressures P 1 in the compressor drum and P 2 on shaft 16 , the necessary mass flow is, as a rule, not achievable with the ratio Ra/Ri because of the great pressure drop in the vortex system.
FIG. 2 shows an alternative to the related art. The construction corresponds essentially to the one of rotor 10 in FIG. 1 . The same components are indicated using the same reference numerals as in FIG. 1 and their function is not explained again.
From bore hole 30 on disk flange 22 , a tube 32 , in the following also referred to as a giggle tube, extends into chamber 26 . End 34 of tube 32 , situated opposite bore hole 30 , is mounted on projections 36 on the sidewalls of rotor disks 12 and 14 . From end 34 of tube 32 , the air flow from compressor drum 28 , which has been conducted through tube 32 and forced into a rigid vortex, may be introduced into the area between rotor disks 12 and 14 . The air may be diverted from there and conveyed to a downstream low-pressure turbine (not shown) for cooling.
FIG. 3 shows a specific embodiment of a rotor according to the present invention. Here also, components which correspond to those in FIGS. 1 and 2 are indicated using the same reference numerals and their construction and function are not explained again.
As is apparent in FIG. 3 , an interrupting element 38 , which extends axially between rotor disks 12 and 14 , is provided in chamber 44 of rotor 10 according to the present invention. In the depicted specific embodiment, interrupting element 38 is mounted on the sidewalls of rotor disks 12 and 14 . A passage 40 is provided in interrupting element 38 which may be designed as a ring which is inserted between rotor disks 12 and 14 . This passage 40 may be designed as a bore hole or may represent a nozzle.
Due to interrupting element 38 , the flow in chamber 26 is interrupted and two radially adjacent chambers 42 and 44 are formed. The flow which enters chamber 44 from compressor drum 28 is subject to a certain turbulence also in this rotor. However, the vortex circumferential velocity is reduced at this point due to interrupting element 38 provided in chamber 26 and passage 40 provided therein. For vortex formation, the ratio of radius Ra 1 , on which blade flanges 22 are provided, to radius Ra 2 , on which interrupting element 38 is provided, and to radius Ri on the hub, is relevant in the rotor according to the present invention. The ratio of Ra/Ri given from the related art is thereby reduced. A vortex, which would occur without interrupting element 38 , is thus divided into two sub-vortexes, thereby reducing the pressure drop.
The present invention is not limited to the depicted specific embodiment. For example, it is within the scope of the present invention to provide more than one interrupting element in chamber 26 . The difference between radius Ra 1 and Ra 2 may be selected according to the requirements and may be smaller than indicated in FIG. 3 . In this case, the interrupting element would be situated displaced in the direction of the disk wing compared to the position shown in FIG. 3 .
The interrupting element is provided over the entire circumference of the rotor. A suitable number of fluid passages is provided over this circumference, in particular corresponding to the number of inlet apertures in the disk flange.
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A rotor ( 10 ) for a power plant, in particular an aero engine or a gas turbine, whereby the rotor ( 10 ) includes at least two bonded rotor discs ( 12, 14 ). The rotor ( 10 ) has an inlet opening ( 30 ) for inlet of fluid from around the rotor ( 10 ) into a chamber ( 26, 44 ) in one or between two adjacent rotor discs ( 12, 14 ) and at least one interrupter element ( 38 ) with at least one fluid passage ( 40 ) is arranged in the chamber ( 26 ).
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BACKGROUND OF THE INVENTION
The invention relates to a spinning mill installation including an overhead conveyor system of the type having rails for the feeding and removal of bobbins from one or more spinning machines.
An overhead conveyor system for a spinning mill installation of this type is known from DE-OS 37 34 505. This known spinning mill installation employs conventional ring spinning machines provided with bobbin carrier creel means. The creels of the ring spinning machines are connected with conveyor rails permitting bobbins to be directly fed to the creel means of the individual ring spinning machines. The creel also carries the slubbing guides and their mounting assemblies. In the known spinning mill installation, the overhead conveyor system is used for feeding full bobbins to the creel means of the ring spinning machines and for removing empty bobbin cores therefrom. In an installation of this type, the overhead conveyor system, i.e. the arrangement and spacing of the rails as well as the rail connections, have to be designed so as to conform to the construction of the specific ring spinning machines. Any replacement of the ring spinning machines thus requires corresponding modifications of the design and construction of the overhead conveyor system.
SUMMARY OF THE INVENTION
It is therefore an object of the invention to devise a spinning mill installation permitting the employed ring spinning machines to be replaced without problems.
This object is attained by a spinning mill installation having an overhead conveyor system and at least one spinning machine, the overhead conveyor system comprising rails for feeding and removal of hanging bobbins to and from the spinning machine, the conveyor system further comprising a plurality of creel rails arranged above and vertically distant to the spinning machine, the plurality of creel rails being provided with a plurality of bobbin locations, and being attached to a frame structure which is supported outside the spinning machine by a ceiling or a floor. remainder of the line in its entirety; and the characterizing features of claim 1.
As a result of the design and construction according to the invention, the functions to be performed by the creel of a conventional spinning machine are assumed by the overhead conveyor system, and "creel-less" spinning machines are utilized, thus permitting the spinning machine to be replaced without problems. It is thus for instance possible to modernize a spinning mill installation without an increase of the accrueing costs by a modification of the overhead conveyor system.
Advantageous additional aspects of the invention are disclosed in the succeeding discussion or are shown in the accompanying drawings. Particular advantages in this context derive from the provision that the system for the displacement of a cleaner device (blower) may be integrated in such a manner that it is possible to do without a separate rail system and/or a separate drive mechanism for the cleaner device. The drive system for the bobbin feeding operation and the displacement of the cleaner device, respectively, may also be designed for cooperation with two spinning machines at the same time. This is also conductive to saving investment and operation costs.
BRIEF DESCRIPTION OF THE DRAWING
Embodiments of the invention shall now be described in detail by way of example with reference to the accompanying drawings, wherein:
FIG. 1 shows a diagrammatic illustration of a first embodiment of a spinning mill installation,
FIG. 2 shows a top plan view of the spinning mill installation according to FIG. 1,
FIG. 3 shows a sectional view of a bobbin station in the installation according to FIG. 1,
FIG. 4 shows a top plan view of a cleaner device, and
FIG. 5 shows a diagrammatic illustration of another embodiment of a spinning mill installation.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The diagrammatic illustration of FIG. 1 shows parts of a spinning mill installation 1, the embodiment shown by way of example including two diagrammatically depicted spinning machines, specifically ring spinning machines 2, installed parallel to one another in the conventional manner and with the usual bobbin creel removed therefrom. Disposed above ring spinning machines 2 is an overhead conveyor system 3 comprising a frame structure 4 composed of a plurality of transverse carrier arms 4a and longitudinal carrier rails 4b. The transverse carrier arms 4a and longitudinal carrier rails 4b are suspended from the roof 5 or a ceiling of a workshop by suspension links 4c.
As also evident in connection with FIG. 2, frame structure 4 is used for mounting a plurality of transverse rail elements 6 extending horizontally on both sides of the longitudinal symmetry plane of the ring spinning machines and arranged in an array. Transverse rails 6 thus extend parallel to one another and perpendicular to the longitudinal planes 29 of ring spinning machines 2. Defined on transverse rails 6 are bobbin stations SP for bobbins to be spin-stripped, the number of such stations at least corresponding to the number of spinning stations of ring spinning machine 2. In the embodiment shown, there are additionally provided bobbin stations greater than the number of bobbins being spin-stripped for use by stand-by bobbins.
Suspended from frame structure 4 by means of suspension links 10 are guides 8 for guiding the slubbings 9 to be spin-stripped from bobbins 7. Guides 8 may be in the form of sheaves, in which case a separate guide is provided for each slubbing 9. It is also possible to provide a common guide 8 for all of the slubbings 9 on each side of the symmetry plane 29 of ring spinning machine 2, in the form of respective bars extending over the full length of the ring spinning machine 2.
Frame structure 4 additionally carries a rail track 11 forming a closed path extending about a respective one of ring-spinning machines 2 outside of transverse rails 6. Rail track 11 is used for feeding full bobbins 7 suspended from carriers 12 to the respective ring spinning machine 2, and connected via suitable switch points 13 to a supply rail track 14. The carriers 12 used in the illustrated example are of the generally known type comprising a stirrup hanger with two casters aligned at right angles to one another and adapted to run on runways of a rail having triangular cross-sectional shape. It is also possible, however, to employ carriers of a different type.
The carriers 12 of the bobbins 7 to be fed are entrained by a drive mechanism 15 comprising an endless entrainment member 17 in the form for instance of a chain to which carriers 12 are connected, or of a belt provided with lugs engaging carriers 12, or in the form of a friction belt cooperating with the casters of carriers 12,, and a motor 16 for driving the mechanism. Entrainment member 17 is disposed in the space between two adjacent ring spinning machines 2 and effective to entrain the carriers on rail tracks 11 of both ring spinning machines 2. The bobbins 7 fed along rail tracks 11 are transferred onto transverse rails 6 in a conventional manner, for instance by means of switch points or by manual transfer, to replace empty bobbins 7 on rails 6. Particularly when the transfer onto transverse rails 6 is by an automatic operation, the empty bobbins 7 are displaced towards the longitudinal center plane of ring spinning machine 2 and transferred thereat onto a discharge conveyor 18 operable to carry the empty bobbin cores away from the vicinity of the spinning stations. Discharge conveyor 18 may again be designed as a known endless conveyor provided with lugs or the like for engaging and entraining the bobbin cores. Discharge conveyor 18 is also carried by frame structure 4.
Extending in the space between the two ring spinning machines 2 and parallel to the longitudinal center planes thereof is a further rail 19 for a cleaner device 20 in the form of a blower having a blower head 21 provided with casters 22a aligned at right angles to one another and adapted to run on correspondingly aligned runways of rail 19, formed to this purpose with a triangular cross-sectional shape. Blower head 21 is provided with further casters 22b acting as guide rollers and running on respective additional runways of the rail tracks 11 of the adjacent ring spinning machines. A tube 23 extending vertically downwards from blower head 21 has its lower end connected to an aspirator funnel 24. From the sides of blower head 21, blower nozzles 25 project laterally to locations adjacent overhead conveyor system 3 for keeping the latter free of fluff. Tube 23 is likewise provided with blower nozzles 26 directed towards components on the opposing sides of the two adjacent ring spinning machines 2 to prevent the accumulation of fluff thereon. In this manner it is possible to use a single cleaner device 20 for cleaning the opposing sides of two adjacent ring spinning machines. The cleaner device 20 according to this example is particularly useful when two ring spinning machines 2 are placed relatively close to one another for space-saving purposes, for instance when the automatic replacement of spin-stripped bobbins permits the space otherwise required between the two ring spinning machines for a bobbin trolley to be saved.
As particularly evident in connection with FIG. 4, cleaner device 20 is entrained by the feed movement of bobbin-feeding carriers 12. To this purpose blower head 21 carries two hitch levers 27a, 27b mounted thereon for pivotal displacement about respective axes. At respective ones of their ends, the two-armed hitch levers 27a, 27b are interconnected by a link bar 28 adapted to be shifted in the displacement direction of cleaner device 20 between two positions and to be locked thereat. The length of link bar 28, the length of hitch levers 27a, 27b and the locations of the pivot axes of hitch levers 27 are so determined that in any of the two positions of link bar 28 one of the hitch levers 27 projects into the path of the carriers on the adjacent rail track 11, while the other hitch levers is retracted from the path of the carriers on rail track 11 of the other ring spinning machine 2. Rail 19 of cleaner device 20 is provided adjacent both of its ends with respective stop pins 29a, 29b cooperating with respective ends of link bar 28. Since the carriers 12 running on the two rail tracks 11 in FIG. 4 are entrained by a common drive mechanism 15 as shown in FIG. 2, the carriers 12 on the sections of rail tracks 11 on opposite sides of rail 19 move in opposite directions, as indicated by arrows A and B in FIGS. 2 and 4. In the state depicted in FIG. 4, hitch lever 27a thus acts to entrain cleaner device 20 in the direction of arrow A until link bar 28 abuts stop pin 29b. This causes link bar 28 to be shifted to its other position, so that hitch lever 27b will then be engaged by a carriage 12, while hitch lever 27a is retracted.
As shown in FIG. 3, each of the bobbin stations SP indicated in FIG. 1 is provided with a readily releasable detent mechanism 30 comprising a detent ball 32 retained in a bore 33 of transverse rail 6 and biased by a spring 31 into engagement with a detent grove 35 in a bobbin holder 34. The detent mechanism 30 may also comprise two detent balls 32 symmetrically disposed on opposite sides of an individual rail 6. The described design results in a readily releasable detent mechanism 30 which is nevertheless effective to prevent the spacing of bobbins 7 suspended from transverse rails 6 from being changed by the tractive forces acting on slubbings 9 as they are being spin-stripped while releasing for movement along rail element 6 under moving forces generated by conventional moving means.
FIG. 5 shows, by way of example, a second embodiment of a spinning mill installation 1', wherein equal or similar components are designated by the same reference numerals, supplemented by a quotation mark, and shall not again be described in detail. This embodiment again provides the employ of creel-less ring spinning machines 2', the functions of a creel being again assumed by an overhead conveyor system 3' comprising a frame structure 4' with transverse carrier arms 4a' suspended by suspension links 4c' from girders 35 supported by columns 36 resting on the floor 37 of a workshop.
Feeder rail tracks 11' may be formed as closed loops as in the preceding example, or as parallel rails.
The overhead conveyor system 3' of this embodiment is designed for feeding the bobbins 7 to be spin-stripped in the longitudinal direction, i.e. parallel to the length of ring spinning machines 2'. To this purpose, a suitable number (in the example shown, two groups of two rails) of longitudinal rails 38 is provided above each ring spinning machine 2' for the accommodation of the required number of bobbin stations SP. When each bobbin has its own carrier 12', the bobbin stations may be provided directly on longitudinal rails 38. It is also possible, however, to employ conveying units in the form of bobbin trains each composed of two carriers and an interconnecting longitudinal bar having a pluraility of bobbins suspended therefrom. In this case the bobbin stations would have to be provided on the longitudinal bar.
Suspended from transverse carrier arms 4a' by means of suspension links 10' are the already described guides 8' for guiding the slubbings 9'. In the example shown, a separate guide 8' is provided for each bobbin station SP. The required spacing between the bobbins 7' to be spin-stripped may be maintained by suitable spacers of a known type, in which case the bobbins need not be locked at their bobbin stations by means of cam members or the like.
In modifications of the described and illustrated embodiments it is of course also possible to interchange the details depicted in the various figures. The overhead conveyor system 3 of FIG. 1 may thus be supported on the floor, or the overhead conveyor system 3' of FIG. 5 may be suspended from the ceiling. Likewise possible is the combined employ of both these mounting arrangements, or the mounting of the overhead conveyor system on any other suitable support. The employ of other carriers of known types and of rails of different cross-sectional shapes is also admissible. The basic concept of the invention, namely, the delegation of functions of a spinning machine to an overhead conveyor system, is also applicable to other types of spinning machines.
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A spinning mill installation including an overhead conveyor system having rails for feeding and removing bobbins to and from at least one creel-less spinning machine. To provide the function of the absent creels, an array of rail elements is positioned above each spinning machine, the rail elements having detent mechanisms defining the locations of the bobbin stations, are provided in the overhead conveyor system. A cleaning device moves along an overhead rail and is provided with a driving device which also drives the bobbin carriers.
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The invention described herein may be manufactured, used, and licensed by the U.S. Government for governmental purposes without the payment of any royalties thereon.
BACKGROUND OF THE INVENTION
In patent application Ser. No. 890,899 for a microchannel-plate-in-wall (MIW) structure, filed on even date herewith by Charles F. Freeman and Kurt (NMI) Villhauer, there is shown a novel image intensifier having a microchannel plate (MCP) with integral generally cylindrical sidewalls and two disk-like end assemblies, one being a photocathode and the other a phosphor type viewing screen. The photocathode and viewing screen assemblies differ only slightly from prior art devices, but the sidewalls and microchannel plate are combined in a manner which differs radically from the accepted techniques. The sidewalls are, in fact, permanently attached to the microchannel by a special glass frit which is melted and devitrified. During this process the plate must be protected to insure that none of its electrical properties are altered.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a method of heat sealing the adjacent edges of a set of cylindrical glass walls to the broad surfaces of a microchannel plate without altering the electrical properties or otherwise damaging the microchannel plate. It is a further object to provide an apparatus which aligns and contacts the above edges and surfaces during sealing and permits localized application of a cover gas to protect the plate during the heat sealing operation.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects of the invention will be best understood by reference to the accompanying drawings, wherein:
FIG. 1 shows a complete image intensifier tube using a MIW structure:
FIG. 2 shows a fixture holding a MIW structure prior to sealing of the walls to the microchannel plate;
FIG. 3 is flow chart of the method of assemblying a MIW; and
FIG. 4 shows an oven and cover gas supply system which supports the fixture of FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring specifically to FIG. 1, there is shown a complete image intensifier tube utilizing an MIW structure. This structure consists of a microchannel plate (MCP) 11 sealed to wall sections 12 and 13 by means of frit seals 14 and 15. The MCP is formed from semiconducting glass with electrodes or conductors deposited on its surfaces. A MCP with an extra wide rim is preferred, e.g. 1.150 in. O.D. with a minimum electrode diameter of 1.123 in. and an active area (channeled portion) having a maximum diameter of 0.775 in. The glass wall sections are made of a lead glass, which has just sufficient conductivity to remove surface charge. For simplicity the walls are assumed to be hollow right circular cylinders or rings, although many other non-uniform cross-sectional shapes can obviously be used. The viewing or anode end of the tube is closed by a twisted fiber-optic faceplate 16, which inverts the visible image. A phosphor screen 17 coated on the inside of the faceplate produces the visible image and includes a conventional conductive layer which extends to and contacts the anode terminal 18. This terminal is fused to the faceplate by a glass seal 19. This same terminal is then sealed to the MIW by melting an indium ring 20 between the two in the trough provided by the terminal. A ring of conventional getter material 21 is formed on the inside of the anode end assembly to preserve the hard vacuum inside the completed tube. The opposite end of the tube is closed by a cathode assembly consisting of a faceplate 22 having a photocathode 23 with an electrode which extends to the outer edge of the faceplate. This faceplate is also sealed to the MIW by an indium seal 24 which can be cold pressed or heated. The terminals deposited on the MCP, like the one on the cathode terminal, extend through the seals 14 and 15 beyond the wall sections 12 and 13 for external connection to a power source. The terminal patterns on the MCP can thus be made quite complex. For example, each broad face may have a plurality of parallel metal strips, orthogonally related between faces, to permit selective x-y switching of the numerous channels, without the need for a special array of output terminals sealed through the tube.
FIG. 2 shows a fixture holding the parts of the MIW structure in position during its manufacture. The body 41 of the fixture is generally cylindrical with an outside diameter substantially greater than that of the microchannel plate. The upper end terminates in a thick flange 41A of still greater diameter. The body is bored through and counterbored from the upper end to accept the stepped end of a lower cup member 42. It is further counterbored more than half its length from the upper end to receive the microchannel plate in a recess 41C and the flange is counterbored to a diameter between its outer diameter and that of the rest the body to form a pressure plate recess 41B. The cup member 42 has a maximum diameter open end within the recess 41C greater than the diameter of the active area of the microchannel plate, i.e. the area containing channel openings; but substantially smaller than the maximum diameter of the plate. The cup member is bored through and counterbored twice to form the two slightly different recesses 42A and 42B within the cup member. The diameter of the larger recess 42A is also larger than that of the active area of the plate. The outer diameter of the bottom portion of this lower cup member is twice reduced to form the portions 42C and 42D which define the stepped end mentioned above. The portion 42D extends a very short distance into the recess 41C so that the stepped end will seal well in the body member 41. The inner wall of the lower cup member below the recesses 42A and 42B is threaded to receive a standard male conduit fitting (not shown). The body and lower cup are drilled and tapped for at least one, preferably three, screws 43 which hold them together.
An upper cup 44 with counterbored recesses 44A and 44B and a pair of retaining rings 45 and 46 are also located in thre recess 41C. The outer surface of the rings are rounded to approximate the surface of a sphere that would just slideably fit within recess 41C. The inner diameter of the rings is somewhat larger than the outer diameter of the cups to provide a narrow clearance space therebetween. The inner proximate edges of the rings are provided with steps 47 and 48 which match the edges of the tube side walls 12 and 13. The inner diameter of the rings can conveniently be made equal to the same diameter of the walls, if desired, and the rings preferably are matched to one another. A pressure plate 49 is provided which just fits the flange recess 41B. The edges of this plate are rounded in a manner similar to the outer surfaces of the rings to provide an easy sliding, but close fit. The plate is drilled through and counterbored at its center to receive the stepped upper portion of cup 44, which is preferably identical to the lower cup. The plate is also drilled and counterbored to match the threaded cup holes, as provided for screws 43, to receive plate screws 54, and the pressure screws 50. The latter are placed near the edge of the plate and are received in holes drilled and tapped through the flange below the recess 41B. Three symmetrically located pressure screws are preferred, symmetrically offset from screws 54. Each pressure screw is provided with a similar compression spring 51 coiled around its stem between its head and the pressure plate. At a plurality of points directly below the lower ring the body is drilled through and tapped for a set screw 52. A compression spring 53 shorter than the tapped hole for screw 52 is placed therein and the screw adjusted so that part of the spring projects into the body recess 41C. Again three symmetrically located screws are preferred, symmetrically offset from screw 43. All parts are preferably made of stainless steel to prevent contamination of the MIW structure.
Referring to the Flow Chart in FIG. 3 the MIW is fabricated as follows:
A. The sidewalls are formed by any of the well known techniques for making hollow glass cylinders with plane edges normal to their axis to moderate tolerance, e.g. centrifugal molding, using a high lead content glass, having the same coefficient of thermal expansion as the MCP such as G12 glass made by the Kimble Glass Co., and then ground and polished within a few thousandths of an inch of its required dimensions (e.g. 1.030" O.D. and 0.15-0.30 axially);
B. The surfaces of the walls are thoroughly cleaned using solvents such as water, acetone and alcohol. Commercially available MCP's with Inconel electrodes have already received all the surface treatment that is required for the frit mentioned above, other MCP's and/or frits may require the deposition of a layer of SiO x where x lies between 1 and 2 (preferably near 1) at least on the rim;
C. These cylindrical walls are then placed in an oven and heated to 450° C. for one hour in a hydrogen atmosphere to reduce the lead in the glass thereby providing a degree of conductivity therein;
D. One toroidal end surface of each wall is then coated with a mixture of glass frit (sealing glass Corning Code 7275) mixed 14 to 1 by weight with amyl acetate having 1.2% nitrocellulose dissolved therein. The frit coating on the glass wall is then dried and glazed. The glazing is performed at a temperature below the devitrification point, which burns off the binder and fuses the frit powder into a mechanically strong vitreous coating, the glazed frit may then be mechanically shaped as required to obtain a desired uniform 0.010 inch thick coating on the end faces of the walls.
E. The walls and microchannel plate are then assembled in the fixture of FIG. 1, ring 46 is first floated with its stepped edge upward on the springs 53, the lower wall is inserted in that ring with the frit covered edge upward, the microchannel plate is placed on the lower wall, the upper wall is placed fritted edge down on the MCP, the upper wall is centered by placing the upper ring on the top edge thereof and manually adjusting the wall until it seats itself in the ring, the upper cup and pressure plate are inserted and screws 50 and 52 adjusted to apply firm and even pressure to the various parts in the fixture, the fixture is kept in an upright position so that ring 45 will gravitate toward the upper wall and the MCP applying pressure therebetween, thus maintained the fixture is nested in a suitable supporting rack, placed in an oven and the upper and lower ends coupled to male conduit connectors therein. Before proceeding further with the method, the oven and cover gas system will be described.
FIG. 4 shows the oven 141 and a cover gas supply system. The cover gas (argon) is supplied under pressure from a tank 42 to a regulator valve 143 which sets the supply pressure for the system. After passing through the regulator valve 143, any oil or water vapor is removed from the gas by a Matheson MDL 450 filter 144 and other particulate matter by an MDL 6134 filter 145. The gas then passes through a first Matheson 602 flowmeter 146 having an integral input valve 147, which controls the inflow to the oven. A pressure gauge 148 monitors the output line 149 from this flowmeter. The output line 149 feeds the input port on a first on-off valve 150. Line 149 is also connected to a by-pass line 151 through a second on-off valve 152. The bypass line 151 is also connected to the input port of a second flowmeter 153 like the flowmeter 146 but having its valve 154 at the output end, which end is then vented to the atmosphere. The input line 149 is coupled to an oven input line through the valve 150. The latter line spirals around the walls of the oven 141 to preheat the gas and terminates in the male coupling 156 which engages the bottom of the fixture. An oven output line 157 runs from the remaining male coupling 158 at the top of the fixture to the input port of a third on-off valve 159. The output port of the valve 159 is coupled to line 151.
Returning to the Flow Chart of FIG. 3, the MCP and sidewalls having been assembled in the clamping fixture and the latter having been mounted in the oven, the MIW fabrication proceeds as follows:
F. With all valves of FIG. 4 initially in their off or closed positions, the valve 147 on flowmeter 146 is fully opened and regulator valve 143 is adjusted to provide an input gauge pressure to meter 148 at 10 psig. At this time the seal between the cups and the MCP is adjusted. A positive pressure bias must be maintained inside the cups before the MCP can be heated to prevent any oxidizing gases from reaching the active surface of the MCP, while the leak rate through the seal must be sufficiently small to not totally purge the oxidizing atmosphere at the frit. Valve 150 is then opened. With valve 147 fully open, the pressure screws of the fixture are manually adjusted until the meter 148 reads less than one psig below the original 10 psig or a desired leak rate is established by meter 146. Next, the flow and fixture pressure of the cover gas are set. Valve 159 is opened and by adjusting valves 147 and 154, the leak rate, input flow, input flow, output flow (meter 153) and the pressure bias of the fixture are established (not all independently). Typically, the input flow is 150 mm (approximately 700 cc/min), the output flow is 120 mm, the pressure bias (meter 148) is 6 psig, and, thus, the leak rate is the input flow less the output flow. Bypass valve 152 is used for calibration purposes; to compare flow meter readings and to determine the upper bound for the fixture pressure, i.e. leak free conditions.
G. With the cover gas flow established (purging time 10-15 minutes), the glass frit is heated by toroidal heating elements in the oven wall. The temperature of the oven is raised gradually (approx 25° C./min) to 260° C., held for 10 minutes and then gradually raised to 450° C. At this temperature the frit melts and devitrifies. After baking for one hour the oven is allowed to cool for 30 minutes without forced air cooling and 30 additional minutes with a cooling fan until the fixture temperature falls below 50° C. The cover gas, which first strikes the electrode on the electron input side of the MCP, protects the plate from damage. Only a slight discoloration of the electrode on the output side occurs with no observable effect on its performance in a finished intensifier tube assembly.
H. The gas flow is now cut off by closing valve 150.
I. The fixture is then decoupled from the oven, disassembled and the finished MIW structure removed. The edges of the cups must be kept clean and smooth to produce a good seal with the MCP, so it is particularly important that they be removable. Polyimide wire enamels sold under the DUPONT trade name "PYRE-M.L." can be used on the cup edges, if desired, to improve the seal. Further processing of the MIW structure into an image intensifier tube is the subject of the copending patent application mentioned above.
Obviously many variations of the above methods and apparatus will be obvious to those skilled in the art but the invention is limited only by the claims which follow.
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A method and apparatus is provided for manufacturing microchannel-plate-iall structures (MIW's) wherein the electrical properties of the microchannel plate are protected by the localized application of a cover gas.
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BACKGROUND OF THE INVENTION
The invention relates to a method and apparatus for machining by electrical discharges an electrode workpiece by way of an electrode tool, wherein consecutive voltage pulses are applied between the electrodes. More particularly, the invention relates to an EDM method and apparatus permitting to develop a variable magnitude which is a characteristic of the machining performance of efficiency factor or index, and to automatically vary step by step one of the machining conditions or parameters such as to operate at the maximum value of the machining performance index.
The cut-off time interval between consecutive voltage pulses, in an EDM apparatus, is an important machining parameter which is known to affect the machining efficiency and which, when properly utilized, permits to obtain maximum machining efficiency. The performance factor or index or, in other words, the machining efficiency, is capable of quantitative representation as a function of any one of a plurality of machining conditions or parameters such as, for example the machining parameter corresponding to the total duration of all the effectively machining electrical discharges within a predetermined time frame. When the length of the cut-off time interval between two consecutive voltage pulses is decreased, a corresponding decrease of the number of effective electrical discharges is observed due to a downgrading of the quality of the electrical discharges, and consequently of the machining efficiency. When, on the contrary, the duration of the cut-off time interval is increased, a corresponding decrease of the number of effective electrical discharges during the same time frame is observed, with the result that the machining efficiency tends to also decrease. Between these extremes in cut-off time interval duration, there exists a zone of operation in which the machining efficiency, or the over-all performance index of the EDM apparatus, reaches a maximum value.
Through the utilization of appropriate logic circuitry, it is possible to provide the machine operator with a visual display of a magnitude representative of the machining efficiency, or to utilize an electrical magnitude representative of the machining efficiency for automatically controlling and modifying the machining parameters such as to optimize the machining conditions as, for example, disclosed in U.S. Pat. No. 4,090,961, assigned to the same assignee as the present application. The speed at which the apparatus corrects itself, so as to be self-adaptative, can yet be improved as provided by the present invention, by automatically varying step by step the duration of the cut-off time interval between consecutive pulses, and by multiplying the difference or increment between consecutive steps by the slope of the representative curve of the machining efficiency in function of the duration or length of the cut-off time interval.
A good approximation of the value of the slope results from effecting the quotient of the change in machining efficiency by the corresponding step increment of the variation in duration of the cut-off time interval that originally caused the resulting change in machining efficiency. In this manner, the increment steps by which the duration of consecutive cut-off time intervals is varied are small when operating proximate the top of the machining efficiency representative curve, and the step increments are wider when operating at a portion of the representative curve distant from its top. However, it has been observed that if there occurs an accidental incursion into a critical zone corresponding to very short cut-off time intervals that cause the representative curve to have a positive slope, an increase of the duration or length of the cut-off time interval does not permit to achieve immediately a substantial improvement of the machining efficiency. In other words, it has been observed that excessive degradation of the machining conditions gives rise to a downgrading phenomenon resembling hysterisis which impedes rapid re-establishment of favorable machining conditions.
The process of the present invention aims at avoiding the recurrent frequent appearance of such a hysterisis phenomenon by providing a determination of the sign of the quotient of the variation of the magnitude representing the machining efficiency by a corresponding change in the machining parameter causing the change in efficiency, and by providing the step increments by which the machining parameter is varied or changed a first value when the resulting quotient is positive and at least one second value, greater than the first, when the resulting quotient is negative.
SUMMARY OF THE INVENTION
The object of the present invention, therefore, is to provide a method and apparatus for electrical discharge machining, or EDM, which renders the EDM apparatus self-adaptive and self-corrective to operate at maximum machining efficiency by varying a given machining parameter by steps until optimum efficiency is achieved, the steps by which the given machining parameter is changed having a representative increment which is much smaller in the zone of operation wherein the machining efficiency varies as a function of the machining parameter with a positive slope, such as to limit to a minimum the amplitude of the variations of the machining parameter. In addition, the invention has for object to provide a buffer or safety zone adjacent to the zone of the curve representative of the machining efficiency or performance having a positive slope, and to provide the step increments by which the variable machining parameter is varied with a yet smaller value when operating within the safety zone. The buffer or safety zone has a width which may be made variable as a function of the incursions of the machining efficiency representative curve into the danger zone where the machining efficiency representative curve has a positive slope. The invention therefore provides a new method and apparatus for EDM permitting to limit, or even to completely prevent, incursions of the machining conditions into a critical or danger zone, and which enables the rapid achievement of optimum machining effeciency.
The present invention will be best understood by those skilled in the art when the following description of the best mode contemplated for practicing the invention is read in conjunction with the accompanying attached drawing illustrating an example of such best mode contemplated for practicing the invention and wherein:
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a graphic representation of an EDM apparatus performance index as a function of a machining parameter;
FIG. 2 is a graphic representation of the performance index as illustrated at FIG. 1 provided with an operative safety zone according to the present invention; and
FIG. 3 is a functional block diagram of an apparatus according to the present invention for practicing the method of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, there is illustrated the general appearance of the performance index curve of an EDM apparatus as a function of a machining parameter, such as the cut-off time interval t B between two consecutive voltage pulses. Representing the performance index as a function of any other machining parameter such as for example the reference voltage of the servomechanism controlling the gap width between the electrode tool and the electrode workpiece would result in a similar graphic representation. As an example, the performance index is characterized at FIG. 1 as being the graphic representation of the total duration of effective electrical discharges during a predetermined period of time, as disclosed in U.S. Pat. No. 4,090,961 assigned to the same assignee as the present application. On the right of the dashed line corresponding to the top P of the curve corresponding in turn to the cut-off interval time t B ,OPT the performance index I decreases substantially, because the number of effective electrical discharge by unit of time decreases. This decrease of effective electrical discharges is generally a function of the length of the cut-off interval t B between consecutive voltage pulses, and this is why the curve is drawn with a slope S which is negative, or S<O. On the left of the top P of the curve, as symbolized by the dashed line, the efficiency index I decreases again because of the apparition of abnormal electrical discharges which can degenerate into localized arcing. This is why that zone, which is characterized by a slope S which is positive, or S>O is called the arcing zone or danger zone.
For a predetermined value of the cut-off time interval t B within that zone, the efficiency index I decreases as a function of the time. In other words, the relationship between the efficiency index and the duration of the cut-off time interval is no longer univocal or unambiguous, and this is why the zone on the left of the curve is shown cross-hatched for the purpose of symbolizing the fact that the efficiency index I can take any value between zero and its maximum theoretical value.
FIG. 1 represents the present state of the art wherein the magnitude of the difference between consecutive steps of the change in the chosen machining condition parameter remains constant and is not varied in accordance with the sign of the slope of the machining performance or efficiency index I, and provides a graphic understanding of the reason why the performance optimization systems prior to the present invention are subject to unstability or to excessively long optimization-seeking time periods. A narrow step toward optimization is conveniently well chosen as long as optimization is sought in proximity to the top P of the representative curve and along the left-hand portion of the curve, but a narrow step is ill-chosen if it is applied to the right-hand portion of the curve which tolerates without danger steps of a wider amplitude. Inversely, a wide step belongs to the right-hand portion of the curve and provides rapid optimization, but a wide step is a source of great difficulties within the left-hand portion of the curve wherein there exists always the possibility of an accidental incursion into the cross-hatched danger zone. As has been previously mentioned, the rapid downgrading of machining efficiency which occurs while operating in the danger zone cannot be immediately corrected. FIG. 1 illustrates clearly the phenomenom of hysterisis of the response of the machining performance index I as a function of the pulse cut-off duration t B which is responsible for the unstability of the known prior art systems:
At point P of the representative curve, the monitoring system of the EDM apparatus witnesses a negative slope in the representative curve and the control system reacts by displacing the point of operation towards the left;
At point Q of the representative curve, during a very short period of time, the machining efficiency index I seems to improve momentarily, but it deteriorates rapidly due to the apparation of abnormal electrical discharges;
At point R, the apparatus monitoring and control system recognizes its error and attempts to correct by increasing the duration of the pulse cut-off time interval t B ;
At point S, not finding the initial machining efficiency corresponding to the time interval t B ,OPP because abnormal discharges continue to occur, the apparatus overcorrects by increasing the duration of the cut-off time intervals t B step by step. The machining efficiency index I improves, but very slowly until point T is reached, along a line ST which has a positive slope, thus causing the apparatus to further increase the cut-off time interval t B . Subsequently, the cut-off time interval duration t B is decreased by successive steps until point P of the curve is reached.
At point P, the whole cycle PQRSTP is repeated, because the apparatus has no capacity for memory storage of the existence of a danger zone.
Such an unstable performance is very inefficient, because it results in a general decrease of the machining performance index I. Further, it is to be noted that the deeper and the longer the incursions into the danger zone as a result of a set-up requiring wide step change of the cut-off time interval, the greater the amplitude of the cycle PQRSTP.
FIG. 1 illustrates the essential character of the present invention, which consists in adopting correction steps A 1 and A 2 for varying or changing the duration of the cut-off time interval t B that are different according to whether operation is effected along the left-hand or right-hand portion of the performance index representative curve with respect to the top of the curve. The discrimination between the width of the step is obtained by detecting the sign of the derivative. A 1 corresponds to the plus sign and A 2 to the minus sign. An approximation of the derivative is obtained by obtaining the quotient of the variation of the performance or efficiency index I by the variation of the time interval t B which has caused that variation of the efficiency index.
The performance index representative curve being sharply curved proximate its top P, it is necessary to multiply the values of the correction step increments A 1 and A 2 by the slope of the curve, in order to ensure a rapid convergenge towards the top P of the curve when operating far from the top P, and a slow convergence when operating close to the top P. The step increment A 1 must be chosen smaller than the step increment A 2 , such as to compensate for the effect of the steep slope which could lead to overcorrecting. FIG. 1 further indicates that the slope of the curve corresponding to high values of the cut-off time interval t B is relatively small. Therefore, it is advantageous to select a step increment A 2 which is relatively large in order to provide a rapid convergence towards the top P of the curve in this particular portion of the curve, the right-hand portion of the performance index representative curve decreasing as a function of the duration of the cut-off interval duration t B .
FIG. 2 illustrates the manner in which the adverse effects resulting from incursions into the danger zone can be substantially decreased or even completely eliminated. It is possible to detect and memorize the existence of the danger zone. The criterium used is, for example, the detection, subsequent to a negative step, either of the predetermined rate of abnormal discharges, or of a very stiff positive slope. The important point is that, subsequently, a third value A 3 is given to the step increment, or to the function factor coefficient relative to the slope when operating in a buffer or safety zone located in the portion of negative slope of the representative curve adjacent to the danger zone in which the slope is positive. At FIG. 2, the safety zone or warning zone is comprised between t B ,OPT and t B ,W.
This third value, A 3 , for the step increments is chosen smaller than the value A 2 of the step increments normally attributed to the negative slope portion of the representative curve, such as to further slow down the approach from the right to the top P of the curve and such as to avoid wide amplitude incursions into the danger zone. It will be appreciated that the method of the present invention can be further refined by subdividing the buffer or safety zone in several zones of progressively decreasing step width, i.e. having decreasing co-efficients of proportionality relative to the slope, designed for progressively slowing down the approach to the top P of the curve and to thus prevent any new incursions of high amplitude into the danger zone.
FIG. 3 is a functional block diagram of an example of structure for an apparatus adapted to practice the method of the present invention. An electrode tool 6 is arranged to machine an electrode workpiece 7 by electro-erosion by way of electrical discharges. A line 61 supplies the machining voltage to a machining monitoring component, or machining conditions detector 1. The machining conditions detector 1 provides at separate outputs a performance index I, a short circuit rate N CC , a representation of the average triggering delay N D of the electrical discharges and at least one value N DA representative of the rate of abnormal discharges. Those different magnitudes or values representative of the conditions of machining are obtained by means of appropriate circuits, such as disclosed for example in U.S. Pat. Nos. 4,090,961, 3,739,137 and 3,860,779, and are supplied, for example as encoded binary signals, in parallel on lines 11, 12, 13 and 14, supplying respectively the values I, N CC , N D and N DA . An optimization circuit 2 receives at its inputs this information data and provides at its output at least one correction or regulation parameter, for example the duration of the time interval t B between two consecutive voltage pulses applied across the electrodes 6 and 7.
The optimization circuit 2 also provides at its output an additional parameter such as, for example, a voltage reference U applied to the EDM apparatus servo-mechanism. Preferably, and still for the purpose of giving an example of a component type, the optimization circuit 2 is in the form of a processor such as a mini-computer HEWLETT-PACKARD model 21MX, DIGITAL model PDP-11 or micro-computer INTEL model 8080, ZILOG model Z80. The processor, or optimization circuit 2, triggers the measuring of the machining conditions by the machining conditions detector 1 by a synchronization or timing signal provided through the line 10 to the machining conditions detector 1 which, upon receiving the timing signal, replies by placing each of the lines 11, 12, 13 and 14 to an appropriate voltage in conformity with the results of the measuring. The time interval t B , provided by the processor 2, is supplied by a line 21 to the pulse generator 3 which provides at its output the consecutive voltage pulses, required for machining the workpiece 7 by electrical discharges, through a line 31 connected to the electrode tool 6. Other machining parameters, which are not affected by the self-regulating optimization in the course of a machining operation, are introduced into the pulse generator 3 by way of lines 8. The reference voltage U, provided in a binary form by the optimization circuit processor 2, is applied through a plurality of lines 22 to the input of a digital/analog converter 4, providing at its output an analog signal which is applied through a line 41 to the EDM apparatus servo-mechanism 5. The servo-mechanism 5 receives the machining voltage across the electrodes 6 and 7 through a line 62, provides a value representative of the width of the machining gap between the electrodes and compares it with the voltage reference U for maintaining the gap at its optimum value by controlling the displacement of the electrode tool 6 relative to the electrode workpiece 7 by the servo-mechanism 5.
The representative value of the cut-off time interval duration between consecutive pulses, or t B , which is provided on the line 21 at the output of the optimization circuit 2 and applied to an input of the machining pulse generator 3, has a variable value tending towards t B ,OPT. Subsequent decreases of the performance index I for sub-optimal cut-off times t B , together with the risk for irreversible arcing in the danger zone, is avoided by memorizing a buffer, safety, or warning zone t B ,W. This value is used as a memory for the learning system, indicating the proximity of the danger zone. The value t B ,W is set to zero at the start of the machining process. It is set to a new value, whenever a decrease of the cut-off interval time t B results in:
(a) an arc situation, for example the line 14 indicates to the optimization circuit 2 that the rate N DA of abnormal discharge of the arc type is higher than 3%, (b) a drastic decrease of the index I appears on the line 11; it must be understood that a program must be written for the optimization circuit 2 for the evaluation of the slope by effecting at each step the quotient of the variation of I by the variation of t B which has caused the variation of I. For example, if I is given in percent of its maximum value and if t B is given in microseconds, a mathematical condition translating "drastic decrease" is a slope value higher than 30.
In both cases (a) and (b) a new value t B ,W is set to the product of the preceding value t B which still yielded no process deterioration by a numerical factor, for example 1.8.
The proportionality factor A is reduced from A 2 =0.15 to A 3 =0.02 when t B is lower than t B ,W. The numerical values must be understood as an example; the important point is that A 3 is lower than A 2 . As a result, the system learns the position of a danger zone and cautiously adjusts the process with small steps when approaching the said danger zone. This avoids repeated process deteriorations as those illustrated in FIG. 2 and strongly reduces the tendency for arcing.
The safety value t B ,W has to be reset if the cause of the process deterioration disappears or if the danger zone shift to lower cut-off interval times. Therefore, t B ,W is lowered each time t B is decreased below the optimum t B ,OPT (S>O) and reaches a value lower than half the present safety value without any further process deterioration. By this way t B ,W is a moving boundary between the different zones; it may move during a single machining operation, for example because dielectric flushing conditions become more and more difficult.
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An EDM apparatus provided with an adaptive self-correcting system for achieving optimum maximum efficiency of machining operations. As the machining performance factor or index of an EDM apparatus continuously varies as a function of one of the machining parameters as, for example, the cut-off time interval between consecutive electrical discharges, such that the maximum performance index, achieved for a given optimum cut-off time interval, deteriorates rapidly when the cut-off time interval is shortened, thus resulting in poor and unstable machining conditions, the invention contemplates varying the cut-off time interval in successive steps, the steps being larger when operating along the negative slope portion of the representative curve of the performance index as a function of the cut-off time interval duration, and the steps being much smaller when operating within the portion of the representative curve having a positive slope. In addition, the invention contemplates reducing the steps to a much smaller value within a buffer or safety zone in the portion of the representative curve of negative slope proximate to the top of the curve.
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BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
This invention relates to a hysteretic energy absorber.
There are circumstances in which it is desired to decrease the application of energy to a body or structure. In some circumstances this may be done by springs, but only when the elastic restoration of the energy can be dealt with. Various devices such as shock absorbers or viscous dampers are used when for some reason the energy must not be restored.
A particularly troublesome situation arises in preventing the cyclic forces imposed by earthquakes from damaging buildings and their contents. The present invention arose in the first place as a means of providing a damper to be connected between the base of a structure and the foundations below the structure. The structure was to be supported by a system, interposed between its base and its foundations, which allowed substantially free horizontal motion of the base. A combination of a flexible base-support system and a set of large-capacity energy absorbers of suitable characteristics would provide, for most structures, a substantial measure of protection from severe earthquake forces, while at the same time preventing frequent troublesome motions.
Common types of energy absorber are not satisfactory. In the first place, those which would absorb enough energy to protect a building in a severe earthquake would be so big as to be unusable. Velocity dampers are unsatisfactory, since they would do nothing to prevent the slow movement of the building. Hydraulic dampers might be made big enough, but they would allow drift from, for instance, wind loads, they would be expensive, and their upkeep would demand frequent attention.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an energy absorber that will go some way to meet the requirements stated above, and to avoid the difficulties of existing types of energy absorber, or will at least provide the public with a useful choice.
A property of low-carbon mild steel when stressed beyond the elastic into the plastic regime provides the basis for a new type of energy absorber. If during stressing of a piece of steel displacement is plotted against load, the line which is at low stresses straight becomes curved when the stress is high. The line followed during the relief of stress is quite distinct from that during stressing, and if a cyclic stress into the plastic region is applied, a closed curve is followed. This is known as a hysteresis curve, and the type of energy absorber which uses this property of steel (the same applies to many other solid materials, but low-carbon steel is especially favourable) is known as a hysteretic energy absorber. The name applies only when the energy to be absorbed is cyclic.
An absorber of this type has already been described and claimed in United States Letters Patent to Skinner, No. 3,831,924 issued August 27, 1974, "Torsional Energy Absorber". It uses the hysteretic property of steel when stressed mainly in torsion, and has two limitations. In conformation it is essentially 3-dimensional, so that it may be relatively bulky and cannot, for instance, be fitted within a sandwich wall, and it will deal with forces applied along only one line. The hysteretic energy absorber to be described later has two general embodiments. In both, the device extends principally in two dimensions and can be fitted within a sandwich wall if required, and in one forces applies in any direction in a plane can be dealt with.
To protect a building, a hysteretic energy absorber capable of operating for motion in any horizontal direction would be particularly effective. There are other applications for which an absorber acting along a single line is appropriate; for example, the two ends of a bridge deck may themselves be designed to allow motion along only the deck's length. Earthquake resistance of the bridge structure might be increased by connecting a hysteretic energy absorber for longitudinal operation between one end of the bridge deck and the abutment.
A further application of energy absorbers is the protection of equipment within buildings such as apparatus racks (which might be 10' high and be relatively heavily loaded) or shelves and the like, from being overturned or wrenched from their foundations, or fractured by earthquakes. Such structures can be anchored to the floor. They can also be anchored to walls by tie rods but it is always possible that the walls will not move in phase with the floor, so that the tie rods might themselves impose forces on articles they were intended to protect. Protection would be possible if a plastic energy absorber could be incorporated in the tie rods, or between the tie rods and the supported equipment.
Accordingly the invention may be said to consist of a cyclic energy absorber designed to be interposed between first and second members of a structure which are caused by in-coming energy to move relative to each other, said energy absorber comprising in combination:
an anchor adapted to be connected rigidly to a first member of the structure;
a main beam rigidly connected at one peripheral plane to said anchor;
loading means connecting a second member of the structure to the main beam at a point remote from the connection to said anchor so that relative to-and-fro motion between said first and second member of the structure causes said main beam to form cyclically in flexure into the plastic range.
The invention consists in the foregoing and also envisages constructions of which the following gives examples only.
BRIEF DESCRIPTION OF THE DRAWING
One preferred form of the invention will now be described with reference to the attached drawings, in which:
FIG. 1 shows a hysteresis loop determined experimentally for a low-carbon mild steel,
FIG. 2 shows partly in cross-section a schematic representation of a multi-directional, cantilever, flexural, hysteretic energy absorber as it might be fitted between the base and foundation of a building after subjecting to a major earthquake,
FIG. 3 shows schematically a single-cantilever hysteretic energy absorber for action along one line in the condition it would have before severe deformation,
FIG. 4 shows partly in cross-section the same device as in FIG. 3 after heavy cyclic forces have been applied to it,
FIG. 5 shows schematically a development of the device of FIG. 2; a beam intended as a multi-directional, hysteretic energy absorber is equipped with two moment-resisting anchors, one attached to the base of the building and the other to a foundation,
FIG. 6 shows a development of the device of FIG. 3, having one anchor about which two of the devices of FIG. 3 are symmetrically located,
FIG. 7 bears the same relation to FIG. 2 that FIG. 6 bears to FIG. 4, showing a multi-directional double cantilever, flexural, hysteretic energy absorber with an anchor at its middle and a force connection at each end,
FIG. 8 is a schematic arrangement of the inverse of FIG. 7; a beam has anchors at each end and a force-applying means at its middle,
FIG. 9 shows a possible means of applying flexural, hysteretic energy absorbers for action along one line within the structure of a building, for instance in a diagonal brace; pairs of units of the type shown in FIG. 3 are joined by free ends of their main beams so forming the analogue of FIG. 5 for action along one line; a diagonal brace is divided and the two divided parts are joined by one or more of the double absorbers.
FIG. 10 shows a variant of FIG. 3 or FIG. 2 in which deformable materials are used to carry out the function of guide bars, and
FIG. 11 shows a simplification of FIGS. 2 and 3 in which the rigidity of the anchor carries out the function of guide bars.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates a basic property of low-carbon mild steel. Other materials have a similar property, but low-carbon mild steel is convenient to use. When a sample of such steel is subjected to a number of cycles of alternating stress, it is possible to plot load against the displacement of some point on the specimen. In the beginning, the steel is at the point A and as the load is applied there is elastic displacement to point B. At this point there is yield and as the load is increased the displacement per unit of additional load is much greater until the point D is reached, at which the stress is slowly reduced. The curve then followed is D-E and not D-B-A. When the stress is reversed the point I is finally reached. If now the stress is once more reduced and reversed, the curve I-G-H is followed. Subsequent cycles of alternating load will follow the closed curve H-E-I-G-H with variations such as are shown at G-F. The area within the closed curve is the energy absorbed per cycle and for low-carbon mild steel the energy absorbed per cycle per pound weight is high.
In a preferred form of the invention, the basic component of the energy absorber is an energy absorbing beam which is attached to a rigid support by a moment-resistant anchor. Energy is absorbed in the fashion disclosed in FIG. 1 when the beam is deformed by a transverse load applied to its free end. The beam can be either single or composite, and may not be all of the same material.
The anchor includes guide beams which are fixed in place against but are not attached to faces of the main beam. This moment-resisting anchor increases substantially the energy absorbing capacity of the beam during deformation.
The first embodiment of the invention is shown in FIG. 2. The dished plate 1 is a moment-resisting anchor. Its precise form is unimportant. It is rigidly connected to a body which in this case is a foundation 2. An energy absorbing beam 3 (here shown deflected) is rigidly attached to the anchor 1. Around its base are guide beams 4. These also are rigidly attached to the anchor and are arranged to have their long axes parallel to the axis of 3; before heavy stressing they are in contact with the beam 3. Beam 3 may be cylindrical or prismatic with any number of sides, from 3 upwards. For any prismatic form of the beam, the cross-section should be as symmetric as possible, in order to present substantially the same resistance to bending for all loading directions perpendicular to the beam axis. If the beam 3 has flat sides it is to be expected that there will be a guide bar 4 for each side. When the beam 3 is cylindrical guide bars 4 may be rods, flat strips, a cylinder or segments of a cylinder replacing the strips shown at 4 in FIG. 4. Guide bars of various lengths have been tested and it is believed that the optimum length is approximately one-third of the length of the main beam between its anchorage and the point at which force is applied. There should be as little circumferential spaced unused between the guide bars as possible. Their optimum thickness is 0.5 to 1.0 times the thickness of the main beam.
At the head of the main beam 3 is the means by which a cyclic load is imposed on it. In FIG. 2,5 is a head whose perimeter is a great circle zone of a sphere; 6 is a squat cylinder attached to the base 7 of the building. The clearance between 5 and 6 is small so that as soon as the building moves, cylinder 6 causes a load to be imposed on the flexural beam 3. The maximum end rotation to be expected of beam 3 is in the neighbourhood of 15°. The depth of cylinder 6 should correspond with this, with a suitable allowance.
When an earthquake moves the foundation, 5 and 6 make contact and beam 3 will bend elastically. It must be understood that the movement between the building 7 and the foundation 2 is purely relative. If the relative movement embodies a great enough force, the beam 3 will be deflected out of its elastic range into its plastic range and it will move the guide beams 4 in front of it. When a heavy alternating force is applied, the main beam suffers alternating elastic deformation, together with alternating plastic deformations. The guide beams suffer alternating elastic deformation and unidirectional plastic deformations. That is to say, after the first large excursion the guide beam will be left in the curved state shown in FIG. 2.
The guide beams contribute several features to the moment-resisting anchor.
1. They increase the volume throughout which plastic deformations occur in the main deformable beam.
2. They prevent the concentration of large plastic strains by increasing the radius of curvature of the main beam when deformed.
3. They apply a rolling action to the surface of the main beam, so long as they have a width at least as great as that of the main beam. This induces a compressive stress in the superficial layers of the deforming beam. It has been shown in a number of scientific papers (see for instance Moore H.L. (1947) and A.S.T.M. (1941) that such compressive stress leads to a reduction in tensile stress in the vulnerable surface layer, and hence to an improvement in the fatigue strength of the specimen.
4. They absorb energy.
With the main beam 3 at 3 inches in length and 1/4 inch in thickness and with guide beams 4 projecting 1 inch from the anchor, it has been found that after a number of excursions into the plastic region, further excursions cause contact between the beam 3 and guide beam 4 over a 1/2 inch length. As the beam 3, after many cycles of stress, approaches failure it is found that cracks are distributed over this 1/2 inch length. When there are no guide beams the same energy is available for forming cracks confined to the immediate neighbourhood of the anchor, so that the useful life of the beam 3 is much shortened. The guide beams increase substantially the number of cycles of deformation for any given amplitude of deformation which can be applied to the beam before failure, so that the beam has an increased capacity for absorbing energy.
FIG. 3 shows a variant of the absorber of FIG. 2 and in addition shows a varied method of mounting that could also be applied to the device for FIG. 2. This method of mounting will be discussed later.
The numbering of FIG. 3 corresponds with the numbering of FIG. 2. 1 is an anchor and the body to which it is attached is not shown and 3 is again the deformable beam and in this embodiment it is transformed into a body of lower symmetry, a strip. As a result, it is suitable for dealing with forces only in the directions shown by the arrows -- it has a single line of action as an absorber. Guide bars 4 are fitted only on the two main faces. The linkage for applying the force to the end of bar 3 is not shown. It may be an analogue of parts 5 and 6 of FIG. 2, but because of the use to which this form can be applied, it may also be a conventional linkage.
Clearly, the anchor 1 of FIG. 3 is different from the anchor of FIG. 2. It consists of a rectangular tube that is slotted on both faces to take both guide bars and main beam. The guide bars are welded to both faces of the tube. The main beam is welded to the guide bars only on the face remote from the applied load.
Guide bars provide a region of decreasing fixity between the anchor and the main beam 3 of both FIGS. 2 and 3, the region extending from the face of the anchor 1 to the part of the main beam which is clear of the guide bars where the main beam is subjected to severe bending deformations. It is believed that the arrangement of FIG. 3 provides a second region of decreasing fixity for the main beam between its welds to the guide bars on the reverse face and the front face 8 of the tubular anchor.
FIG. 4 shows the conformation of an absorber according to the pattern of FIG. 3 after it has been subjected to severe stressing. Guide bars 4 are permanently bent. When main beam 3 is again moved to make contact wiht the guide bars in their new position they can be deflected still further elastically about their present position. If they are stressed still more heavily they can be plastically moved to a new position which is still more deflected.
Since in the embodiment of FIG. 3 the axis of the main beam and of the guide bars and the line of action of the loads will all be in the same plane, these absorbers can be designed to take up only a small transverse space and can be put within a wall panel. The absorbers of FIG. 2 could also be used in this way but they are less suitable.
It is obvious that the embodiment of FIG. 3 can be considered as an extension of the embodiment of FIG. 2 in which a number of square beams lie side by side. This process may be extended by installing absorbers in multiple.
As an alternative, absorbers may be duplicated by joining two end-to-end. In FIG. 5 is shown an absorber which is effectively two of the embodiments of FIG. 2 joined by their free ends. The force-transfer means 5 and 6 are no longer needed. There are two anchors 1 and 11, a single main beam 3, and two sets of guide bars 4 and 14. The two anchors are rigidly fixed. One could be fixed to the foundation 2 and the other to the base 7 of a building. In FIG. 5 is shown also a development which is required in some circumstances, i.e. when a tall building on a small base is subjected to earthquake forces it may suffer uplift. The extensions 13 and 23 on the main beam 3 are continuous with main beam 3 and form a tensile member. Extension 13 is rigidly fixed within the building and extension 23 is rigidly fixed to the foundation. A number of units corresponding with FIG. 5, installed around the edge of a building, can be a safeguard against uplift.
FIG. 6 shows a doubling of the pattern of FIG. 3. The anchor 1 is now the mid-point of a main beam 3/13 and rigidly fixed to it are guide bars 4 and 14. Force is applied at the two free ends of the main beam. It would be normal to arrange that the two ends were so connected that the forces applied were in phase and this reduces moments on the anchor 1. FIG. 7 shows a doubling of the pattern of FIG. 2, corresponding in general with the doubling of FIG. 3 which is shown in FIG. 6. The absorber is extended by a reflection about its base. At the middle of the main beam 3/13 is a connection 7 to one of the two members which move relative to each other and fitted to it are guide bars 4 and 14. 5/6 and 15/16 are symmetrical means for moving the main bar in phase at its two ends.
In FIG. 8, the pattern of FIG. 2 is duplicated by reflection about its free end. The anchor now comprises a bracket 20, similar to that which holds an upper force applying means 15/16 in FIG. 7. It now holds an upper anchor 11. The short cylinder 6 is replaced by a hole in a force applying bar 7. Guide bars are advantageous at the ends of the beam, and there should be some provision for axial motion of a beam end.
An energy absorber which contains one or more of the basic components may be designed for an endurance which lies in the range from a few tens of cycles to a few hundreds. It may be designed for an force from a few tens of Newtons to a few Mega-Newtons.
FIG. 10 shows a variation of FIG. 3 which is also applicable to FIG. 2. Guide bars 4 in both these Figures have been assumed to be of mild steel. FIG. 10 shows a pattern that has been found effective if a more readily deformable material such as lead is used. Bars 24 are of lead. Bars 25 may be of lead, or of steel if greater stiffness is wanted. It has been found that if both 24 and 25 are of lead, a region of decreasing strain is induced in that part of the main beam 3 adjacent to anchor 1.
FIG. 11 shows a simplification that may be applied to the pattern of either FIG. 2 or FIG. 3. These Figures show a system of guide bars that involves rather expensive welding. In FIG. 11, increase of rigidity in the anchor (by thickening in the Figure, but other methods are possible) is, in a sense, a replacement for guide bars. It will be noted that beam 3 is welded only on the side of anchor 1 which is remote from the applied force. When a force is applied, the effect of the stiffness of the anchor is to increase the volume in which plastic strain occurs in beam 1, and decrease the concentration of strain in it.
The energy absorbers have so far been discussed principally in relation to the absorption between a foundation and a structure above. A number of other applications have been envisaged and one of them is one of the two matters shown in FIG. 9. The first matter is a further extension of the device of FIG. 3. Two of these devices were taken and were joined at their free ends. They would be absorbers in relation to forces applied relatively at the two anchors. FIG. 9 shows a possible application for one or more of the double ended version of FIG. 3 to absorbing the energy with absorbers mounted in a diagonal brace in a framed structure.
Absorbers according to FIGS. 2 and 3 have a still further field of application. They can provide a component which is rigid when subjected to moderate loads, but is flexible when subjected to severe loads. They could in other words provide a cheap, compact but very stiff spring. The shape of response against applied force could be controlled by the relative proportions of the deformation beam and the guide bars.
In this description, the axes of a deformation beam and of guide bars are referred to as being perpendicular to the anchor so that they are fixed at a peripheral plane of the beam and guide bars, i.e. a plane perpendicular to the axis. This arrangement is not essential. The axes of the anchor and of the beam may be inclined to each other.
The forms of anchor so far described are somewhat particular. Other forms than those referred to may be used, so long as they hold the foot of the main deformable beam and the feet of the guide beams with what is effectively complete rigidity. The invention may in fact be considered to be a means of providing a beam adapted to bend under load, especially under cyclic load, and to be of such a composite form that at its anchor it is held with effectively absolute rigidity, and at a short distance away from its anchor it is so constrained by parts additional to the main beam and not attached to it that the stiffness of the additional parts, equal to the substantial part of the stiffness of the main beam, is added to that of the main beam. As a result, the maximum radius of curvature of the main beam is decreased and stress concentration is reduced. At the same time, relative motion between the main and subsidiary beams causes, by imposing surface compressive stresses, an increase in the fatigue strength of the main beam. It is considered that any conformation which will lead to the attainment of these objectives will lie within the present invention.
REFERENCES
1. surface Stressing of Metals. Moore, Murray, Alman, Horger and Kosting. American Society for Metals, Cleveland, U.S.A. 1947 (p. 40-43).
2. Proceedings of the 44th Annual Meeting, June 1941 of the American Society for Testing Materials. American Society for Testing Materials, Vol. 41, 1941 (p. 672).
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A cyclic absorber of energy in massive quantities. It is suitable for installation between two parts of a structure that would be caused to move relative to each other by earthquakes or heavy winds. Energy is absorbed by the cyclic, flexural deformation into the plastic range of a main beam which may be a single or double cantilever. Strain of the main beam may be distributed and the capacity of the device increased, by short auxiliary cantilevers initially in contact with the main beam.
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This is a continuation of application Ser. No. 07/483,609, filed on Feb. 22, 1990 now abandoned.
TECHNICAL FIELD
The present invention relates to fluid dispensers and more particularly to squeeze-bottle dispensers having collapsible, fluid-containing bags therein. Even more particularly, the present invention relates to means for resisting the collapse of a fluid-containing bag near the discharge end of a bag-in-squeeze-bottle fluid dispenser.
The present invention further relates, in a particularly preferred embodiments, to such means which can be readily inserted within the collapsible, fluid-containing bag after the bag has been filled with the fluid to be dispensed.
BACKGROUND ART
Prior art flexible walled bottles, which are manually deformable to decrease their inner volumes so as to force out the contents thereof, are known as squeeze-bottles. When the deformed bottle wall is released, it is designed to be self-restoring to its undeformed condition. As the bottle is emptied of its fluid, air is drawn into the bottle to replace the fluid. The fluid being dispensed is typically incompressible and heavier than air. When the bottle is set upright on its base, the fluid flows to the bottom of the bottle. If a nearly empty squeeze-bottle remains substantially upright, no fluid is dispensed when it is squeezed, since air is first pumped out and then sucked back into the bottle. If the same bottle is inverted, and the fluid is resistant to flow, the fluid remains inaccessible until it has had time to flow from the bottom of the bottle to substantially block the bottle's discharge opening. Only then does squeezing the bottle compress air behind the fluid and force it out of the discharge opening. The wait may be quite inconvenient, especially when fluids resistant to flow are residing in nearly empty, tall bottles. In extreme cases, gravity alone does not enable such a fluid to flow to the discharge opening in the bottle.
Consequently, consumers have recognized the need for an "always ready to dispense" squeeze-bottle for flow resistant fluids. One known means for satisfying that need involves the addition of a collapsible fluid-containing bag inside a squeeze-bottle. Streck U.S. Pat. No. 4,865,224 and Uhlig U.S. Pat. No. 4,098,434 disclose such structures. When a fluid-containing bag is sealingly secured to the discharge end of such a squeeze-bottle, air is trapped between the inside of the squeeze-bottle and the outside of the bag. This air is compressed when the bottle is subsequently squeezed. Air pressure is thereby transmitted to the bag, causing the bag to discharge its fluid. Compression of the air trapped between the inside of the squeeze bottle and the outside of the bag can be accomplished by blocking a vent hole in the squeeze bottle with a finger or by providing the squeeze bottle with a one-way vent valve.
When a bag-in-squeeze-bottle dispenser functions properly, successive squeezes of the bottle cause the bag inside to collapse around the decreasing volume of fluid remaining in the bag. However, the "always ready to dispense" benefit is not automatically realized in prior art bag-in-squeeze-bottle dispensers unless the bag is prevented from collapsing upon itself near the discharge opening. Unless means are provided to prevent the premature choking off of fluid flow, not only will the "always ready to dispense" benefit be lost, but a significant volume of fluid will remain completely inaccessible within the bag. This causes the consumer to either waster the fluid product remaining within the dispenser or go to the trouble of manually breaking the package open to access the fluid product remaining therein. Neither of these alternatives are acceptable to most consumers.
Although it is believed that air pressure developed around the outside of the flexible bag by squeezing of the outer container is uniformly distributed in prior art bag-in-squeeze-bottle packages, it has been observed that, if left unsecured to the outer container, the flexible bag tends to first collapse on itself at its discharge end regardless of the dispenser's orientation. When the bottle is inverted, the unconstrained bag is free to slump toward the discharge end where its folds may further aggravate this fluid flow choking problem. Accordingly, one object of the present invention is to prevent the collapse of a fluid-containing bag in a squeeze-bottle in order to avoid disruption of fluid discharge until substantially all of the fluid has been dispensed from the bag.
Prior art attempts to solve this problem have involved securement of the bottom end of the bag to the bottom end of the container to force the bag to collapse in an inwardly radial direction. However, solutions of this type have proven difficult to implement. In addition, they have not proved completely effective, since the uppermost portion of the bag may still prematurely collapse and prevent fluid product in the lowermost portions of the bag from reaching the bag's discharge orifice.
Another means of preventing such premature collapse of the fluid-containing bag is by securing the bag to the inner sidewall of a squeeze-bottle approximately midway along the longitudinal axis of the bottle. Such constraint is intended to cause the bag to collapse in a predictable fashion, i.e., the bag inverts substantially about its mid-point securement and thereby avoids the fluid choking problem.
Harrison U.S. Pat. No. 2,608,320 discloses a squeezable container having a cylindrical bag cartridge consisting of both a flexible lower cylinder half and a rigid upper cylinder half. The discharge end of the dispenser is at the upper end of the rigid half. The fluid-containing bag requires connection to the lowermost end of the rigid portion of the container. This design provides controlled bag collapse by inversion of the flexible portion of the bag into the rigid portion of the container.
One difficulty associated with squeeze bottles employing such invertible bags is that it may be difficult to readily gain the access needed to secure the flexible bag and the outer container to one another at the desired predetermined points. To provide suitable access for the sealing tools may negatively impact dispenser production speeds or impose design limitations on the shape of the dispenser.
Another difficulty with squeeze bottles employing such invertible bags is that when a bag inverts axially upward relative to the base of the container, the uppermost end of the container becomes heavier, thereby requiring a relatively wide base to maintain stability against tipping toward the end of the dispenser's life cycle. This factor tends to limit design flexibility in terms of the shape of the outer container.
Accordingly, it is another object of the present invention to provide a bag-in-squeeze-bottle fluid dispenser which can be reliably manufactured and filled at high speed and which overcomes many of the aforementioned problems and/or design limitations inherent in prior art bag-in-squeeze-bottle dispensers.
DISCLOSURE OF THE INVENTION
To provide maximum flexibility for squeeze-bottle shape and design, it has been found desirable to substantially limit bag collapse axially upward and to encourage radial bag collapse instead.
However, to minimize the difficulty of implementation, no attempt is made to secure any portion of the flexible bag to the bottom or sidewalls of the flexible squeeze-bottle. Rather, it has been found that suitable support means can be inserted inside the flexible bag, said support means extending from the discharge orifice of the container substantially to the bottom of the bag. The internal bag support means substantially prevents the bottom of the bag from moving in the direction of the discharge orifice when the dispenser is inverted and product is dispensed.
The bag support means preferably comprises a three-dimensional structure having at least one internal fluid passageway extending along its entire length and exhibiting a relatively high open area long its entire length. The high open area of the bag support means makes it nearly impossible for the radially collapsing flexible bag to completely block the flow of fluid product from within the bag into the internal passageway defined by the bag support means and ultimately out the discharge orifice of the dispenser, at least until the bag has been substantially emptied.
In a particularly preferred embodiment of the present invention, the internal bag support means is inserted through the discharge orifice of the dispenser after the flexible bag has been inserted into the bottle, the bag's discharge orifice has been secured in sealed relation to the discharge orifice of the bottle and the bag has been filled with the fluid product to be dispensed. This eliminates any possible interference of the internal bag support means with the filling operation and permits relatively high speed handling of dispensers of the present invention by the manufacturer during the filling, support inserting and closure applying operations.
In a particularly preferred embodiment, the objects of the present invention are achieved by employing an open helix structure as an internal bag support means in a bag-in-squeeze-bottle fluid dispenser of the present invention. A preferred dispenser comprises: an outer container or bottle having at least one resiliently deformable sidewall and an open discharge end comprising a discharge orifice which is normally located within the container's finish; a fluid-containing flexible bag housed within the outer container and having a discharge orifice secured in sealed relation across the discharge orifice of the outer container; vent means in communication with the space between the outer container and the flexible bag, the vent means being capable of forming a seal to the atmosphere to permit the application of air pressure to the flexible bag by squeezing the resiliently deformable sidewall of the outer container and venting of the space between the flexible bag and the outer container to atmosphere when the resiliently deformable sidewall is released; and internal bag support means extending from the discharge orifice of the flexible bag substantially to the bottom of the flexible bag for resisting the collapse of the bag near its discharge end as well as along substantially its entire length. The internal bag support means enables fluid from all regions of the bag to reach the discharge orifice of the bag with minimum flow restriction until substantially all of the fluid has been dispensed from the flexible bag.
The particular manner in which the bag is secured in sealed relation to the discharge orifice of the outer container is non-critical in the practice of the present invention. The same is true with respect to the particular manner in which the internal bag support means is secured within the flexible bag of the dispenser. However, in its most preferred form, the internal bag support means disclosed herein can be inserted through the discharge orifice of the dispenser after the filling operation has been completed. Thus, bag-in-squeeze-bottle fluid dispensers of the present invention can readily be filled with fluid product at high speed using filling nozzles which penetrate the discharge orifice of the dispenser during the filling operation without any interference from the internal bag support means.
In a particularly preferred embodiment of the present invention, a hollow stepped tube to which the discharge orifice of the flexible bag is sealingly secured includes an internal fluid passage through which the bag support may be axially slid after the filling operation has been completed. This passage provides fluid communication from the discharge orifice of the flexible bag through the discharge orifice of the squeeze bottle. The bore in the hollow stepped tube is preferably sized to substantially coincide with the external cross-section of the internal support means and is of sufficient length that the internal bag support means is precluded from substantial lateral movement after it has been fully inserted substantially to the bottom of the flexible bag. The bottom of the flexible bag will substantially prevent the internal bag support means from becoming dislodged inside the container, since the length of the bag will limit the axial penetration of the bag support means throughout the life of the dispenser. If desired, the internal bag support may also be prevented from moving axially out of the dispenser by securing an ancillary retaining member, a product discharge valve or both across the discharge orifice of the hollow stepped tube. Thus, the internal bag support means is unsealingly held within the passage in the hollow stepped tube or housing.
Several alternative means for resisting bag collapse may be employed in practicing the present invention. One particularly preferred means comprises an extruded plastic helix with a pitch equal to about half of its diameter. The ratio of helix diameter to extrusion diameter generally determines the flexibility of such an extruded plastic helix. A flexible helix which not only bends as the bottle is tilted, but which also compresses to a limited degree to permit the bag to collapse axially somewhat when the dispenser is inverted is particularly preferred. Allowing a limited, but controlled degree of axial collapse in the flexible bag allows the bag to maintain a greater axial cross-section for a longer portion of the dispenser's life cycle. Thus, contact between the flexible bag and the longitudinally extending portions of the internal bag support means is not generally made until a substantial portion of the dispenser's fluid contents has been discharged. The high open area of the helix along with its longitudinal and axial flexibility normally results in very small amounts of residual fluid being left within the thin flexible bags employed in dispensers of the present invention when the package's useful life is at an end.
Another preferred internal bag support means comprises a spline having multiple open channels extending substantially the length of the bag. In a particularly preferred embodiment if comprises an extruded plastic spline with 3 to 6 radial webs cantilevered from a centrally located cylindrical member. The radial webs prevent collapse of the flexible bag against the centrally located cylindrical member. Thus, fluid is free to enter and pass along each channel between adjacent webs when the resiliently deformable sidewall of the outer container is squeezed. This particular alternative is believed to be one of the least expensive bag collapse resisting means to fabricate.
Another preferred internal bag support means suitable for practicing the present invention comprises an extruded plastic scrim tube, which like the helix, has some structural flexibility as well as high open area.
Still another preferred internal bag support means comprises a flexible plastic conduit having a multiplicity of apertures extending substantially along its entire length.
In a particularly preferred embodiment of the present invention the means for securing the bag in sealed relation to the discharge orifice in the outer container comprises a substantially rigid, hollow stepped tube or housing having an outermost surface which is sealingly secured in the discharge orifice of the outer container. The smaller diameter lowermost portion of the stepped tube includes a circumferential groove for retaining an elastic band. The open end or neck portion of the bag containing the bag's discharge orifice slips over the smaller lowermost end of the stepped tube, and the elastic band sealingly gathers the bag's discharge orifice into the groove. The bag and stepped tube are preferably preassembled while the bag is in a collapsed or folded state and thereafter inserted through the discharge orifice of the outer container as an assembly prior to filling. The collapsed or folded bag is thereafter expanded by a gas pressure pulse introduced through the fluid passage in the stepped tube.
Since the sealed bag/stepped tube connection is inside the container when the dispenser is in use, any pressure applied to the bag by squeezing the outer container is also applied across this connection between the flexible bag and the stepped tube. Thus, once sealed the bag/stepped tube connection remains leak-tight regardless of how much pressure is applied by squeezing the outer container.
In a particularly preferred embodiment a bag-in-squeeze-bottle dispenser of the present invention further comprises a one-way fluid discharge valve to prevent or at least control the volume of outside air being sucked back into the fluid-containing bag when the squeezing forces are removed from the squeeze bottle.
BRIEF DESCRIPTION OF THE DRAWINGS
While the specification concludes with claims that particularly point out and distinctly claim the subject matter regarded as forming the present invention, it is believed that the invention will be better understood from the following detailed description with reference to the drawings in which:
FIG. 1 is a greatly simplified schematic perspective view of a non-round bag-in-squeeze-bottle fluid dispenser of the present invention taken from its discharge end;
FIG. 2 is a greatly simplified schematic exploded elevation view of the bag-in-squeeze-bottle dispenser of FIG. 1, showing the various components which are contained inside the squeeze-bottle shown in FIG. 1;
FIG. 3 is a greatly simplified schematic cross-sectional elevation view of the squeeze-bottle of FIG. 1, taken along section line 3--3 of FIG. 1;
FIG. 4 is a greatly simplified schematic, partially exploded cross-sectional elevation view of the various components shown in FIG. 2;
FIG. 5 is a greatly simplified schematic, partially exploded, cross-sectional elevation view of an alternative construction for the internal bag support means for resisting bag collapse which may be employed with flexible bags of the type disclosed in FIGS. 2-4;
FIG. 5A is a greatly simplified schematic cross-sectional view of the internal bag support means shown in FIG. 5, said view being taken along section line 5A--5A of FIG. 5;
FIG. 6 is a greatly simplified schematic, partially exploded, cross-sectional elevation view of another alternative construction for the internal bag support means for resisting bag collapse which may be employed with flexible bags of the type disclosed in FIGS. 2-4;
FIG. 7 is a greatly simplified schematic, partially exploded, cross-sectional elevation view of still another alternative construction for the internal bag support means for resisting bag collapse which may be employed with flexible bags of the type disclosed in FIG. 2-4; and
FIG. 8 is a greatly simplified schematic, cross-sectional elevation view of still another alternative construction for the internal bag support means for resisting bag collapse which may be employed with flexible bags of the type disclosed in FIGS. 2-4.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings, and more particularly to FIG. 1, there is shown a preferred bag-in-squeeze-bottle fluid dispenser embodiment of the present invention, generally indicated as 20. Bag-in-squeeze-bottle dispenser 20 comprises a squeeze-bottle 22 having flexible sidewalls 122; a discharge orifice 24 located within finish 124; and plug 100, having a discharge opening 30. Discharge opening 30 is preferably between about 0.100 inches and about 0.300 inches in diameter, depending on the flow resistance of the fluid to be dispensed and the normal dosage volume. Because of the relatively small size of discharge opening 30, plug 100 is normally inserted into the discharge orifice 24 of squeeze bottle 22 after fluid filling in order to provide maximum clearance for the filling nozzle.
The flexible container comprising squeeze-bottle 22 is preferably oval in cross-section having a minor axis 34 and major axis 36. Although the present invention functions irrespective of squeeze-bottle shape, it is believed that an oval bottle provides the greatest internal volume displacement for a given sidewall deflection. For example, a 6 oz. oval bottle with major/minor axis ratio of 1.9 has a displacement of 21 percent of its total volume when its sidewalls are squeezed 0.75 inches; whereas a round bottle with similar volume has a displacement of only 6 percent of its total volume with the same squeeze deflection.
The greater the volume displacement per unit of deflection of the squeeze-bottle's sidewalls, the lower will be the deflection needed for a given dose of fluid to be dispensed. Since squeeze force generally increases with deflection, and low squeeze force is in most instances preferred, lower sidewall deflection for a desired dose has also been found to be generally preferred. Although maximizing the major/minor axis ration of the oval will also maximize the volume of fluid dispensed for a given deflection of the sidewalls, this ratio is normally limited by other practical considerations, such as bottle toppling stability, bottle forming considerations, and overall aesthetics. The preferred oval squeeze-bottle major/minor axis ration used in practicing the present invention preferably ranges from about 1.1 to about 3.0, and most preferably from about 1.5 to about 1.9.
The bottle finish 124 of squeeze-bottle 22 normally includes some type of securement means (now shown) on its outermost surface for securing a removable closure (also not shown) thereto, e.g., screw threads, grooves, bosses, etc. Which mate with a complementary fastening feature on the closure.
FIG. 1 shows the uppermost flange 72 of hollow stepped tube 70. The flange 72 helps to seal first cylindrical surface 74 of stepped tube 70 within the discharge orifice 24 in finish 124 of squeeze-bottle 22. Hollow stepped tube 70 is more fully illustrated in FIGS. 2 and 3. Stepped tube 70 is preferably a substantially rigid cylindrical housing and can be formed of plastic by injection molding to provide accurate dimensional tolerances. Its primary purpose is to provide a suitable means for connecting various parts employed within dispenser 20 in sealed relation to one another and to the discharge orifice 24 in finish 124 of squeeze-bottle 22.
In the embodiment shown in FIGS. 1-3, stepped tube 70 has an uppermost flange 72 and a first cylindrical surface 74. First cylindrical surface 74 is sized to interference fit stepped tube 70 into discharge orifice 24 in finish 124 of squeeze-bottle 22 in an air-tight manner. It also has a secondary cylindrical surface 76 which is smaller than the first cylindrical surface 74 so that it will fit inside the discharge orifice 42 of flexible bag 40. A circumferential groove 80 is provided about the periphery of secondary cylindrical surface 76 and is sized such that an elastic band 50 may be stretched over the neck portion 46 of bag 40 containing discharge orifice 42, sealingly gathering the neck portion of the bag into circumferential groove 80 without the stretched diameter of elastic band 50 exceeding the diameter of first cylindrical surface 74.
The particular means employed to sealingly secure discharge orifice 42 of bag 40 about secondary cylindrical surface 76 of hollow stepped tube 70 is non-critical, provided the particular means selected does not exceed the cross-section of first cylindrical surface 74, e.g., adhesives, heat sealing, etc. Maintaining the aforementioned size relationship facilitates easy insertion of the lowermost portion of hollow stepped tube 70 into the discharge orifice 24 in finish 124 of squeeze-bottle 22 with the bag 40 sealingly secured thereto.
Flexible bag 40 is preferably comprised of a thin plastic film, preferably having a thickness from about 0.5 to about 5.0 mils thick, and even more preferably from about 1.0 to about 2.5 mils thick. The bag's wall thickness is limited primarily by stiffness and cost considerations. When inserted into squeeze-bottle 22 through the discharge 24 in finish 124, the flat bag 40 is preferably folded or otherwise gathered. Expansion of the folded or wrinkled bag 40 inside the preferred oval shaped squeeze-bottle 22 is readily achieved by injecting a low pressure gaseous pulse through hollow stepped tube 70 when the bag wall thickness is less than about 5.0 mils.
Minimizing the bag's thickness will, of course, provide maximum economy from a cost of materials standpoint. Quite unexpectedly, however, there appears to be a relationship between lower bag wall thickness and higher levels of residual fluid which cannot be removed from the bag at the end of the dispenser's life cycle. Therefore, the lower limit on bag wall thickness may, as a practical matter, be a compromise between maximum fluid removal capability and minimum cost of the bag material.
To construct preferred flat flexible bags 40 of the present invention two layers of film or one layer of film folded upon itself are first fin-sealed in the flat, preferably by heat fusion, and then trimmed to the desired shape. The resulting fin-sealed perimeter 44 shown in FIGS. 2 and 3 is shaped to enable flexible bag 40 to be expanded within squeeze-bottle 22 of dispenser 20 such that the outermost surfaces of bag 40 will substantially coincide with and contact the inside surfaces of flexible squeeze-bottle 22. When the collapsed flexible bag 40 is fully expanded within squeeze-bottle 22, the internal volume of bag 40 preferably approaches at least about 90 percent of the available volume inside squeeze-bottle 22.
In order for flexible bag 40 to be fully expanded within an oval squeeze-bottle 22, flexible bag 40 is preferably oriented upon insertion so that its flat plane is substantially aligned with the major axis 36 of squeeze-bottle 22 during the bag and stepped tube insertion process. If desired, a pair of complementary guides, such as a raised boss and a complementary keyway (not shown) can be provided on first cylindrical surface 74 of hollow stepped tube 70 and on the interior of the discharge orifice 24 of squeeze-bottle 22, respectively, to ensure consistent alignment of the flat plane of bag 40 with the major axis 36 of oval squeeze-bottle 22. The particular alignment system employed in the practice of the present invention is non-critical, provided it does not adversely affect the atmospheric seals which must be established at various locations within the dispenser.
The viscosities of fluids normally used in bag-in-squeeze-bottle dispensers of the present invention typically range from about 100 cps to about 1000,000 cps; most typically from about 3,000 cps for shampoos to about 30,000 cps for beauty fluids.
To ensure that such fluids are maintained at the discharge orifice of the dispenser in a condition ready to dispense at all times, a one-way product discharge valve may be installed to substantially prevent outside air from being sucked back into the bag 40 after fluid flow from the dispenser terminates and the squeezing force applied to the resiliently deformable sidewalls 122 of squeeze-bottle 22 is released. The need for such a valve depends upon the discharge opening design of the dispenser and the resistance of the fluid to flow. Such a fluid discharge valve is particularly beneficial for lower viscosity fluids.
In FIG. 2 a preferred fluid product discharge valve is shown as 90. Valve 90 is what is commonly known in the art as a "duckbill" valve. Duckbill valve 90 is shown inserted between plug 100 and hollow stepped tube 70. As can be seen more clearly in FIGS. 2-4, duckbill valve 90 is assembled partially inside cylindrical plug 100, which in turn is sealingly secured inside bore 88 of hollow stepped tube 70, as by an interference fit. Plug 100 thereby helps to establish a resilient seal between flange 94 on duckbill valve 90 and fluid passage 86 in stepped tube 70. The discharge end 92 of duckbill 90 is inside and adjacent the discharge opening 30 of plug 100. Product discharge valve 90 will permit fluid to pass through its discharge end 92 when the resiliently deformable sidewalls 122 of squeeze-bottle 22 are squeezed, but will substantially prevent air from being drawn back inside flexible bag 40 when the squeezing force is removed from resiliently deformable sidewalls 122.
A one-way vent valve 32 is preferably installed in the shoulder of squeeze-bottle 22 to admit air from the atmosphere into the area between flexible bag 40 and squeeze-bottle 22 to compensate for any dispensed fluid. The one-way feature allows air pressure to be developed inside squeeze-bottle 22 when it is squeezed. In the illustrated embodiment one-way vent valve 32 also comprises a standard flanged rubber duckbill valve which preferably fits into an aperture 38 in the shoulder of squeeze bottle 22.
Valve 32 is preferably interference fit into hole 38 in the shoulder of squeeze-bottle 22 to form a seal therewith so that its discharge end 34 is inwardly oriented, i.e., so that atmospheric air will enter squeeze-bottle 22 when the squeezing force is removed form resiliently deformable sidewalls 122. If the interference fit does not establish a seal, valve 32 can be adhesively bonded at hole 38, with silicone adhesive for example. For the attachment of valve 32 to be air-tight, the shoulder of squeeze-bottle 22 should experience minimum deformation when the squeeze-bottle's resiliently deformable sidewalls 122 are deflected. There are many other venting alternatives possible, such as a flapper valve or umbrella valve in the bottom of the squeeze-bottle 22 or even a ball check valve in an independent passageway through stepped tube 70. Such one-way vent valves are well known in the art.
The vent valve can also be eliminated altogether and a simple aperture provided in one of the resiliently deformable sidewalls 122 of squeeze-bottle 22. In the latter instance the user merely covers the hole with a finger when the bottle is squeezed to generate pressure within the bottle. Uncovering the hole when the squeezing force is removed vents the space between the squeeze-bottle 22 and flexible bag 40 to atmosphere.
FIG. 3 is a cross-section of the assembled dispenser embodiment 20 shown in FIG. 1. Flexible bag 40 is shown fully expanded within oval squeeze-bottle 22. Flexible bag 40 is sealingly secured by elastic band 50 to hollow stepped tube 70, which in turn is sealingly seated into the discharge orifice 24 in finish 124 of squeeze-bottle 22. Flexible bag 40 is shown in FIG. 3 filled with fluid 150 to be dispensed.
Axially secured within hollow stepped tube 70 is an extruded flexible plastic helix 60. Flexible plastic helix 60 helps to prevent flexible bag 40 from collapsing not only at the entrance to the bag's discharge orifice 42 which abuts fluid passageway 86 in hollow stepped tube 70, but substantially all along its length, which extends substantially to the bottom of flexible bag 40.
FIG. 4 is a cross-sectional, partially exploded view of the components comprising bag-in-squeeze-bottle dispenser 20 shown in FIGS. 1-3.
when uppermost flange 72 of hollow stepped tube 70 seats against the uppermost surface 26 of the finish 24 of squeeze-bottle 22 flexible bag 40 reaches its preferred axial position inside the squeeze-bottle 22. Then 2 and 3 psig compressed air is preferably applied to fluid passage 86 in stepped tube 70 in order to fully expand the folded or collapsed flexible bag 40 within squeeze-bottle 22. As flexible bag 40 expands, the displaced air between the interior of squeeze-bottle 22 and flexible bag 40 escapes to the atmosphere through hole 38 in squeeze bottle 22.
One-way vent valve 32 is sealingly secured in hole 38 in squeeze bottle 22 after the folded or collapsed flexible bag 4- has been fully expanded within squeeze bottle 22 to avoid trapping air in the space between flexible bag 40 and squeeze bottle 22, as this would interfere with expansion of the bag.
Once expanded, flexible bag 40 may be filled with fluid 150 through fluid passage 86 in stepped tube 70. After flexible bag 40 is filled, extruded plastic helix 60, which is axially slidable within fluid passage 86 in stepped tube 70, is inserted until its lowermost end approaches the bottom of the filled flexible bag 40.
Plug 100, with fluid discharge valve 90 preassembled into it, may thereafter be pressed into the bore 88 of stepped tube 70 to form a seal therewith and complete the assembly of dispenser 20. Flange 94 of resilient duckbill valve 90 provides an airtight resilient seal with fluid passage 86 in stepped tube 70 when sandwiched between plug 100 and stepped tube 70, as generally shown in FIG. 3. a closure (not shown) is normally applied to complete the manufacturing process and to ready the filled dispenser 20 for shipment to the end user.
Insertion of plug 100 and discharge valve 90 into bore 88 of stepped tube 70 also secures the axially slidable internal bag support member comprising helix 60 in substantial axial alignment with the discharge end of dispensing package 20. The bottom of the flexible bag 40 prevents the helix 60 from becoming downwardly dislodged from fluid passage 86 in stepped tube 70, while plug 100 and valve 90 prevent it from becoming upwardly dislodged from fluid passage 86 in stepped tube 70.
Referring now to FIGS. 5, 6 and 7, alternative internal bag support constructions are shown. The remaining components of the dispenser are identical to those described in conjunction with FIGS. 1-4. Accordingly, only the subassembly comprising flexible bag 40, stepped tube 70 and elastic band 50, which is identical to the corresponding subassembly shown in FIG. 4, and various alternative embodiments of the internal bag support means which are ultimately inserted into the flexible bag 40 after the dispenser has been filled with fluid are shown in FIGS. 5, 6 and 7.
FIG. 5 shows a subassembly comprising flexible bag 40 sealingly secured to a hollow stepped tube 70 in a manner identical to that shown and described in connection with dispenser 20 shown in FIGS. 1-4. The subassembly is inserted into squeeze-bottle 22 (not shown in FIG. 5) which is also identical to that shown in FIGS. 1-4. However, after the flexible bag 40 has been filled with the particular fluid to be dispensed, an internal bag support member comprising a spline 160 is inserted through fluid passage 86 in stepped tube 70 and into flexible bag 40.
Spline 160 preferably comprises a flexible extruded plastic cross-shaped piece having four perpendicular radial webs 162 extending from a central cylindrical portion, as shown in the cross-section of FIG. 5A. The radially extending webs 162 act to prevent collapse of flexible bag 40 in a manner generally similar to that described in connection with the flexible plastic helix 60. Between each radial web 162 is a channel which permits fluid to reach fluid passage 86 in stepped tube 70 from any point along the length of the spline.
If desired, the splines employed on internal support member 160 can be non-linear along the length of the spline, e.g., they may be twisted for form a continuous helix.
Alternative splines may have more or fewer radial webs and consequently more or fewer corresponding channels along their length.
Spline 160, like helix 60 shown in FIGS. 2-4, has a length which always maintains one of its ends axially secured within fluid passage 86. Axial movement of spline 160 is limited by the bottom of flexible bag 40 at one end and by the plug 100 and discharge valve 90 at the other end.
FIG. 6 shows another subassembly of the present invention wherein a flexible bag 40 is sealingly secured to a hollow stepped tube 70 in a manner identical to that shown and described in connection with dispenser 20 of FIGS. 1-4. The internal bag support means disclosed in FIG. 6 comprises an extruded plastic scrim tube 260 which can be slid axially into the fluid passage 86 in stepped tube 70 after filling of flexible bag 40.
Scrim tube 260 is preferably cut from a continuously formed tube of filaments extruded from counterrotating dies. The open area of scrim tube 260 may be varied by the process through a range estimated at from about 20 percent to about 80 percent. In general, the higher the open area of the scrim the more flexible will be the scrim. The practical upper limit on open area is believed to be just short of the point at which the scrim tube may be completely collapsed upon itself when the resiliently deformable sidewalls 122 of squeeze-bottle 22 are squeezed.
FIG. 7 shows yet another subassembly of the present invention wherein a flexible bag 40 is sealingly secured to a stepped tube 70 in a manner identical to that described in connection with dispenser 20 shown in FIGS. 1-4. The internal support means disclosed in FIG. 7 comprises a perforated conduit which can be slid axially into the fluid passage 86 in stepped tube 70 after filling of flexible bag 40. Perforated conduit 360 preferably comprises an extruded plastic tube with holes 365 mechanically punched in the tube wall from at least two different angles.
Alternative perforated conduits may have widely differing open areas, depending on the viscosity of the fluid to be dispensed and the geometry and stiffness of flexible bag 40. A particularly preferred conduit comprises a plastic straw with 0.31 inch outside diameter and 0.28 inch internal diameter having 0.25 inch diameter holes punched every 0.5 inches along its length, staggered at 90° to each other. It has an open area of about 20 percent.
In general, it has been observed that the fewer the number of perforations in the conduit, the greater will be the volume of residual fluid left in the dispenser at the end of its useful life.
FIG. 8 discloses still another embodiment of internal bag support means which may be employed to resist premature collapse of flexible bag 40 during the dispensing cycle. The subassembly shown in FIG. 8 may be substituted for any of the subassemblies shown in FIGS. 5, 6 or 7 for use in the dispenser 20 shown in FIGS. 1-4.
The flexible bag 40, having discharge orifice 42 secured by an elastic ring 50 in a groove on stepped tube 870 are identical to the correspondingly numbered elements shown in FIGS. 5, 6 and 7. However, stepped tube 870 differs from stepped tube 70 in one principle respect. Namely, it includes a third cylindrical portion 878 depending from secondary cylindrical portion 876, as generally shown in FIG. 8. Fluid passageway 886 in stepped tube 870 extends through cylindrical portions 874, 876 and 878, as generally shown in FIG. 8
The third cylindrical portion 878 of stepped tube 870 can be employed to mount the internal bag support means 860, such as the extruded plastic scrim 860 shown in FIG. 8. The inside diameter of the internal bag support means 860 is preferably sized so that the external surface of third cylindrical portion 878 will securely engage the support means 860. Alternatively, adhesives, heat seals or mating mechanical elements may be employed to secure the bag support means 860 to the cylindrical portion 878 of stepped tube 870.
As will be appreciated, a spiral plastic helix or an apertured conduit could easily be substituted for the scrim illustrated in FIG. 8.
The subassembly illustrated in FIG. 8 differs from the subassemblies illustrated in FIGS. 5, 6 and 7 in that the internal bag support means is not slidably secured within the discharge orifice of the flexible bag 40 or plastic bottle 22.
Accordingly, the internal support means 860 is inserted along with the collapsed bag 40 through the discharge orifice 24 of squeeze-bottle 22 and the bag is thereafter expanded. Filling of the bag with fluid product is performed with the internal bag support means 860 in place in the embodiment shown in FIG. 8.
As pointed out earlier herein, the particular means employed to secure the discharge orifice of flexible bag 40 in sealed relation to the discharge orifice 24 of squeeze-bottle 22 is non-critical. Accordingly, it is also possible in the practice of the present invention to sealingly secure the discharge orifice 42 of flexible bag 40 across the discharge orifice 24 in squeeze-bottle 22 without employing a stepped tube such as 70 or 870. If desired, the flexible bag may thereafter be filled with fluid product and the internal support means thereafter inserted through the discharge orifice 42 of the filled bag 40. In the latter situation, it is generally preferred that some type of structure comparable to stepped tube 70 or 870 be employed to permanently secure the discharge orifice 42 of bag 40 in sealed relation to the discharge orifice 24 in squeeze-bottle 22, as by a compression fit. If an orifice securement structure comparable to stepped tube 70 is employed for this purpose, the internal bag support means can be inserted as an independent operation. Alternatively, if an orifice securement structure comparable to stepped tube 870 is employed, the internal bag support means is preferably secured thereto prior to insertion of the orifice securement structure into the discharge orifice 42 of flexible bag 40.
Whatever method of assembly is selected for the internal bag support means, flexible bag and squeeze bottle, the remainder of the assembly operation may be identical to that described in connection with dispenser embodiment 20 illustrated in FIGS. 1-4, i.e., plug 100 containing one-way product discharge valve 90 may be press fit into counter bore 888 of stepped tube 870.
SAMPLE BAG-IN-SQUEEZE-BOTTLE PACKAGE
In constructing a sample embodiment of the present invention a 6 oz. transparent polyvinyl chloride "special oval" squeeze-bottle with a #24-415 finish having a discharge orifice 24 measuring approximately 0.69 inches in diameter and measuring approximately 2.38 inches about its major axis 36 by about 1.25 inches along its minor axis 34 was obtained from Owens Brockway of Toledo, Ohio to serve as a squeeze bottle 22. The average wall thickness of the squeeze bottle's resiliently deformable sidewalls 122 was about 0.020 inches. The squeeze bottle 22 exhibited a 1.9 major/minor axis ration and a dimension of about 5.25 inches from its base to the start of its shoulder. It was about 6.5 inches tall overall.
Hollow stepped tube 70, which was machined from polycarbonate, was about 1.44 inches long. First cylindrical surface 74 of stepped tube 70 exhibited a 0.725 inch diameter; second cylindrical surface 76 of stepped tube 70 exhibited a 0.60 inch diameter; groove 80 was about 0.19 inches wide and exhibited a 0.42 inch root diameter; bore 88 of stepped tube 70 exhibited a 0.560 inch diameter; and fluid passage 86 in stepped tube 70 exhibited a 0.33 inch diameter.
Flexible bag 40 was comprised of 1.25 mil thick low density polyethylene film.
Elastic band 50 comprised a 0.50 inch outside diameter by 0.30 inch inside diameter latex Elastrator Ring #C233N, as available from NASCO Farm & Ranch of Fort Atkinson, Wisconsin. Rubber duckbill valves 90 and 32 were comprised of rubber valves #VL196-145 and #VL1735-101, respectively, as available from Vernay Laboratories, Inc. of Yellow Springs, Ohio. Flexible plastic helix 60 comprised a 0.06 inch diameter polypropylene extrusion, with a helix inside diameter of about 0.19 inches, a helix outside diameter of approximately 0.31 inches, a helix pitch of approximately 0.16 inches and an overall length of approximately 5.75 inches. Plug 100 exhibited a discharge opening 30 measuring approximately 0.25 inches in diameter. Upon insertion, plug 100 helped to establish a resilient seal between the flange 94 in duckbill valve 90 and fluid passage 86 in stepped tube 70.
The construction of the bag-in-squeeze-bottle package was generally in accordance with that shown in FIGS. 1-4.
The resultant dispenser 20 was filled prior to insertion of the helix 60 with approximately 148 milliliters of Press® Hair Conditioner having a specific gravity substantially equal to that of water and a viscosity of about 3000 cps. The valve 90 and plug 100 were thereafter inserted. The dispenser was thereafter successively actuated by squeezing its side walls 122 until it no longer dispensed any fluid when squeezed. When disassembled, a residual of approximately 9 milliliters of product remained within the support helix 60 and flexible bag 40. Thus, approximately 94 percent of the fluid product was successfully and reliably dispensed over the dispenser's useful life.
It is believed that the bag-in-squeeze-bottle dispenser of the present invention, and many of its attendant advantages, will be readily understood from the foregoing description. Various changes may be made to its form, construction and arrangement without departing from the spirit and scope of the invention or sacrificing of its operational advantages, the forms hereinbefore described being merely preferred or exemplary embodiments thereof.
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A bag in squeeze bottle fluid dispenser capable of dispensing substantially all of the fluid product contained therein. A suitable bag support element is inserted inside the flexible bag to prevent substantial axial movement of the bag in the direction of its discharge orifice and to encourage radial collapse of the bag instead. The internal bag support means, which in a preferred embodiment comprises an extruded plastic helix, has an internal fluid passage formed within the coils of the helix and fluid communication to allow fluid contained within the bag to access the internal fluid passage along substantially the entire length of the internal bag support element. Thus, radial collapse of the flexible bag does not block the passage of fluid remaining in the bag through the discharge orifice in the bag until substantially all of the fluid contained within the bag has been dispensed. In a particularly preferred embodiment, the internal bag support element is inserted into the dispenser through the discharge orifice of the bag to a point substantially coinciding with the opposite end of the flexible bag after the bag has been filled with the fluid to be dispensed.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to German Patent Application Serial Number 102006044821.9-15, filed Sep. 14, 2006, the entire disclosure of which is hereby incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The invention relates to a refrigerant compressor provided with a muffler for an air conditioning unit in a vehicle, and more particularly to a muffler including a partition wall having a plurality of apertures formed therein.
BACKGROUND OF THE INVENTION
[0003] In vehicles, mufflers are used in order to damp noise, especially noise caused by pressure pulsations. The process of compression of a refrigerant such as CO 2 , for example, in a compressor causes pressure pulsations which can be transmitted to an air conditioning unit over an inlet and an outlet of the compressor. The pressure pulsations can be perceived as unwanted noise in an interior of a vehicle by occupants of the vehicle.
[0004] In practice, different structures are used to reduce the noise by attenuating the pressure pulsation inside or outside of the compressor.
[0005] In DE 43 42 299 A1, a refrigerant compressor is disclosed for an air conditioning unit for use in a vehicle. The compressor includes a swash plate with axially moving pistons arranged in cylinder bodies, a suction side with a suction channel and inlet valves, and a high-pressure side with outlet valves. In the compressor, a damping device is disposed including a diffuser insert disposed in the suction channel. The diffuser insert includes an inflow pipe connection followed by a pipe with a closed face and a pipe jacket with holes. The holes form a fluid connection between the suction channel and the inflow pipe connection. A disadvantage of the invention is that the diffuser is an insert that has to be manufactured separately, which increases manufacturing costs and may cause incorrect flow in a sealing region of the suction or the pressure connections.
[0006] In DE 100 11 023 A1, a muffler for a connection to a pressure outlet of a compressor is disclosed. A partition wall is disposed between a bottom wall and a top wall dividing an interior of a casing into an inflow chamber and an outflow chamber. The partition wall includes a passage zone having several small holes. Parallel to the partition wall, a passage zone is at a distance to an inflow opening and an outflow opening. The partition wall is disposed such that a gaseous medium delivered by the compressor flows from the inflow opening through the inflow chamber to the passage zone and from the passage zone through the outflow chamber to the outflow opening.
[0007] A particular disadvantage of the muffler as an external component is the amount of assembly space for disposition of the compressor. In addition, the muffler can only be used on the high pressure side of the compressor.
[0008] Further, in U.S. Pat. No. 3,577,891, a swash plate compressor is disclosed having a muffler on a high-pressure side. The muffler comprises a stilling chamber into which a pipe leads which is established as a separate component and is provided with holes for a refrigerant. The pipe is disposed in a portion of the high-pressure channel. Two disadvantages of the invention are: (1) the pipe, as a separate component, increases manufacturing costs; and (2) the muffler is prevented from being used on the suction side of the swash plate compressor.
[0009] Furthermore, in EP 1 270 945 A1, a compressor is disclosed with a structure for pressure pulsation attenuation. The structure includes two holes distanced from each other that connect an outlet chamber to an outlet. The defined distance between both holes causes two pressure waves to develop with corresponding amplitudes. The superposition of which results in a pressure wave having a reduced amplitude, and hence, in sound damping of the pressure pulsations. However, the pressure pulsations generated by a refrigerant compressor capable of utilizing CO 2 are prevented from being sufficiently attenuated.
[0010] It would be desirable to produce a refrigerant compressor having a muffler for an air conditioning unit in a vehicle that efficiently attenuates pressure pulsations and is cost effective.
SUMMARY OF THE INVENTION
[0011] In concordance and agreement with the present invention, a refrigerant compressor having a muffler for an air conditioning unit in a vehicle that efficiently attenuates pressure pulsations and is cost effective, has been surprisingly discovered.
[0012] According to the concept of the invention, a refrigerant compressor having a muffler for an air conditioning unit in a vehicle includes a swash plate or pivoting ring rotatably supported in a casing of the refrigerant compressor for driving axially moving pistons arranged in cylinder bodies, a suction side provided with an inlet channel and an inlet chamber, and a pressure side provided with an outlet channel and an outlet chamber. A muffler is provided that includes a partition wall with a plurality of apertures.
[0013] In one embodiment, the partition wall is an integral component of the inlet channel and directed towards the inlet chamber, whereby the apertures allow a refrigerant of the low-pressure side to flow between the inlet channel and the inlet chamber.
[0014] In another embodiment, the partition wall is an integral component of the outlet channel and be directed towards the outlet chamber, whereby the apertures allow a refrigerant of the high-pressure side to flow between the outlet channel and the outlet chamber.
[0015] Favorable results have been found for CO 2 refrigerant compressors. However, the CO 2 causes more intense pressure pulsations than conventional refrigerants due to a high system pressure in the vehicle air conditioning unit. Therefore, pressure pulsation attenuation of refrigerant compressors capable of using CO 2 is of considerable importance.
[0016] An advantage of the invention is the feasibility of manufacturing the complex design of the muffler. The partition wall of the muffler is an integral component of the casing which can be manufactured in one process step together with the casing, rendering the invention more cost-efficient as compared to prior art. Furthermore, the integral partition wall of the muffler can be loaded with a higher system pressure.
[0017] The partition wall is an integral component of at least one of the inlet channel or the outlet channel, causing the casing to be formed having a generally curved cross-sectional shape such as semicircular, for example, with the apertures in the curved wall extending substantially parallel to each other. The longitudinal axes of the apertures are substantially orthogonal to a direction of flow of the refrigerant into the inlet channel and to a direction of flow of the refrigerant out of the outlet channel. A face of the inlet channel and a face of the outlet channel are directed towards the inlet chamber and the outlet chamber, respectively. The faces are closed to be substantially media-tight. The apertures can be factory-made holes or capillaries with a defined flow cross-section.
[0018] Efficient pressure pulsation is achieved by dividing the flow into partial flows with the sum of the flow cross-sectional areas of all apertures in the partition wall being smaller than the flow cross-section area of the channel in which the partition is disposed. Therefore, according to the fundamentals of hydrodynamics, a hydrodynamic pressure proportion and a hydrostatic pressure proportion of the total refrigerant pressure are caused to interchange.
[0019] On the suction side of the refrigerant compressor, the reduction in cross-sectional area achieved by the apertures of the partition wall compared with the cross-sectional area of the inlet channel increases a hydrodynamic pressure and decreases a hydrostatic pressure of the refrigerant. When the refrigerant flows out of the apertures of the partition wall into the inlet chamber, the cross-sectional area increases, causing the hydrodynamic pressure and the hydrostatic pressure proportions to change.
[0020] On the pressure side of the refrigerant compressor, identical effects are achieved in that the reduction of the cross-sectional area by the apertures causes an increased hydrodynamic pressure and a decreased hydrostatic pressure of the refrigerant. When the refrigerant at a high pressure flows out of the apertures into the outlet channel, the hydrodynamic pressure and hydrostatic pressure proportions of the total refrigerant pressure are caused to change.
[0021] In another embodiment of the invention, the sum of the flow cross-sectional areas of all of the apertures in the partition wall is approximately 0.3 to 0.7 of the flow cross-sectional area of the inlet channel or the outlet channel. A smaller number of flow cross-sectional areas of all of the apertures in the partition wall is shown to improve the pressure pulsation attenuation. More generally, the flow cross-sectional area of the inlet channel or the outlet channel is always a multiple of the sum of the flow cross-sectional areas of all of the apertures in the partition wall. The minimum number of apertures in the partition wall is two, while a larger number of apertures improves pressure pulsation attenuation.
[0022] According to the invention, the reduction of the cross-sectional area for the refrigerant flow results in an increased pressure pulsation attenuation and, thus, a reduced perceptible noise in the interior of the vehicle and higher pressure losses. Therefore, the interdependent parameters are dimensioned such that a critical pressure loss of the refrigerant is not exceeded and a maximum pressure pulsation attenuation is optimized.
[0023] In order to ensure a high possible refrigerant mass flow, i.e. to avoid flow losses, the apertures of the suction side partition wall and the pressure side partition wall have different cross-sectional areas dependent on the positions of the apertures on the partition wall. The apertures disposed in a longer flow path of the refrigerant are formed to have larger cross-sectional areas to compensate for the lower pressures.
[0024] The arrangement of the apertures in the integral partition wall of the casing, or the division of the flow into several flow paths, leads to theoretically higher flow losses compared with only one opening. In another embodiment of the invention, the theoretical increase of the flow pressure losses of the refrigerant is lessened by forming the apertures such that the direction of the inflow of the refrigerant into the inlet channel or the direction of the outflow of the refrigerant out of the outlet channel is substantially curved or inclined with respect to the longitudinal axis of the inlet channel or the outlet channel, respectively. The apertures of the partition wall may be formed to have a generally circular, oval or angular cross-sectional shape, for example. For apertures having flow cross-sectional shapes other than circular, the hydraulic diameter is determined according to the formula
[0000]
d
hyd
=
4
A
U
.
[0025] Experiments have shown that when CO 2 is used as a refrigerant, efficient pressure pulsation attenuation is achieved by forming five apertures in the partition wall. Each aperture having a circular diameter of 3 mm.
[0026] Several advantages and features of the invention over prior art are:
Division of the flow into several partial flows; Multiple interchange of the hydrodynamic and hydrostatic pressure proportions of the total refrigerant pressure reflects the pressure waves, thereby efficiently reducing the pressure pulsations of the refrigerant and the operational noise perceived by the vehicle occupants; Optional placement of the partition wall in both the suction side between the inlet channel and the inlet chamber and the pressure side between the outlet chamber and the outlet channel; Higher pressure loadability of the compressor casing resulting from the use of the integral partition wall; Less space required for the refrigerant compressor as a result of functional integration of the muffler, rendering the refrigerant compressor suitable for use in smaller engine bays; and Lower manufacturing costs resulting from reduced material and manufacturing demand because the partition wall is an integral part of the casing.
DESCRIPTION OF THE DRAWINGS
[0033] The objects and advantages of the present invention will become readily apparent to those skilled in the art from the following detailed description of the exemplary, not-limiting embodiments here preferred when considered in the light of the accompanying drawings in which is shown by:
[0034] FIG. 1 is a schematic of a refrigerant compressor from prior art;
[0035] FIG. 2 is a schematic of a refrigerant compressor provided with a muffler including a partition wall having a plurality of apertures disposed in a suction-side of the compressor according to an embodiment of the invention;
[0036] FIG. 3 is a schematic of a refrigerant compressor provided with a muffler including a partition wall having a plurality of apertures disposed in a pressure-side of the compressor according to another embodiment of the invention; and
[0037] FIG. 4 is a perspective view of a refrigerant compressor with an inlet channel and an inlet chamber.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0038] The following detailed description and appended drawings describe and illustrate various exemplary embodiments of the invention. The description and drawings serve to enable one skilled in the art to make and use the invention, and are not intended to limit the scope of the invention in any manner.
[0039] FIG. 1 shows a refrigerant compressor 1 of prior art. The refrigerant compressor 1 includes a casing 2 , an inlet channel 3 leading into a inlet chamber 4 having a generally circular cross-sectional shape, an outlet chamber 5 having a generally annular cross-sectional shape surrounding the inlet chamber 4 , and an outlet channel 6 which in a direction of a flow of a compressed refrigerant is disposed subsequently to the outlet chamber 5 .
[0040] As clearly shown in FIG. 1 , the inlet channel 3 having a substantially uniform cross-section is formed to extend through the outlet chamber 5 . The refrigerant flows into the inlet chamber 4 passing through a face-side opening, or through an unobstructed cross-sectional area of the inlet channel 3 . The outlet channel 6 having a substantially uniform cross-section is formed to militate against the acceleration and deceleration of the refrigerant flowing from the outlet chamber 5 into the outlet channel 6 , as there is only one face-side opening, or unobstructed cross-section of the outlet channel 6 . The refrigerant drawn into and through the inlet chamber 4 flows in direction of the longitudinal axis of the inlet channel 3 , and the compressed refrigerant drawn into and through the outlet chamber 5 flows in direction of the longitudinal axis of the outlet channel 6 .
[0041] FIG. 2 illustrates a refrigerant compressor 1 according to an embodiment of the invention provided with a muffler 8 disposed in a suction side of the compressor 1 . The basic structure of the refrigerant compressor 1 is similar to the refrigerant compressor illustrated in FIG. 1 . The muffler 8 includes a partition wall 7 having a plurality of apertures 9 formed therein. The partition wall 7 is an integral component of an inlet channel 3 and thus also of a casing 2 . An inlet chamber 4 extends from a first distal end passing through an annular outlet chamber 5 to a second distal end, which ends within the inlet chamber 4 . In the region of the second distal end, which ends within the inlet chamber 4 , the apertures 9 of the partition wall 7 are adapted for the flow of a refrigerant therethrough. In the embodiment shown, the partition wall 7 includes seven apertures 9 disposed in two rows. The second distal end of the inlet channel 3 , the distal end ending within the inlet chamber 4 , has a face side which is substantially closed tight to mediums. All apertures 9 are substantially equidistant from each other for hydrodynamic reasons such that neighboring apertures 9 of a row and neighboring apertures 9 of column are substantially equidistant from each other.
[0042] A direction of flow of the refrigerant follows from the position of the apertures 9 , which extend substantially orthogonal to a longitudinal axis of the inlet channel 3 and substantially parallel to each other. Therefore, the direction of flow is generally redirected about 90 degrees within the inlet channel 3 , resulting in a flow pressure loss. The flow pressure loss is compensated for by a greater number of apertures 9 . However, the number and cross-sectional area of the apertures 9 are dependent on the cross-sectional area of the inlet channel 3 such as the sum of the cross-sectional areas of all apertures 9 formed in the partition wall 7 is equal to 0.5-fold of the cross-sectional area of the inlet channel 3 . In contrast, the outlet channel 6 has only one aperture 9 formed in the direction of the longitudinal axis of the outlet channel 6 . The aperture 9 is formed by the face of the outlet channel 6 , the face being open in the direction of the outlet chamber 5 .
[0043] FIG. 3 shows a refrigerant compressor 1 according to another embodiment of the invention having a muffler 8 for pressure pulsation attenuation disposed in the pressure side of the refrigerant compressor 1 . The basic structure of the refrigerant compressor 1 is similar to the refrigerant compressor illustrated in FIGS. 1 and 2 . The muffler 8 includes a partition wall 7 and is an integral component of an outlet channel 6 and thus a casing 2 . Within the partition wall 7 , in the region of an outlet chamber 5 , a plurality of apertures 9 is formed therein substantially parallel and equidistant to each other. In the embodiment shown, the partition wall 7 includes five apertures formed therein.
[0044] A flow connection between the outlet chamber 5 and the outlet channel 6 for a compressed refrigerant is achieved through the apertures 9 . The inlet channel 3 extending through the annular outlet chamber 5 includes at least one aperture 9 . In the embodiment shown, the inlet channel 3 includes one aperture 9 which corresponds to the cross-section of the inlet channel 3 . The face of the inlet channel 3 , which is directed towards the inlet chamber 4 , and the face of the outlet channel 6 , which is directed towards the outlet chamber 5 , are substantially closed tight to mediums.
[0045] The apertures 9 of the partition wall 7 of the muffler 8 disposed in the pressure side and the aperture 9 leading into the inlet chamber 4 of the inlet channel 3 are formed substantially orthogonal to the direction of inflow of the refrigerant into the refrigerant compressor 1 and orthogonal to the direction of outflow of the refrigerant out of the refrigerant compressor 1 , respectively. Therefore the flow of refrigerant into the inlet chamber 4 and the outlet channel 6 subsequent the pressure increase is redirected.
[0046] The path of the inventive idea will not be left even if both the inlet channel 3 and the outlet channel 6 of the refrigerant compressor 1 are provided with a muffler 8 including a partition wall 7 having a plurality of apertures 9 .
[0047] FIG. 4 illustrates a refrigerant compressor 1 provided with a muffler 8 according to another embodiment of the invention. In the embodiment shown, the muffler 8 includes a partition wall 7 having five apertures 9 . The partition wall 7 , which limits an inlet chamber 4 against an inlet channel 3 , is an integral component of the cylindrical inlet channel 3 and therefore a casing 2 . The apertures 9 are disposed in at least one row, each aperture 9 having a generally circular cross-section. A flow connection between an inlet channel 3 and an inlet chamber 4 for a refrigerant drawn into and through the inlet channel 3 into the inlet chamber 4 is achieved through the apertures 9 .
[0048] From the foregoing description, one ordinarily skilled in the art can easily ascertain the essential characteristics of this invention and, without departing from the spirit and scope thereof, can make various changes and modifications to the invention to adapt it to various usages and conditions.
[0000]
NOMENCLATURE
1
refrigerant compressor
2
casing
3
inlet channel
4
inlet chamber
5
outlet chamber
6
outlet channel
7
partition wall
8
muffler
9
apertures
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The invention relates to a refrigerant compressor provided with a muffler for an air conditioning unit in a vehicle, wherein the refrigerant compressor includes a swash plate or pivoting ring rotatably supported in a casing of the refrigerant compressor for driving axially moving pistons arranged in cylinders, a suction side provided with an inlet channel and an inlet chamber, and a pressure side provided with an outlet channel and an outlet chamber. The muffler including a partition wall having a plurality of apertures formed therein is disposed in at least one of the suction side and the outlet side of the casing.
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CROSS REFERENCE TO RELATED APPLICATIONS
The present application is related to U.S. patent application Ser. No. 10/122,877 entitled “POSITIVE FLOW METER” filed concurrently with this application and also to U.S. patent application Ser. No. 10/122,878 entitled “DISTRIBUTED RESIDENTAL ALARM SYSTEM AND METHOD THEREFOR” also filed concurrently with this application.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to water control systems, and more specifically, to a system for controlling a household water supply.
2. Background of the Invention
Water supplies connected to a household are typically controlled only at the points of service, e.g., sink faucets, shower valves and appliances that connect to the water supply provide individual shut-off for water flow. The household water supply connection is typically controlled by a manual external valve that can be used to shut-off water flow in the event of an emergency water leak or for servicing the water supply system plumbing or replacing appliances.
Flooding due to plumbing failures is a major source of damage to structures and fixtures such as carpeting, wood flooring, wallboard, etc. The most frequent water supply emergency events are failure due to freezing temperatures inside the water supply plumbing and failure of the water heater tank. A freezing condition usually occurs when the house is unoccupied, for example, a vacation home that is unoccupied during winter is at risk for damage due to bursting of water supply lines due to freezing. Other water supply emergency events may occur when the house is unoccupied, such as failure of a polyvinyl chloride (PVC) plumbing joint, or water heater tank wall erosion and leakage.
Since water pressure needs to be available while persons are present in the household, the supply pressure must be available when the household is occupied. Also, certain automatic water users such as icemakers, dishwashers and washing machines make automatic demands on the water supply that may occur when the household is unoccupied. It is also inconvenient to manually control a household water supply upon entering or exiting a household.
Systems have been implemented that shut off the household water supply in response to detection of leaks using detectors located near water heaters, sinks, etc. But, these systems only protect against leaks where water reaches the detectors and could require a large number of detectors for adequate coverage. Other systems have been developed that measure water flow and shut off the water supply if excessive flow occurs based on whether or not the house is occupied as programmed manually by a switch. The flow type systems typically use flow meters that are incapable of detecting water flows below a certain threshold, such as a dripping faucet.
Therefore, it would be desirable to provide a method and system for controlling a household water supply to prevent flooding. It would further be desirable to control a household water supply in a manner that automatic water users are able to obtain water, while preventing leaks that occur while the water supply is not being used.
SUMMARY OF THE INVENTION
The above objective of preventing flooding due to plumbing failure is achieved in a method and system that automatically control a household water supply. The system includes an electrically controllable valve, a motion sensor and a control system for controlling the automatic valve in conformity with a motion detector output.
The foregoing and other objectives, features, and advantages of the invention will be apparent from the following, more particular, description of the preferred embodiment of the invention, as illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram depicting a household water supply coupled to a system in accordance with an embodiment of the present invention.
FIG. 2 is a block diagram depicting a system in accordance with an embodiment of the present invention.
FIG. 3 is a pictorial diagram depicting control panel 34 of FIG. 2 .
FIG. 4 is a flowchart depicting operation a system in accordance with an embodiment of the present invention.
FIG. 5 is a flowchart depicting further operation of a system in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the figures and in particular to FIG. 1, a household water supply coupled to a system in accordance with an embodiment of the present invention is shown. Within household 10 , a cold water supply line 11 routes the water supply to various fixtures such as sinks 14 , a refrigerator 16 containing an ice maker 17 toilets 15 , and so forth. A water heater 12 is also coupled to cold water supply line 11 , to supply a hot water supply line 13 , which is routed to sinks 14 and other fixtures in household 10 . Cold water supply line 11 is also coupled to lawn sprinklers 18 by electrically controlled sprinkler valves 19 that are activated and deactivated by an electric sprinkler control 20 system.
Water pressure for the entire household 10 water supply system is provided by a water supply main coupling controlled by electrically controllable valve 21 . A control system 30 in accordance with an embodiment of the present invention is electrically coupled to electrically controlled valve 21 , to shut off the water supply to household 10 in the presence of a detected abnormal flow condition. Flow of water into household 10 is detected by flow meter 24 which is generally a positive flow meter as described in co-pending U.S. Patent Application entitled: “POSITIVE FLOW METER”, filed concurrently herewith and the specification of which is incorporated herein by reference. Use of a valve in accordance with the embodiment described in the above-referenced patent application permits the detection of very small flow rates associated with small leaks. As the present invention detects a leak in accordance with starting and stopping of water flow, a valve that can measure a very small continuous flow is exceptionally useful in embodiments of the present invention.
Within household 10 , are located motion sensors 22 , providing an indication of occupancy of household, and consequently, whether flow through flow meter 24 is normal use by an occupant of household 10 . A motion sensor 22 may also be located near an entrance 23 in addition to or in alternative to locating motion sensors 22 throughout household 10 . If motion sensors 22 are located adjacent to every used entrance 23 of household 23 , occupancy may be determined, but generally not activity of occupants. If motion sensors 22 are located throughout household 10 , the system of the present invention may control water flow in accordance with activity of occupants. Specific embodiments of the present invention may locate motion sensors near zones of use, such as near a shower or bathtub, so that larger flows produced by these fixtures may be correlated with the activity of an occupant.
Control system 30 derives information from motion sensors 22 and flow meter 24 in order to control the household 10 water supply via electrically controllable valve 21 . Information from other sensors for detecting abnormal conditions may also be provided to control system 30 as well as manual controls and operating controls. Sprinkler control 20 is electrically coupled to control system 30 to provide a signal of normal sprinkler usage.
Referring now to FIG. 2, details of control circuit 30 and its interconnections are depicted. Control circuit 30 receives motion sensor inputs and sprinkler control inputs, as well as an input from a seismic activity detector 31 , a temperature detector 32 and a control panel 34 . Temperature detector 32 is used to predict potentially freezing conditions within cold water supply line 11 and electrically controllable valve 21 may be shut off in conformity with detecting the potentially freezing condition. Likewise, seismic activity detector 31 provides an indication of earthquake activity, and electrically controllable valve 21 may be shut off in conformity with detecting an earthquake. Temperature detector 32 and seismic activity detector 31 may be switches activated upon detection of the associated event, or they may be sensors and the detection circuitry may be provided within control circuit 30 .
Control panel 34 provides for manual control of control circuit (and thus the system of the present invention) via controls 36 and provides an indication of operational state via visual indicators 35 and a beeper 37 for providing an audible alarm. Remote control and indication of state may be provided by a modem/network interface 33 which may be coupled to a telephone network or other suitable network connection such as Digital Subscriber Link (DSL), cable modem or a router connection deriving therefrom. Control operations may be performed within control circuit 30 in response to codes received by modem/network interface 33 and system status may be provided by control circuit 30 to a remote location via modem/network interface 33 .
Within control circuit 30 , control is provided by program code executed from memory 42 by a processor 41 . Memory 42 and processor 41 are provided by a programmable logic controller 40 , although other forms of processing system such as single board computers, may be used to implement control algorithms in accordance with the present invention and dedicated circuits may also be used. A particular advantage of programmable logic controller 40 is that remote control modules such as X10 controllers are commercially available to couple control circuit 30 to various sensors, e.g. packaged motion sensors are available with X10 connections that transmit signals via household 10 power lines, making it unnecessary to directly wire motion sensors to control circuit 30 . Additionally, controls are available so that electrically controllable valve could be operated by an X10 controller. However, particular advantages associated with a manual override within the present invention might make remote control of electrically controllable valve 21 undesirable.
Programmable logic controller 40 controls electrically controllable valve 21 via relay K 1 . A manual override timer 43 provides a timeout when a system user operates a manual “on” control from control panel 34 . Relay K 2 is activated when the manual “on” control is pressed, turning on electrically controllable valve 21 until the timeout occurs (generally one hour). The system uses a battery 38 to supply operating power for control circuit 30 , but the manual override may be used in event of failure of portions of the system or loss of the programmable logic controller 40 control program. Loss of household 10 primary power may also affect portions of the system, depending on implementation, so manual override timer 43 may also be useful during a power failure. A battery charging and sensing circuit 39 connects to battery 38 from control circuit 30 . Battery 38 is maintained in a charged state by charging and sensing circuit 39 , and automatic operation of the system may be held off while battery 38 has insufficient charge to properly operate the system.
Since battery power should be conserved by the system, electrically controllable valve 21 is preferably a pulse type valve (latching solenoid valve). Therefore, programmable logic lab controller 40 or manual override timer 43 activate electrically controllable valve 21 using a pulse (generally on the order of 0.5 second) to either turn on or turn off electrically controllable valve. Special circuits within control circuit 30 may be used to produce the pulses, or programmable logic controller 40 may be programmed to produce the desired pulse. Manual override timer 43 will generally comprise a one-shot pulse generator that generates a pulse to turn off electrically controllable valve 21 after the timeout has occurred.
Referring now to FIG. 3, details of control panel 34 are depicted. Controls are provided as follows: Reset switch 36 A provides a means to reset programmable logic controller 40 and other circuits within control circuit 30 ; water on switch 36 B provides one hour of manual override water flow via manual override timer 43 ; water off switch turns of water flow 36 C; and learn mode switch 36 D activates a learn mode of operation. Indicators 35 are provided on control panel 34 and may also be located remotely. A monitor indicator notifies a user that the system is actively monitoring water flow; an away indicator indicates that lack of motion sensor activity has caused the system to enter “away” mode. A seismic alarm, low temp alarm and water flow alarm indicator are used to indicate earthquake detect, freezing detect or leak detect, respectively. A buzzer 37 is integrated within control panel 34 to provide an audible alarm, generally in accordance with a logical-OR combination of the above alarm indications.
Learn mode operation in the context of the present invention refers to the determination of water usage cycles. The present invention uses a “short” cycle and a “long” cycle to control operation of electrically controllable valve 21 . A short cycle is the time period that water is permitted to flow before an alarm condition is entered. This permits appliances such as icemakers to operate. A long cycle is the time period that water is permitted to flow when motion sensors have detected activity recently within household 10 , this permits an occupant to use water normally, e.g., to draw a bath, without the short cycle expiring, causing an interruption of water flow. The short and long cycles are adjustable, depending on the programmable logic controller program. Code within the programmable logic controller program measures typical water usage by occupants of the household and automated systems such as icemakers and possibly sprinklers (if a connection is not provided to override the short cycle for sprinkler operation). The typical use is turned into operational variables to control the short and long cycles, generally the long cycle will be within the range of ½ to 2 hours and the short cycle within the range of 1 to 5 minutes. The programmable logic controller program adapts the cycles when learn mode is selected and learn mode is generally self-terminated after, for example a 24 hour period.
Referring now to FIG. 4, operation of a system in At accordance with an embodiment of the present invention is depicted. First, a battery-charging loop is activated (step 60 ) that controls charging of battery 38 , so that operation may be initiated only after battery 38 has sufficient charge to operate the system. The battery voltage is sampled and when the battery voltage is sufficient (decision 61 ), the motion sense flow control program is started (step 62 ). During operation, a manual override switch may interrupt operation (decision 63 ) to pulse the valve control circuit (step 64 ) to provide or stop water flow. If water on switch 36 B was pressed (i.e. the water is on) (decision 65 ) then the manual override timer 66 provides the timeout that pulses valve control (step 64 ) to shut off the valve.
Referring now to FIG. 5, further operation of a system in accordance with an embodiment of the invention is depicted. FIG. 5 illustrates the automatic operation of the motion sense flow control program activated in step 62 of FIG. 4 . Water flow is monitored (step 70 ) and if a short cycle is detected (decision 71 ) corresponding to detection of a normal use of it water, the short and long cycle timers are reset (step 75 ). If motion is detected from a motion sensor (decision 72 ) and the water is currently turned off (decision 73 ) the water is turned on (step 74 ). If motion was detected in step 72 , the short and long cycle timers are reset (step 75 ). Next, the system checks for a long cycle timeout (decision 76 ), if the long cycle was exceeded, the water is shut off (step 78 ) and an alarm indication is sent (step 79 ) which may be a visual indication via indicator 35 , an audible alarm via buzzer 37 , a remote message via modem/network interface 33 , or a combination of the above. If motion is not detected for a long period (decision 80 ) (generally 12 hours), then away mode is activated (step 81 ), which essentially sets the long cycle to zero causing an alarm on any water usage.
While the invention has been particularly shown and described with reference to the preferred embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes in form, and details may be made therein without departing from the spirit and scope of the invention.
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A method and system for controlling a household water supply provides protection of structures and fixtures from water damage due to plumbing failure or other causes. The household water supply is shut-off in conformity with a determination that the household is unoccupied and thereby provides automatic protection from water damage.
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[0001] This application is a continuation-in-part of application Ser. No. 09/578,649, filed May 25, 2000, the entire disclosure of which is incorporated by reference herein.
FIELD OF THE INVENTION
[0002] The invention relates to the use of novel flavonoid and steroidal glycosidic compounds from HOSTA for preventing and treating cancer. The invention further includes methods for making and methods for using the invention.
BACKGROUND OF THE INVENTION
[0003] Since ancient times a vast number of natural remedies of plant and animal origin has been used for medical treatment and disease prevention. The famous Chinese medicine Encyclopaedia “Ben Cao Gang Mu” (52 Volumes) was written by Li Shih Zhen and published in 1596 [1]. This book described 1892 drugs shape, character, taste, source, method of collection and preparation and treatment, prevention of various disease.
[0004] A fast growing body of evidence obtained in the recent years by utilization of modem scientific, experimental and clinical methods confirms the biological activity of many micro components of plants that can be utilized in prevention or treatment of a variety of chronic diseases, including cancer and cardiovascular disease [2-4].
[0005] Despite the fact that scientific evaluation of medicinal plants historically has been responsible for discovery of a multitude of modern medicine, approximately only 1% of plants has been analyzed so far.
[0006] The analysis of botanical material is not a trivial matter. Usually, a sample to be analyzed contains a very complex mixture of many components. Only some of them might be biologically active, while other may be toxic. Components of these complex mixtures are usually interacting amongst themselves . Frequently, in many plants, dozens of-species and strains of the same genus, differ substantially in content of the active ingredients. Even within the same plant, different parts often have different chemical composition. Furthermore, the presence and concentration of some substances depend greatly on the soil, location, season, time of harvest, storage conditions, handling methods, conditions and solvents used for extraction, etc. This diversity of important conditions affecting the quality of botanical remedies requires therefore implementation of stringent, well-designed and closely-monitored standard operating procedures of manufacturing to ensure consistency from batch to batch of a nutraceutical product, followed by application of an appropriate analysis to ensure consistent potency and efficacy.
[0007] The major aims of qualitative analyses in phytochemistry include monitoring of the preparative isolation and purification of phytochemicals, chemotaxonomic testing and drug identification and/or detection of adulterants [5-6].
[0008] Plant constituents often exist in the form of glycosides. These conjugates may or may not occur together with their respective aglycones. Many glycosides play an important role as drugs and dyes. Glycosides are thermally labile, polar and non-volatile compounds frequently differing in their solubility and biological activity from their respective aglycones. By changing a type and/or number of attached saccharides the physicochemical and biological properties of the glycosides can be modified [7].
[0009] Among phytochemicals existing in the glycosilated form that deserve a special attention due to their wide distribution in nature and a high number of beneficial biological and medicinal properties, are saponins and flavonoid glycosides. Saponins are high molecular weight glycosides consisting of a sugar moiety linked to triterpine or steroid aglycones [8]. The most common sugars encountered in saponins are hexoses (glucose, galactose and mannose), 6-deoxyhexoses (rhamnose), pentose (arabinose and xylose), uronic acids (glucuronic acid and galacturonic acid) or amino sugars (glucosamine and galactosamine). Sugars may be linked to the sapogenin at one or two glycosylation sites (through an ether or/and an ester linkage), giving the corresponding monodesmodic or bidesmosidic saponins, respectively [9-10].
[0010] Because of the glycosylation of their hydrophobic aglycones, saponins act as biological detergents and, when agitated with water, form a soapy lather that gives rise to name of this group of compound [8]. From a biological point of view saponins have diverse group properties, some deleterious, but many beneficial. Some saponins have been used as plant drugs in folk medicine. They may exhibit cardiac activity, hemolytic activity, activity as fish poisons, hypocholesterolemic [11] immunostimulatory and anti-tumorigenic activity [8]. They can be used as bitterness and sweetness modifiers, allelochemicals and cosmetic ingredients. The second important classes of phytochemicals, which attracted a high interest due to its wide distribution in nature and diversified biological properties are flavonoids [12-13]. These polyphenolic compounds, apart from catechins and proanthocyanidins, consist mainly of glycosides of flavonols, flavons, flavanones, anthocyanins and less frequently isoflavons or free aglycones. Flavonoids represent an important constituent of many edible plants and are present in foods and beverages derived from plants.
[0011] Some flavonoid-containing species have been used in traditional medicine. Recently these phytomedicines have been extensively investigated and their health benefits confirmed in many cases for the long-term treatment of mild and chronic diseases or in attaining and maintaining a condition of well-being. Flavonoids function as strong antioxidants [3], free-radical scavengers, and metal chelators and their biological properties can also be linked with their interaction with enzymes, adenosine receptors, and biomembranes [14-15]. Many of the bioflavonoids exhibit very beneficial pharmacological activities, such as anti-inflammatory, antiallergic, antimicrobial, antioxidative, enzyme-inhibitory effects, and etc. [3]
[0012] The identification of individual flavonoids, sapogenins and their glycosides has long been carried out by Mass Spectrometry [8, 12, 16], Ultraviolet Spectroscopy [8, 12, 17] and 13C-NMR [8, 18]. These techniques were executed on highly purified compounds and were not applied to mixtures.
[0013] Separation of individual flavonoids, sapogenins and their glycosides from each other has long been carried out by Paper, Thin Layer and Open Column Chromatography [8, 12].
[0014] More recently HPLC has been used for the separation of individual flavonoids, sapogenins and their glycosides from each other [8, 12 ]. These techniques gave limited resolution between individual glycosides of either the flavonoids or the sapogenins.
[0015] The combination of HPLC and Diode Array UV-Visible Detection gave new possibilities in qualitative analysis of flavonoids in plant extracts [19-20]. Information about the type and number of glycosidic units was lost due to the preparation. The extraction and purification did not address the identification and quantization of individual glycosides. Mass Spectrometry with thermospray Ionization permitted routine online analysis of a number of glycosides of both flavonoid and sapogenin classes, but sensitivity was limited and interpretation was complicated by the frequent formation of artifacts [21-22]. Moreover, due to the relatively energetic ionization of the thermospray technique the higher glycosides were not observed. Continuous Flow Fast Atom Bombardment gave some advantages in ionization of small polar molecules but at the cost of instrumental complexity and reliability [23].
[0016] The advent of Electrospray Ionization permitted molecules to be ionized with very low energies under atmospheric pressures and at room temperatures. Very polar, high molecular weight species could be routinely analyzed with little artifact formation that could complicate interpretation [24-25]. The technique also permits the use of Collision Induced Fragmentation for generating ions that aids in structure elucidation [26].
[0017] The combination of three powerful techniques LC/DAD/ESIMS was used to study the aglycones and glycosides present in berries [24]. These works however largely concentrated on the identification of the flavonoid aglycones or of glycosides of no greater than two units.
[0018] The present invention provides a fast and reliable method for the simultaneous analysis of both flavonoid glycosides and steroidal glycosides in one procedure. As a model to show the usefulness of this technique we have chosen plants from Hosta genus which belongs to the subfamily Asphodeloideae in Liliaceae. These plants are widely distributed thus offering easy and economical access to this source of flavonoid and steroidal glycosides of potential medicinal application. The flowers, leaves and rhizomata of hosta have been used as a folk medicine in China [1, 27]. A steroidal saponin identified as hexasaccharide and prepared from the extract of dried Hosta leaves by O. Masamitsu, et al. [28-29] exhibit antibacterial and antitumor activity while some of the steroidal glycosides identified by M. Mimaki group displayed cytostatic activity on HL-60 cells.
[0019] Although eight kaempferol glycosides [30] and twenty six steroidal glycosides [28-29, 31-37] have been previously separated from Hosta leaves and Hosta rhizomers, respectively, there has been no reports of any comprehensive procedure to extract simultaneously both classes of glycosides from the Hosta leaves.
SUMMARY OF THE INVENTION
[0020] The present invention is based on the discovery of novel flavonoid glycosides and steroidal glycosides from Hosta that exhibit anti-cancer activities. The present invention provides a method to prevent or treat susceptible cancers in humans comprising administering a cancer-treating amount of these compounds. Preferably, the present method will be utilized to treat or prevent chronic myelogenous leukemia, liver cancer and lung cancer. Another aspect of the present invention is a method as disclosed which utilizes oral or intravenous administration.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] [0021]FIG. 1 is a graph illustrating details of the instrumental setup.
[0022] [0022]FIG. 2 is a graph showing an application of Collisionally Induced Dissociation for the identification of sugars from a steroidal hexaglycoside where the steroidal aglycone corresponds to an open spiro ring sapogenin and the losses of m/e 162 fragment indicates the presence of five hexose (most likely glucose) moieties and the loss of m/e 146 fragment indicates the presence of one 6- deoxyhexose (most likely α-L-rhamnose).
[0023] [0023]FIG. 3 is a graph showing an application of Collisionally Induced Dissociation for the identification of sugars from a flavonoid tetraglycoside where the flavonoid aglycone corresponds to kaempferol and the loss of m/e 162 fragment indicates the presence of hexose (most likely glucose).
[0024] [0024]FIG. 4 is a graph depicting chemical structures of eight kaempferol glycosides, previously found in the extract of Hosta leaves.
[0025] [0025]FIG. 5 is a graph depicting chemical structures of four steroidal glycosides, previously found in the extract of Hosta rhizomers.
[0026] [0026]FIG. 6 is a table containing a list of all flavonoid and steroidal glycosides from the Hosta leaves extracts found by the application of this invention, and compared with glycosides previously identified in the literature.
[0027] [0027]FIG. 7 is a table containing a list of eight new glycosidic compounds identified for the first time in the Hosta leaves extracts by application of the presented procedure.
[0028] [0028]FIG. 8 is a graph that summarizes the procedure used for extraction, pre-purification and analyses of Hosta leaves in Example 1.
[0029] [0029]FIG. 9 is a LC/MS chromatogram of the raw extract from Example 1.
[0030] [0030]FIG. 10 is a graph that summarizes the procedure used for extraction, prepurification and analyses of Hosta leaves in Example 2.
[0031] [0031]FIG. 11 is a LC/MS chromatogram of a pre-purified mixture of flavonoid and steroidal glycosides extract from Example 2.
[0032] [0032]FIG. 12 is a graph which summarizes the procedure used for extraction, prepurification and analyses of Hosta leaves in Example 3
[0033] [0033]FIG. 13 is a LC/MS chromatogram of the raw extract from Example 3.
[0034] [0034]FIG. 14 is the result of a cell assay that showed specific anti-cancer activity of S1, an extract containing primarily a steroidal glycosides of molecular weight 1,406 Da. This sample exhibits considerable anti-proliferation activity against three cell lines from CML, liver, and lung cancer.
[0035] [0035]FIG. 15 is the result of a cell assay that showed specific anti-cancer activity of F2-2, a flavonoid glycoside mixture exhibited selective activity on inhibition of a lung cancer cell line
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0036] The present invention is based on the discovery of novel flavonoid glycosides and steroidal glycosides from Hosta that exhibit anti-cancer activities. The present invention is applicable, but not limited, to the extraction, isolation and simultaneous determination of both flavonoid and steroidal glycosides from plants, fresh or dried, and other potential natural sources of nutraceuticals. This procedure is also fully applicable to qualitative and quantitative analysis of different forms of herbal supplementations, such as powders, tinctures, suspensions, solutions, syrups, capsules, tablets, etc.
[0037] The biological material, such as plant, should be collected and stored under properly designed and controlled conditions, to ensure the consistency in the content of active components. Measures should be applied to avoid the presence of any harmful contaminants, such as pesticides, herbicides, heavy metals, etc. If drying is recommended, the chemical and enzymatic sensitivity of the active components should be considered. Thus the avoidance of exposure to light, elevated temperatures, oxygen presence or prolonged storage in aqueous solution prone to facilitate biochemical degradation should be considered and applied, if necessary.
[0038] Prior to the extraction procedure sample should be prepared by chopping into small pieces, blending, grounding or crushing, in order to improve the contact of solvent with the extracted matter.
[0039] In the present invention, for analytical purposes, the extraction of the polar phytochemicals such as bioflavonoids or saponins from the plant or marine matter or their formulations is achieved by the application of water or aqueous solutions of a variety of polar solvents such as lower alcohols, ketones, or acetonitrile. The elevated temperature and repeated extraction procedures might be used to improve the extraction effectiveness. The effectiveness can be further enhanced by stirring, shaking or sonication.
[0040] Plant or marine matter consist of a multitude of components, both polar and nonpolar. In order to provide a simple, sensitive and reliable method for analyzing for phytochemicals, such as flavonoid and steroidal glycosides, the sample should be treated to remove contaminants and other undesired components that would interfere with the analysis. Such a removal, for analytical purposes, can be achieved by precipitation of some undesired compounds by means of concentration of the extract volume and/or refrigeration.
[0041] Further removal of interfering less polar compounds can be achieved by subjecting the crude extract to liquid-liquid extraction with a water immiscible organic solvent, such as alkanes, cycloalkanes, ethers or lower esters.
[0042] The purification of sample from polar components such as inorganic salts, simple sugars, and aminoacids that could interfere with the final analysis of the phytochemicals of interest can be achieved, for analytical purposes, by application of open column or flash column chromatography using a variety of different stationary phases, such as polyamide resin or a weakly acidic cation exchange resin, such as Amberlite IRC-50, and mixture of water and lower alcohols as mobile phase.
[0043] Such separation can be easily monitored by HPLC or TLC with a variety of detection methods. The column chromatography may also utilize other modes, such as normal phase chromatography with application of silica gel or alumina or gel filtration approach.
[0044] Thus such extracted and pre-purified sample can be then subjected to qualitative and quantitative analysis by the application of reverse phase HPLC in an isocratic or preferably gradient mode. The combined application of two independent and powerful detection techniques of Electrospray Mass Spectrometry and Diode Array Spectroscopy allow for the selective and simultaneous identification of the individual components, such as phytochemicals of interest, contained in the pre-purified extract. The application of Electrospray Mass Spectrometry detection for the thermally liable compounds prevents creation of artifacts that may lead to misinterpretation of the instrumental data that was frequently possible with the previously used ionization techniques. It was found that the application of negative ion mode yields patterns that are more informative than other techniques, decreasing at the same time the risk of the artifact formation and data misinterpretation. Furthermore, the post-column application of triethylamine enhances the sensitivity of this method of detection. FIG. 1 details the instrumental setup.
[0045] The sample preparation combined with the applied detection system presented in this invention yield sensitive and extensive qualitative information about the individual components of the analyzed extract, such as, for example flavonoid and steroidal glycosides. This information includes, but is not limited, to molecular weight, number and type of glycoside substituents, and from the Diode Array Spectroscopy absorption patterns, this technique allows for differentiation amongst different types of aglycones present in the components of the extract.
[0046] The application of the presented procedure in combination with the use of Collisionally Induced Dissociation can produce mass spectral patterns that can allow structural data to be deduced. Those skilled in the art will recognize that Mile 162 fragment could be related to a loss of hexose (e.g. glucose), that of m/e 146 fragment from the loss of 6-deoxyhexoses (e.g. rhamnose), and that of m/e 132 fragment from the loss of pentose (e.g. xylose) (see FIG. 2 and FIG. 3).
[0047] As a very educational and powerful example for the application of this invention can serve the application of the present procedure for the extraction, purification and analysis of flavonoid and steroidal glycosides from Hosta leaves. Thus this invention has allowed for the first time simultaneously identify a total of twenty glycosides, both from the flavonoid and steroidal class (Table 1, FIG. 4). Among the identified glycosidic compounds were all eight kaempferol glycosides, previously reported by J. Budzianowski (structures of which are shown in FIG. 5), and 4 steroidal glycosides, previously reported in the literature by the Japanese researchers for the extracts of Hosta rhizomers (structures of which are shown in FIG. 6). This procedure, with application of Collisionaly Induced Dissociation also allowed for the identification of eight new, previously not detected in the Hosta plant extracts clycosidic compounds, seven of which were identified as steroidal tetra, penta, and hexaglycosides, and one as kaempferol tetraglycoside (Table 2, FIG. 7).
[0048] These novel compounds can be used for treatment of cancer. Particularly, the steroidal glycosides can be used to treat chronic myelogenous leukemia, liver, and lung cancer since these compounds showed anti-proliferation activity against cell lines from these diseases (FIG. 14). The flavonoid glycoside mixture F2-2, and the individual compounds contained in it, can be used to treat lung cancer as shown in FIG. 15. Treatment in accordance with the present invention can be accomplished by oral or intravenous administration along with a pharmaceutically acceptable carrier such as rice syrup solids, maltodextrin, and hydroxypropylcellulose, or in a food, to a patient having cancer. Orally-administrable dosage forms of the invention may include, but are not limited to, capsules, tablets, powders and liquids. The amount of active ingredient to be administered may vary depending upon the type of cancer and the body weight of the individual being treated. Dosages of the active ingredient may be in the range of 1 mg/kg per day to 30 mg/kg/day. These dosages should be continued until no detection of cancer is determined by standard means.
[0049] Another aspect of the present invention is a method as disclosed which utilizes oral or intravenous administration. However, those in the art will recognize that many avenues of administration are possible. For instance, administration of drug may be via capsule, tablet, solution, sachet, suspension, intravenously, orally, intramuscularly, including implantation into the tumor itself, topically or parenterally.
[0050] The present invention is believed to be utilizable with other types of cancers other than those described herein as would be known to those skilled in the art. The application of the presented method of extraction, purification and separation can be easily adopted to a preparation of pre-purified and standardized mixtures of phytochemicals or the individual compounds in a pure form for additional structural elucidation and/or conformation (e.g., by means of NMR spectroscopy or X-ray analysis) as well as for their screening for biological activity.
[0051] The presented invention does not require any additional steps, such as chemical derivation. However, it can be combined with either an analysis of partly and/or fully hydrolyzed material, as well as consecutive derivation of glycosides, and subjecting these samples to further HPLC/MSD/DAD or other methods of analysis. Applications of appropriate standards allow for an easy, sensitive and highly reliable method of quantitative analysis, and therefore, can be widely utilized for standardization of nutraceuticals.
[0052] Thus the presented procedure represents a much more industrially advantageous method for the execution of these analyses, particularly in the field of research, standardization and quality control of herbal and marine matter, or any of their nutraceutical supplement formulations.
EXAMPLE 1
[0053] The procedure for extraction, pre-purification and analysis of Hosta leaves is depicted in FIG. 8. The fresh Hosta leaves (Golden Tiara) were hand picked in October. Fresh leaves (20 g) were chopped into small pieces and then ground in a blender with water (500 mL), followed by sonication for 2 hours at 50° C. The extract was filtrated to separate and remove fibrous material. The extraction of the separated solid material was then repeated with another portion of water (500 mL). Both extracts were combined and concentrated to ca. 25 mL under reduced pressure on a Rotovapor. The concentrated aqueous solution was extracted twice with hexane (25 mL) followed by two-time extraction with ethyl acetate (25 mL). The aqueous phase was evaporated under vacuum to dryness to afford 0.28 g (1.4% yield) of the raw extract of flavonoid and steroidal glycosides in the form of powder. This powder (0.28 g) was dissolved in 3.0 mL of a mixture of water and ethanol (1:1) and subjected to HPLC/MS analysis.
[0054] The solution of this raw extract was separated by a column chromatography on Amberlite IRC-50 resin (16-50 mesh, Sigma Company) with gradient elution of increasingly higher content of ethanol in water. The chromatography was monitored by HPLC/MSD/DAD. The first fraction eluted with water (500 mL) contained mainly some polar interfering compounds, such as sugars; the evaporation under vacuum to dryness yielded a solid powder (110 mg). The second fraction was eluted with 5% ethanol-water solution (200 mL). The third fraction was eluted with 10% ethanol-water solution (200 mL) and the fourth fraction eluted with 20% ethanol-water solution (200 mL). The second, third and fourth fractions were combined and evaporated under vacuum to dryness to afford 48 mg (0.24% yield) of a crude mixture of flavonoid glycosides. The fifth fraction was eluted with 50% ethanol-water solution (200 mL). This fraction was evaporated separately under vacuum to dryness to afford 28 mg (0.14% yield) of a crude mixture of steroidal glycosides.
[0055] The HPLC/MSD/DAD analysis was performed with a system that consisted of an HPLC 1100 series LC/MSD (Hewlett-Packard) instrument, autoinjector, quaternary pump with on-line vacuum degassing unit, thermostated column compartment and diode array detector. At the same time, a mass detector was used. The API-EI mode was chosen. The negative ion mode provided better sensitivity and the interpretation of the spectra was found to be easier. So the analysis results were obtained in negative mode at fragmentation potential of 100 cV. A standard Zorbax C8 column (150 mm long×2.1 mm I.D.) with 5 μm particle size was used in these examples.
[0056] Operation conditions for the analysis were as follows:
[0057] Temperature 30° C.
[0058] Mobile phase consisted of an ACN/water mixture gradient:
[0059] 0-6 minutes ACN 15%,
[0060] 6-18 minutes ACN from 15% to 90%
[0061] 18-20 minutes ACN from 90% to 15%
[0062] The mobile phase flow rate was 0.4 mL/min.
[0063] Wavelength of UV detector was recorded on 280 nm.
[0064] The mass ion scan was from 100 to 1800.
[0065] The recorded LC/MS chromatogram of the raw extract is presented in FIG. 9.
EXAMPLE 2
[0066] The procedure for extraction, pre-purification and analysis of Hosta leaves is depicted in FIG. 10. The fresh Hosta leaves (Lemon Lime) were hand picked in September. Fresh leaves (150 g) were chopped into small pieces and then ground in a blender with 50% aqueous ethanol solution (500 mL), followed by sonication for 2 hours at 50° C. The extract was filtrated to separate and remove fibrous material. The extract was concentrated to ca. 50 mL under reduced pressure on a Rotovapor. The concentrated aqueous solution was diluted to 300 mL with water, refrigerated overnight and the formed precipitate of undesired components such as alkylphenols and fat was filtered out. The resulted filtrate was extracted twice with hexane (25 mL) followed by two time extraction with ethyl acetate (25 mL). The aqueous phase was evaporated under vacuum to dryness to afford 2.7 g (1.8% yield) of the raw extract of flavonoid and steroidal glycosides in the form of powder. This powder (0.5 g) was dissolved in 5.0 mL of a mixture of water and ethanol (1:1) and subjected to chromatographic separation. The separation was performed by a column chromatography on Amberlite IRC-50 resin (16-50 mesh, Sigma Company) with gradient elution of increasingly higher content of ethanol in water. The chromatography was monitored by HPLC/UV and the analysis of the final combined fractions by HPLC/MSD/DAD. The first fraction eluted with water (500 mL) contained mainly some polar interfering compounds, such as sugars; the evaporation under vacuum to dryness yielded a solid powder (260 mg). The second fraction was eluted with 5% ethanol-water solution (150 mL). The third fraction was eluted with 10% ethanol-water solution (150 mL) and the fourth fraction eluted with 20% ethanol-water solution (150 mL). The second, third and fourth fractions were combined and evaporated under vacuum to dryness to afford 45 mg (0.16% yield) of a crude mixture of flavonoid glycosides. The fifth fraction was eluted with 50% ethanol-water solution (150 mL) and the sixth one with 80% ethanol-water solution (200 mL). Fractions five and six were combined and evaporated separately under vacuum to dryness to afford 40.5 mg (0.145% yield) of a crude mixture of steroidal glycosides.
[0067] The HPLC/MSD/DAD analysis was performed with a system that consisted of an HPLC 1100 series LC/MSD (Hewlett-Packard) instrument, autoinjector, quaternary pump with on-line vacuum degassing unit, thermostated column compartment and diode array detector. At the same time, a mass detector was used. The API-EI mode was chosen. The negative ion mode provided better sensitivity and the interpretation of the spectra was found to be easier. So the analysis results were obtained in negative mode at fragmentation potential of 400 eV. A standard Zorbax C8 column (150 mm long×2.1 mm I.D.) with 5 μm particle size was used in these examples. Operation conditions for the analysis were as follows: Temperature 30° C. Mobile phase consisted of an ACN/water mixture gradient:
[0068] 0-15 minutes ACN 15%
[0069] 15-20 minutes ACN from 15% to 90%
[0070] 20-25 minutes ACN 90%
[0071] 25-30 minutes ACN from 90% to 15%
[0072] The mobile phase flow rate was 0.4 mL/min.
[0073] Wavelength of UV detector was recorded on 280 nm.
[0074] The mass ion scan was from 100 to 1800.
[0075] The recorded LC/MS chromatogram of the pre-purified extract is presented in FIG.
EXAMPLE 3
[0076] The procedure for extraction, pre-purification and analysis of Hosta leaves is depicted in FIG. 12. The fresh Hosta leaves (Blue Dimples) were hand picked in September. Fresh leaves (40 g) were chopped into small pieces and then ground in a blender with 50% acetonitrile solution in water (250 mL), followed by sonication for 2 hours at 20-40° C. The extract was filtrated to separate and remove fibrous material. The extract was concentrated to ca. 5 mL under reduced pressure on a Rotovapor. The concentrated solution was extracted twice with hexane (3 mL) followed by two-time extraction with ethyl acetate (3 mL). The aqueous phase was evaporated under vacuum to dryness to afford 1.8 g (4.5% yield) of the raw extract of flavonoid and steroidal glycosides in the form of powder. This powder (1.8 g) was dissolved in 10.0 mL of a mixture of water and acetonitrile (1:1) and subjected to HPLC/MS analysis.
[0077] The solution of this raw extract was separated by a column chromatography on polyamide resin (25 g, 80 mesh) with gradient elution of increasingly higher content of ethanol in water. The chromatography was monitored by HPLC/MSD/DAD. The first fraction eluted with water (500 mL) contained mainly some polar interfering compounds, such as sugars; the evaporation under vacuum to dryness yielded a solid powder (1273 mg). The second fraction was eluted with 5% ethanol-water solution (200 mL). The third fraction was eluted with 10% ethanol-water solution (200 mL) and the fourth fraction eluted with 20% ethanol-water solution (200 mL). The second, third and fourth fractions were combined and evaporated under vacuum to dryness to afford 80.75 mg (0.2% yield) of a crude mixture of flavonoid glycosides. The fifth fraction was eluted with 50% ethanol-water solution (250 mL). This fraction was evaporated separately under vacuum to dryness to afford 252 mg (0.63% yield) of a crude mixture of steroidal glycosides.
[0078] The HPLC/MSD/DAD analysis was performed with a system that consisted of an HPLC 1100 series LC/MSD (Hewlett-Packard) instrument, autoinjector, quaternary pump with on-line vacuum degassing unit, thermostated column compartment and diode array detector. At the same time, a mass detector was used. The API-EI mode was chosen. The negative ion mode provided better sensitivity and the interpretation of the spectra was found to be easier. So the analysis results were obtained in negative mode at fragmentation potential of 100 eV. A standard Zorbax C8 column (150 mm long×2.1 mm I.D.) with 5 μm particle size was used in these examples.
[0079] Operation conditions for the analysis were as follows: Temperature 30° C.
[0080] Mobile phase consisted of an ACN/water mixture gradient:
[0081] 0-6 minutes ACN 15%
[0082] 6-18 minutes ACN from 15% to 90%
[0083] 18-20 minutes ACN from 90% to 15%
[0084] The mobile phase flow rate was 0.4 ml/min.
[0085] Wavelength of UV detector was recorded on 280 nm.
[0086] The mass ion scan was from 100 to 1800.
[0087] The recorded LC/MS chromatogram of the raw extract is presented in FIG. 13.
EXAMPLE 4
[0088] These novel compounds were tested against seven cancer cell lines for anti-tumor activity. The assays were performed with extracts obtained one step prior to the final purification of individual compounds. The percentage of each component in the extracts was characterized. The anti-cancer activity of these compounds was examined over a wide concentration range between 100 ug/mL to 0.191 ng/mL. S1, the extract containing five steroidal glycosides wherein 53.8% is a compound of molecular weight of 1,406 Da, exhibits considerable anti-proliferation activity against three cell lines from CML, liver, and lung cancer (FIG. 14). One of the flavonoid glycoside mixture, F2-2, showed selective activity on inhibition of the lung cancer cell line A549 (FIG. 15). This mixture contains five flavonoid glycosides of molecular weight of 756, 918, 888, 726, and 902 Dalton respectively. The relative amount for each compound is 12.6, 39.9, 24.2, 14.5, 4.8, and 3.8%, respectively.
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[0112] (18) Agrawel, P. K., (ed) Carbon-13 NMR of Flavonoids, Elsevier, Amsterdam 1989
[0113] (19) Hasler, A., et al. Journal of Chromatography 1990, 508, 236-240.
[0114] (20) Inado, S., et al U.S. Pat. No. 4,968,787
[0115] (21) Wolfender, J. L., et al. Journal of Chromatography 1993, 647, 183-190.
[0116] (22) Pietta, P., et al. Journal of Chromatography A 1994, 661, 121-126.
[0117] (23) Wolfender, J. L., et al. Journal of Chromatography A 1995, 712, 155-168.
[0118] (24) Hakkinen, S., et al. Journal of Chromatography A 1998, 829, 91-100.
[0119] (25) Mauri, P. L., et al. Rapid Communications in Mass Spectrometry 1999, 13, 924-931
[0120] (26) Gelpi, E., Journal of ChromatographyA 1995, 703, 59-80.
[0121] (27) Yu, Chuan Long (eds), Zhong Yao Ci Hai ( Vol. 1), Chinese Medicine Technology Publisher, 1993 1347-1348
[0122] (28) Ochi, M., et al. Steroid Saponin from Hosta and Antimicrobial and Antitumor Agents Containing It 1998, JP 10 114,791 [198 114,791] (C1. C107J171/100), 116 May 1998, Appl. 1996/1270,1292, 1911 October 1996; 1912 pp; CA 1129: 32293w.
[0123] (29) Ochi, M., et al. Novel Steroidal Saponin and Antimicrobial Agents and Antitumor Agents Containing It 1998, JP 10 158,295 [198 158,295] (C1. C107J171), 116 June 1998, Appl. 1996/1320, 1142, 1929 November 1996; 1912 pp; CA 1129: 113511t.
[0124] (30) Budzianowski, J., et al. Phytochemistry 1990, 29, 3463-3467.
[0125] (31) Takeda, K., et al. Tetrahedron 1965, 21, 2089-2093.
[0126] (32) Takeda, K., et al. Journal of Chemical Society C 1967, 9, 876-882.
[0127] (33) Takeda, K., et al. Chemical and Pharmaceutical Bulletin 1968, 16, 275-279.
[0128] (34) Mimaki, Y., et al. Chemical and Pharmaceutical Bulletin 1995, 43, 1190-1196.
[0129] (35) Mimaki, Y., et al. Phytochemistry 1996, 42, 1065-1070.
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The invention relates to the use of flavonoid glycosides and steroidal glycosides from Hosta or their derivatives as functional ingredients in functional food, OTC and pharmaceutical composition to prevent or treat cancer. The invention further includes methods for making and methods for using the invention.
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CROSS REFERENCE TO RELATED APPLICATION
This application claims the filing benefit under 35 U.S.C. §119(e) of U.S. Provisional Application No. 61/458,331, filed Nov. 22, 2010, which is hereby incorporated by reference.
TECHNICAL FIELD
The present invention pertains generally to the coefficient of friction of a thermoplastic elastomer (TPE), and more particularly to a composition and which increases the wet coefficient of friction (COF) of the TPE.
BACKGROUND OF THE INVENTION
Most surfaces become “slippery” when they are exposed to water. However in many instances a slippery surface is not desired and presents a problem. In these instances there is therefore a need for a composition which increases the wet coefficient of friction. For example, surfing traction is one of the most difficult wet COF issues to address. It is a high performance, dynamic sport done at speed while executing radical maneuvers and extreme changes of directions. Surfboards typically have a fiberglass outer surface which can become slippery when wet. As such, at the interface of the surfboard and the surfers feet a specially blended wax is used for traction. However, this wax melts off in high temperatures or wears off during use and needs to be reapplied prior to or during each surfing session. The wax also must have a certain degree of tackiness, but not too great as it will irritate and/or rub the skin off of the surfer. (some surfers do wear rash guards, a light weight nylon vest to protect their chest area from rash or irritation in the chest area). The wax must not have any abrasive particles which would cause skin irritation or abrasion, because when paddling the surfer's skin contacts the deck of the surfboard. In view of the above, it would be advantageous to provide a surfboard surface which has a high wet COE without the need to repeatedly apply wax.
One such possible surface would include a thermoplastic elastomer (TPE) also referred to as thermoplastic rubbers. TPEs are a class of copolymers (typically plastic and synthetic rubber) which exhibit both thermoplastic and elastomeric properties. Some TPE polymers are also known as gels or visco-elactic, is a synthetic rubber like product having the super soft malleable characteristics of Jello®, which also has shock absorbing properties. Most TPE's while dry are very slip-resistant, however if water is added to the surface they become very slippery. One or more additives can be added to chemically modify the TPE polymer to produce the desired high wet COF and other useful properties, but without adding abrasive particles.
To that end, U.S. Pat. No. 5,314,940 to Stone issued in 1994 resolved the wet slipperiness issue in a broad line of TPE's using petrolatum jelly (commonly known as Vaseline) prior to the advent and commercialization of the TPE's referred to as gels or visco-elastic material. The gel/viscoelastic TPE's are commonly infused with an extra-ordinary amount of mineral oil (plasticizer), which gives them the extra softness and flexibility (Jello®-like characteristics).
U.S. Pat. No. 7,316,597 discloses a traction pad for a personal water board. The traction pad utilizes a thermoplastic elastomer (TPE). Additionally, Patent Publication US 2008/0097270 discloses an elastomeric material and discusses possible manufacturer products.
BRIEF SUMMARY OF THE INVENTION
The present invention is directed to a method and composition which increases the wet COF of a TPE. The present invention uses a TPE polymer as the base compound, and adds two or more other compounds (e.g. microcrystalline wax, APOA, and ethylene/propylene and olefins) to enhance the wet COF and other properties of the combination. In final form the compositions comprises a sheet of polymer material (e.g. 0.5 to 3.0 millimeters thick) which can be used by itself, or can be bonded to the surface of an object such as a surfboard. The present invention does the following:
1. Greatly enhances the wet traction of certain TPE polymers without abrasive particles.
2. Only slightly changes the hardness and elongation properties of the TPE material.
3. An additional benefit is that these formulas aid in the bonding of certain of these TPE polymers to a secondary substrate by absorbing the mineral oils and/or changing the polarity and making them more compatible to bonding to another substrate.
4. Very small amounts of the slightly tacky microcrystalline wax (micro-traction) are transferred from the surface of the gel to the surface of the human foot during use greatly enhances the wet traction of the foot, especially in elderly humans where the body oils are greatly reduced and/or not present if the invention is used in the manufacture of bath or showermats for hospitals, residential, or commercial use.
* Dry skin equals reduced traction (such as in cold weather, skin dries out, difficult to pick up objects with hands, apply hand lotion (restores some of the lost natural body oils) aids in picking up objects. Another example would be a bank teller that touches her finger tips to a pad of wax to enable her to count money without her fingers slipping.
5. The natural characteristics of these gels are known to have good shock absorbing and dampening characteristics in relation to their thickness
6. Conformable—The softness of the composition means increased surface area which means increased traction or grip (as opposed to a harder composition polymer).
Some of the numerous applications of the composition of the present invention are: surfboard traction pads, sports equipment used in wet environments, decks of wakeboards, wake/skate boards, shoe soles for wake/skate boarding, bindings for water skis, mats for clean rooms, shower stalls, bath mats, all types of sporting gloves, golf grips, baseball bats, yachting mats, conveyor belts for delicate fruits, vegetables, or food products, and even for additional chest protection from irritation or abrasion when applied or attached to the chest area of rash guards, the thin nylon vest that surfers wear to protect their chest area from irritation or abrasion when prone paddling. The composition can also be applied to the bottom of disposable booties used in operating room. Another application is handle grips either molded or in tape form that can be applied to paddles used for stand up surfboards and other similar types of equipment used in sports. The composition would help prevent blisters because of its softness and slight transfer of microcrystalline wax to the skin to help prevent skin from drying out completely.
In accordance with an embodiment, a method for increasing the wet coefficient of friction of a thermoplastic elastomer includes:
adding a microcrystalline wax and at least one of (1) an amorphous polyalphaolefin ethylene copolymer, and (2) a copolymer ethylene/propylene and olefins, to the thermoplastic elastomer.
In accordance with another embodiment:
adding both amorphous polyalphaolefin ethylene copolymer and copolymer ethylene/propylene and olefins to the thermoplastic elastomer.
In accordance with another embodiment:
the resulting composition has the following weight ratios;
the thermoplastic elastomer being about 93 weight percent; the microcrystalline wax being about 2.3 weight percent; the amorphous polyalphaolefin ethylene copolymer being about 2.3 weight percent; and, the copolymer ethylene/propylene and olefins being about 2.3 weight percent.
In accordance with another embodiment:
the resulting composition having the following weight ratios;
the thermoplastic elastomer being about 87 weight percent; the microcrystalline wax being about 4.3 weight percent; the amorphous polyalphaolefin ethylene copolymer being about 4.3 weight percent; and, the copolymer ethylene/propylene and olefins being about 4.3 weight percent.
In accordance with another embodiment:
the resulting composition having the following weight rations:
the thermoplastic elastomer being between about 87 weight percent and about 93 weight percent; said microcrystalline wax being between about 2.3 weight percent and about 4.3 weight percent; said amorphous polyalphaolefin ethylene copolymer being between about 2.3 weight percent and about 4.3 weight percent; and, said copolymer ethylene/propylene and olefins being between about 2.3 weight percent and about 4.3 weight percent.
In accordance with another embodiment:
adding copolymer ethylene/propylene and olefins to the thermoplastic elastomer.
In accordance with another embodiment:
the resulting composition having the following weight ratios;
the thermoplastic elastomer being about 83.3 weight percent; the microcrystalline wax being about 8.3 weight percent; and the copolymer ethylene/propylene and olefins being about 8.3 weight percent.
Other embodiments, in addition to the embodiments enumerated above, will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the method and composition.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan view of surfboard with sheets of the composition of the present invention applied to the top surface; and,
FIG. 2 is a top plan view of another surfboard with sheets of the composition of the present invention applied to the top surface.
DETAILED DESCRIPTION OF THE INVENTION
The present invention utilizes a TPE as the primary ingredient. Once formed through heat and pressure, TPEs can be reformed by re-heating. Conversely thermoset polymers cannot be reformed by reheating or pressure. One particularly useful group of TPE's are known as visco-elastic or gels. These are the super soft polymers where the durometer (hardness) is so low that they are not measured for durometer in the commonly known Shore A or Shore D Scale, but in the specially developed Shore 00 Scale for super soft gel-like materials having a durometer of less than 20 on the Shore A scale.
The method and composition of the present invention adds two or more additives to the TPE. Specifically three additives have been found useful—microcrystalline wax, APOA, and ethylene/propylene and olefins. These three additive copolymers are basic off the shelf materials, commonly used in the plastics industry in a broad spectrum of products and formulas. Some of the more common products are pressure sensitive adhesives (PSA), such as masking tapes, Band aids, bubble gum, hot melt adhesives, surfboard waxes etc and are also processing aids in injection molding. Additionally, there are many additives known as tackifiers for polymers, which enhance the tackiness when mixed into polymer formulations, such as used in masking tape and adhesive notes, can be used. A problem is that many of these tackifiers exhibit excellent tack properties when dry, but when wet with water they become super slick, like water on glass. (certain microcrystalline waxes are a general exception to this rule).
The composition of the present invention can include the following four compounds, which can be used in a variety of combinations and weight percent ratios:
1. Ingredient A—GLS Versaflex® 2003X.
Generic: (TPE low durometer visco-elastic gel)
Main ingredient to be modified to give it wet traction.
Material Characteristics—Soft Rubbery pellet with slight oily feel.
Shore Hardness, 10 sec delay—30, ASTM D2240
Shore hardness 30 Shore 00
Specific Gravity—0.86, ASTM D792, 23/23° C.
Tensile Strength—280 psi ASTM D$12-Dia C, 2 hrs, 23° C.
Elongation at Break—1290%, ASTM D412-Die C, 2 hrs, 23° C.
100% Modulus—9 psi, ASTM D412-Die C, 2 hrs, 23° C.
300% Modulus—15 psi, ASTM D412-Die C, 2 hrs, 23° C.
Tear Strength—40 psi, ASTM D624
Apparent Viscosity @ 200° C. 11170/sec—1300 cPs, ASTM D 3835
Manufacturer:
GLS thermoplastic Elastomers
PolyOne Corp.
833 Ridgeview Dr.
McHenry, Ill. 60050-7050
Tel. 1-800-457-8777
alternate Ingredient A (TPE)—Gelsmart® M gel #4125 (a styrenic block copolymer)
Manufacturer:
Gelsmart®
30 Leslie Court
Whippany, N.J. 07981
973-884-8995
Ingredient A is also available as Ultramelt™ M-PTF from Soft Polymers a.k.a. Crinnis Corp. 1835 W. 169 th St., Gardena Ca.
2. Ingredient B—Frank Ross Microcrystalline Wax 1275 ML
Generic: Microcrystalline Wax
Primary ingredient giving Versaflex® the wet traction
Material Characteristics—Semi-soft waxy feel & tacky feel
Melting point 170° F.-180° F., needle penetration 77° F., 25-35
Supplier:
Frank Ross Wax
970-H New Brunswick Avenue
Rahway, N.J. 07065
732-669-0810
3. Ingredient C—Rextac® RT 2585
Generic: Amorphous Polyalphaolefin (APAO) ethylene copolymer
Believed to control the tackiness of the microcrystalline wax at elevated ambient temperatures and trap microcrystalline wax in the Versaflex® to prevent leaching or migration of the wax out of the Versaflex®. May also aid in maintaining the elongation and flexibility of the Versaflex® that the addition or loading of the microcrystalline wax diminished.
Material Characteristics—Hard putty like waxy feel that is somewhat stringy when pulled.
Brookfield Viscosity cps (at 190° C.)-8500
Needle Pen dmm—40
Ring and Ball Softening Point (C.°)—132
Glass Transition (C.°)—−37
Open Time (sec)—60
Tensile Strength (MPA)—0.34, PSI—50
Manufacturer:
Rextac®
PO Box 418
2501 S. Grandview
Odessa, Tex. 79766
432 332 0058
4. Ingredient D—Petrolite® EP-700
Generic: copolymer ethylene/propylene and olefins (synthetic waxes)
This may help absorb some of the mineral oil in the Versaflex® and enhance the bonding characteristics of the Versaflex® to other substrates, possibly by changing the polarity of the Versaflex®.
Material Characteristics—Hard random size pellets smaller than a BB very slight waxy feel.
Molecular Weight—650 (GPC)
Viscosity, (cP@ 300° F., 149° C.)—7 (ASTM D-3236)
Melting Point (F.°)—204 (ASTM D-127)
Penetration (0.1 mm@77° F., 25° C.)—6 (ASTM D-1321)
Penetration (0.1 mm@140° F.)—47 (ASTM D-1321)
Branches Molecule (Approx.)—<1
Manufacturer:
Baker Hughes/Baker Petrolite®
PO Box 669
Barnsdall, Okla. 74002
918 847 2522
In one embodiment of the invention the composition comprises the following ingredient ratios by weight (i.e. weight percent):
1.
TPE (Versaflex ® 2003X)
about 93%
2.
Microcrystalline wax (1275 ML)
about 2.3%
3.
APAO (Rextac ® RT 2585)
about 2.3%
4.
ethylene/propylene and olefins
about 2.3%
(Petrolite ® EP 700)
Respective weight of about 560 grams, about 14 grams, about 14 grams, and about 14 grams produce the approximate weight percent ratios shown above.
In other embodiments of the invention the composition comprises the following ingredient ratios by weight (i.e. weight percent):
A.
Ultramelt ™ M-PTF
8.0 grams (about 83.3 weight percent)
Ross Microcrystalline
0.8 grams (about 8.3 weight percent)
Wax 1275
Petrolite ® EP-700
0.8 grams (about 8.3 weight percent)
Little or no tackiness
to touch
B.
Ultramelt ™ M-PTF
8.0 grams (about 87 weight percent)
Ross Microcrystalline
0.4 grams (about 4.3 weight percent)
Wax 1275
Petrolite ® EP-700
0.4 grams (about 4.3 weight percent)
Rextac ® 2585
0.4 grams (about 4.3 weight percent)
Tacky to touch
C.
Ultramelt ™ M-PTF
12.0 grams (about 87 weight percent)
Ross Microcrystalline
0.6 grams (about 4.3 weight percent)
Wax 1275
Petrolite ® EP-700
0.6 grams (about 4.3 weight percent)
Rextac ®
0.6 grams (about 4.3 weight percent)
Tacky to touch
D.
Ultramelt ™ M-PTF
12.0 grams (about 83.3 weight percent)
Ross Microcrystalline
1.2 grams (about 8.3 weight percent)
Wax 1275
Petrolite ® EP-700
1.2 grams (about 8.3 weight percent)
Light tackiness
to touch
It may be appreciated however, that the three additives, can be used singularly with TPE, or in various other combinations and percentages. For example, TPE and only microcrystalline wax could be used, TPE and only APAO used, or TPE and only ethylene/propylene and olefins used. Other possibilities include TPE+microcrystalline wax+APAO, TPE+microcrystalline wax+ethylene/propylene and olefins, and TPE+APAO+ethylene/propylene and olefins. It is noted that all of the additives enhance the wet COF of the TPE if used to modify the TPE by themselves, but can destroy certain desirable properties of the TPE such as elongation and softness.
Some examples of extreme formulations and results are shown below:
1. Versaflex ® 2003X 66% Microcrystalline wax 34% Result Greatly enhances wet COF (but less wet COF than ideal formula). Makes hard durometer rigid material. Greatly reduces elongation. 2. Versaflex ® 2003X 66% Rextac RT 2585 34% Result Gooey putty like mess. Consistency of cold peanut butter 3. Versaflex ® 2003X 66% Petrolite EP 700 34% Result Greatly enhances wet COF (but less wet COF of than ideal formula). Makes hard durometer rigid material. Greatly reduces elongation
Processing:
All the weighted ingredients are placed together into a melting kettle and slowly heated to about 350-375° F. and slowly stirred constantly. The heated mixture is then poured into an aluminum mold or any type of suitable mold material sufficient to tolerate the processing temperatures. For high volume production injection molding can be used. Other methods for mixing the ingredients would be through extruders used for mixing hot melt materials and/or reactors commonly known in the chemical processing industry. The compounded ingredients from these mixing processes would then be either injection molded or reheated to a liquid and poured into a suitable mold to produce a finished consumer product.
Theory and Comments of how and why the Additives Work:
Microcrystalline waxes blended into the TPE greatly increase the wet traction of the TPE and imparts tackiness. Too much microcrystalline wax and the TPE loses it's softness and elongation properties.
Ethylene/propylene and olefins help to diminish the mineral oils (maybe absorb the mineral oil) in the TPE, aids in bonding to a secondary substrate, also increases wet COF, may also allow microcrystalline wax to migrate to surface, thereby restoring wet traction that may have been lost through time, use, and wear. Also possibly aids in preventing the “rubber eraser effect” which is common in TPE's infused with large quantities of mineral oil. “Rubber eraser” effect is the surface degradation over time of the TPE with large quantities of mineral oil that produce a rubber eraser type debris when rubbed vigorously with the finger.
The APAO combines with and or controls the tackiness of the microcrystalline waxes at elevated ambient temperatures and aids in the wet traction properties. Increase the APOA and the tackiness increases.
Of special note, these are some commonly know manufacturing techniques that can be used in giving the TPE a degree of rigidity if needed for handling and application in the finished product. For example, a piece of non-woven fabric (ex. Pellon 910) or surfacing veil, with sufficient heat resistance (commonly known material & practice) is molded into the back of certain of these products such as the surfboard traction mats to give them a slight rigidity that makes them easier to handle when trying to apply a large piece of gel like material to a substrate with accuracy. (without the nonwoven, the Jello®-like material with a pressure sensitive adhesive on the back would be almost impossible to handle and apply correctly to the substrate). Other known methods of increasing the rigidity of the TPE polymers would be to add a chopped strand material to the gel at some stage in forming the TPE into a finished product. Another known method would be to co-mold another layer of a more rigid/harder polymer to the back or bottom of the traction pad at the time of manufacture. Also the non-woven fabric could be applied after molding the pads with an adhesive.
By adjusting the amount of additives micro-crystalline wax and/or APAO individually or collectively the tackiness of the wet traction can be increased or decreased. For some surfboards extreme tackiness may be required or desired by some surfers under certain conditions.
In other possible embodiments, commonly known methods of reducing the weight of an item (e.g. one made from the compositions disclosed herein) could be employed such as by perforating the item and removing excess material (the same as racing car frames perforated to reduce weight). Or another method of reducing the weight of finished products manufactured with the compositions of the present invention would be to utilize commonly known processing equipment which infuses the hot melt material with air or nitrogen gas immediately prior to molding a finished product or application to a surface. This infusion or entrapment of air or nitrogen gas in the hot melt material, among other advantages greatly reduces the weight of the finished product by creating a foam like material, reduces the amount of material used in the finished product and reduces molding cycle time, among other benefits.
Surfboard Applications:
Currently most surfboard traction pads are made from EVA foams that have a coarsely textured surface (which is abrasive), or an EVA foam that has a molded in texture, which is more slippery than surfboard wax. FIGS. 1 and 2 show application of sheets of the composition 20 of the present invention (the crosshatched portions are the sheets) to the surface of a surfboard 500 . The sheets serve as traction pads which can be of various sizes and shapes, and can be placed at any desired location(s) on the surface of the surfboard 500 . The pads are commonly bonded with a double sided pressure sensitive adhesive (PSA). The PSA could be a liquid or film which is bonded to the back of the traction pad, and then after removing a protective release material and exposing the opposite side of the PSA, is firmly attached to the deck of the surfboard (or otherwise) to the deck of the surfboard in the user's desired location. Eventually it may be possible to coat the entire deck of a surfboard with the composition of the present invention. The surfboard traction pads of the present invention are low profile, provide excellent wet traction, and are soft and compressible under the chest of surfer when paddling.
Controlling the thickness of the finished product can be critical in end use applications. For example: A traction pad on the rear of the surfboard would be thinner than the one on the nose. The turning power on a surfboard is usually generated from the rear, if the rear pad is too thick it might act to dampen or decouple the transmission of the foot power needed to turn or maneuver the surfboard. Nose riding doesn't require the raw power needed for turning but requires subtle light touches and may benefit somewhat from increased thickness. The finish of the molded parts also plays a part in wet traction, a dulled, satin or flat surface finish in a molded part would enhance wet traction (but more difficult to keep clean). A glossy or shiny finished surface in a molded part is going to be more slippery, easier to keep clean.
Other Applications of the Composition:
Possible applications in skateboarding on the decks of skateboards used in clean environments, such as indoor skate parks and during skateboard competitions where dirt or debris would not accumulate on the traction material. Material would act somewhat like fly paper helping to stick the skater to the deck better, but also being able to give a certain degree of release.
The composition could also be used in the sole of special shoes worn by skateboarders in clean environments.
The composition of the present invention can be injection molded into finished products or by using what are commonly known in the industry as hot melt manufacturing techniques, such as hot melt spray or slot die coaters that apply a dot pattern random or controlled to the bottom of disposable hospital booties or into palm of wet suit gloves to increase wet COF.
In another embodiment of the invention, antimicrobial protection compounds can be added to the present invention at time of manufacture. This is particularly applicable to bath tub/shower mats and also sporting goods. A supplier for such a compound is: Microban International, Ltd., Microban®
11400 Vanstory Drive
Huntersville, N.C. 28078
United States
Ph: +1 (704) 875-0806
Additional Information Regarding TPEs:
Patent Publication US 2008/0097270 discloses in part:
“[0008] In some embodiments, the hardness may be no more than about 30 or 35 Shore 00. For example, a currently favored material for manufacturing the pad is Gel Concepts thermoplastic rubber compound, which is a proprietary, oil-plasticized styrene block copolymer elastomer, manufactured by Gel Concepts L.L.C. of Whippany, N.J., particularly Product No. 4125. This is a transparent material, very soft, with a Shore 00 hardness of about 14 Another useful candidate material is Versaflex® CL 2003× thermoplastic rubber compound, manufactured by GLS Corp. of McHenry, Ill., having a Shore 00 hardness of about 29, and having other physical parameters as described in the above-cited Patent Application Publication No. US2006/0079823 A1, the disclosures of which are incorporated by reference herein.”
The embodiments of the method and composition described herein are exemplary and numerous modifications, combinations, variations, and rearrangements can be readily envisioned to achieve an equivalent result, all of which are intended to be embraced within the scope of the appended claims. Further, nothing in the above-provided discussions of the method and composition should be construed as limiting the invention to a particular embodiment or combination of embodiments. The scope of the invention is best defined by the appended claims.
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A method for increasing the wet coefficient of friction of a thermoplastic elastomer includes adding various ingredients to the thermoplastic elastomer. In one embodiment microcrystalline wax, amorphous polyalphaolefin ethylene copolymer, and a copolymer ethylene/propylene and olefins are added to the thermoplastic elastomer. And in another embodiment, microcrystalline wax and copolymer ethylene/propylene and olefins are added to the thermoplastic elastomer. The above compositions are formed into a sheet which can be used alone as a slip-resistant pad, or can be applied to a desired surface (such as that of a surfboard).
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This application is a continuation of application Ser. No. 06/636,773 filed Aug. 1, 1984, now abandoned, which is a division of application Ser. No. 06/419,345 filed Sept. 17, 1982, now abandoned.
BACKGROUND AND SUMMARY OF THE INVENTION
This invention relates to an improved ceramic fiber molding and the method of making the same.
Ceramic fiber moldings are formed into many shapes and used for many purposes, generally moldings are used as furnace lining in the form of plates, cylinders and furnace construction members such as burner blocks. Presently, such ceramic fiber moldings are produced by dispersing and suspending the fibers in a large amount of water together with a binder such as colloidal silica and colloidal alumina. The suspended cermic fibers are collected by filtering to form the desired shape by either wet pressing or vacuum forming. Ceramic fibers for such purposes include aluminosilicate fiber and high alumina fibers. The aluminosilicate fiber is produced by blowing or spinning a melt consisting of 43 to 57 wt% of silica, 43 to 57 wt% of alumina, and less than 3 wt% of metal oxides or impurities. The high alumina fiber is produced by spinning a viscous solution of salts consisting of 3 to 20 wt% of silica, 80 to 97 wt% of alumina, and less than 1 wt% of other metal oxides, and subsequently converting the spun fibers into polycrystals of oxides by heating.
It is known that when chromium oxide, in an amount of 0.5 to 10 weight percent is incorporated into the ceramic fiber composition or chemically attached to the fiber surface the heat resistance of the cermic fiber is improved. However, the method of making aluminosilicate fiber by blowing or spinning a melt has the disadvantage in that the addition of chromium oxide to the composition changes the properties of the composition, particularly the viscosity of the melt, to such an extent that it is difficult to control the blowing or spinning of the fibers. On the other hand, the method of chemically attaching the chromium oxide to the fiber surface has a shortcoming in that the chromium oxide attached to the fiber surface evaporates within a short period of time when exposed to high temperatures.
The present invention discloses a method which prevents the chromium oxide from evaporating at high temperatures when ceramic fiber moldings are impregnated with chromium oxides. This method limits shrinkage and corrosion of the ceramic fiber moldings.
The process characterizing the present invention comprises dipping a ceramic fiber molding into a suspension containing either or both colloidal silica and colloidal alumina, in an amount of 0.2 to 1.0 wt% as solids based on the weight of the water of the suspension, and containing chromium oxide powder having a particle diameter smaller than 62 microns in an amount less than 30 wt% based on the weight of the water of the suspension, thereby impregnating said alumina-silica ceramic fiber molding with chromium oxide powder in an amount of 10 to 50 wt% based on the weight of the undipped ceramic fiber molding.
It is an object of this invention to produce ceramic fiber moldings which exhibit improved resistance to linear shrinking.
It is the further object of this invention to produce a ceramic fiber molding which is corrosion resistant.
DETAILED DESCRIPTION OF THE INVENTION
In accordance with the present invention an improved ceramic fiber molding exhibiting a significant high temperature shrink resistance and corrosion resistance is produced by a novel method of impregnating the fiber molding with chromium oxide powder. The ceramic fiber material produced by this technique has shown a greater resistance to corrosion and linear shrinkage at elevated temperatures than unimpregnated material.
When a ceramic fiber molding is simply dipped in an aqueous dispersion of chromium oxide powder, the impregnation is limited to only the surface of the molding because of the filtration action of fine ceramic fibers which are mostly 1 to 5 microns in diameter. Uniform impregnation, however, can be accomplished when chromium oxide powder is dispersed in a solution containing colloidal silica and colloidal alumina, the chromium oxide is carried into the central structure of the ceramic fiber molding by capillary action. With such uniform impregnation, the ceramic fibers are coated with chromium oxide powder and colloidal silica-alumina, the impregnated chromium oxide reacts with the aluminium oxide in the ceramic fiber, and builds up a Cr 2 O 3 --Al 2 O 3 solid solution when subjected to a high temperature. This solid solution prevents chromium oxide from evaporating and improves the resistance to heat and corrosion particularly to corrosion caused by iron and iron oxide.
The ceramic fiber molding which has undergone the dipping process embodied in this invention may be used as such, but further improvement can be accomplished if the product is subject to heat treatment at 900° to 1200° C. after dipping.
The chromium oxide powder used in this invention should be one which has a particle diameter smaller than about 62 microns. Powder coarser than this size does not infiltrate the ceramic fiber molding but stays in the vicinity of the surface of the molding.
The colloidal silica and colloidal alumina are not effective when added in amounts less than 0.2 wt% since amounts less than 0.2 wt% are too small to carry the chromium oxide into the central structure of the ceramic fiber molding. On the other hand, if added in an amount greater than 1 wt%, decreases the effect of the impregnated chromium oxide to resist linear shrinkage and corrosion when the molding is subjected to high temperatures, since the colloidal alumina-silica increases the heat shrinkage of the molding.
Since chromium oxide powder added to water in amounts greater than 30 weight percent settles to the bottom of the mixing container it is necessary to agitate the dispersion while dipping the ceramic fiber molding. In the case of thin dispersion repetitive dipping is required until the ceramic fiber molding is impregnated with as much chromium oxide as necessary. On the other hand, a thick dispersion will cause clogging to occur at the surface of the ceramic fiber molding thereby preventing the uniform coating of all the ceramic fibers.
This invention will be described with reference to the following tests.
Samples 1-8
A slurry was prepared by dispersing 100 parts by weight of aluminosilicate fiber (sold under the trademark KAOWOOL by The Babcock & Wilcox Company, consisting of about 52.3 wt% of SiO 2 and about 47.3 wt% of Al 2 O 3 and about 0.4 wt% of impurities), into 5000 parts by weight water and then adding with agitation 20 parts by weight of commercial colloidal silica in aqueous solution. A flat plate ceramic fiber molding, 20 mm thick, having a bulk density of 0.25 g/cm 3 was produced by depositing the slurry together with a binder onto a suction screen, wet pressing and thereafter drying the slurry.
The ceramic fiber molding made in the above manner was impregnated with chromium oxide by dipping it into the dispersion prepared by adding alumina sol in an amount of 0.3 wt% as solids and silica sol in an amount of 0.2 wt% as solids to water, and then adding chromium oxide powder in an amount of 5 to 30 wt% based on the weight of the water. The chromium oxide powder contains 96 wt% of particles that pass through a sieve of 325 mesh.
After drying, ceramic fiber moldings impregnated with chromium oxide were subjected to heat shrinkage tests run at 1100° C. and 1200° C. for 24 hours each.
The results are shown in Table 1. It is noted that the specimens impregnated with chromium oxide exhibit less linear shrinkage than those specimens not impregnated with chromium oxide. The coating of chromium oxide in Samples 1 and 2 showed signs of warping, separating and cracking during heating. Samples 3 to 7 had less chromium oxide impregnated on the fibers and these Samples experienced little or no warping and cracking. Sample 8 which had no chromium oxide impregnated thereon was used as the control sample.
TABLE 1______________________________________Content of Quantity ofChromium Time of chromium Linear Shrinkageoxide of Impreg- oxide im- on heatingSample impregnant nation pregnated 1100° C. 1200° C.No. (%) (sec) (%) (%) (%)______________________________________1 30 30 68 1.3 1.42 25 30 59 1.2 1.43 20 30 52 1.3 1.54 15 30 41 1.5 1.75 10 30 32 1.8 2.16 5 20 18 2.2 2.57 2 20 6 2.4 2.98 0 20 0 2.6 3.2______________________________________
SAMPLES 9-14
A flat plate ceramic fiber molding, 20 mm thick, having a bulk density of 0.15 g/cm 3 , was produced in the same manner as in Samples 1 to 8 from a slurry prepared by dispersing 50 parts by weight of the same aluminosilicate fiber and 50 parts by weight of high-alumina fiber (sold under the trademark SAFFIL by Imperial Chemical Industries, Limited), consisting of about 5 wt% of SiO 2 and about 95 wt% of Al 2 O 3 .
The ceramic fiber molding prepared in the above step was impregnated with chromium oxide and alumina sol and silica sol as in Samples 1-8.
After drying, ceramic fiber moldings impregnated with chromium oxide were subjected to heat shrinkage tests for 24 hours each at 1300° C. and 1400° C. The moldings were also subjected to corrosion resistance tests in which iron powder was spread onto the sample in an amount of 0.05 g/cm 2 before heating at 1400° C. for 24 hours.
The results are shown in Table 2. The samples impregnated with at least 20% chromium oxide, Samples 9 to 12, exhibited almost no corrosion while Sample 13 and Sample 14 experienced considerable corrosion.
TABLE 2______________________________________Content of Quantity ofChromium Time of chromium Linear Shrinkageoxide of Impreg- oxide im- on heatingSample impregnant nation pregnated 1300° C. 1400° C.No. (%) (sec) (%) (%) (%)______________________________________ 9 30 30 71 0.6 0.610 20 20 51 0.6 0.611 10 20 36 0.6 0.712 5 20 20 0.8 0.913 2 20 7 0.9 0.914 0 20 0 0.9 1.0______________________________________
It is possible to impregnate the ceramic fiber molding with as much as 70 wt% chromium oxide based on the weight of the undipped molding, but impregnation of more than about 50 wt% becomes nonuniform. On the other hand, impregnation less than 10 wt% does not provide sufficient heat resistance and corrosion resistance. As shown above, the best results are obtained when impregnation is carried out in the range of about 10 to 50 wt%, in combination with the binder of colloidal silica and alumina.
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A process for producing an improved ceramic fiber molding by submersing the molding into a suspension containing colloidal silica and/or colloidal alumina and chromium oxide powder. The chromium oxide is deposited onto the ceramic fibers thereby increasing the molding's resistance to linear shrinkage and corrosion when subjected to high temperatures.
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This invention relates to a method for recycling paper products. In particular, this invention relates to the removal and control of stickies and to deinking of pulp and paper in papermaking processes using wastepaper.
BACKGROUND OF THE INVENTION
Recycling of post consumer paper products has become much more important in the last few years. Growing concerns about the environment, alternatives to solid waste disposal, increasing consumer demand for quality recycled papers, and various state and federal laws that mandate levels of recycled fibers all have combined to increase the use of recycled paper in paper making. See Paper Recycling, edited by K. L. Patrick, Miller Freeman Inc., San Francisco, 1991.
There are several sources of contaminates in recycled paper. One obvious source of contamination during recycling is the accidental inclusion of foreign material in the paper as it is collected. Another source of contaminants is materials such as binders, adhesives, sealants, glues, etc. These troublesome contaminants can be more generally categorized as "stickies". Their varying sources include polyvinyl acetate and polyvinyl alcohol resins, hot melt adhesives, wet strength residuals, SBR and vinylacrylic rubber lattices, pressure sensitive adhesives, and so forth.
Stickies are so chemically diverse that removal by chemical means alone is very difficult. Stickles interfere with paper production by fouling equipment and reducing the quality of the finished product. Stickies are generally considered to be the product of additions to the paper as contrasted with "pitch" which derives from naturally occurring resinous byproducts in the wood.
Stickies accumulate in white water recycle systems resulting mostly in deposits on paper forming fabrics, on felt and on wet end equipment. Consequently, quality problems such as pinholes, increased down time due to frequent break down and clean ups, additional costs for cleaning and prevention, inherent damages to felt, fabric, and drying equipment are commonly encountered in the production and use Of secondary or recycled fiber furnish. See Moreland, Robert D., "Stickies Control by Detackification." 1986 Pulping Conference, Tappi Press, Atlanta, 1986, p. 193. As will be readily understood, these problems cost mills time and money.
Larger sized (>0.42 mm) stickies generally can be easily removed by mechanical screening and sieving processes and are not a significant problem. Medium sized stickies (0.075-0.42 mm) cannot be effectively removed by mechanical means. They may be pliable making them difficult to remove by screening. Small size stickies are not a problem as long as they remain stable in the furnish. However, once they become unstable, they accumulate, agglomerate, and stick onto surfaces of the papermaking equipment. They eventually grow larger and are subsequently released into the pulp resulting in pinholes, breakages in the sheet, and poor paper quality.
The other class of contaminants in recycled paper addressed by the present invention is ink. Since ink by its nature is colored (usually black), the presence or retention of ink in the formed sheet reduces brightness and can cause dark spots. The increasing use of mixed office waste as a source of recycled fiber for printing and writing grades poses a particular problem in recycling waste paper. Mixed office waste contains a high percentage of nonimpact printed material such as xerographic or laser printed paper that is difficult to deink. The toner particles when removed from the fiber surface have been found to be flat and platelike. Also the density of the separated ink material tends to be about equal to that of the medium which makes removal by conventional mechanical means such as screening, cleaning, flotation and washing difficult. The best solution to ink contamination is to remove the ink prior to paper formation.
Current techniques for stickies control as reported in the general literature can be grossly categorized into mechanical methods and chemical methods. Mechanical methods include combinations of coarse and fine screening, hydrodynamic washing and high intensity dispersion. The high intensity dispersion units readily break the stickies into very small particulates that can be absorbed onto the pulp fiber without adversely impacting the quality of the finished sheet. High consistency pulping combined with agglomeration chemistry also contributes to stickies removal through consolidation of the stickies into large enough mass that enhances easy removal by mechanical means.
Use of chemical additives is a much more common approach to stickies control. Traditional additives include talc, organic solvents, alum, sequestering agents, dispersants (cationic, anionic, and nonionic), zirconium compounds, and organotitanium compounds. See Doshi, Mahendra R., "Properties and Control of Stickies", Recycled Paper Technology, Tappi Press, Atlanta, 1994, p. 73. All these chemical additives have exhibited some, albeit limited, success in the control of stickies. The mechanisms associated with chemical additives involve dispersion, electrostatic attraction, agglomeration, surface tension modification, adsorption, detackification and so forth. Conventional chemical methods for controlling stickies detackify, disperse and retain the stickies in the finished pulp. However, dispersed stickies may accumulate in white water, become unstable, agglomerate and result in poor paper quality and decreased machine performance. Although the objective of preventing the stickies from adhering to equipment is attained, the stickies end up being incorporated into the finished sheet. Also, retained stickies may contribute to increased dirt and lower the brightness of the pulp.
U.S. Pat. No. 4,964,955 to Lamar and other literature teach pitch control processes using cationic polymeric agents and/or chemically modified bentonites and clays in papermaking processes. See also Hassler, Thord. "Pitch Deposition in Papermaking and the Function of Pitch-Control Agents", Tappi Journal, Vol. 71 (6) 1988, p. 195. Lamar, in particular, discloses reducing pitch through the addition of a cationic particulate such as kaolin to the furnish. However, using the Lamar method, the,pitch is not removed but ends up being dispersed and retained in the paper.
U.S. Pat. No. 5,151,155 to Cody teaches a deinking process using a cationic smectite clay. Cody teaches removing the ink waste by either flotation or washing. Cody proposes that it would be highly desirable if the process also removed tacky contaminants. As noted in Moore, D. M. and Robert C. Reynolds, Jr., X-Ray Diffraction and the Identification and Analysis of Clay Minerals, Oxford University Press, Oxford, N.Y., 1989, pp. 119-121, smectite is a group of clay minerals with a layer charge between 0.2 and 0.6 charge per formula unit which swell in the presence of water. Kaolin, in contrast, has approximately a zero layer charge. There are critical nontrivial differences between the process as taught by Cody and the use of cationic kaolins in accordance with the present invention. In particular, suspensions of modified smectite clays cannot be obtained in concentrations substantially greater than about 7.2% solids which makes them expensive to ship, whereas suspensions of cationic kaolins are generally obtained in concentrations greater than about 40%. In addition, the Cody process requires about 26% or about 535 pounds of smectite clay on a dry basis per ton dry pulp. By contrast, the process of the present invention can require as little as 20 pounds of cationic kaolin per ton of pulp on a dry basis.
U.S. Pat. No. 5,131,982 to St. John teaches the use of cationic polymers in effect as a retention aid in the treatment of coated broke. Undesirable components are caused to attach to the fibers of the coated broke after they have been repulped and are retained in the pulp.
U.S. Pat. No. 4,190,491 further teaches the use of cationic polymer as a pitch retention aid. The pitch control additive functions to disperse the pitch and deposit or retain the dispersed pitch into the pulp in finely divided form.
U.S. Pat. No. 5,221,436 discloses use of cationic polyelectrolytes and a clay mineral for pitch control by incorporation. Oleic acid was used to simulate pitch and the effectiveness in a real papermaking system is questionable. This patent does not mention stickies and is of no relevance to the product of our invention.
SUMMARY OF THE INVENTION
The present invention provides a method for controlling stickies in pulping and papermaking operations using wastepaper in which stickies are removed from the system, thus eliminating their retention in the paper and accumulation in the whitewater. The method of the present invention also appears to be effective in deinking. In accordance with the invention, not only is the number of stickles greatly reduced, but the dirt level decreases. Dirt, according to TAPPI Test Method T437 OM-90, "Dirt in Paper and Paperboard", is any foreign matter embedded in the sheet which when examined by reflected light has a contrasting color to the rest of the surface and has an equivalent black area of 0.04 mm 2 or over. Ink is included under the specifications of dirt. This invention simultaneously results in a reduction in the number of stickies and in a reduction in dirt in the finished pulp or paper product. Since a major source of dirt in recycled paper is the ink remaining in the paper, it appears that the method of the present invention removes some residual ink particles. It should be noted that the dispersion and retention of pitch in the paper as taught by Lamar is very undesirable in the case of ink particles. As shown by Doshi in "Recycled Paper Technologies", Tappi Press, 1994, p. 73, even if the ink is dispersed, a removal step must be included to improve brightness.
In accordance with the invention, a cationic kaolin is added to a wastepaper pulp furnish and reacts with the stickies. The kaolin is then removed from the pulp using conventional cleaners. The cationic kaolin attaches to the stickies and the ink particles, thereby modifying the stickies and ink in such a manner that enables easy removal with conventional cleaners. Although the exact mechanism is unknown, it is hypothesized that the attachment of the cationic kaolin to ink and stickies particles results in an increase in the apparent specific gravity of the ink or stickie particle. The resulting stickie or ink particles laden with kaolin particles now has a higher specific gravity than the surrounding liquid medium, thereby facilitating removal by centrifugal cleaners.
DETAILED DESCRIPTION OF THE INVENTION
The wastepaper can be pulped in a conventional manner. FIG. 1 illustrates schematically the operations in a typical plant for producing pulp from wastepaper. The term "wastepaper" as used herein includes newsprint, paperboard, old corrugated containers, mixed office waste, etc. It includes any recyclable wastepaper for which stickies removal and/or deinking would be desirable. One example of a wastepaper pulping process is carried out at a consistency of about 4 to 16%. The pulp from the pulper is diluted, screened, and then dewatered to a consistency of about 8 to 10%. Pulp from the thickener is first sent to a screw press and then to a disperser. Pulp accepts from the disperser are conveyed to the feed chest of the flotation unit where they are diluted with water to a consistency of about 1%. The pulp is fed to the flotation cell where air is added. Ink-containing foam on top of the pulp is then removed either mechanically or drawn off by vacuum. The deinked pulp is cleaned with light cleaners such as tangential flow centrifugal cleaners. Lighter weight rejects are removed separately from the bottom of the conical part of the cleaners while the accepts stock is discharged tangentially. Heavier contaminants can be removed in heavy cleaners such as posiflow centrifugal cleaners. The cleaned pulp is screened to provide the finished product.
In accordance with the invention, the cationic kaolin can be added to the stock at any point in the process prior to the cleaners. It is particularly convenient to add the kaolin to the furnish after it has been screened to remove gross contaminants such as staples, tape, thread and the like, but the kaolin can also be added at the pulper or disperser. The amount of cationic kaolin added to the pulp usually ranges from about 5 to 200 pounds per short ton of dry pulp on a dry basis and preferably from about 10 to 60 pounds per dry short ton. In many cases as little as 20 pounds per dry short ton is effective. However, the amount can be varied depending on the amount of stickies and ink contained in the pulp. The complex (cationic kaolin plus stickies or ink) is removed at the centrifugal cleaning stage.
Control data shows that processing the pulp without cationic kaolin does not reduce the number of stickies and only reduces the total area covered by stickies by 7%. When a cationic kaolin is added at the 1% level (dry on dry pulp), there is a dramatic reduction in the number of stickies and in the total area covered by stickies in the finished product. When samples from each beneficiation step are examined, the data suggests a mechanism of action for the invention. In the flotation cells there is little or no reduction in the number of stickles and only a 20% reduction in the area covered by stickies. However, in the cleaners battery a 41% reduction in the number of stickies and a 33% reduction in the area covered by stickies has been observed. Most of the removal occurs in the cleaners. This data is consistent with attachment and removal based on an increase in apparent density. This data showing the collection points can be seen in Table I.
Dirt particulates are divided into those greater than or equal to 0.08 mm 2 and those greater than or equal to 0.04 mm 2 (see Table II). When the product of invention is added to recycled pulp (as compared to the pretrial with no addition), the number of larger dirt particles increases but the number of smaller dirt particles decreases by almost 44%. To determine whether the product of invention is retained in the paper, the ash is measured. The pretrial pulp ash is higher than the treated pulp ash. This indicates that the product of invention is not retained in the finished pulp.
TABLE I______________________________________ Number of Stickies Area of Stickies**Sampling Point* Control Trial Control Trial______________________________________Disperser 12 13 1.78 1.94Flotation Cell -- 13 -- 1.64Centrifugal -- 13 -- 1.66Light CleanerCentrifugal -- 12 -- 1.47Heavy CleanerFinished Pulp 13 8 1.64 0.92______________________________________ *Samples from the process stream just prior to the processing stage excep the finished pulp. **mm.sup.2 /150 dry gram pulp.
TABLE II______________________________________Dirt (ppm) ≧0.08 (mm.sup.2) ≧0.04 (mm.sup.2)______________________________________Control 2.4 12.8Trial 3.9 7.2______________________________________
In summary, it has been observed that the cationic kaolin reduces the total number of stickies and their total area in the finished product when deployed in recycled office waste. Stickies are not removed in the flotation cells. Reduction in numbers of stickies occurs at the cleaners. The ash content does not increase in the finished pulp.
The stickies were determined in the pulp using the following procedure: The pulp is taken at any point in the process and diluted to 3% consistency and disintegrated for 5 minutes on the British Standard Disintegrator. One hundred and fifty dry grams of pulp (5,000 wet grams at 3% consistency) is slowly added over a five minute period to a Sommerville screen with 150 μm slots. After the pulp is added, the screen is washed for an additional 15 minutes. The material retained on the screen is carefully scraped off using a TEFLON ruler and transferred to 500 ml of deionized water. The resulting stickies suspension is filtered on a Whatman filter paper #111 using a Buchner funnel. The filter paper with retained impurities is oven dried at 105° C. for exactly 10 minutes. After drying the filter paper is dipped in a 1% solution of nonpolar blue dye in heptane for 5 to 10 seconds and then dried again at 105° C. for exactly two minutes. Using a light microscope and a sharp pointed instrument, the stickies on the filter paper are determined using the color and the plastic character (determined by probing each particle) of each particle. The number of stickies (sticky particles at room temperature) and the area are determined using Tappi Test Method T 213 OM-89 dirt chart.
From the standpoint of the convenience of operations, the cationic kaolin can be added to the pulp at the pulper, kneader or disperser or a combination thereof. While it is anticipated that the cationic kaolin may be more effective in stickies removal and deinking under certain conditions as opposed to others, the cationic kaolin appears to be effective at the pulp consistencies, pH and temperatures generally encountered in repulping operations.
Kaolin is a naturally hydrophilic clay mineral consisting essentially of hydrous aluminum silicates in the form of alternating silicon-oxide and aluminum-hydroxyl layers or sheets having an approximate composition of Al 2 O3.2SiO 2 .2H 2 O. In its natural state, kaolin is negatively charged and shows little or no tendency to adsorb stickies. The kaolin from which the cationic kaolin is prepared can range in particle size from fine, about 0.1 μm, to coarse, about 40 μm.
The addition of the cationic polymer to the kaolin is generally carried out at room temperature (about 25° C.), although addition can be carried out at any suitable temperature which will facilitate adsorption of the polymer onto its surfaces. Moderate stirring, e.g., at from about 100 to about 1000 rpm will also facilitate adsorption. Alternatively, slurries of cationic kaolin useful in the present invention can be prepared by passing an aqueous solution of a cationic polymer and an aqueous dispersion of kaolin through a static mixer. The adsorption reaction proceeds at room temperature. Examples of the preparation of the kaolin are provided below.
The amount of cationic polymer added should be sufficient to provide kaolin having a Muetek value (charge density) (Muetek Analytical Inc., Marietta, Ga.) of at least about +30 μeq/g and preferably a Muetek value of from about +45 to about +250 μeq/g. Typically, the resulting aqueous slurry of cationic kaolin will have a solids content ranging from about 40% to about 70%, and preferably from about 50% to about 60%. While the kaolin can be diluted and used at lower solids, shipping costs render the diluted product economically undesirable.
The particular cationic polymer employed, its molecular weight and charge density, and the average particle size of the kaolin all play a part in determining the amount of polymer used to provide a kaolin having a sufficient number of positively charged polymer molecules attached to the substrate particles to give a mass having a Muetek value within the above-stated range. Any water soluble cationic polymer which can be adsorbed on the kaolin and provides the aforementioned Muetek value should be useful in the present invention. Preferably, the polymers have a charge density of at least about 4,000 to about 8,000 μeq/g and a molecular weight of 10,000 to 500,000 daltons. Representative examples of some commercially available polymers that have been used include Nalco 94 DC 047 and Nalco 8117 cationic epichlorohydrin dimethylamide polymers available from Nalco Chemical Company, Prochem 3100, a cationic epichlorohydrin polymer available from Southern Water Consultants, and Sharpe 1144, a poly(diallyldialkylammonium halide) cationic polymer from Sharpe Chemical Co., and a polyalkylester of a tertiary amine halide such as Stabiron C826, Synechron, Inc., Morgantown, N.C. However, it is anticipated that the cationic polymers described in Lamar, U.S. Pat. No. 4,964,955 at column 9, line 50 to column 10, line 35 should also be useful herein. In particular, the poly(diallyldimethylammonium halides) are useful.
The invention will be described in more detail by reference to the following non-limiting examples.
EXAMPLE 1
One hundred forty grams of water and 10 grams of Nalco 94 DC 047 (Nalco Chemical Company) were mixed and 329 grams of 60.8% solids Norcote II Kaolin (Nord Kaolin Company) was slowly added with stirring at 400 RPM. To this starting mixture, 329 grams of 60.8% solids Norcote II Kaolin and 10 grams of Nalco 94 DC 047 were simultaneously added with stirring. The final suspension contained 50.1% solids. The dosage was 100 pounds Nalco 94 DC 047 per dry ton of Norcote II.
EXAMPLE 2
The process described in Example 1 was repeated except Prochem 3100 (Southern Water Consultants) was substituted for the Nalco 94 DC 047 on an equal weight basis.
EXAMPLE 3
The process described in Example 1 was repeated except Sharpe 1144 (Sharpe Chemical Co.) was substituted for the Nalco 94 DC 047 on an equal weight basis.
EXAMPLE 4
A five gallon sample of pulp containing "stickies" originating as rejects from a screen were received from a commercial paper recycling mill. The pulp consistency was determined at 13%. To identify and isolate stickies, pulp was diluted with water to 1% consistency. Stickies were located, verified and removed with a pipette.
For effects and interactions with the cationic kaolin produced in Example 1, the pulp was diluted to 1% consistency and under vigorous agitation in a blender mixed with untreated kaolin, cationic kaolin, or no additives, for 15 seconds. Qualitative assessment of the "stickies" was conducted visually and an evaluation of the effects of the kaolins was conducted with scanning electron microscopy (SEM). The stickies that floated in the water seemed to be comprised of relatively large amounts of fibers which appeared to be held together by an adhesive material. Floating stickies were found to sink to the bottom when treated with small amounts of the cationic kaolin. No similar sinking was observed with equal amounts of untreated kaolin. This result is an indication of the effect of the cationic kaolin on "stickies" behavior.
Ten pounds per ton and 20 pounds per ton dry on dry of the cationic kaolin of Example 1 or an untreated kaolin were added to a pulp slurry of about 1% consistency. Thereafter, the "stickies" were isolated and evaluated with SEM. Micrographs of the "stickies" elucidate the effectiveness of the invention. Stickies appear to consist of large smooth areas containing cracks and crevices. These cracks/crevices appeared to be most favored point of attachment of the products of the invention. With the untreated kaolin, very few clay particles were visible on the surface of the stickies or even within the crevices. Stickies treated in accordance with the invention, on the other hand, showed a high concentration of particles attached to the surface of the stickies within the crevices. From these results, it appears that the cationic kaolin successfully adhered to the surface of the stickies. Untreated kaolin failed to attach to the surface of the stickies.
EXAMPLE 5
Deinking was evaluated using photocopier toner in water as a model system. Two different particle size kaolins were tested: Norcote II, a relatively fine kaolin at about 80% <2 μm (Median 0.45 μm) and Norfil, a relatively coarse kaolin at about 53%<2 μm (Median 0.8 μm). These kaolins were made cationic by the procedure used in Example 1 using Nalco 94 DC 047. The Norcote II clarified the suspension of toner in water faster than the coarser Norfil. When scanning electron micrographs were made of the various mixtures, the cationic kaolin made with Norcote II was observed to more completely cover the surface of the photocopy toner particles than did the particulate made with 5 Norfil. The respective untreated kaolins Norcote II and Norfil did not attach to the photocopy toner particles.
Based on these results, further work using a standardized printed photocopied paper as a feed stock and pulping chemicals as processing aides was conducted. It was observed that the processing chemical reduced the dirt in the sheet by 17% but the addition of the cationic kaolin made with Norcote II and Nalco 94 DC 047 reduced the dirt by 47%. See Table III.
TABLE III______________________________________Deinking Efficiency of Product of Invention Number ofConditions Dirt Particles % Removed______________________________________Heat Only 195 --Heat and chemicals 162 17Heat, chemical and 104 47cationic kaolin______________________________________
EXAMPLE 6
Using a more complicated system involving xerographic paper to simulate ink and computer labels to simulate stickies, tests were run. Stickies, dirt and brightness were measured. One hundred grams of xerographic sheets with 2 grams of computer labels attached were cut into 1" squares and added to 2500 grams of water at 90° C. The mixture was cooked for 10 minutes with occasional stirring. One thousand two hundred and fifty grams of the mixture was put in a large Waring blender and blended for 10 seconds. One percent by dry weight (based on dry weight of sheets and labels) of the cationic kaolin of Example 1 was added and the mixture blunged for 20 seconds. The contents of the blender were transferred to a 21/2 gallon bucket which was then completely filled with warm water. A few drops of a liquid detergent were added and the pulp mixture was subjected to a wash/flotation process. About 30 grams of the strained pulp was made into a handsheet. The brightness and Hunter L,a,b values were determined by averaging 10 readings. A 32 sq. in. sheet was cut out and dirt determined by Tappi Method T 213 OM-89 dirt chart. The same sheet was sprayed with 0.1% crystal violet. After drying, the number of stickies was determined by counting using a light box. The results are shown in Table IV.
TABLE IV__________________________________________________________________________ Number Dirt.sup.(4) G.E. Hunter Values ofPolymer Dose.sup.(1) Count Brightness L a b Stickies__________________________________________________________________________Nalco 146 44 81.2 91.29 0.59 2.57 3894DC047Nalco 8117 158 47 81.0 91.45 0.63 2.89 44Sharpe 1144 84 34 81.7 91.55 0.55 2.52 33Nalco 105 41 81.1 91.28 0.57 2.59 4194DC047Pigment -- 62 80.1 90.54 0.57 2.36 49Control.sup.(2)Control.sup.(3) -- 161 77.2 88.6 0.54 1.82 66__________________________________________________________________________ .sup.(1) Pounds polymer per ton of kaolin (dry/dry). .sup.(2) Untreated kaolin. .sup.(3) Control with no washing and no kaolin. .sup.(4) Tappi method. T 213 OM89.
1) Pounds polymer per ton of kaolin (dry/dry).
2) Untreated kaolin.
3) Control with no washing and no kaolin.
4) Tappi method. T 213 0M-89.
As can be seen, the product of invention reduces the dirt and the number of stickies. The brightness and L value are also improved.
EXAMPLE 7
A mill trial was conducted at a post consumer office paper recycling facility. The product of Example 1 was added at 14:30 hours and pulp samples were collected before the disperser and at the end of the run. A schematic diagram is shown in FIG. I.
Table V tabulates the number of stickies before the disperser and in the product for various times after the product of the invention was added. The percent reduction of stickies is calculated by subtracting the number of stickies in the product from the number of stickies in the pulp at the disperser and dividing the difference by the number of stickies at the disperser. The resulting answer is converted to percent by multiplying by 100. The same procedure is used for the area of the stickies and the percent reduction.
As can be seen, even though the feed (before disperser) values varied widely, the product was always lower than the feed for both stickies and total stickies area.
TABLE V______________________________________ Time 14:30 18:00 21:00 24:00 3:00______________________________________Stickies No. at Disperser 21 20 12 12 11Stickies No. in Product 19 13 8 6 6Stickies Area at Disperser* 2.71 2.68 1.90 1.58 1.45Stickies Area in Product* 1.69 1.65 1.03 0.59 0.79Stickies Reduction (%)** 10 35 33 54 46Area Reduction (%)** 38 38 45 63 46______________________________________ *mm.sup.2 /150 grams dry pulp. **The percent reduction was calculated by taking one minus the ratio of the finished product value to the disperser value times 100.
TABLE VI______________________________________Effective Sampling Point and Time on Stickies NumberSampling TIME ---------------------------→Point* 14:00 18:00 21:00 0:0 3:00 9:00 18:00 21:00______________________________________Disperser 21 -- 12 -- -- -- -- --Flotation 21 20 12 12 11 16 16 10CellFinished Pulp 19 13 8 6 6 10 8 6______________________________________ *Samples taken from process stream just prior to processing stage except the finished pulp.
Flotation cell and cleaner rejects were analyzed by SEM and energy dispersive spectroscopic analysis (EDS). EDS mapping indicated that the kaolin was attached to the stickies of the cleaner rejects. Although a specimen of another large, flake-like aluminosilicate was found in the flotation cell rejects, this aluminosilicate resembled coating material and was found to contain titanium dioxide and thus could not originate from the cationic kaolin. Stickies were not found in the flotation cell rejects.
Having described the invention in detail and by reference to specific embodiments thereof, it will be apparent that numerous modifications are possible without departing from the spirit of the invention as defined by the following claims.
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Methods for reducing stickies and removing ink from wastepaper fiber wherein a cationic kaolin is added to a wastepaper fiber furnish under conditions such that the kaolin attaches to the stickies or the ink and the stickies or ink are removed from the furnish using a centrifugal cleaner.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not applicable.
BACKGROUND
[0002] 1. Field of the Invention
[0003] The present invention relates to the field of measuring the geometry of multi-fiber optic ferrules and connectors by means of interferometric microscopes. More specifically, the invention relates to interferometric measurement of end face surface angle.
[0004] 2. Description of the Related Art
[0005] Manufacturers of fiber optic connectors seek ways to produce the connectors with low transmission loss and low back reflection. End faces of fiber optic connectors must satisfy certain criteria for effective fiber mating as required by the industry standards. They must be clean and their surface geometry must provide for good physical contact and low signal loss.
[0006] Connector manufacturing procedure includes end face polishing for achieving the surface parameters that ensure good mating of the connectors in plugs. End face flatness needs to be verified that can be done by measuring the end face surface angle.
[0007] International Electrotechnical Commission standard IEC 61-300-3-30 defines surface angle as the angle between a reference plane which is perpendicular to the average guide pin axis and the connector end face surface.
[0008] The end face parameters, including the surface angle, are measured in an interferometric system. Special fixtures for positioning the connectors in the system are used. In case of multi-fiber connectors, the fixtures enable precise connector alignment in the interferometric system with the use of two guide pins. In the same way, in multi-fiber connector plugs two guide pins enable precise alignment between mating male and female connectors to minimize the optical insertion loss,
[0009] The fixtures are accurately adjusted and calibrated before measurement so that calibration angles of the pins relative to the optical axis of the interferometric microscope are known. The surface angle is calculated as the angle between the surface end face plane and a reference plane perpendicular to the optical axis of the interferometric microscope with known calibration angle correction.
[0010] Guide holes of multi-fiber connectors or ferrules are not strictly parallel. There is always some parallelism deviation as demonstrated on FIG. 1 . On this figure the reference number 1 represents a multi-fiber connector or ferrule, the top image being the top view of the connector or ferrule and the bottom image being its side view.
[0011] Reference plane 5 is perpendicular to the optical axis 2 of the interferometric system. When guide pins 3 and 3 ′ of a fixture are inserted into the connector guide holes which have some deviation from being parallel, the guide pins become deviated too. The alignment angle of pins is changed. The reference number 6 demonstrates deviation angle of one of the guide pins. In the same way, the other guide pin has a deviation angle as well.
[0012] Since during the surface angle calculation the deviation angle is not taken into account, the measured angle value has some calculation error.
[0013] The present invention suggests measuring precise alignment angle of the guide pins by scanning them from side together with inspecting the connector end face in one measurement or in several subsequent measurement without re-inserting the connector or ferrule. The measured values of the angles between the guide pin axes are taken into account when calculating the surface angles. Such surface measurement method allows to increase measurement accuracy by considering the deviation angle of the guide pins in calculations.
[0014] There is a known method for determining precise orientation of the axis of guide pin holes of a multi-fiber ferrule and precise angle of the ferrule (see Dean, D., (2004) U.S. Pat. No. 006,786,65).
[0015] The present invention employs the same technique of measuring fiber optic connectors as described in a related patent application by the same inventor (see Towfiq, F., (2015) U.S. patent application Ser. No. 14/697,784). The interferometric data is obtained from a side face of the guide pins which allows to measure the alignment angles of the guide pins of the connector or ferrule with two degrees of freedom.
SUMMARY OF THE INVENTION
[0016] The present method aims at interferometric measurement of surface angle of multi-fiber connectors and ferrules that takes into account precise alignment angle of the guide holes. The main concept of the present method is obtaining the interferometric data simultaneously from multi-fiber connector or ferrule guide pins by scanning them from side, and from the connector end face. The guide pins can be present in a male connector or can be inserted into a female connector or ferrule from a special fixture used for connector positioning.
[0017] The measurement is performed in an interferometric system with the help of special fixtures for simultaneous scanning of side face and end face. The special fixtures position the connector or ferrule so that its end face is approximately perpendicular to the optical axis of the interferometric microscope and the axes of its guide holes are parallel to it.
[0018] The special fixtures also contain a mirror element that turns the image obtained from the guide pins and directs it into the interferometer objective. Interferometric fringe patterns are created on the guide pins and on the end face.
[0019] The method works well for both multi-fiber female connectors or ferrules and male connectors. The alignment angle is measured for either the guide pins of the male connector or guide pins of the fixture inserted into the guide holes of the female connector or ferrule.
[0020] The required surface angles X and Y are calculated from the data obtained during the interferometric scanning First angles X and Y between each guide pin axis and system Z axis are calculated. These angles are then taken into account when calculating end face surface angles. Thus, the resulting angle values consider precise alignment angle of the guide holes.
[0021] The provided method can be applied to multi-fiber MTP/MPO connectors and MT ferrules with 2, 4, 8, 12, 16, 24, 48, 72 and other numbers of fibers, of both PC and APC types.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The presented method can be better understood with reference to the following drawings. Like reference numerals designate corresponding parts throughout several drawings.
[0023] FIG. 1 demonstrates related art problem with surface angle measurement.
[0024] FIG. 2 shows a measurement system being prepared for testing.
[0025] FIG. 3 demonstrates the use of the special fixture in interferometric system.
[0026] FIG. 4 is a flowchart of the measurement method in accordance with the present invention.
[0027] FIG. 5 illustrates the coordinates system.
[0028] FIG. 6 is a top view of the object being measured with the illustrated guide pin angles.
[0029] FIG. 7 is a side view of the object being measured with the illustrated guide pin angles.
[0030] FIG. 8 is a top view of the object being measured with the illustrated surface angle.
[0031] FIG. 9 is a side view of the object being measured with the illustrated surface angle.
[0032] FIG. 10 is a flowchart of calibration of the mirror surface angle of the fixture.
[0033] FIG. 11 is a side view of the object being calibrated with illustrated angles which are measured during the calibration procedure.
[0000]
REFERENCE NUMERALS IN THE DRAWINGS
1 multi-fiber connector or ferrule
2 optical axis of interferometric
system
3, 3′ guide pins inserted into
4, 4′ guide hole axes
guide holes of the connector
or ferrule
5 reference plane
6, 6′ deviation angles of the
guide holes
7 interferometric microscope
8 opening on the microscope front
panel
9 special fixture
10 mirror element of the fixture
11 fiber holes
12, 12′ guide holes
13 system Z axis
14, 14′ X angles between the
system Z axis and the axes of
the guide holes
15, 15′ Y angles between the
16 end surface plane
system Z axis and the axes
of the guide holes
17 guide pins
18 end surface angle of polish
along X axis
19 end surface angle of polish
20 pin axis in mirror
along Y axis
21 perpendicular to connector
22 Y angle between optical axis
end face
and pin image in mirror
23Y angle between optical axis
24 Y angle between optical axis
and perpendicular to connector
and mirror
end face
25 mirror surface
DETAILED DESCRIPTION OF THE INVENTION
[0034] Reference will now be made in detail to the presented measurement method illustrated in the accompanying drawings.
[0035] FIG. 2 illustrates an exemplary embodiment of the present invention. The reference number 7 represents an interferometric microscope. A special fixture 9 for simultaneous measurements of the connector end face and the side face of the guide pins is mounted on the microscope which has an opening 8 to receive the fixture. A multi-fiber connector or ferrule 1 is inserted into the fixture for interferometric measurements.
[0036] FIG. 3 provides a section view of the special fixture 9 with inserted connector or ferrule 1 . The fixture contains a mirror element 10 that turns the image from guide pins 17 . The light from the side surface of the guide pins is reflected from the mirror surface and directed into the interferometer. Thus simultaneous measurement of the connector end face and the side surfaces of the guide pins is possible.
[0037] FIG. 4 represents a method flowchart of end face surface angle measurement of multi-fiber connectors or ferrules according to the present invention. The surface angle is measured by an interferometric microscope. Special fixture for simultaneous scanning of the end face and side surfaces of the guide pins is provided together with the microscope for positioning of the ferrule in the measurement system. The special fixture is mounted on the interferometric microscope and the connector or ferrule is inserted into the fixture.
[0038] After the connector or ferrule is inserted into the special fixture and is ready for measurements, the interferometric microscope is focused and a fringe pattern is created on the guide pins and the end face of the connector or ferrule. Interferometric data is obtained from the side surfaces of the guide pins and from the end face of the connector or ferrule.
[0039] The position of the system Z axis which is the averaged line of the two guide pin holes is determined. Then calculations of alignment angles of the guide holes along axis X and along axis Y are performed.
[0040] The final step is calculations of end face surface angles X and Y in which alignment angles of the guide holes along axis X and along axis Y are taken into account.
[0041] FIG. 5 explains a system of coordinates X and Y. An X-axis passes through centers of first and second guide holes 12 and 12 ′ on the ferrule end face. A perpendicular Y-axis passes through the midpoint of the line connecting the guide holes' centers.
[0042] The top and side views of the connector or ferrule 1 represented on FIG. 6 and FIG. 7 respectively demonstrate relative angles of the axes 4 and 4 ′ of the guide holes with inserted guide pins 3 and 3 ′. The relative angles of the guide holes represent their alignment angles.
[0043] The reference numerals 14 and 14 ′ designate the angles along axis X between the averaged line 13 (the system Z axis) and the guide hole axes 4 and 4 ′ respectively.
[0044] The reference numerals 15 and 15 ′ designate the angles along axis Y between the averaged line 13 (the system Z axis) and the guide hole axes 4 and 4 ′ respectively.
[0045] The top and side views of the connector or ferrule 1 represented on FIG. 8 and FIG. 9 respectively demonstrate end face surface angles. The surface angles 18 and 19 along axes X and Y are calculated as the angles between the reference plane 5 and the end face surface 16 . In the resulting surface angles 18 and 19 , the alignment angles 6 and 6 ′ of the guide holes are taken into account.
[0046] FIG. 10 illustrates the method of calibrating angle of the mirror surface of the fixture that turns the image from the side surface of the guide pins and directs it into the interferometric microscope. The fixture is mounted on the interferometric microscope and the connector or ferrule is inserted into the fixture in its first position.
[0047] After the connector or ferrule is inserted into the special fixture and is ready for measurements, the interferometric microscope is focused and a fringe pattern is created on the guide pins and on the end face of the connector. Interferometric data is obtained from the side surfaces of the guide pins and from the end face of the connector.
[0048] Angles between the optical axis and the pin image in mirror and between the optical axis and the line perpendicular to the connector end face are calculated for the first position of the connector.
[0049] Then the connector is rotated by 180 degrees and inserted into the fixture in its second position. The interferometric microscope is focused again and a fringe pattern is created on the guide pins and on the end face of the connector or ferrule. Second set of the interferometric data is obtained from the side surfaces of the guide pins and from the end face of the connector.
[0050] Angles between the optical axis and the pin image in mirror and between the optical axis and the line perpendicular to the connector end face are calculated for the second position of the connector.
[0051] The final step is calculation of angles between the mirror surface of the fixture and the optical axis of the interferometric system.
[0052] FIG. 11 illustrates the angles Y measured during the calibration of the mirror surface angle. The side view of the connector and fixture is provided. The angles along the axis X are defined similarly.
[0053] Reference number 2 represents optical axis of interferometric microscope 7 . The multi-fiber connector or ferrule 1 is inserted into a special fixture with a mirror element. For simplicity, only the mirror element 10 of the fixture is shown and all other parts of the fixture are omitted. The mirror surface is designated by the reference number 25 .
[0054] The angle between the optical axis 2 and the pin axis in mirror 20 is represented by the reference numeral 22 . The angle between the line 21 perpendicular to the connector end face is represented by the reference numeral 23 . The resulting angle between the mirror surface 25 and the optical axis is represented by the reference numeral 24 .
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An interferometric measurement method aims at calculating end face surface angle of multi-fiber connector or ferrule taking into account parallelism deviation angles of the connector or ferrule guide holes. The parallelism deviation angles are measured by scanning the side surfaces of guide pins inserted into the guide holes, which is done simultaneously with the end face scanning Interferometric data from connector or ferrule end face and side surfaces of the guide pins is gathered during one scanning session—either one simultaneous scan or several scans without moving or re-inserting the connector or ferrule.
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FIELD OF THE INVENTION
[0001] This invention relates to messaging systems which communicate presence information. In particular, this invention relates to expanding presence system capabilities to include video or image presence information.
BACKGROUND OF THE INVENTION
[0002] Businesses are critically reliant on effective and efficient communication. The drive to improve communication, in conjunction with rapid advances in processing technology, have lead to sophisticated messaging systems which handle voice, text, facsimiles and other types of data. For example, instant messaging systems are available that support a text exchange between parties, along with basic presence indicators.
[0003] Presence indicators attempt to give a potential caller an indication of whether another individual is available to take a call, answer an instant message, or otherwise engage in a communication session. However, the presence indicators (e.g., ‘Busy’) are primarily manually set and adjusted, leading to inaccurate indications of presence. Thus, even though a caller may check presence prior to calling, the presence indicator is frequently incorrect. The caller then wastes time initiating a call and waiting for the callee to answer, only to be redirected to voice mail.
[0004] In limited cases, presence indicators are automatically set. As one example, an instant messaging program may watch for mouse, keyboard, or other user input. When no input is detected for a predetermined time period, the instant messaging program changes the presence state to ‘Away’ or another indicator of unavailability. However, whether an individual is present is not necessarily dependent on whether they are interacting with their computer. In other words, automatically set presence indicators are often no more accurate than manually set presence.
[0005] Each attempt to initiate a messaging session consumes valuable, limited, resources. Each time a caller places a call, for example, the supporting messaging system and network infrastructure consume a portion of those limited resources. Each call consumes processor time, network bandwidth, physical channel (e.g., TDMA time slot) capacity, and other resources. Nevertheless, in prior messaging systems, a caller would often attempt to establish a messaging session based on inaccurate or incomplete presence indicators.
[0006] A need has long existed for improved presence indication for messaging services.
SUMMARY
[0007] A messaging system supports visual presence indication. Before establishing a communication session, the destination endpoint provides an image, video, or other visualization to the originating endpoint of the potential communication session. The visualization shows the surroundings of the destination endpoint. The originating endpoint thereby obtains a supplemented or independent indication of presence status associated with the destination endpoint. In the context of a voice call, for example, the person calling need not waste time allowing the callee's phone to ring, only to be redirected to voicemail. Instead, the caller may immediately see that the callee is not available to answer his phone and may immediately end the call attempt and return to productivity.
[0008] A presence enabled communication system determines a destination endpoint with which to establish a desired communication session. The communication system may be the originating endpoint, or may be another system interacting with the originating and destination endpoints. The communication system sends a notification message to the destination endpoint regarding the desired communication session. Prior to establishing the desired communication session and in response to the notification message, the communication system receives image capture data.
[0009] The image capture data provides a visualization of the surroundings of the endpoint. The originating endpoint uses the image capture data to provide an image capture display that may be employed as a supplemental or independent presence indicator. The originating endpoint may also obtain a decision (e.g., from an operator of the originating endpoint) regarding whether to continue or terminate the attempt to establish the desired communication session.
[0010] The image capture data may be a digital picture of the environment surrounding the destination endpoint. Alternatively or additionally, the image capture data may be a video or video stream of the environment. The image capture data may visualize any environment in which an automated or non-automated endpoint may be located, including offices, conference rooms, parking garages, video, audio or other program providers, or other environments.
[0011] The present invention is defined by the following claims, and nothing in this section should be taken as a limitation on those claims. Further aspects and advantages of the invention are discussed below in conjunction with the preferred embodiments. Any one or more of the above described aspects or aspects described below may be used independently or in combination with other aspects herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 illustrates a messaging network in which endpoints send and receive presence indicators in the form of image capture data.
[0013] FIG. 2 illustrates data flow in a video enhanced messaging system.
[0014] FIG. 3 illustrates a destination endpoint.
[0015] FIG. 4 illustrates an originating endpoint.
[0016] FIG. 5 illustrates acts that may be taken by an originating endpoint.
[0017] FIG. 6 illustrates acts that may be taken by a destination endpoint.
DETAILED DESCRIPTION
[0018] The elements illustrated in the Figures interoperate as explained in more detail below. Before setting forth the detailed explanation, however, it is noted that all of the discussion below, regardless of the particular implementation being described, is exemplary in nature, rather than limiting. For example, although selected aspects, features, or components of the implementations are depicted as being stored in memories, all or part of systems and methods consistent with the messaging systems may be stored on, distributed across, or read from other machine-readable media, for example, secondary storage devices such as hard disks, floppy disks, and CD-ROMs; a signal received from a network; or other forms of ROM or RAM either currently known or later developed.
[0019] Furthermore, although specific components of the messaging and presence systems will be described, methods, systems, and articles of manufacture consistent with the messaging systems may include additional or different components. For example, a processor may be implemented as a microprocessor, microcontroller, application specific integrated circuit (ASIC), discrete logic, or a combination of other types of circuits or logic. Similarly, memories may be DRAM, SRAM, Flash or any other type of memory. Flags, data, databases, tables, and other data structures may be separately stored and managed, may be incorporated into a single memory or database, may be distributed, or may be logically and physically organized in many different ways. The programs discussed below may be parts of a single program, separate programs, or distributed across several memories and processors.
[0020] FIG. 1 shows a messaging network 100 which establishes and manages communication sessions between endpoints. The messaging network 100 may also initiate communication sessions in certain situations. The communication sessions may include voice, text, image or other types of data. The communication sessions may be telephone calls, instant messaging sessions, fax messaging sessions, multi-media messaging sessions, text messaging exchanges, or other types of communication sessions.
[0021] The entities interacting in the network 100 include the originating endpoint 102 (e.g., a caller), the destination endpoint 104 (e.g., a callee), and the networks 106 . The entities also include a messaging system 108 and a presence information system 110 which communicate through the networks 106 . The messaging system 108 and presence information system 110 may be systems commercially available from Siemens Communications, Inc. Furthermore, the endpoints 102 and 104 , messaging system 108 , and/or presence information system 110 may incorporate or perform any of the processing described below with regard to any of the entities interacting in the network 100 . For example, the originating endpoint 102 may implement the functions and/or features of both an endpoint and the messaging system 108 .
[0022] In the example shown in FIG. 1 , the destination endpoint 104 is a phone in an office 112 where an individual 114 works. The destination endpoint 104 may include or may exchange data with a video camera 116 , a still picture camera 118 , or any other image capture device. The image capture devices obtain and transmit image capture data. The image capture data may be used to render an image capture display 120 showing the destination endpoint surroundings. Thus, the image capture display 120 provides visual confirmation of whether the individual 114 is present.
[0023] The image capture devices may be positioned to provide a field of view of any location in whole or in part. Thus, the image capture devices may cover the entire office 112 , a part of the office around the endpoint 104 (e.g., an office desk and chair), or any other portion of the office surroundings. The image capture devices thereby provide the image capture data for rendering a visualization of whether the individual 114 is present in the office 112 and/or available to interact with the destination endpoint 104 .
[0024] The image capture devices may be added to any location where a visual representation of presence is desired. As examples, image capture devices may be added to conference rooms, lunch rooms, or other office locations; elevators, parking garages, hallways, stairwells, or other publicly accessible locations; and street signs, lampposts, intersections, or other traffic locations. The image capture devices may provide image capture data for interactive destination endpoints such as office phones, cell phones, and personal data assistants, or may provide image capture data for non-interactive destination endpoints such as automated response or information systems. Examples of non-interactive destination endpoints include cable television providers which may respond with image capture data showing movies that are currently playing or which are available for play, weather information providers which may responds with image capture data showing weather conditions, or any other automated response system.
[0025] The individual 114 subscribes to the presence information system 110 and/or messaging system 108 . Accordingly, the destination endpoint 104 provides presence information for the individual 114 to the entities communicating over the networks 106 directly, or indirectly through the presence information system 110 . The presence information includes image capture data provided by the video camera 116 , picture camera 118 , or other image capture devices.
[0026] The entities and networks 106 may exchange information using a packet based protocol. For example, the messaging system 108 , presence information system 110 , and endpoints 102 and 104 may employ the Real Time Protocol (RTP) over the User Datagram Protocol (UDP). Other protocols, including the Transmission Control Protocol/Internet Protocol (TCP/IP) or other network protocols may be additionally or alternatively employed. In addition, the signaling between the entities may proceed according to the H.323 packet-based multimedia communications system standard published by the International Telecommunications Union (ITU). The network or interconnection of networks 110 may include the Public Switched Telephone Network (PSTN) and may deliver data to cell phones, wireline phones, internet phones, or other communication devices.
[0027] The entities in the network 100 may employ protocols that adhere to any desired specification. For example, the entities may employ the Session Initiation Protocol (SIP) developed for Internet conferencing, telephony, presence, events notification and instant messaging, the Jabber protocol, or SIP for Instant Messaging and Presence Leveraging Extensions (SIMPLE). The form and content of the presence information may be established according to protocols consistent with the Internet Engineering Task Force (IETF) Request for Comments (RFC) 2778 or IETF RFC 2779. Alternatively, the entities may employ extensions to RFC 2778 or RFC 2779, or may employ proprietary protocols.
[0028] The endpoints 102 and 104 may be communication devices, automated response systems, or other types of devices. The endpoints 102 and 104 may include audio reproduction capability employed to deliver voice messages to a subscriber. The endpoints 102 and 104 may alternatively or additionally be cellular phones, desk phones, pagers, Personal Data Assistants (PDAs), computers, specific programs executing on the computers, or other devices or programs.
[0029] The individual 114 may have one or more presence states with respect to one or more endpoints, including the destination endpoint 104 . Examples of presence states include ‘Available’, when the individual 114 is in the office 112 and available to receive messages; ‘Out of Office’, when the individual 114 is not in the office and is not available to receive message; and ‘On Vacation’, when the individual 114 is out of the office on vacation.
[0030] As an addition to, or as an alternative to such presence states, the video camera 116 and picture camera 118 provide image capture data. The image capture data provides a visual representation of presence for the individual 114 . The entities communicating in the network 110 may communicate the image capture data between the endpoints 102 and 104 . In one implementation, the destination endpoint 104 communicates the image capture data directly to the originating endpoint 102 . In other implementations, the image capture data may be stored and/or archived in the presence information system 110 . The presence information system 110 may then provide the image capture data to the originating endpoint 102 .
[0031] Accordingly, for example, rather than allow a callee's phone to repeatedly ring until a voicemail system answers, an operator at the originating endpoint 102 may observe that no one is present to answer the call. The operator may then instruct the originating endpoint 102 to hang up without wasting time as the callee's phone continues to ring. The early termination of the call attempt may also save network bandwidth and processing resources for handling what would otherwise be a continued, but fruitless, call attempt.
[0032] The originating endpoint 102 may provide a decision of whether to continue the call attempt. For example, when the image capture display 120 reveals that the individual 114 is absent, the originating endpoint 102 may provide a decision to terminate the call attempt. Otherwise, the call attempt may proceed, and the endpoints 102 and 104 may establish the communication session 122 with or without the assistance of the messaging system 108 and/or the presence information system 110 .
[0033] FIG. 2 shows the flow of messages between the originating endpoint 102 and the destination endpoint 104 . Although discussed below in the context of a voice call, the video enhanced systems may provide video presence for any type of communication session. The originating endpoint 102 (e.g., a telephone program on a personal computer) determines that the destination endpoint 104 (e.g., an office phone) is the desired endpoint for the voice call.
[0034] The originating endpoint 102 sends a notification message 202 to the destination endpoint 104 . Alternatively, the originating endpoint 102 may inform the messaging system 108 that a communication session should be established between the endpoints 102 and 104 . The messaging system 108 may then send the notification message 202 to the destination endpoint 104 .
[0035] The notification message 202 may be accompanied by a media specifier 204 which is part of the notification message 202 or which may be a separate message. The media specifier 204 includes one or more data fields that inform the destination endpoint 104 of the media handling capabilities and/or media requests of the originating endpoint 102 . Accordingly, the media specifier 204 may indicate that the originating endpoint 102 requests and/or can process images, video, video streams, or any combination of image data.
[0036] The destination endpoint 104 communicates directly or indirectly with the capture device 206 . In response to the notification 202 and informed by the media specifier 204 , the destination endpoint 104 may command the capture device 206 to capture an image, multiple images, a video, begin a streaming video, or provide any combination of video information. Also, in reply to the notification 202 , the destination endpoint 104 or the messaging system 108 may provide a response 208 .
[0037] The response 208 may provide a status of the initiation of the communication session to the originating endpoint 102 . For example, the response 208 may indicate that the destination endpoint 104 is ‘ringing’, or is otherwise awaiting a response from an operator of the destination endpoint 104 . In the same response 208 , or in one or more additional messages, the destination endpoint may communicate the image capture data 210 to the originating endpoint 102 . Alternatively or additionally, the destination endpoint 104 may provide the image capture data 210 to the presence information system 110 .
[0038] The originating endpoint 102 receives the image capture data 210 . An image processing program in the originating endpoint 102 interprets and renders the image capture data as an image capture display 120 . The image processing program may be a program which displays .jpg, .gif, .bmp, .mpg, .avi, or .wmv files or any other type of image or video file.
[0039] With the visualization of presence, the operator interacting with the originating endpoint 102 may decide whether to continue the call attempt or terminate the call attempt. To that end, the operator provides a decision 212 to the originating endpoint 102 . When the decision is to terminate the call attempt, the originating endpoint 102 and/or messaging system 108 may release the resources previously devoted to the attempt and thereby converse valuable and limited communication and processing resources.
[0040] Otherwise, the call attempt continues, and the callee may answer. The endpoints 102 and 104 establish the communication session 122 . Communication data 214 flows between both endpoints 102 and 104 . The communication data 214 may represent packetized voice data, or any other type of information.
[0041] In one implementation, the notification message 202 may be a SIP /INVITE/ message. The /INVITE/ message may be followed by the media specifier 204 . Similarly, the response message 208 may be a SIP /RINGING/ message. Other notification and response messages may be employed, however.
[0042] FIG. 3 shows one example of a destination endpoint 104 in a visualization enhanced presence system. The destination endpoint 104 includes a processor 302 , a memory 304 , and an interface 306 . The interface communicates with the capture device 206 .
[0043] The memory 304 stores presence state data 308 , image capture data 310 , and an image enable flag 312 . The presence state data 308 may represent manually or automatically derived presence states obtained, for example, from the presence information system 110 . For example, the presence state data 308 may indicate whether the individual 114 is unavailable, in a meeting, on vacation, or any other presence information. The image capture data 310 may be image files, video files, or any other type of visualization data.
[0044] The individual 114 may set or clear one or more image enable flags 312 to determine when the destination endpoint 104 is allowed to acquire image captures. An image enable flag 312 may apply to every request for image capture data. Alternatively, image enable flags 312 may be established for image capture data requests from specific individuals or groups of individuals, for certain times or dates, or may otherwise have specific application. Furthermore, image enable flags 312 may be provided on a global or individual basis for any of the image capture devices in communication with the destination endpoint 104 .
[0045] The memory 304 also stores a notification processing program 314 and a capture device control program 316 . The notification processing program 314 receives the notification 202 of the desired communication session and the media specifiers 204 . When the originating endpoint 102 has requested pre-communication session visualization, the notification processing program 314 may check the enable flags 312 to determine whether image capture is authorized.
[0046] When image capture is requested and authorized, the capture device control program 316 issues a capture command 318 to the capture device 206 . The capture command 318 may direct the capture device 206 to obtain one or more images, obtain a video, start video streaming, or take any other visualization action. The capture device 206 thereby obtains a visualization of the surroundings of the destination endpoint 104 . The capture device 206 returns capture device data 320 to the destination endpoint 104 . The capture device data 320 may be raw compressed or uncompressed image data or video frames, or may be pre-processed images or video data in any format (e.g., an industry standard .jpg file), or any other type of image data.
[0047] FIG. 4 shows one example of an originating endpoint 102 in a visualization enhanced presence system. The originating endpoint 102 includes a processor 402 , a memory 404 , an interface 406 , and a display 408 . The interface 406 communicates with the networks 106 to send notification messages 202 and receive image captures 210 . The interface 406 may also receive the decisions 212 to continue and/or terminate call attempts. To that end, the interface 406 may include operator mouse and keyboard interfaces as well as network interfaces.
[0048] The memory 404 includes presence state data 408 , image capture data 410 , and media capability flags 412 . The presence state data 408 may represent manually or automatically derived presence states as described above. The originating endpoint 102 receives the present state data 408 for the destination endpoint 104 directly from the destination endpoint 104 , the presence information system 110 , or another presence provider. The image capture data 410 may be image files, video files, or any other type of visualization data received from the destination endpoint 104 , the presence information system 110 , or another presence provider.
[0049] The media capability flags 412 may be set or cleared to indicate what types of visualizations the originating endpoint 102 is capable of processing and/or displaying. As examples, the media capability flags 412 may specify image, video, video streaming, certain types, formats, encoding, or protocols for images, video, or video streaming, or other media types. The media capability flags 412 may also specify from which destination endpoints the originating endpoint 102 will request image capture data.
[0050] The memory 404 also includes an image processing program 414 and a notification processing program 416 . The notification processing program 416 prepares and communicates the notification message 202 . The notification processing program 416 may execute in response to a user requesting that a communication session be established between the endpoints 102 and 104 . The notification processing program 416 also may read the media capability flags 412 , prepare and communicate the media specifiers 204 , and receive the response 208 and/or image capture data 210 .
[0051] The image processing program 414 renders the image capture data as an image capture display. To that end, the image processing program 414 may read the image capture data 410 , interpret the image capture data 410 , and provide the image capture display 120 to the display 408 . The image processing program 414 may be a picture viewer, media player, or any other type of program which renders images on the display 408 .
[0052] FIG. 5 provides a flow diagram 500 that summarizes the acts that may be taken by the originating endpoint 102 and the programs operating in the originating endpoint 102 . At any time, the originating endpoint 102 determines that it will attempt to establish a communication session for a phone call, instant messaging sessions, or any other type of communication session. The originating endpoint 102 determines the destination endpoint for the communication session (Act 502 ). To that end, the originating endpoint 102 may consult a table of endpoint names or other identifiers, choose a contact from a contact or telephone number list, or otherwise identify the destination endpoint 104 .
[0053] The originating endpoint 102 may then prepare and send the notification message 202 (Act 504 ) and the media specifier 204 (Act 506 ). The originating endpoint 102 receives a response 208 (Act 508 ), such as an indication that a callee's phone is ‘ringing’. If requested and the destination endpoint 104 has authorized it, the originating endpoint 102 may receive image capture data 210 from the destination endpoint 104 (Act 510 ).
[0054] The image capture data may represent the surroundings or environment of the destination endpoint 104 . Pictures, movies, streaming video, or other types of visualization may capture the surroundings. The display 408 associated with the endpoint 102 shows the visualization (Act 512 ). The operator of the endpoint 102 may then refer to the visualization as a supplement to other presence information for the endpoint 104 , or as an independent statement of presence for the endpoint 104 .
[0055] The operator of the endpoint 102 may issue a decision 212 of whether to continue the call attempt or terminate the call attempt. The endpoint 102 receives the decision (Act 514 ) through a keyboard, mouse, voice command, or other input mechanism. Alternatively or additionally, the endpoint 102 may perform automated or semi-automated image processing on the image capture data to determine the presence or absence of image features relevant to presence. For example, the endpoint 102 may apply an image processing algorithm to locate, identify, or determine the presence of a person, shape, or environmental condition. The endpoint 102 may then provide its own decision of whether to continue the call attempt, depending on the presence or absence of the person, shape, or environmental condition present in the image.
[0056] The endpoint evaluates the decision 212 (Act 516 ). When the decision 212 is to terminate, the endpoint 102 ends the call attempt. Otherwise, the endpoint 102 continues the call attempt and may establish the communication session (Act 518 ). Any established communication session eventually terminates (Act 520 ).
[0057] FIG. 6 provides a flow diagram 600 which summarizes the acts that may be taken by the destination endpoint 104 and the programs operating in the originating endpoint 104 . The destination endpoint 104 receives a notification message ( 202 ) from an entity in the network 100 (Act 602 ) and also receives a media specifier ( 204 ) (Act 604 ). The destination endpoint 104 sends a response ( 208 ) to the notification (Act 606 ). The response may include a flag, field, or other data which indicates whether the destination endpoint 104 has the capability to capture image data or make any other response requested by the originating endpoint 102 .
[0058] The media specifier ( 204 ) may indicate that the originating endpoint 102 has asked for image capture. Before filling that request, the destination endpoint 104 may read the image enable flags 312 (Act 608 ) and may determine whether the originating endpoint 102 is authorized to receive image captures (Act 610 ). When authorized, the destination endpoint 102 captures image data (Act 612 ) and communicates the image capture data 210 to the originating endpoint 102 or other entity in the network 100 (Act 614 ).
[0059] The destination endpoint 104 may or may not be capable or authorized to provide the image capture data 210 . Regardless, the destination endpoint 104 may establish the communication session (Act 616 ). The established communication session eventually terminates (Act 618 ).
[0060] The origination endpoint 102 and destination endpoint 104 support visualization of presence. Before establishing a communication session 122 , the destination endpoint 104 captures a picture or video and provides the picture or video to the originating endpoint. The visualization shows the surroundings of the destination endpoint. The visualized presence provides an independent indication of presence status associated with the destination endpoint.
[0061] The visualization may show the operator of the originating endpoint 102 that no one is present to respond to the instant message. Rather than allowing an instant messaging system to repeatedly prompt for an answer, the originating endpoint 102 may then terminate the attempt to establish the instant messaging session. The originating endpoint 102 thereby saves network bandwidth and processing resources devoted to what will be an unsuccessful attempt.
[0062] The destination endpoint 104 may be an automated (e.g., a parking garage camera) or non-automated (e.g., a personal cell phone) endpoint. Accordingly, the image capture data may provide a view of an office, conference room, parking garage or other space. Automated endpoints may be established at service providers, such as cable television providers. The cable television endpoints may return image capture data representative of movies available for pay-per-view, movies currently playing on one or more television channels, services available from the cable television provider, or image capture data for any other purpose.
[0063] It is therefore intended that the foregoing detailed description be regarded as illustrative rather than limiting, and that it be understood that it is the following claims, including all equivalents, that are intended to define the spirit and scope of this invention.
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An originating endpoint supports visual presence indications. The originating endpoint determines a destination endpoint with which to establish a desired communication session. A network communicates a notification message to the destination endpoint regarding the desired communication session. Prior to establishing the desired communication session and in response to the notification message, the originating endpoint receives image capture data representing the surroundings of the destination endpoint. The originating endpoint may then determine from the image capture data whether to continue or terminate the attempt to establish the communication session. Visual presence indications may increase productivity by reducing the time that would otherwise be spent on unsuccessful call attempts. Visual presence indications may also conserve network bandwidth and processing resources that would otherwise be spent on the unsuccessful call attempts.
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REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation-in-part of U.S. patent application Ser. No. 11/154,039, filed Jun. 16, 2005, the entire content of which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] This invention relates generally to actuators and corresponding methods and systems for controlling such actuators, and in particular, to actuators providing independent lift and timing control with minimum energy consumption.
BACKGROUND OF THE INVENTION
[0003] Various systems can be used to actively control the timing and lift of engine valves to achieve improvements in engine performance, fuel economy, emissions, and other characteristics. Depending on the means of the control or the actuator, these systems can be classified as mechanical, electrohydraulic, and electromechanical (sometimes called electromagnetic). Depending on the extent of the control, they can be classified as variable valve-lift and timing, variable valve-timing, and variable valve-lift. They can also be classified as cam-based or indirect acting and camless or direct acting.
[0004] In the case of a cam-based system, the traditional engine cam system is kept and modified somewhat to indirectly adjust valve timing and/or lift. In a camless system, the traditional engine cam system is completely replaced with electrohydraulic or electro-mechanical actuators that directly drive individual engine valves. All current production variable valve systems are cam-based, although camless systems, will offer broader controllability, such as cylinder and valve deactivation, and thus better fuel economy.
[0005] Problems with an electromechanical camless system include difficulty associated with soft-landing, high electrical power demand, inability or difficulty to control lift, and limited ability to deal with high and/or varying cylinder air pressure. An electrohydraulic camless system can generally overcome such problems, but it does have its own problems such as performance at high engine speeds and design or control complexity, resulting from the conflict between the response time and flow capability. To operate at up to 6,000 to 7,000 rpm, an actuator has to first accelerate and then decelerate an engine valve over a range of 8 mm within a period of 2.5 to 3 milliseconds. The engine valve has to travel at a peak speed of about 5 m/s. These requirements have stretched the limit of conventional electrohydraulic technologies.
[0006] One way to overcome this performance limit is to incorporate, in an electrohydraulic system like in an electromechanical system, a pair of opposing springs which work with the moving mass of the system to create a spring-mass resonance or pendulum system. In the quiescent state, the opposing springs center an engine valve between its end positions, i.e., the open and closed positions. To keep the engine valve at one end position, the system has to have some latch mechanism to fight the net returning force from the spring pair, which accumulates potential energy at either of the two ends. When traveling from one end position to the other, the engine valve is first driven and accelerated by the spring returning force, powered by the spring-stored potential energy, until the mid of the stroke where it reaches its maximum speed and possesses the associated kinetic energy; and it then keeps moving forward fighting against the spring returning force, powered by the kinetic energy, until the other end, where its speed drops to zero, and the associated kinetic energy is converted to the spring-stored potential energy.
[0007] With its well known working principle, this spring-mass system by itself is very efficient in energy conversion and reliable. Much of the technical development has been to design an effective and reliable latch-release mechanism which can hold the engine valve to its open or closed position, release it as desired, add additional energy to compensate for frictions and highly variable engine cylinder air pressure, and damp out extra energy before its landing on the other end. As discussed above, there have been difficulties associated with electromechanical or electromagnetic latch-release devices. There has also been effort in the development of electrohydraulic latch-release devices.
[0008] Disclosed in U.S. Pat. No. 4,930,464, assigned to DaimlerChrysler, is an electrohydraulic actuator including a double-ended rod cylinder, a pair of opposing springs that tends to center the piston in the middle of the cylinder, and a bypass that short-circuits the two chambers of the cylinder over a large portion of the stroke where the hydraulic cylinder does not waste energy. When the engine valve is at the closed position, the bypass is not in effect, the piston divides the cylinder into a larger open-side chamber and a smaller closed-side chamber, and the engine valve can be latched when the open-side and closed-side chambers are exposed to high and low pressure sources, respectively, because of the resulting differential pressure force on the piston in opposite to the returning spring force. When the engine valve is at the open position, the piston divides the cylinder into a larger closed-side chamber and a smaller open-side chamber, and the engine valve can be latched by exposing a larger closed-side chamber and smaller open-side chamber with high and low pressure sources, respectively.
[0009] At either open or closed position, the engine valve is unlatched by briefly opening a 2-way trigger valve to release the pressure in the larger chamber and thus eliminate the differential pressure force on the piston, triggering the pendulum dynamics of the spring-mass system. The 2-way valve has to be closed very quickly again, before the stroke is over, so that the larger chamber pressure can be raised soon enough to latch the piston and thus the engine valve at its new end position. This configuration also has a 2-way boost valve to introduce extra driving force on the top end surface of the valve stem during the opening stroke.
[0010] The system just described has several potential problems. The 2-way trigger valve has to be opened and closed in a timely manner within a very short time period, no more than 3 ms. The 2-way boost valve is driven by differential pressure inside the two cylinder chambers, or stroke spaces as the inventers refer as, and there is potentially too much time delay and hydraulic transient waves between the boost valve and cylinder chambers. Near the end of each stroke, the larger cylinder chamber has to be back-filled by the fluid fed through a restrictor, which demands a fairly decent opening size on the part of the restrictor. On the other hand, at the onset of the each stroke, the 2-way trigger valve has to relieve the larger chamber which is in fluid communication with the high pressure fluid source through the same restrictor. During a closing stroke, there is no effective means to add additional hydraulic energy until near the very end of the stroke, which may be a problem if there are too much frictional losses. Also, this invention does not have means to adjust its lift.
[0011] DaimlerChrysler has also been assigned U.S. Pat. Nos. 5,595,148, 5,765,515, 5,809,950, 6,167,853, 6,491,007, and 6,601,552, which disclose improvements to the teachings of U.S. Pat. No. 4,930,464. The subject matter up to U.S. Pat. No. 6,167,853 resulted in various hydraulic spring means to add additional hydraulic energy at the beginning of the opening stroke to overcome engine cylinder air pressure force. One drawback of the hydraulic spring is its rapid pressure drop once the engine valve movement starts.
[0012] In U.S. Pat. No. 6,601,552, a pressure control means is provided to maintain a constant pressure in the hydraulic spring means over a variable portion of the valve lift, which however demands that the switch valve be turned between two positions within a very short period time, say 1 millisecond. The system again contains two compression springs: a first and second springs tend to drive the engine valve assembly to the closed and open positions, respectively. The hydraulic spring means is physically in serial with the second compression spring. During a substantial portion of an opening stroke, it is attempted to maintain the pressure in the hydraulic spring despite of the valve movement and thus provide additional driving force to overcome the engine cylinder air pressure and other friction, resulting in a net fluid volume increase in the hydraulic spring means and an effective preload increase in the second compression spring because of a force balance between the hydraulic and compression springs. In the following valve closing stroke, the engine valve may not be pushed all the way to a full closing because of higher resistance from the second compression spring.
[0013] A concern common to this entire family of inventions is that there have to be two switchover actions of the control valve for each opening or closing stroke. Another common issue is the length of the actuator with the two compression springs separated by a hydraulic spring. When the springs are aligned on the same axis, as disclosed in U.S. Pat. No. 5,809,950, the total height may be excessive. In the remaining patents of this family, the springs are not aligned on a straight axis, but are instead bent at the hydraulic spring, and the fluid inertia, frictional losses, and transient hydraulic waves and delays may become serious problems. Another common problem is that the closing stroke is driven by the spring pendulum energy only, and an existence of substantial frictional losses may pose a serious threat to the normal operation. As to the unlatching or release mechanism, some embodiments use a 3-way trigger valve to briefly pressurize the smaller chamber of the cylinder to equalize the pressure on both surfaces of the piston and reduce the differential pressure force on the piston from a favorable latching force to zero. Still the trigger valve has to perform two actions within a very short period of time.
[0014] U.S. Pat. No. 5,248,123 discloses another electrohydraulic actuator including a double-ended rod cylinder, a pair of opposing springs that tends to center the piston in the middle of the cylinder, and a bypass that short-circuits the two chambers of the cylinder over a large portion of the stroke where the hydraulic cylinder does not waste energy. Much like the referenced DaimlerChrysler patents, it has the larger chamber of the hydraulic cylinder connected to the high pressure supply all the time. Different from DaimlerChrysler, however, it uses a 5-way 2-position valve to initiate the valve switch and requires only one valve action per stroke. The valve has five external hydraulic lines: a low-pressure source line, a high-pressure source line, a constant high-pressure output line, and two other output lines that have opposite and switchable pressure values. The constant high pressure output line is connected with the larger chamber of the cylinder. The two other output lines are connected to the two ends of the cylinder and are selectively in communication with the smaller chamber of the cylinder. Much like the DaimlerChrysler disclosures, it has no effective means to add hydraulic energy at the beginning of a stroke to compensate for the engine cylinder air force and friction losses. It is not capable of adjusting valve lift either.
SUMMARY OF THE INVENTION
[0015] Briefly stated, in one aspect of the invention, one preferred embodiment of an electrohydraulic actuator comprises an actuator housing, a actuation cylinder in the actuator housing, a longitudinal axis defined by the actuation cylinder with a first and second directions, an actuation piston disposed in the actuation cylinder and moveable along the longitudinal axis in the first and second directions, and first and second ports in the actuator housing. The actuation cylinder comprises first and second ends. The actuation piston comprises first and second surfaces. One preferred embodiment further comprises a first piston rod connected to the first surface of the actuation piston and disposed slideably inside a first bearing distal to the first end of the actuation cylinder, and a second piston rod connected to the second surface of the actuation piston and disposed slideably inside a second bearing distal to the second end of the actuation cylinder, a first fluid space defined by the first end of the actuation cylinder and the first surface of the actuation piston, a second fluid space defined by the second end of the actuation cylinder and the second surface of the actuation piston, a bypass means that hydraulically short-circuits the first and second fluid spaces when the actuation piston is not proximate to either of the first or second end of the actuation cylinder, a first flow mechanism between the first fluid space and the first port, a second flow mechanism between the second fluid space and the second port, first and second actuation springs biasing the actuation piston in the first and second directions, an engine valve operably connected to the second piston rod, and one or more snubbing means.
[0016] The actuation piston can be latched to the first end of the actuation cylinder, such that with the engine valve in a closed position, when the second and first fluid spaces are exposed to high- and low-pressure fluid, respectively, and not short-circuited by the bypass means because the resulting differential pressure force on the piston is in opposite to and greater than a returning force from the first and second actuation spring. Likewise, the actuation piston can be latched to the second end of the actuation cylinder, such that with the engine valve in an open position, when the first and second fluid spaces are exposed to high- and low-pressure fluid, respectively, and not short-circuited by the bypass means.
[0017] At either open or closed position, the engine valve is unlatched or released by toggling an actuation switch valve so that the pressure levels in the first and second fluid spaces are reversed, instead of being equalized as in the prior art, and thus the differential pressure force on the piston is also reversed, instead of just being reduced to almost zero like in prior art. Before the switch, the differential pressure force on the actuation piston is in opposite to and greater than the spring returning force to latch the engine valve. After the switch, the differential pressure force keeps substantially the same magnitude and reverses its direction to help the spring returning force drive the engine valve to the other position, feeding additional hydraulic energy into the system.
[0018] In one preferred embodiment, the bypass means comprises one or more passages embedded in the housing and with openings to the fluid spaces. In an alternative embodiment, the bypass means is simply an undercut around the cylinder wall.
[0019] According to the invention, the engine valve is initialized to the closed position by supply high pressure fluid to a chamber under a start piston fixed on the first piston rod. Alternatively, the engine valve is initialized to the open position by supply high pressure fluid into a chamber directly above the first piston rod. In yet another alternative embodiment, a start shaft assembly is used to selectively close and disable the bypass means so that the actuation piston and cylinder system can be directly used for its own startup. Also, by blocking the bypass means with this start shaft assembly, the actuator can be operated selectively with a much smaller lift. In another alternative embodiment, pneumatic actuation springs are used, and they may be configured to complete the initialization of the actuator either in the first or second direction.
[0020] The present invention provides significant advantages over other actuators and valve control systems, and methods for controlling actuators and/or engine valves. For example, by adding a substantial hydraulic force to coincide with the spring returning force at the beginning of each stroke, the system can help overcome the engine-cylinder air pressure and compensate for frictional losses. The ability of an alternative preferred embodiment to provide a shorter valve lift is very beneficial to achieve efficient low load operation in certain engine control strategies. The present invention is able to incorporate lash adjustment into all alternative preferred embodiments. It is also possible to trigger and complete one engine valve stroke by just one, instead of two, switch actions of the actuation switch valve. Certain embodiments of the present invention are able to exert additional fluid pressure force in the second direction during the bypass mode, which may be necessary in some engine exhaust valve applications.
[0021] The present invention, together with further objects and advantages, will be best understood by reference to the following detailed description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1 is a schematic illustration of one preferred embodiment of the hydraulic actuator and hydraulic supply system;
[0023] FIG. 2 is a schematic illustration of one preferred embodiment of the hydraulic actuator, which is being initialized. For simplicity, this and rest of the illustrations do not include the hydraulic supply system;
[0024] FIG. 3 is a schematic illustration of one preferred embodiment of the hydraulic actuator, which is complete with initialization. The engine valve is in closed position;
[0025] FIG. 4 is a schematic illustration of one preferred embodiment of the hydraulic actuator, with an opening travel just started and with the bypass not in effect;
[0026] FIG. 5 is a schematic illustration of one preferred embodiment of the hydraulic actuator, with the actuator in the middle range of an opening travel and with the bypass in effect;
[0027] FIG. 6 is a schematic illustration of one preferred embodiment of the hydraulic actuator, with the actuator near the end of an opening travel and with the bypass not in effect;
[0028] FIG. 7 is a schematic illustration of one preferred embodiment with the engine valve fully open;
[0029] FIG. 8 is a schematic illustration of another preferred embodiment which utilizes the first piston rod directly as the start mechanism. It also features tapered end surfaces of the actuation piston and cylinder;
[0030] FIG. 9 is a schematic illustration of another preferred embodiment which has in the actuation cylinder one or more undercuts as the bypass;
[0031] FIG. 10 is a schematic illustration of the start-up process of another preferred embodiment;
[0032] FIG. 11 is a schematic illustration of the engine valve opening process of another preferred embodiment which uses a shaft assembly to block a single bypass passage;
[0033] FIG. 12 is a schematic illustration of the short valve lift opening process of another preferred embodiment which uses a shaft assembly to block a single bypass passage;
[0034] FIG. 13 is an alternate embodiment of the device illustrated in FIG. 1 ;
[0035] FIG. 14 is a schematic illustration of another embodiment of the invention which comprises a single piston rod and offers additional pressure force in the second direction;
[0036] FIG. 15 is a schematic illustration of another embodiment of the invention which comprises one pneumatic spring and two piston rods, with the first piston rod being smaller than the second one, and offers additional pressure force in the second direction;
[0037] FIG. 16 is a schematic illustration of a further alternative embodiment of the invention which comprises two piston rods, with the first piston rod primarily for additional snubbing function, and offers additional pressure force in the second direction; and
[0038] FIG. 17 is a schematic illustration of a different embodiment of the invention which comprises two pneumatic springs and two piston rods, with the first piston rod being provided for additional snubbing and mechanical support, and offers additional pressure force in the second direction.
DETAILED DESCRIPTION OF THE INVENTION
[0039] Referring now to FIG. 1 , a preferred embodiment of the invention provides an engine valve control system using two pistons, one or more bypass passages, and a pair of spring means. The system comprises an engine valve 20 , a hydraulic actuator 30 , a high-pressure hydraulic source 70 , a low-pressure hydraulic assembly 76 , an actuation switch valve 80 , and a start switch valve 82 .
[0040] The high-pressure hydraulic source 70 includes a hydraulic pump 71 , a high-pressure regulating valve 73 , a high-pressure accumulator or reservoir 74 , a high-pressure supply line 75 , and a hydraulic tank 72 . The high-pressure hydraulic source 70 provides necessary hydraulic flow at a high-pressure P_H. The hydraulic pump 71 circulates hydraulic fluid from the hydraulic tank 72 to the rest of the system through the high-pressure supply line 75 . The high-pressure P_H is regulated through the high-pressure regulating valve 73 . The high-pressure accumulator 74 helps smooth out pressure and flow fluctuation and is optional depending on the total system capacity or elasticity, flow balance, and/or functional needs. The hydraulic pump 71 can be either of a variable- or fixed-displacement type, with the former being more energy efficient. The high-pressure regulating valve 73 may be able to vary the high-pressure value for functional needs and/or energy efficiency.
[0041] The low-pressure hydraulic assembly 76 includes a low-pressure accumulator or reservoir 77 , the hydraulic tank 72 , a low-pressure regulating valve 78 , and a low-pressure line 79 . The low-pressure hydraulic assembly 76 accommodates exhaust flows at a back-up or low-pressure P_L. The low-pressure line 79 takes all exhaust flows back to the hydraulic tank 72 through the low-pressure regulating valve 78 . The low-pressure regulating valve 78 is to maintain a design or minimum value of the low-pressure P_L. The low-pressure P_L is elevated above the atmosphere pressure to facilitate back-filling without cavitation and/or over-retardation. The low-pressure regulating valve 78 can be simply a spring-loaded check valve as shown in FIG. 1 or an electrohydraulic valve if more control is desired. The low-pressure accumulator 77 helps smooth out pressure and flow fluctuation and is optional depending on the total system capacity or elasticity, flow balance, and/or functional needs.
[0042] The actuation switch valve 80 and start switch valve 82 supply the ports of the hydraulic actuator 30 with proper flow supply lines. The start switch valve 82 shown in FIG. 1 is a 2-position 3-way valve. It is 3-way because it has three external hydraulic lines that include two input lines, i.e., low pressure P_L and high pressure P_H, and a fluid line 190 . It is 2-position because it has two stable control positions symbolized by left and right blocks or positions in FIG. 1 . The left position is secured by the action of a return spring when a solenoid is not energized, and it is also called the default position. The right position is secured by energizing the solenoid. At the left and right positions, the valve 82 connects the fluid line 190 with the low-pressure P_L and high-pressure P_H lines, respectively.
[0043] Following the same conventions, the actuation switch valve 80 is a 2-position 4-way valve. It has four external hydraulic lines: a low-pressure P_L line, a high-pressure P_H line, a fluid line 192 and a fluid line 194 . Its default position is the right position secured by a return spring, and its other position is the left position forced by a solenoid. At its default or right position, the valve 80 connects the fluid lines 192 and 194 with the low pressure P_L and high pressure P_H lines, respectively. The connection order is switched when the valve 80 is at its left position.
[0044] The engine valve 20 includes an engine valve head 22 and an engine valve stem 24 . The engine valve 20 is mechanically connected with and driven by the hydraulic actuator 30 along a longitudinal axis 116 through the engine valve stem 24 , which is slideably disposed in the engine valve guide 120 . When the engine valve 20 is fully closed, the engine valve head 22 is in contact with an engine valve seat 26 , sealing off the air flow in/out of the associated engine cylinder.
[0045] The hydraulic actuator 30 comprises an actuator housing 64 , within which, along the longitudinal axis 116 and from a first to a second direction (from the top to the bottom in the drawing), there are a start cylinder 32 , a first bearing 68 , a first chamber 40 , a first control bore 110 , an actuation cylinder 114 , a second control bore 102 , a second chamber 104 , and a second bearing 106 . Within these hollow elements from the first to the second direction lies a shaft assembly 31 comprising a start piston 196 , a first piston rod 34 , a first shoulder 44 , an actuation piston 46 , a second shoulder 50 , a second piston rod 66 , and a spring seat 60 . The first piston rod 34 further comprises a first-piston-rod second neck 38 , a first land 90 , and a first-piston-rod first neck 39 . The second piston rod 66 further comprises a second-piston-rod first neck 53 , a second land 52 , and a second-piston-rod second neck 54 .
[0046] In the actuation cylinder 114 , there is a first fluid space 84 defined by the actuation cylinder first end 132 and the actuation piston first surface 92 and a second fluid space 86 defined by the actuation cylinder second end 134 and the actuation piston second surface 98 .
[0047] The shaft assembly 31 can be substantially radially supported by some or all of the following mating surfaces from the first to the second direction: the start piston 196 and the start cylinder 32 , the first piston rod 34 and the first bearing 68 , the actuation piston 46 and the actuation cylinder 114 , and the second piston rod 66 and the second bearing 106 . Each pair of the above listed mating surfaces has tight clearance, provides substantial hydraulic seal, and yet offers tolerable resistance to relative motions, including translation along and, if desired, rotation around the longitudinal axis 116 , between the shaft assembly 31 and the housing 64 . The start cylinder 32 communicates hydraulically with the start switch valve 82 through a start port 36 and the fluid line 190 . The actuation switch valve 80 communicates with the first chamber 40 through a first port 42 and the fluid line 192 and with the second chamber 104 through a second port 56 and the fluid line 194 .
[0048] Through the side wall of the actuation cylinder 114 , there are one or more bypass passages 48 , which provide a hydraulic short circuit over a substantial length of the actuation cylinder 114 . The bypass passages 48 are preferably arranged in such a way that there is on the actuation piston 46 minimum net side force due to hydraulic static pressure. With the hydraulic short circuit, fluid may flow with substantially low resistance between the first and second fluid spaces 84 and 86 , and the entire actuation cylinder 114 is at substantially equal pressure. The hydraulic short circuit is not effective either when the actuation piston first surface 92 is distal, in the first direction, to the bypass first edge 94 or the actuation piston second surface 98 is distal, in the second direction, to the bypass second edge 100 . The longitudinal distance between the bypass first edge 94 and the actuation cylinder first end 132 is L_ 1 . The longitudinal distance between the bypass second edge 100 and the actuation cylinder second end 134 is L_ 2 .
[0049] The first land 90 , the first control bore 110 , and the first-piston-rod first and second necks 39 and 38 work together as a flow mechanism. The first land 90 selectively blocks fluid flow between the first chamber 40 and the first fluid space 84 of the actuation cylinder 114 , which occurs when the first land 90 is longitudinally located in or overlaps the first control bore 110 , with the radial clearance between the first land 90 and the first control bore 110 being substantially small and restrictive to fluid flow. The second land 52 , the second control bore 102 , and the second-piston-rod first and second necks 53 and 54 work together as another flow mechanism. The second land 52 selectively blocks fluid flow between the second chamber 104 and the second fluid space 86 of the actuation cylinder 114 , which occurs when the second land 52 is longitudinally located in or overlaps the second control bore 102 , with the radial clearance between the second land 52 and the second control bore 102 being substantially small and restrictive to fluid flow.
[0050] The longitudinal locations of the first land 90 and the second land 52 along the shaft assembly 31 are such that each of the two lands 90 and 52 blocks fluid flow when the actuation piston 46 sits or travels in-between the bypass first and second edges 94 and 100 , i.e., the bypass passages 48 being in effect. This prevents an open flow, through the bypass passages 48 , between the first chamber 40 and the second chamber 104 and saves energy. When the bypass passages 48 are not effective, the two lands 90 and 52 disengage or underlap their respective control bores 110 and 102 and allow substantial flow between the first chamber 40 and the first fluid space 84 and between the second chamber 104 and the second fluid space 86 .
[0051] The lengths of the actuation piston 46 and cylinder 114 are designed such that the piston 46 can travel with a stroke of ST plus an allowance for the engine valve lash adjustment. When moving in the second direction and opening the engine valve, the actuation piston 46 stops when its second surface 98 hits the actuation cylinder second end 134 . When moving in the first direction and closing the engine valve, the engine valve head 22 hits the valve seat 26 first while there is still a distance L_lash (see FIG. 3 ) or less between the actuation piston first surface 92 and the actuation cylinder first end 132 . The distance L_lash is allowance for the engine valve lash adjustment. Preferably, the sum of the lengths L_ 1 and L_ 2 is substantially less than the valve stroke ST to minimize the loss of hydraulic energy.
[0052] The first and second shoulders 44 and 50 are intended to work together with the first and second control bores 110 and 102 as snubbers to provide damping of the shaft assembly 31 near the end of the travel in the first and second directions, respectively. When traveling in the first direction, the actuation piston 46 pushes hydraulic fluid from the first fluid space 84 to the first chamber 40 once the actuation piston first surface 92 is distal to the bypass first edge 94 . At roughly the same time, the first shoulder 44 is pushed into the first control bore 110 , resulting in a flow restriction because of a narrower radial clearance between the first shoulder 44 and the first control bore 110 and thus a rising pressure on the actuation piston first surface 92 , which slows down the shaft assembly. A similar flow restriction through the radial clearance between the second shoulder 50 and the second control bore 102 helps dampen the motion of the shaft assembly 31 and the engine valve 20 in the second direction.
[0053] Concentrically wrapped around the engine valve stem 24 and the second piston rod 66 , respectively, are a first actuation spring 62 and a second actuation spring 58 . The second actuation spring 58 is supported by the housing surface 122 and the spring seat 60 , whereas the first actuation spring 62 is supported by cylinder head surface 124 and spring seat 60 . The actuation springs 62 and 58 are always under compression. They are preferably identical in major geometrical, physical and material parameters, such as stiffness, pitch and wire diameters, and free-length, such that the net spring force resulting from the two opposing spring forces is substantially equal to zero at the neutral position shown in FIG. 1 .
[0054] The spring seat 60 is designed such that when it is located substantially half-way between the housing surface 122 and the cylinder head surface 124 and when the actuation piston 46 is at the longitudinal center of the actuation cylinder 114 as shown in FIG. 1 , the two actuation springs 62 and 58 are under equal compression. As such the net spring force is zero, which is also the neutral position of the hydraulic actuator 30 , with the engine valve 20 being open at half of its stroke ST. The spring seat 60 also offers a mechanical connection between the shaft assembly 31 and the engine valve 20 or, more specifically or locally, between the second piston rod 66 and the engine valve stem 24 .
[0055] The shaft assembly 31 is generally under three static hydraulic forces and two spring forces. The three static hydraulic forces are the pressure forces at the actuation piston first and second surfaces 92 and 98 and the start piston second surface 127 . The start piston first surface 126 is preferably exposed to the air or a low pressure fluid. In case of a hydraulic leakage around the start piston 196 , a passage may be included to channel the leak flow from the top of the piston 196 to the hydraulic tank. The two spring forces are from the two actuation springs 62 and 58 to the spring seat 60 .
[0056] The engine valve 20 is generally exposed to two air pressure forces on the first surface 128 and the second surface 130 of the engine valve head 22 . The hydraulic actuator 30 and the engine valve 20 also experience various friction forces, steady-state flow forces, transient flow forces, and inertia forces. Steady-state flow forces are caused by the static pressure redistribution due to fluid flow or the Bernoulli effect. Transient flow forces are caused by the acceleration of the fluid mass. Inertia forces result from the acceleration of objects, excluding fluid here, with inertia, and they are very substantial in an engine valve assembly because of the large magnitude of the acceleration or the fast timing.
Start-Up
[0057] When the power is off, the status of the system is substantially equal to that shown in FIG. 1 . Two switch valves 80 and 82 are at their default positions. The start port 36 is connected to the P_L line, and the first port 42 and the second port 56 are connected to the P_L and P_H lines, respectively. Both the P_H and P_L lines are at zero gage pressure because the pump 71 is off. There is no net hydraulic force on the hydraulic actuator 30 , and there is no air force on the engine valve 20 either because the engine is not running.
[0058] Ignoring the gravitational force, the two springs 62 and 58 have to be compressed equally to keep force balance, resulting in a longitudinally centered position for the spring seat 60 between the housing surface 122 and the cylinder head surface 124 , a longitudinally centered position for the actuation piston 46 in the actuation cylinder 114 , and a half-open position for the engine valve 20 .
[0059] At engine start, the hydraulic pump 71 is turned on first to pressurize the hydraulic circuit. During vehicle operation, the hydraulic pump 71 is preferably driven directly by the engine. One may have to use a supplemental electrical means (not shown here) to start the hydraulic pump 71 , or to add an electrically-driven supplemental pump (also not shown).
[0060] Even with the system pressurized, however, the actuation piston 46 is stationary because its two surfaces 92 and 98 are exposed to substantially the same pressure due to the bypasse(s) 48 . Instead, the start switch valve 82 has to be turned to its start or right position as shown in FIG. 2 , with the second surface 127 of the start piston 196 being exposed to the high pressure P_H. The start piston 196 thus pulls, in the first direction, the shaft assembly 31 and the engine valve 20 , overcoming the net spring force. Note that the actuation switch valve 80 is still in its default or right position as shown in FIG. 2 , and it supplies the first chamber 40 and the second chamber 104 with the low pressure P_L and high pressure P_H lines, respectively.
[0061] Once the actuation piston first surface 92 travels past the bypass first edge 94 , the bypass passages 48 are blocked or disabled, and flows through the first and second control bores 110 and 102 are no longer blocked by the first and second lands 90 and 52 , resulting in a driving force in the first direction on the actuation piston 46 with the high pressure P_H and low pressure P_L at its second and first surfaces 98 and 92 , respectively. This differential pressure force is set to be strong enough to hold the shaft assembly 31 and the engine valve 20 in the closed position against the spring force even after the start switch valve 82 is switched back to its default or non-start position and supplies only low pressure P_L fluid to the start cylinder 32 as shown in FIG. 3 .
[0062] At the state shown in FIG. 3 , the start-up process is complete, start switch valve 82 will remain in the default or non-start or left position until the next engine starting, and the start cylinder 32 will remain filled with low-pressure fluid and contribute negligible force to hydraulic actuator 31 . Due to the back-and-forth movements of the start piston 196 during the normal operation, the pressure inside the start cylinder 32 deviates from the system low-pressure P_L. To prevent unnecessary losses, this deviation can be minimized by having shorter and larger flow passages in the fluid line 190 and the start switch valve 82 . The time response requirement for the start-up is generally not as stringent as that for the engine valve switching, the start switch valve 82 can be made with larger openings.
[0063] The state in FIG. 3 is a stable state for the engine valve 20 , which for a typical engine operation stays closed roughly ¾ of the thermodynamic cycle. For the most of the rest of the cycle, the engine valve 20 travels to the other stable state (the fully open state), stays there, and returns from it.
Valve Opening
[0064] To open the engine valve 20 , the actuation switch valve 80 is turned to the left position as shown in FIG. 4 , wherein the first and second chambers 40 and 104 are connected with the high pressure P_H and low pressure P_L, respectively. Due to the open communication through the second control bore 102 , the pressure in the second fluid space 86 quickly drops close to the low pressure P_L. Although the first control bore 110 is somewhat restricted by the first shoulder 44 , the pressure in the first fluid space 84 still can reach close to the high pressure P_H within a reasonable amount of time because of a low initial piston speed and flow rate. With these actuations, the differential hydraulic force on the actuation piston 46 changes its direction from in the first direction to in the second direction. This hydraulic force in the second direction works with the net spring force in the same direction to accelerate the shaft assembly 31 and the engine valve 20 , and also helps overcome whatever engine cylinder air force on the engine valve head 22 .
[0065] When the engine valve opening is between (L_ 1 -L_lash) and (ST-L_ 2 ) during the travel in the second direction as shown in FIG. 5 , the first and second control bores 110 and 102 are substantially blocked by the first and second lands 90 and 52 , respectively, and the displacement of the actuation piston 46 is accomplished by flows through the bypass passages 48 . Hydraulic power is no longer used, and the hydraulic actuator 31 is driven primarily by the actuation springs 62 and 58 . The potential energy stored in the springs 62 and 58 is released and continues to accelerate the hydraulic actuator 31 and the engine valve 20 until passing through the half-way point of the stroke, when the actuation springs 62 and 58 start resisting the movement in the second direction and converts the kinetic energy into the potential energy.
[0066] When the engine valve opening is between (ST-L_ 2 ) and ST during a travel in the second direction as shown in FIG. 6 , both the first and second control bores 110 and 102 are open for flows. Within this travel range, the net spring force is in the first direction, increases with the travel, and slows down the shaft assembly 31 and engine valve. When the actuation piston second surface 98 just passes the bypass second edge 100 , the first and second surfaces 92 and 98 of the actuation piston 46 are now exposed to the high pressure P_H and low pressure P_L, respectively, resulting in a net static hydraulic force in the second direction.
[0067] As the second shoulder 50 penetrates deeper into the second control bore 102 , the resulting flow restriction generates a dynamic pressure rise in the second fluid space 86 , resulting in a dynamic snubbing force in the first direction to slow down the shaft assembly 31 and the engine valve 20 . The snubbing force increases with the travel and travel velocity and drops to zero when the travel stops
[0068] There are therefore three primary forces: the spring force in the first direction, the static hydraulic force in the second direction, and the dynamic snubbing force in the first direction. The spring force resists and slows down the engine valve opening. The static hydraulic force assists the engine valve opening, especially if there has been excessive energy loss along the way and not enough kinetic energy in the shaft assembly 31 and the engine valve 20 for them to travel all the way to a full opening. The snubbing force tends to slow down the shaft assembly 31 and the engine valve 20 if they travel too fast before the actuation piston 46 hits the actuation cylinder 114 . At the full opening as shown in FIG. 7 , the snubbing force disappears, and the static hydraulic force should be large enough to hold the engine valve 20 in place against the net spring force and other minor forces.
Valve Closing
[0069] Closing the engine valve is effectively a reversal of the opening process just described. It is triggered by turning the actuation switch valve 80 to its default or right position as shown in FIG. 3 . Upon completion, the hydraulic actuator 30 and the engine valve 20 are back to their default states as shown in FIG. 3 .
[0070] FIG. 8 depicts an alternative embodiment of the invention. The primary physical difference between this embodiment and that illustrated in FIGS. 1 through 7 lies in the start-up mechanism. This alternative configuration does not include a start piston, but instead utilizes a combination of the first piston rod 34 and a new first bearing 68 b , which is more extended longitudinally than the first bearing 68 in FIGS. 1-7 .
[0071] In operation, the start switch valve 82 is turned to its start or right position as shown in FIG. 8 and supplies the high pressure P_H fluid to the first bearing 68 b , resulting in a hydraulic force on the first-piston-rod end surface 136 , which pushes the shaft assembly 31 b and the engine valve 20 to the full open position. To complete the initialization, the actuation switch valve 80 has to be turned to its left position as shown in FIG. 8 so that the first and second chambers 40 and 104 are supplied with the high pressure P_H and low pressure P_L fluids, respectively.
[0072] Once the start-up is complete, this embodiment operates like the embodiment in FIGS. 1 through 7 . This alternative embodiment has a simpler starting mechanism, but application may be limited by the available space between the fully-opened engine valve 20 and the top of the engine piston at the top dead center to avoid physical interference or impact. This embodiment also features tapered end surfaces for the actuation piston 46 b and actuation cylinder 114 b . When the actuation piston second surface 98 b hits the actuation cylinder second end 134 b , the tapered surfaces may have better stress distribution and longer service life. Although in a preferable design, the actuation piston first surface 92 b will never hit the actuation cylinder first end 132 b , still their tapered shape may help release local stress caused by high snubbing pressure. To achieve the same flow blocking function and logic, the first and second lands 90 b and 52 b are extended in their lengths compared with the lands in other preferred embodiments.
[0073] Refer now to FIG. 9 , there is a drawing of another alternative embodiment of the invention. The main physical difference between this embodiment and that illustrated in FIGS. 1 through 7 lies in the design of the bypass in the actuation cylinder 114 . In this embodiment, the bypass is one or more bypass undercuts 138 . This design provides smoother or freer bypass flow around the actuation piston 46 between the first and second edges 94 b and 100 b and less friction on the piston 46 .
[0074] Refer now to FIG. 10 , which is a drawing of yet another alternative embodiment of the invention. Compared with the embodiment in FIG. 8 , this embodiment is different primarily in its start mechanism 150 , which is designed to block a bypass passage 152 , preferably the only bypass passage around the actuation cylinder 114 . Also, the shaft assembly 31 d does not include the first land 90 b as in FIG. 8 , resulting in an extended neck 389 . The reason for the elimination of the first land 90 will become clear when the operation of this embodiment is explained below.
[0075] The start mechanism 150 includes a start shaft 154 comprising a first head 156 , a second head 160 and a stem 158 in between the two heads 156 and 160 . The start shaft 154 moves inside the bypass passage 152 , which is extended longitudinally beyond the length necessary for the bypass flow function to accommodate the whole length of the start shaft 154 . Two ends of the bypass passage 152 are hydraulically connected to start first and second ports 162 and 164 , respectively. Between the bypass passage 152 and the start first port 162 , there is a smaller passage 166 , offering a limit shoulder 140 to offer the limit in the first direction for the movement of the start shaft 154 . A return spring 168 resides inside the small passage 166 and, when the start shaft 154 is not all the way against the limit shoulder 140 , a part of the bypass passage 152 to urge the start shaft towards the second direction. The start first port 162 is always connected with the low pressure P_L line, whereas the start second port 164 is connected with either the high pressure P_H or low pressure P_L lines through the start switch valve 170 .
[0076] The bypass passage 152 and the start shaft 154 have a reasonable radial clearance to ensure a smooth sliding movement for the shaft 154 and minimum hydraulic leakage. From the first to the second direction along the longitudinal axis of the bypass passage 152 , there are a first bypass groove 172 , a second bypass groove 174 and a check valve groove 176 . From the first to the second direction along the longitudinal axis of the actuation cylinder 114 , there are a first actuation cylinder groove 178 and a second actuation cylinder groove 180 . These five grooves are intended to reduce or eliminate hydraulic force imbalance on the start shaft 154 and the actuation piston 46 and to facilitate the reduction of the flow resistance. The first bypass groove 172 is in hydraulic communication with the first actuation cylinder groove 178 , whereas the second bypass groove 174 is in hydraulic communication with the second actuation cylinder groove 180 . The check valve groove 176 is in hydraulic communication, C-to-C, with the downstream side of a check valve 182 , whereas the upstream end of the check valve 182 is in hydraulic communication with the second port 56 or, not shown in FIG. 10 , with the second chamber 104 .
[0077] In start operation as shown in FIG. 10 , the start switch valve 170 is energized and set at the left position, connecting the start second port 164 to the low pressure P_L line. The start shaft 154 is pushed by the return spring 168 in the second direction and blocks, with the first head 156 , the first bypass groove 172 and the bypass passage 152 , and the actuation piston 46 functions like a normal piston. Also, the actuation switch valve 80 is in its default or right position, connecting the first and second ports 42 and 56 to the low pressure P_L and high pressure P_H lines, respectively. The first fluid space 84 is now exposed the low pressure P_L because it is in hydraulic communication with the first port 42 though the first chamber 40 and the first control bore 110 , which is not blocked by the first land 90 b as in FIG. 8 .
[0078] Although the second control bore 102 is blocked by the second land 52 , the second fluid space 86 is still exposed to the high pressure P_H because it is in hydraulic communication with the second port 56 through the check valve 182 , the hydraulic communication C-to-C, the check valve groove 176 , a portion of the bypass passage 152 , the second bypass groove 174 , and the second actuation cylinder groove 180 . The resulting differential pressure pushes the actuation piston 46 and thus the shaft assembly 31 d and engine valve 20 all the way to the fully closed position, which completes the start-up process. Near the end of this travel, the second land 52 slides out the second control bore 102 to further ensure the connectivity between the second fluid space 86 and the second port 56 .
[0079] In normal operation as shown in FIG. 11 , the start switch valve 170 is de-energized and returned to its default or right position to keep the start second port 164 pressurized and to hold the start shaft 154 against the returning spring 168 , resulting in a substantially open bypass passage 152 and a blocked check valve groove 176 , which disables the check valve 182 . Thus, hydraulic actuator 31 d in FIG. 11 functions much like the hydraulic actuator 31 b in FIG. 8 , except that in FIG. 11 there is only one blocking land, the second land 52 to block the free flow between the first and second ports 42 and 56 during the middle portion of a stroke when the bypass passage 152 is open.
[0080] In an engine valve opening stroke as illustrated in FIG. 11 , the actuation switch valve 80 is de-energized or at its left position and connects the first and second ports 42 and 56 to the high pressure P_H and low pressure P_L lines, respectively, and the actuation piston 46 has moved to the middle range of the movement in the second direction where the bypass passage 152 is open. At this point, the entire actuation cylinder 114 is exposed to high pressure P_H through the bypass passage 152 and first control bore 110 . The net hydraulic force on the actuation piston 46 is still equal to zero. Therefore, the elimination of the first land 90 or 90 b does not fundamentally change the function of the system although it may introduce a little more flow leakage between the first and second ports 42 and 56 because it eliminates one of the two main barriers in the flow path. It is also workable to eliminate the first land 90 or 90 b in other preferred embodiments in FIGS. 1-9 .
[0081] This latest embodiment is also able to drive the engine valve 20 with a small lift, which is a great plus for engine calibration and control strategy. As shown in FIG. 12 , the actuation switch valve 80 is at its left position, and the hydraulic assembly 31 d is in a travel in the second direction. However, the start switch valve 170 is at its left position, and the start shaft 154 is at its lower position, blocking the bypass passage 152 .
[0082] As shown in FIG. 12 , the actuation piston 46 has just traveled a distance of (L_ 1 -L_lash), and the second land 52 is about to enter the second control bore 102 . At this point, the second fluid space 86 is a closed or trapped volume, without hydraulic communication with anyone of the ports 42 and 56 . Any further motion in the second direction by the actuation piston 46 will cause a volume reduction and pressurization. The total piston travel is thus limited, barring any severe leakage, to not too much more than (L_ 1 -L_lash).
[0083] Once the actuation switch valve 80 is turned to the right position and connects the first and second ports 42 and 56 to low pressure P_L and P_H lines, respectively, the high pressure fluid will enter the closed second fluid space 86 through the check valve 182 and the C-to-C connection. Shortly after that, the second land 52 is out of the second control bore 102 , and the high-pressure fluid can flow more freely into the second fluid space 86 and complete the return stroke, against the spring force, which intends to push the assembly to the neutral or middle position. During this short lift operation, the two springs 62 and 58 cannot contribute much, and entire operation has to be sustained by the hydraulic system, which is still feasible because of the shorter stroke.
[0084] Various switch valves 80 , 82 , and 170 are used for the illustration purpose only and should not be considered to be the only valves that can be used. For example, the actuation switch valve 80 may be replaced by two 2-position 3-way valves 80 a and 80 b , each of them being able to control one of the two fluid lines 192 and 194 for its connection with the high pressure P_H and low pressure P_L lines as shown in FIG. 13 . In general, a 3-way valve is easier to manufacture than a 4-way valve.
[0085] One can purposely introduce a time delay between the actions of the two actuation switch valves 80 a and 80 b for certain functions. During the engine valve opening operation, for example, one can reduce the hydraulic energy input at the beginning of the stroke by delaying the switch of the valve 80 a and thus keeping the first chamber 40 at low pressure P_L a little bit longer, which may be desirable if the engine air cylinder pressure is expected to be low. Also, either or both of the two switch valves 80 and 82 may be controlled by two, instead of one, solenoids. If necessary, some of these switch valves may be controlled by pilot valves. This flexibility in valve selection applies to other preferred embodiments as well.
[0086] Although in each of the illustrations so far, there is one start switch valve and one actuation switch valve for each hydraulic actuator or engine valve, this need not be the case. As many modern engines have two intake and/or two exhaust valves per engine cylinder, one actuation switch valve may simultaneously control two intake or exhaust valves on the same engine cylinder if the control strategy does not call for asymmetric opening. One start switch valve may control all the engine valves in an entire engine.
[0087] With continuing reference to the drawings, FIG. 14 illustrates another embodiment of the invention. A main feature of this actuator, depicted generally at 30 j , is the lack of a first piston rod. In this case, the first flow mechanism comprises a first control bore 110 j which is always open for fluid communication between the first port 42 and the first fluid space 84 (except for the snubbing action when it is substantially restricted by the first shoulder 44 ). There will still be no open flow between the first and second ports 42 and 56 , because its second flow mechanism retains the second piston rod 66 and the associated second land 52 and is able to substantially block fluid communication between the second port 56 and the second fluid space 86 .
[0088] With only one piston rod, the effective pressure exposure area is greater on the actuation piston first surface 92 than on the actuation piston second surface 98 , when considering the exposed area left open by the missing first piston rod. As a result, there is a net pressure force in the second direction during the bypass stage of a travel, and this net pressure force is especially significant during a travel in the second direction when the first port 42 and thus both the first and second fluid spaces 84 and 86 are at the system high pressure P_H.
[0089] When traveling through the bypass mode in the first direction, the first port 42 , and thus both the first and second fluid spaces 84 and 86 , are at the system low pressure P_L, and the net pressure force is still in the second direction but relatively small. This embodiment may be used as an actuator for engine exhaust valves with significant engine cylinder air pressure force, against which a significant, asymmetric force is needed. In many cases such as exhaust valves of large two-stroke marine diesel engines, this additional force is as great as, if not more than, the force needed for engine valve acceleration.
[0090] The above discussed asymmetrical area arrangement and net pressure force can also be utilized to start the actuator by switching the actuation switch valve, which doubles as a start switch valve, to its left block or position as shown in FIG. 14 , applying a high system pressure P_H to the first port 42 . The resulting net fluid pressure force pushes the engine valve 20 to the fully open position and initialize the actuator 30 j.
[0091] If the actuator has to be initialized to a fully closed position, a separate starting mechanism can be incorporated. For example, a mechanism such as that illustrated in FIGS. 10-12 can be used to temporarily block the bypass passage for an effective initialization in the first direction.
[0092] The embodiment of FIG. 14 comprises an optional first snubber check valve 142 , which helps backfill and reduce potential cavitation in the first fluid space 84 at the beginning of travel in the second direction. The first snubber check valve 142 allows for flow from the first port 42 or the first control bore 110 j (not shown in FIG. 14 ) to the first fluid space 84 , but not in the opposite direction. Similar snubber check valves can be applied to other snubbers of this invention when desired and practical. The illustration in FIG. 14 is more as a symbol than the actual design form of a check valve. Such valves can incorporate, for example, a ball with a preload spring or a reed. In general, these check valves should exhibit a fast dynamic response. In situations where an appropriate check valve is not available, it is preferable for the snubber to have a reasonable minimum fluid volume and a rational minimum orifice or opening area.
[0093] The embodiment of FIG. 14 further includes first and second spring retainers 236 and 234 and associated first and second locks 240 and 238 , which are one possible variation of the spring seat 60 shown in earlier embodiments. The second spring retainer 234 and second lock 238 are assembled to the piston second rod end 242 . The assembly helps hold the second actuation spring 58 . The first spring retainer 236 and the first lock 240 are assembled to the engine valve stem end 244 to help hold the first actuation spring 62 . After the final assembly, the piston second rod end 242 and the engine valve stem end 244 are kept in physical contact, either directly or through one or more shims (not shown) to help compensate for manufacturing inaccuracy.
[0094] FIG. 15 shows another alternative embodiment of the invention. This actuator, depicted generally at 30 k , includes a first piston rod 34 k , its diameter being substantially smaller than that of the second piston rod 66 , resulting in a net pressure force in the second direction during the bypass stage of a travel. This is functionally similar to that of the actuator 30 j illustrated in FIG. 14 , although most likely with a relatively smaller net or asymmetric force because of the presence, however small, of the cross section area of the first piston rod 34 k.
[0095] The actuator 30 k in FIG. 15 can be initialized in ways akin to those of actuator 30 j in FIG. 14 due to the similar asymmetric fluid actuation design. The actuator 30 k may be used in situations where an exhaust valve experiences relatively lower engine cylinder air pressure. Still, with the first piston rod 34 k supported in radial direction, it is more feasible for the actuator 30 k to adopt a simple undercut as its bypass passage 138 . Its first flow mechanism comprises the first control bore 110 k , which is not sufficiently restricted by the first piston rod 34 k with a smaller diameter. The fluid communication between the first port 42 and the first fluid space 84 is always open except for the snubbing action, when it is substantially restricted by the first shoulder 44 . The second flow mechanism is identical to that of the embodiment in FIG. 14 , and is able to close during the bypass mode.
[0096] In the embodiment illustrated in FIG. 15 , the second actuation spring 58 is a pneumatic spring, wherein a pressurized volume of gas is enclosed in a pneumatic cylinder 254 and a pneumatic piston 250 including an optional pneumatic piston seal 252 . The design of the pneumatic spring can be optionally replaced by other common variations, such as a bladder type of construction (not shown in FIG. 15 ) for better leakage prevention. The pneumatic cylinder 254 can be fabricated inside the housing 64 k (as shown in FIG. 15 ) or in a separate mechanical block. For leakage compensation, spring force curve control, optional initialization, and other functions, the second actuation spring 58 is connected through a pneumatic port 264 and a pneumatic valve 268 , with one or more gas supplies, for example high pressure P_H_gas and low pressure P_L_gas supplies. The low pressure P_L_gas supply may not be needed in some applications, especially if the gas used is simply air. In certain applications, the pneumatic valve 268 may be replaced by a pneumatic pump (not shown in FIG. 15 ), pumping directly from a low-pressure gas supply.
[0097] The force curve control includes regulating and/or changing, in real time per functional needs and operational conditions, the force curve of the second actuation spring 58 relative to the fixed force curve of the first actuation spring 62 to achieve a desired asymmetric net spring force. This can be used, for example, to generate a load-dependent force biased on average in the second direction to help move against the engine cylinder air pressure. The real-time adjustment may be also needed for temperature compensation because of the temperature sensitive gas properties.
[0098] The second actuation space 58 may be set at a low pressure or force so that the engine valve stays at or returns to the closed position because of a stronger force from the first actuation spring 62 when the engine is off, which may be a beneficial function by itself for many applications and will also help set the actuator for a proper initialization. At the next engine start, one can initialize the actuator 30 k first by turning the actuation switch valve 80 to the right position or block as shown in FIG. 15 , then pressuring the second actuation spring 58 .
[0099] The actuator 30 k may include a normally-open pneumatic valve 266 for applications where seating of engine valves is absolutely necessary, for example, to avoid hitting engine pistons, when the engine is off or when the electrical system is interrupted. When the solenoid is on, the normally-open pneumatic valve 266 stays at the right position, in a closed condition, and does not contribute to actuator operation. When the solenoid is off, valve 266 is driven by a return spring to the left position, opening the pneumatic port 264 to a low pressure supply (as shown in FIG. 15 ), or directly to atmosphere (not shown), and secures the return of the engine valve to its seating position. The normally-open pneumatic valve 266 can be eliminated if its function can be incorporated in the pneumatic valve 268 .
[0100] The actuator 30 k may include an optional pneumatic bleed hole 256 to relieve the pressure on the back or non-functional side of the pneumatic piston 250 in case of an otherwise air-tight design as implied in FIG. 15 . If desired, the second actuation spring 58 can also be located between the first actuation spring 62 and the actuation piston 46 . This pneumatic spring concept and its variations may be applied to other embodiments of this invention as well, including the example shown in FIG. 17 . Most of other embodiments may also adopt another concept used in this embodiment: placing the two actuation springs, whether they are mechanical or pneumatic type, at the two longitudinal sides of the actuation piston.
[0101] FIG. 16 shows yet a further alternative embodiment of the invention. The actuator, labeled 30 m , is a variation of the actuators 30 j and 30 k from FIGS. 14 and 15 . Like the actuator 30 k , it possesses a fist piston rod 34 m ; however, it does not provide substantial mechanical support in a radial direction, and is intended to work with the dead-ended first bearing 68 m and associated one or more notches 69 as an end snubber, functional when travel approaches the end of the first direction. At the remainder of the travel or positions, the first piston rod 34 m is not close to being supported, and the first-piston-rod end surface 136 m is exposed to the pressure at the first port 42 . As a consequence, the pressure force distribution is very much like that experienced by the actuator 30 j in FIG. 14 .
[0102] Like actuator 30 j , actuator 30 m is effective to drive a load, such as an exhaust engine valve, with asymmetric load needs in the first and second directions. With the added end snubber, it provides better control over valve seating velocity. When desired, an end snubber valve 208 may be used and turned on to deactivate the end snubber by opening fluid communication between the dead-ended first bearing 68 m and the first port 42 , thus equalizing pressure. This function is useful in keeping two engine valve seating velocities for idle and wild-open-throttle operations, respectively, if other parameter control methods are not sufficient. If more precise, or continuously variable, control is desired, an end flow regulator 212 may be used to continuously regulate the extent of the fluid communication between the dead-ended first bearing 68 m and the first port 42 . Either of the end snubber valve 208 and the end flow regulator 212 can be controlled or actuated externally or within the actuator itself by using an existing signal such as the system high pressure P_H.
[0103] FIG. 17 shows yet a different alternative embodiment of the invention. In this embodiment, the first piston rod 34 n works with the dead-ended first bearing 68 n and associated one or more notches 69 as an end snubber, provides mechanical support in radial direction by being received in the first bearing 68 n over the entire range of travel. The embodiment also offers, in the bypass mode, asymmetric fluid pressure force by interrupting the first bearing 68 n with a first end groove 67 that is in fluid communication with the first port 42 through a first-end-groove connection 88 , thereby exposing the first-piston-rod end surface 136 n with the pressure at the first port 42 .
[0104] The first-end-groove connection 88 can be functionally replaced, without jeopardizing the radial support for the first piston rod 34 n , by one or more grooves or undercuts (not shown in FIG. 17 ) on the inner surface of the first bearing 68 n , running longitudinally between the first end groove 67 and the first control bore 110 , and intermittently distributed around the circumference of the first bearing 68 n . If desired, the end snubber valve 208 or the end flow regulator 212 as illustrated in FIG. 16 can be incorporated to control the end snubber in this embodiment as well.
[0105] In the embodiment in FIG. 17 , the first and second actuation springs 62 and 58 are pneumatic springs; that is, they include gaseous volumes enclosed in a pneumatic cylinder 254 and separated by a pneumatic piston 250 with an optional pneumatic piston seal 252 . The design of the pneumatic springs can be optionally replaced by other common variations, such as a bladder type of construction (not shown in FIG. 17 ) for better leakage prevention. The pneumatic cylinder 254 can be fabricated inside the housing 64 n (as shown in FIG. 17 ) or in a separate mechanical block.
[0106] The first and second actuation springs 62 and 58 are connected with one or more gas sources (not shown in FIG. 17 ) through pneumatic first and second ports 260 and 262 respectively and one or more associated pneumatic control valves (not shown in FIG. 17 ) for leakage compensation, spring stiffness control and optional initialization. Alternatively, it is possible to eliminate one of the pneumatic first and second ports 260 and 262 by allowing a certain leakage between the two pneumatic springs. The spring stiffness control includes regulating and/or changing, in real time per functional needs and operational conditions, the absolute stiffness level and the stiffness differential of the two pneumatic springs. The stiffness differential helps create asymmetric net spring force desired for certain applications. The actuator 30 n can be initialized by creating a pressure differential across the two springs 62 and 58 at the startup. For example, it can be initialized to a fully closed position by causing higher pressure in the first actuation spring 62 than in the second actuation spring 58 .
[0107] In all the above descriptions, the first and second actuation springs 62 and 58 are each identified or illustrated, for convenience, as a single spring. When needed for strength, durability or packaging, however each or any one of the first and second actuation springs 62 and 58 may include a combination of two or more springs. In the case of mechanical compression springs, they can be nested concentrically, for example. The spring subsystem may also include a single mechanical spring (not shown) that can take both tension and compression. The spring subsystem may also include a combination of pneumatic and mechanical springs.
[0108] Also in many illustrations and descriptions, the fluid medium is assumed to be hydraulic or in liquid form. In most cases, the same concepts can be applied with proper scaling to pneumatic actuators and systems. As such, the term “fluid” as used herein is meant to include both liquids and gases. Also, in many illustrations and descriptions so far, the application of the hydraulic actuator 30 is defaulted to be in engine valve control, and it is not limited so. The hydraulic actuator 30 can be applied to other situations where a fast and/or energy efficient control of the motion is needed.
[0109] Although the present invention has been described with reference to the preferred embodiments, those skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. As such, it is intended that the foregoing detailed description be regarded as illustrative rather than limiting and that it is the appended claims, including all equivalents thereof, which are intended to define the scope of this invention.
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Actuators, and corresponding methods and systems for controlling such actuators, provide independent lift and timing control with minimum energy consumption. In an exemplary embodiment, an actuation cylinder in a housing defines a longitudinal axis and having first and second ends in first and second directions. An actuation piston in the cylinder, with first and second surfaces, is moveable along the longitudinal axis. First and second actuation springs bias the actuation piston in the first and second directions, respectively. A first fluid space is defined by the first end of the actuation cylinder and the first surface of the actuation piston, and a second fluid space is defined by the second end of the actuation cylinder and the second surface of the actuation piston. A fluid bypass short-circuits the first and second fluid spaces when the actuation piston is not substantially proximate to either the first or second end of the actuation cylinder. A first flow mechanism is provided in fluid communication between the first fluid space and a first port, and a second flow mechanism is provided in fluid communication between the second fluid space and a second port. The term “fluid” includes both liquids and gases, and the actuator may be coupled to a stem to form a variable valve actuator in an internal combustion engine, for example.
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CROSSREFERENCES TO RELATED APPLICATIONS
[0001] This application is a continuation of copending international patent application PCT/EP2004/013701, filed on Dec. 2, 2004 and designating the U.S., which claims priority of German patent application DE 10 2004 001 461.2, filed on Jan. 8, 2004.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to a device for handling a catheter with an elongate valve body, a lever arm which is prestressed by means of a spring element and mounted pivotably on the valve body so as to be pivotable from a first end position into a second end position counter to the prestressing force of the spring element, a pressure piston which is received in the valve body and can be moved in the longitudinal direction by means of the lever arm in order to open a sealing element in the valve body when the lever arm is moved in the direction of the second end position, and a catch mechanism which has an arresting arrangement and a catch tongue interacting therewith in order to hold the lever arm in at least one catching position.
[0004] 2. Related Prior Art
[0005] Such a device is known from DE 195 26 075 C1, for example. In this device, for actuating a pressure piston introduced in a valve body by means of a lever arm, a flexible arresting piece with a catch nose is designed in one piece on a valve body, with which piece a catching end of the lever arm can be held in a catching position. The arresting piece extends essentially at right angles to the valve body. In the catching position, a clamping force is exerted on a catheter guided through the valve body and the pressure piston in order to secure the catheter against unintentional displacement in the axial direction.
[0006] A further such device is known from WO 01/15768 A1, for example. In this device, the arresting piece has a number of catch noses for locking the lever arm in a number of catching positions and an actuating wing which is aligned in prolongation of the lever arm in the catching positions of the lever arm.
SUMMARY OF THE INVENTION
[0007] Although the abovementioned device can be operated very easily and ergonomically, a desire exists on the part of the user for the usability to be improved further.
[0008] Against this background, the object of the present invention is to develop the device referred to in the introduction in such a way that easier operation is made possible.
[0009] This object is achieved in the abovementioned device by virtue of the fact that the catch mechanism is designed in such a way that the arresting arrangement and the catch tongue come out of engagement when the second end position of the lever arm is reached, so that the spring element guides the lever arm back into the first end position.
[0010] In other words, the catch mechanism is designed in such a way that the user simply has to press the lever arm into the second end position in order to arrive at the first end position again. When the lever arm reaches the second end position, the catch tongue is released from the arresting arrangement and as it were frees the catch mechanism, so that the lever arm can then move into the first end position. In this connection, the spring element ensures the return of the lever arm into the first end position.
[0011] The reason operation is so simple for the user is that in the end he has to perform only one movement of the lever arm, namely pressing the lever arm in the direction of the second end position. It is consequently no longer necessary to release the catching position of the lever arm by, for example, pressing an actuating wing as is proposed in the publication WO 01/15768 A1 referred to above.
[0012] In a preferred development of the invention, the arresting arrangement has a number of catch noses which are arranged along a concentric line around the fulcrum of the lever arm in order to define a number of catching positions of the lever arm between the two end positions.
[0013] These measures have the advantage that the several catching positions further simplify usability as the user can better adjust the clamping force acting on the catheter.
[0014] In a further preferred embodiment, the catch nose facing the valve body follows a guide surface extending at an angle in order, when the second end position of the lever arm is reached, to guide the catch tongue onto that side of the arresting arrangement facing away from the catch nose, so that the catch tongue cannot enter into engagement with the catch noses when the lever arm is returned into the first end position.
[0015] In other words, a surface which extends upward at an angle (away from the valve body) toward the rear surface in relation to the catch noses is provided at that end of the arresting arrangement facing the valve body. The catch tongue on the lever arm is thus guided onto the rear side of the catch noses when the second end position is reached, so that the catch tongue cannot come into contact with the catch noses during the travel of the lever arm into the first end position.
[0016] This measure results in a very simple design of the arresting arrangement and makes very safe operation possible.
[0017] In a further preferred embodiment, the catch tongue and the catch noses extend transversely to the longitudinal direction of the valve body.
[0018] This measure is especially simple as far as construction is concerned.
[0019] In a preferred development, the lever arm has an elongated hole, through which a lateral tube starting from the valve body extends.
[0020] This measure makes a very compact device with great stability possible, in particular also with regard to the lever arm, which can be stabilized additionally by the interaction of elongated hole and lateral tube.
[0021] The valve body and/or the lever arm are preferably designed as injection-molded parts, the valve body and the arresting arrangement preferably being provided as one-piece components.
[0022] Further advantages and developments of the invention emerge from the description and the accompanying drawing.
[0023] It is clear that the features mentioned above and those still to be explained below can be used not only in the combination indicated in each case but also in other combinations or individually without leaving the scope of the present invention.
BRIEF DESCRIPTION OF THE FIGURES
[0024] The invention is now explained by way of example with reference to a preferred embodiment and the drawing, in which:
[0025] FIG. 1 shows a diagrammatic side view of the device according to the invention;
[0026] FIG. 2 shows a diagrammatic illustration of the catch mechanism;
[0027] FIG. 3 shows a diagrammatic top view of the lever arm, and
[0028] FIGS. 4A to 4 I show different illustrations of the catch mechanism in different positions in order to describe its functioning.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0029] In FIG. 1 , a device according to the invention is shown in a diagrammatic illustration from the side and designated by reference number 10 . The device 10 has an elongate valve body 12 which has an axial valve body guide-through (not illustrated). The valve body 12 thus constitutes a tubular element which is open at both its ends. A lateral tube 14 is attached in one piece to the valve body 12 in a central longitudinal region, the lateral tube 14 extending at an angle to the longitudinal axis of the valve body, for example at an angle of 45°. In this connection, the lateral tube 14 runs into the valve body guide-through.
[0030] At a connection end 16 , which faces away from the body of a patient when the device 10 is used as intended, a rotary cuff 18 is provided, with which the valve body 12 can be closed in a sealed way in a manner known per se when a guide catheter has been introduced. In an end 20 opposite the connection end 16 , which faces the body of a patient when the device 10 is used as intended, a sealing arrangement 22 is provided, which consists of a pressure piston 24 and a sealing stopper provided in the valve body guide-through and located at the inner end of the pressure piston 24 . The sealing stopper, which cannot be seen in FIG. 1 , is made from an elastic material and has a continuous opening in the longitudinal direction which can be closed under pressure load in the longitudinal direction. This pressure load is applied to the sealing stopper by means of the pressure piston 24 .
[0031] The device 10 also has a lever arm 26 which is mounted pivotably about a spindle 28 on the connection end 20 .
[0032] The lever arm 26 is prestressed into a first end position shown in FIG. 1 by means of a torsion spring 30 . For this, the torsion spring 30 provided with helical turns has an end portion 32 which is fixed to the valve body 12 and an end portion which is fixed to a surface of the lever arm 26 which faces the valve body 12 but cannot be seen in the figure.
[0033] The lever arm 26 can be rotated about the spindle 28 from the first end position, which is shown, in the direction of the arrow P into a second end position 34 counter to the force of the torsion spring 30 . Without corresponding loading of the lever arm 26 , it is guided back into the first end position, which is shown, again by means of the torsion spring 30 .
[0034] A component not illustrated in FIG. 1 , which interacts with the pressure piston 24 in such a way that, when the lever arm 26 is moved into the second end position 34 , the pressure piston 24 is displaced in the longitudinal direction in order to reduce the load on the sealing stopper and thus to open the guide-through in the sealing stopper, is provided on the lever arm 26 . In other words, the pressure piston 24 is pressed so strongly against the sealing stopper when the prestressed lever arm 26 is in the first end position that the guide-through is completely closed.
[0035] The purpose of such a medical device is generally known and is therefore not to be described in greater detail. Briefly, the device 10 serves for clamping sealingly by means of the sealing stopper a catheter running through the valve body 12 ; the clamping force can be reduced, in order for it to be possible to move the catheter in the longitudinal direction, by actuating the lever arm 26 .
[0036] As for the rest, reference is made to WO 01/15768 with regard to the functioning and the construction of the valve body 12 . The content of the disclosure of this publication is to this extent included in the present application by reference.
[0037] In order for it to be possible to hold the lever arm 26 in different positions, a catch mechanism 40 is provided, which comprises an arresting arrangement 42 assigned to the valve body 12 and a catch tongue arrangement 44 assigned to the lever arm 26 .
[0038] The arresting arrangement 42 is designed as a plate-shaped part which is provided on the lateral tube 14 . A number of catch noses 48 , three by way of example in the present embodiment, are provided in the edge region 46 facing away from the lateral tube 14 .
[0039] For its part, the catch tongue arrangement 44 has a catch tongue 50 which can interact with the catch noses 48 . The catch noses 48 and the catch tongue 50 consequently lie on a concentric line K around the spindle 28 .
[0040] The catch tongue arrangement 44 is provided on the lower side of the lever arm 26 facing the valve body, likewise in the form of a strip-shaped or plate-shaped element.
[0041] The catch mechanism 40 is shown again, separately, in an enlarged diagrammatic illustration in FIG. 2 . In this connection, the view is from the connection end 20 , so that the plate-shaped part of the arresting arrangement 42 , which is designated by reference number 52 , conceals a portion of the edge region. This is illustrated by the dotted line and the slightly lighter hatching of the edge region 46 .
[0042] The catch tongue 50 of the catch tongue arrangement 44 is designed as a triangular component, for example, which projects in relation to the basic body 54 of the catch tongue arrangement 44 . With respect to the drawing plane in FIG. 2 , the catch tongue 50 thus lies in front of the basic body 54 . The catch tongue 50 has a catching surface 56 and a surface 58 extending at an angle thereto. The catching surface 56 extends approximately on a radial line in relation to the spindle 28 .
[0043] The arresting arrangement 42 has the said three catch noses 48 , which are designed as triangular recesses in the edge region 46 . The triangular recesses each have a catching surface 60 , these surfaces being approximately parallel to the catching surface 56 .
[0044] The catch tongue 50 and the catch noses 48 are dimensioned in such a way that the catching surface 56 can in each case interact with the catching surface 60 of the three catch noses 48 over as full an area as possible. In order to facilitate release of the catch connection, each catch nose 48 has a surface 62 extending downward to the left at an angle in relation to the catching surface 60 . This surface 62 interacts with the surface 58 extending at an angle of the catch tongue 50 in such a way that the catch tongue arrangement 44 is moved out of the catch nose 48 when a downward movement takes place.
[0045] In order to ensure that the catch tongue 50 passes into the upper catch nose 48 when the lever arm 26 is moved out of the first end position, the edge region has an upper edge surface 64 falling to the left at an angle (related to the illustration shown in FIG. 2 ). This edge surface 64 prevents the catch nose 50 passing onto the rear side 66 , facing away from the catch noses 48 , of the edge region 46 when the lever arm 26 is moved out of the first end position.
[0046] An edge surface 68 which (related to the illustration in FIG. 2 ) falls to the left at an angle is likewise provided at the lower end of the edge region 46 . The purpose of this edge surface 68 is to guide the catch nose arrangement 44 onto the rear side 66 after the lowest catch nose 48 has been passed and the actuating force has been released. In this connection, the catching surface 56 of the catch tongue 50 slides along the edge surface 68 .
[0047] With the aid of this catch mechanism, it is consequently possible to lock the lever arm 26 in three predetermined catching positions and to bring it back into the original, first end position by pressing the lever arm 26 into the lower, second end position 34 and then releasing it. In this connection, the spring force acting on the lever arm 26 causes the catch tongue 50 to slide along the lower edge surface 68 and to be guided onto the rear side 66 of the arresting arrangement 42 . As there are no catch noses here, the lever arm 26 can pivot back into the first end position unhindered.
[0048] FIG. 3 shows the lever arm 26 in an enlarged diagrammatic illustration. In this connection, it can be seen that the lever arm 26 has an elongated hole 70 , through which the lateral tube 14 extends. Moreover, the lever arm 26 has a recessed grip 72 , which ends at the edge 74 illustrated.
[0049] FIG. 3 also shows that the lateral tube 14 has two laterally provided webs 76 which lie in a radial plane (related to the lateral tube 14 ). The dimension in the radial direction (in relation to the lateral tube 14 ) is selected in such a way that the webs 76 end shortly before the respective edge of the elongated hole 70 . These webs 76 are intended to prevent the lever arm 26 being capable of moving at right angles to the longitudinal axis. This is because such a movement at right angles (parallel to the spindle 28 ) could result in the catch tongue 50 coming out of a catch nose 48 as catch nose 48 and catch tongue 50 extend in this direction (at right angles to the longitudinal axis of the valve body). The webs 76 consequently serve for guiding the lever arm 26 in a plane of rotation. As emerges from FIG. 1 , the webs 76 extend longitudinally in relation to the lateral tube 14 in the direction of the valve body 12 .
[0050] The functioning of the catch mechanism 40 is explained again, in detail, in FIGS. 4A to 4 I. For simplification, however, the reference numbers used in FIG. 2 have not been shown again. In this connection, the sequence of the positions illustrated in FIGS. 4A to 4 I corresponds to a movement of the lever arm 26 from the first, upper end position into the second, lower end position 34 and back into the first end position again. FIG. 4B shows the catch tongue arrangement 44 in a first catching position, FIG. 4D in a second catching position and FIG. 4E in a third catching position. If the lever arm 26 is pressed further in the direction of the valve body 12 counter to the spring force 30 , the catch tongue 50 passes onto the edge surface 68 , as illustrated in FIG. 4F , and slides along this onto the rear side 66 of the arresting arrangement 42 when the lever arm 26 is released. On this rear side 66 , the catch tongue 50 then slides upward back into the first end position, as illustrated in FIGS. 4G to 4 I.
[0051] As the lever arm 26 and thus the catch tongue 50 cannot be moved in the direction of the spindle. 28 , which is prevented by the webs 76 , the lever arm 26 can be brought back into the first end position from any of the catching positions only by movement into the second end position 34 . It is consequently not possible to move back directly into the first end position from a catching position.
[0052] As the user of the device 10 accordingly has to perform only one movement of the lever arm 26 for catching and releasing the lever arm, operation is especially easy.
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The invention relates to a device for handling a catheter with an elongate valve body ( 12 ), a lever arm ( 26 ) which is, prestressed by means of a spring element and mounted pivotably on the valve body ( 12 ) so as to be pivotable from a first end position into a second end position ( 34 ) counter to the prestressing force of the spring element, a pressure piston ( 24 ) which is received in the valve body ( 12 ) and can be moved in the longitudinal direction by means of the lever arm ( 26 ) in order to open a sealing element in the valve body ( 12 ) when the lever arm ( 26 ) is moved in the direction of the second end position ( 34 ), and a catch mechanism ( 40 ) which has an arresting arrangement ( 42 ) and a catch tongue ( 50 ) interacting therewith in order to hold the lever arm ( 26 ) in at least one catching position. The catch mechanism ( 40 ) is designed in such a way that the arresting arrangement ( 42 ) and the catch tongue ( 50 ) come out of engagement when the second end position ( 34 ) of the lever arm ( 26 ) is reached, so that the spring element guides the lever arm ( 26 ) back into the first end position
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CROSS REFERENCE TO RELATED APPLICATION
This application claims the benefit of U.S. Provisional Application No. 60/535,426 filed Jan. 9, 2004 which is incorporated by reference as if fully set forth.
FIELD OF INVENTION
The present invention is related to a wireless communication system. More particularly, the present invention is related to transport format combination (TFC) selection in wireless transmit/receive units (WTRUs).
BACKGROUND
Under the current Third Generation Partnership Project (3GPP) standards, a WTRU is required to estimate a transmission power for each TFC. In the case that a certain TFC would require more transmission power than the maximum allowed WTRU transmission power, the WTRU should limit the usage of that TFC.
The WTRU continuously evaluates which TFCs can be used for transmission. The evaluation is performed using the estimated WTRU transmit power of a given TFC. When any TFC is restricted for exceeding a transmit power limit, the medium access control (MAC) entity in the WTRU notifies an upper layer to reduce the data rate, if applicable.
Under the current 3GPP standards, a WTRU has only one coded composite transport channel (CCTrCH) in uplink transmission. Therefore, the WTRU transmit power is the transmit power of the CCTrCH, which is determined by the TFC used for the CCTrCH.
In order to improve uplink coverage, throughput and transmission latency for uplink transmissions, enhanced uplink (EU) is currently being investigated in 3GPP. With EU implementation, a WTRU may have more than one CCTrCH in uplink transmissions; one for the regular dedicated channel (DCH) and the other for EU enhanced dedicated channel (E-DCH). In this case, the WTRU transmit power will be the sum of the transmit power of two CCTrCHs.
The WTRU transmit power is determined jointly by the TFCs of the two CCTrCHs. The combination of the TFC used by the dedicated CCTrCH and the TFC used by the EU CCTrCH is defined as the TFC pair of the WTRU whose transmit power is determined jointly by the TFCs of the two CCTrCHs. This is not an optimal method of determining the TFCs for more than one CCTrCH.
There is a need for an efficient method for selecting a combination of TFCs for more than one CCTrCHs in uplink transmission.
SUMMARY
The present invention is related to a method and apparatus for selecting a TFC in a WTRU. The WTRU is configured to process more than one CCTrCH for uplink transmission. The WTRU estimates a transmit power for each of a plurality of available TFCs and selects a TFC for each CCTrCH such that the sum of the estimated WTRU transmit power for the selected TFCs is within the allowed maximum WTRU transmit power.
The WTRU may give priority to a particular CCTrCH, whereby the TFC for that particular CCTrCH is selected first and the TFC for the other CCTrCH is selected within the estimated remaining WTRU transmit power after power required for the selected TFC on the prioritized CCTrCH is deducted from the maximum allowed WTRU transmit power. This method allows for transmission of channels mapped to the first CCTrCH to be prioritized over channels mapped to the other CCTrCH.
Alternatively, the WTRU may reserve a minimum set of TFCs for the other CCTrCH, whereby a TFC for the prioritized CCTrCH is first selected within the maximum allowed WTRU transmit power less the power required to support a minimum set of TFCs on the other CCTrCH. Then the TFC for the other CCTrCH is selected within the remaining WTRU transmit power after power required for the selected TFC on the prioritized CCTrCH is deducted from the maximum allowed WTRU transmit power. This method allows for transmission of channels mapped to the first CCTrCH to be prioritized over channels mapped to the other CCTrCHs while reserving transmit power to allow for a minimum set of TFCs on the other CCTrCH to be transmitted without being effected by the maximum allowed WTRU transmit power limit.
Alternatively, the WTRU may be configured for individual maximum transmit power for each of the plurality of CCTrCHs, whereby a TFC for each CCTrCH is selected within the individual maximum transmit power designated to each CCTrCH. This method allows each CCTrCH to be given a quality of service (QoS) relative to the other CCTrCH. Activity on one CCTrCH does not take priority or reduce the rate of the other CCTrCH.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a flow diagram of a general process for selecting TFCs in accordance with a first embodiment of the present invention.
FIG. 2 is a flow diagram of a process for selecting TFCs in accordance with a second embodiment of the present invention.
FIG. 3 is a flow diagram of a process for selecting TFCs in accordance with a third embodiment of the present invention.
FIG. 4 is a flow diagram of a process for selecting TFCs in accordance with a fourth embodiment of the present invention.
FIG. 5 is a block diagram of an apparatus for selecting TFCs in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereafter, the terminology “WTRU” includes but is not limited to a user equipment, a mobile station, a fixed or mobile subscriber unit, a pager, or any other type of device capable of operating in a wireless environment.
The features of the present invention may be incorporated into an integrated circuit (IC) or be configured in a circuit comprising a multitude of interconnecting components.
Hereinafter, the present invention will be described with reference to a system supporting two CCTrCHs, (i.e., a dedicated CCTrCH and an EU CCTrCH). However, it should be noted that the present invention is applicable to a system supporting more than two CCTrCHs.
FIG. 1 is a flow diagram of a process 100 for selecting TFCs in accordance with a first embodiment of the present invention. The WTRU is configured to process a dedicated CCTrCH and an EU CCTrCH simultaneously in uplink transmission. The transmit power of the WTRU is limited to a maximum allowed WTRU transmit power, which is set by the wireless communication system. In each transmit time interval (TTI), the WTRU estimates the transmit power for each of a plurality of available TFCs (step 102 ) for each CCTrCH. The WTRU estimates the transmit power of each TFC over a predetermined period taking into account the gain factor of each corresponding TFC. The WTRU then selects TFCs for transmission on each CCTrCH among a plurality of available TFCs, such that the sum of the estimated transmit power of the selected TFCs for the dedicated CCTrCH and the EU CCTrCH does not exceed the maximum allowed WTRU transmit power (step 104 ).
Additionally, the dedicated CCTrCH, the EU CCTrCH, or both may be provided with a capability of transmitting a reserved minimum set of TFCs even when the power required for transmission of these TFCs exceeds the maximum allowed WTRU transmit power. TFCs that require power greater then the maximum allowed transmit power are defined to be in an excess power state. The minimum set is for reserving a lowest rate in a CCTrCH, thereby maintaining the basic services for the channel. Since in the EU CCTrCH there is only one TrCH, the minimum set corresponds to a lowest rate per logical channel or MAC-d flow mapped to the EU TrCH. The minimum set of TFCs may be one transport block per TTI for each channel mapped to the CCTrCH or a number of transport blocks per TTI corresponding to a guaranteed bit rate (GBR).
The reserved minimum set of TFCs may be transmitted in an excess power state. In order to maintain the transmit power within the allowed maximum level, a WTRU scales down power on physical channels mapped to the dedicated CCTrCH, the EU CCTrCH, or all physical channels present.
Regardless of the TFC selection, the EU CCTrCH may be provided with a minimum reserved set of TFCs that is one or more transport blocks per logical channel or MAC-d flow mapped to the EU CCTrCH. A transport block is one or more radio link control (RLC) protocol data units (PDUs). One or more transport blocks is equivalent to a data rate. The reserved set of TFCs can be transmitted in an excess power state by scaling down power on either the physical channels mapped to the EU CCTrCH, the dedicated CCTrCH or all present UL channels.
FIG. 2 is a flow diagram of a process 200 for selecting TFCs in accordance with a second embodiment of the present invention. TFC selection of the dedicated CCTrCH is prioritized over TFC selection of the EU CCTrCH. In each TTI of the dedicated CCTrCH, the WTRU estimates the transmit power requirement for each of a plurality of available TFCs configured for the dedicated CCTrCH (step 202 ). The WTRU selects a TFC for the dedicated CCTrCH first, without considering the power requirement of the EU CCTrCH (step 204 ). After the TFC for the dedicated CCTrCH is selected, at each TTI of the EU CCTrCH the WTRU selects a TFC for the EU CCTrCH within the remaining WTRU transmit power after the power required for the selected TFC for the dedicated CCTrCH is deducted from the maximum allowed WTRU transmit power (step 206 ). The TFC selection of the dedicated CCTrCH is not affected by the operation of EU CCTrCH, while the TFC selection of the EU CCTrCH is affected and limited by the operation of the dedicated CCTrCH.
The remaining power for the EU CCTrCH is estimated either each dedicated CCTrCH TTI or each EU CCTrCH TTI. At each TTI of the EU CCTrCH, the remaining power available for the EU CCTrCH is estimated as the maximum allowed WTRU transmit power minus the power required by transmission of the selected dedicated CCTrCH TFC. Alternatively, at each TTI of the dedicated CCTrCH, the remaining power available for the EU CCTrCH is estimated as the maximum allowed WTRU transmit power minus the power required to support transmission of the selected dedicated CCTrCH TFC.
In process 200 , the EU CCTrCH may allow transmission of a minimum set of TFCs even when these TFCs are in excess power state. An EU TFC is in excess power state when the estimated remaining power is less then the calculated transmission power requirement for the EU CCTrCH TFC. The EU minimum set reserves a lowest or guaranteed rate on channels mapped to the EU CCTrCH, and thereby maintains the basic services for EU channels. Since in the EU CCTrCH there is only one TrCH, the minimum set corresponds to a lowest rate per logical channel or MAC-d flow mapped to the EU TrCH. The minimum set of TFCs may be one transport block per TTI for each channel mapped to the CCTrCH or a number of transport blocks per TTI corresponding to a guaranteed bit rate (GBR). When transmitting a TFC in excess power state, in order to maintain the transmit power within the allowed maximum level, the WTRU scales down power on physical channels mapped to the EU CCTrCH, the dedicated CCTrCH, or all physical channels present.
FIG. 3 is a flow diagram of a process 300 for selecting TFCs in accordance with a fourth embodiment of the present invention. The WTRU gives priority to dedicated CCTrCH TFC selection while reserving transmit power for a minimum set of EU CCTrCH TFCs (step 302 ). A minimum set of TFCs for an EU CCTrCH is defined to reserve a lowest or guaranteed rate for channels mapped to the EU CCTrCH. Since in the EU CCTrCH there is only one TrCH, the minimum set corresponds to a lowest rate per logical channel or MAC-d flow mapped to the EU TrCH. The minimum set of TFCs may be one transport block per TTI for each channel mapped to the CCTrCH, or a number of transport blocks per TTI corresponding to a GBR.
The EU CCTrCH may allow transmission of a minimum set of TFCs even when these TFCs are in excess power state. An EU TFC is in excess power state when the estimated remaining power is less then the calculated transmission power requirement for the EU TFC. When transmitting a TFC in excess power state, in order to maintain the transmit power within the allowed maximum level, the WTRU scales down power on physical channels mapped to the EU CCTrCH, the dedicated CCTrCH, or all physical channels present.
When a TFC is in an excess power state (with reduced power), the quality of the transmission is reduced, (i.e., lower SIR, higher BLER, etc). This may defeat the purpose of maintaining the minimum set. Therefore, in order to minimize the possibility that the EU CCTrCH TFC has to be transmitted in an excess power state, and to further insure the minimum set is really supported, in process 300 transmit power is reserved for the EU minimum set when TFC selection is performed on the prioritized dedicated CCTrCH.
TFC selection of the dedicated CCTrCH is prioritized over TFC selection of the EU CCTrCH. In each TTI of the dedicated CCTrCH, the WTRU estimates the transmit power for each of a plurality of available TFCs configured for the dedicated CCTrCH and TFCs associated with the EU CCTrCH minimum set (step 304 ). The WTRU selects a TFC for the dedicated CCTrCH that has a power requirement that does not exceed the maximum allowed transmit power minus the power required to support the minimum set of TFCs on the EU CCTrCH (step 306 ). After the TFC for the dedicated CCTrCH is selected, at each TTI of the EU CCTrCH the WTRU selects a TFC for the EU CCTrCH with the remaining transmit power after power required for the selected the TFC for the dedicated CCTrCH is deducted from the maximum allowed transmit power (step 308 ).
The remaining power for the EU CCTrCH is estimated either each dedicated CCTrCH TTI or each EU CCTrCH TTI. At each TTI of the EU CCTrCH, the remaining power available for the EU CCTrCH is estimated as the maximum allowed WTRU transmit power minus the power required by transmission of the selected dedicated CCTrCH TFC. Alternatively, at each TTI of the dedicated CCTrCH, the remaining power available for the EU CCTrCH is estimated as the maximum allowed WTRU transmit power minus the power required to support transmission of the selected dedicated CCTrCH TFC.
Since the dedicated CCTrCH TFC selection takes precedence over the EU CCTrCH, and the power requirement may change during the dedicated TTI, the minimum set of TFCs of the EU CCTrCH may still be transmitted in an excess power state even though power was reserved when the dedicated TFC was selected. In this situation, in order to maintain the transmit power within the allowed maximum level, the WTRU scales down all physical channels mapped to the EU CCTrCH, the dedicated CCTrCH, or all physical channels present.
FIG. 4 is a flow diagram of a process 400 for selecting TFCs in accordance with a third embodiment of the present invention. The WTRU sets an individual maximum transmit power, or a ratio relative to the maximum allowed WTRU transmit power, for a dedicated CCTrCH and an EU CCTrCH (step 402 ). The maximum power level (or the ratio) for each CCTrCH is a configurable parameter. The factors for determining the maximum power level (or the ratio) for each CCTrCH may include, but are not limited to, a data rate of each CCTrCH, quality-of-service (QoS) of each CCTrCH and a relative priority between the CCTrCHs.
In each TTI of the dedicated CCTrCH and in each TTI of the EU CCTrCH, the WTRU estimates the transmit power for each of a plurality of available TFCs (step 404 ). The WTRU then selects a TFC for each CCTrCH within the individual maximum transmit power of each CCTrCH (step 406 ). The TFC selection process for each CCTrCH operates independently. The TFC of each CCTrCH is selected from only those TFCs that can be supported by the individual maximum power level determined for a particular CCTrCH.
The dedicated CCTrCH, the EU CCTrCH, or both may be provided with a capability of transmitting a minimum set of TFCs. The minimum set is for reserving a lowest rate for each channel mapped to the CCTrCH, thereby maintaining the basic services for each channel. Since in the EU CCTrCH there is only one TrCH, the minimum set corresponds to a lowest rate per logical channel or MAC-d flow mapped to the EU TrCH. The minimum set of TFCs may be one transport block per TTI for each channel mapped to the CCTrCH or a number of transport blocks per TTI corresponding to a GBR.
The minimum set of TFCs may be transmitted in an excess power state. In this situation, in order to maintain the transmit power within the allowed maximum level, the WTRU scales down all physical channels mapped to the EU CCTrCH, the dedicated CCTrCH, or all physical channels present.
FIG. 5 is a block diagram of an apparatus 500 for selecting TFCs in accordance with the present invention. The apparatus comprises a transmit power estimation unit 502 , a TFC selection unit 504 , and a measurement unit 506 . The transmit power estimation unit 502 calculates an estimate of a transmit power for each of a plurality of available TFCs. The TFC selection unit 504 selects a TFC for each CCTrCH such that the sum of the estimated WTRU transmit power for the selected TFCs is within a maximum WTRU transmit power. The measurement unit 506 performs physical measurements of the WTRU transmit power over a predetermined period, and the transmit power estimation unit 502 calculates the estimate of a transmit power of each TFC using the measurement results and a gain factor of the corresponding TFC.
Although the features and elements of the present invention are described in the preferred embodiments in particular combinations, each feature or element can be used alone without the other features and elements of the preferred embodiments or in various combinations with or without other features and elements of the present invention.
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A method for selecting a transport format combination (TFC) in a wireless transmit/receive unit (WTRU) is disclosed. The WTRU is configured to process more than one coded composite transport channel (CCTrCH) for uplink transmission. The WTRU estimates a transmit power for each of a plurality of available TFCs and selects a TFC for each CCTrCH such that the sum of the estimated WTRU transmit power for selected TFCs is within a maximum WTRU transmit power.
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BACKGROUND
[0001] The present disclosure is generally directed, in various embodiments, to imaging members. More particularly, the disclosure relates to various embodiments of an imaging member such as photoreceptor comprising a substrate, a charge generation layer, a first charge transport layer, a second charge transport layer, and an optional overcoat layer. More particularly, the first charge transport layer is formed from a first CTL formulation comprising an aromatic monoamine and a first polymeric film forming binder material. The second charge transport layer is formed from a second CTL formulation comprising aromatic diamine and a second polymeric film forming binder material. The imaging member has gained improved properties such as removal of anti-curl layer, desirable structural flatness, electrical properties, mechanical robustness, and flexibility, among others.
[0002] Imaging members such as photoreceptors can be provided in a number of forms, such as rigid drum configuration and flexible belt configuration. For a flexible belt, it can be either seamless or seamed. For example, the photoreceptor can be a homogeneous layer of a single material, such as vitreous selenium; or it can be a composite layer containing a photoconductive layer and another material; or it can be layered. Current layered photoreceptors generally have at least a flexible substrate support layer and two active layers. These active layers generally include a charge generation layer containing a light absorbing material, and a charge transport layer containing electron donor molecules. These layers can be in any order, and sometimes can be combined in a single or a mixed layer.
[0003] Sometimes, however, tendency to curl is a problem associated with a photoreceptor belt. Curling is believed to be the result of differential thermal expansion of the individual layers within the photoreceptor. For example, when a production web stock of several thousand feet of coated multilayered photoreceptor is obtained after finishing the charge transport layer coating/drying process, it is seen to spontaneously curl upward toward the applied coating layers. The exhibition of spontaneous upward photoreceptor web stock curling after completion of charge transport layer coating has been determined to be the consequence of thermal contraction mismatch between the applied charge transport layer and the substrate support under the conditions of elevated temperature heating/drying the solution applied wet coating and eventual cooling down to room ambient temperature. Since the charge transport layer in a typical prior art photoreceptor device has a coefficient of thermal contraction approximately 3 1/2 times larger than that of the substrate support, it does, upon cooling down to room ambient temperature, result in greater dimensional contraction than that of the substrate support, causing upward photoreceptor curling. What is worse, the curling may give rise to crackling, crazing and layer delamination.
[0004] To prevent curling, an additional anti-curling blocking coating (ACBC) layer may be applied to the side of the supporting substrate opposite the photoconductive layer to counteract the tendency to upward curling and ensure photoreceptor flatness. For example, US Patent Application Publication No. 2004/0072088 has disclosed several anti-curl back coating solutions. The contents of this application are incorporated entirely herein by reference. Some of the ACBC solutions were prepared in methylene chloride by combining a polyester resin (Vitel PE-200); and a polyphthalate carbonate resin (Lexan PPC 4701 having the following formula, available from GE Company), or a bisphenol A polycarbonate, or a polyether sulfone, or a polystyrene etc. The anti-curl back coating solution was then applied to the rear surface of a substrate (the side opposite the photoimaging layer) of the imaging member and dried at 135° C. to produce an optically transparent dried anti-curl back coating thickness of about 13.1 micrometers.
wherein x is an integer from about 1 to about 10, and n is the degree of copolymerization. Other ACBC solutions were prepared using styrene acrylonitrile copolymer and poly(1,4-cyclohexylene-dimethylene terephthalate) Eastar PETG copolyester; or using Makrolon 5705 and Eastar PETG; or Polysulfone, Ardel Polyarylate, or Polyphenylene Sulfone (all available from Amoco Performance Products, Inc.).
[0005] Generally, the ACBC layer must have very good wear resistance, good adhesion to the substrate and good physical stability during all applied environment. Also, the transparency and conductivity are necessary in some cases. Expensive and elaborate packaging are needed to obtain excellent ACBC for photoreceptors. Subsequent wear of the ACBC tends to cause debris in the xerographic cavity which leads to numerous problems.
[0006] As such, new solutions are needed to manufacture an imaging member such as photoreceptor, which does not require the anti-curl layer and still maintains desirable structural flatness, electrical properties, mechanical robustness, flexibility, longevity, and copy image qualities over extended use, among others.
BRIEF DESCRIPTION
[0007] In one exemplary embodiment, an imaging member is provided. The imaging member comprises a substrate, a charge generation layer, a first charge transport layer, a second charge transport layer, and an optional overcoat layer. The first charge transport layer is formed from a first CTL formulation comprising an aromatic monoamine and a first polymeric film forming binder material. The second charge transport layer is formed from a second CTL formulation comprising aromatic diamine and a second polymeric film forming binder material.
[0008] In another exemplary embodiment, a method of preparing an imaging member is provided. The method comprises (i) providing a substrate, (ii) coating a charge generation layer above the substrate, (iii) coating a first charge transport layer above the charge generation layer, (iv) coating a second charge transport layer above the first charge transport layer, and (v) optionally coating an overcoat layer above the second charge transport layer. The first charge transport layer is formed from a first CTL formulation comprising an aromatic monoamine and a first polymeric film forming binder material; and the second charge transport layer is formed from a second CTL formulation comprising aromatic diamine and a second polymeric film forming binder material.
[0009] In still another exemplary embodiment, a method of imaging is provided. The imaging method comprises generating an electrostatic latent image on an imaging member comprising a first charge transport layer and a second charge transport layer, developing the latent image, and transferring the developed electrostatic image to a suitable substrate.
[0010] These and other non-limiting embodiments will be more particularly described with regard to the drawings and detailed description set forth below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The following is a brief description of the drawings which is presented for the purposes of illustrating the disclosure set forth herein and not for the purposes of limiting the same.
[0012] FIG. 1 is a schematic cross-sectional view of a photoconductive imaging member in accordance with the present disclosure.
[0013] FIG. 2 shows the photoinduced discharge curve (PIDC) of a photoreceptor that is fabricated according to an embodiment of the present disclosure.
DETAILED DESCRIPTION
[0014] The present disclosure relates to a photoconductive imaging member comprising a substrate, a charge generation layer, a first charge transport layer (CTL), a second charge transport layer, and an optional overcoat layer disposed over the second charge transport layer. The first charge transport layer is formed from a first CTL formulation comprising an aromatic monoamine and a first polymeric film forming binder material. The second charge transport layer is formed from a second CTL formulation comprising aromatic diamine and a second polymeric film forming binder material. The present disclosure also relates to a process for forming the photoconductive imaging member, the first charge transport layer, and the second charge transport layer.
[0015] Also included within the scope of the present disclosure are methods of preparing the imaging member as described supra.
[0016] Further included within the scope of the present disclosure are methods of imaging and printing with the photoresponsive devices illustrated herein. These methods generally involve the formation of an electrostatic latent image on the imaging member, followed by developing the image with a toner composition comprised, for example, of thermoplastic resin, colorant, such as pigment, charge additive, and surface additives, reference U.S. Pat. Nos. 4,560,635; 4,298,697; and, 4,338,390, the disclosures of which are totally incorporated herein by reference, subsequently transferring the image to a suitable substrate, and permanently affixing the image thereto.
[0017] A more complete understanding of the processes and apparatuses disclosed herein can be obtained by reference to the accompanying drawings. These figures are merely schematic representations based on convenience and the ease of demonstrating the present development, and are, therefore, not intended to indicate relative size and dimensions of the imaging members or components thereof.
[0018] Although specific terms are used in the following description for the sake of clarity, these terms are intended to refer only to the particular structure of the embodiments selected for illustration in the drawings, and are not intended to define or limit the scope of the disclosure. In the drawings and the following description below, it is to be understood that like numeric designations refer to component of like function.
[0019] With reference to FIG. 1 , a photoconductive imaging member in accordance with the present disclosure is shown. Photoconductive imaging member 10 comprises a substrate 12 , a charge generating or photogenerating layer 14 , a first charge transport layer 161 , a second charge transport layer 162 , and an optional overcoating layer 18 . The first charge transport layer 161 is formed from a first CTL formulation comprising an aromatic monoamine and a first polymeric film forming binder material in accordance with the present disclosure. The second charge transport layer 162 is formed from a second CTL formulation comprising an aromatic diamine and a second polymeric film forming binder material in accordance with the present disclosure.
[0020] It is to be understood herein, that if a “range” or “group” is mentioned with respect to a particular characteristic of the present disclosure, for example, percentage, chemical species, and temperature etc., it relates to and explicitly incorporates herein each and every specific member and combination of sub-ranges or sub-groups therein whatsoever. Thus, any specified range or group is to be understood as a shorthand way of referring to each and every member of a range or group individually as well as each and every possible sub-ranges or sub-groups encompassed therein; and similarly with respect to any sub-ranges or sub-groups therein.
[0021] In this regard, disclosed herein is a first CTL formulation comprising an aromatic monoamine and a first polymeric film forming binder material.
[0022] In another regard, disclosed herein is a second CTL formulation comprising an aromatic diamine and a second polymeric film forming binder material.
[0023] The aromatic monoamine of the present disclosure is defined as a compound that contains one amine group and one or more aryl groups. The aromatic diamine is defined as a compound that contains two amine groups and one or more aryl groups. The term aryl group is defined herein as a group derived from arene or heteroarene by removal of one or more hydrogen atoms.
[0024] In a variety of exemplary embodiments, aromatic monoamine of the present disclosure may be represented by the following formula I T :
in which n T is independent of each other an integral number and 1≦n T ≦5; and R T is independent of each other selected from the group consisting of hydrogen, C 1 -C 6 alkyls, halo groups, and mixture thereof.
[0025] Exemplary aromatic monoamines include, but are not limited to, compounds with the following formulas:
and the like.
[0026] In a specific embodiment, the aromatic monoamine of the first CTL formulation is the compound with formula T 1 as shown below (TTA):
[0027] Optionally, one or more of other charge transporting compounds may be combined with the aromatic monoamine. Examples of such charge transporting compounds include, bur are not limited to, pyrene, carbazole, hydrazone, oxazole, oxadiazole, pyrazoline, arylmethane, benzidine, thiazole, stilbene and butadiene compounds; for example, pyrazolines such as 1-phenyl-3-(4′-diethylaminostyryl)-5-(4′-diethylamino phenyl)pyrazoline; hydrazones such as N-phenyl-N-methyl-3-(9-ethyl)carbazyl hydrazone and 4-diethyl amino benzaldehyde-1,2-diphenyl hydrazone; oxadiazoles such as 2,5-bis (4-N,N′-diethylaminophenyl)-1,2,4-oxadiazole; and the like.
[0028] Optionally, one or more of charge transporting polymers may be combined with the aromatic monoamine. Examples of charge transporting polymers include, but are not limited to, poly-N-vinylcarbazole, poly-N-vinylcarbazole halide, polyvinyl pyrene, polyvinylanthracene, polyvinylacridine, a pyrene-formaldehyde resin, polysilylenes, an ethylcarbazole-formaldehyde resin, polymeric arylamine compounds a triphenylmethane polymer and polysilane, and the like. More examples are described in U.S. Pat. Nos. 4,806,443, 4,806,444, 4,801,517, 4,818,650, 4,935,487 and 4,956,440, the disclosures of which are incorporated herein by reference in their entirety.
[0029] Based on the total weight of the first CTL formulation, the amount of the aromatic monoamine and other optional charge transporting compound(s) present in the first CTL formulation in accordance with the present disclosure is from about 95 to about 5 wt %, including from about 75 to about 15 wt %, and from about 60 to about 25 wt %.
[0030] It is believed that the aromatic monoamine such as TTA in the first CTL renders the belt photoreceptor having minimal curling problems.
[0031] Any suitable binder material may be employed as the first polymeric film forming binder material to form the matrix for the first charge transport layer. Typical polymeric film forming materials include those described, for example, in U.S. Pat. No. 3,121,006. Thus, the first polymeric film forming binder material may be thermoplastic and thermosetting resins which include, but are not limited to, polycarbonates, polyesters, polyamides, polyurethanes, polystyrenes, polyarylethers, polyarylsulfones, polybutadienes, polysulfones, polyethersulfones, polyethylenes, polypropylenes, polyimides, polymethylpentenes, polyphenylene sulfides, polyvinyl acetate, polysiloxanes, polyacrylates, polyvinyl acetals, polyamides, polyimides, amino resins, phenylene oxide resins, terephthalic acid resins, phenoxy resins, epoxy resins, phenolic resins, polystyrene and acrylonitrile copolymers, polyvinylchloride, vinylchloride and vinyl acetate copolymers, acrylate copolymers, alkyd resins, cellulosic film formers, poly(amideimide), styrenebutadiene copolymers, vinylidenechloride-vinylchloride copolymers, vinylacetate-vinylidenechloride copolymers, styrene-alkyd resins, polyvinylcarbazole, and the like. These polymers may be block, random or alternating copolymers.
[0032] In a variety of exemplary embodiments, the first polymeric film forming binder material of the present disclosure may comprise a polycarbonate. Exemplary polycarbonates include poly(4,4′-isopropylidene-diphenylene)carbonate (also referred to as bisphenol-A-polycarbonate); poly(4,4′-cyclohexylidinediphenylene) carbonate (referred to as bisphenol-Z polycarbonate); poly(4,4′-isopropylidene-3,3′-dimethyl-diphenyl)carbonate (also referred to as bisphenol-C-polycarbonate); and the like. An example of commercially available Bisphenol A polycarbonate is Makrolon® 5705 from Farbensabricken Bayer A.G. Bayer Co., which has a molecular weight of about 170,000.
[0033] If desired, the first CTL formulation may further comprise a polymeric film forming binder material that not only functions as a binder, but also functions to improve electrical prosperities of photoreceptor. For example, TTA has cycle-up problem, and a polymer containing hydroxyl groups and/or carboxyl groups may be added to the first CTL formulation to overcome this problem. In a variety of exemplary embodiments, the polymer containing hydroxyl groups and/or carboxyl groups may comprise a polymeric film forming reaction product of at least vinyl chloride, vinyl acetate and hydroxyalkyl acrylate. The polymer may be prepared using conventional emulsion or suspension polymerization techniques. The chain length can be controlled by varying the reaction temperature and time. One embodiment of the polymer may be formed from a reaction mixture comprising from about 80 percent to about 90 percent by weight vinyl chloride, from about 3 percent to about 15 percent by weight vinyl acetate, and from about 6 percent to about 20 percent by weight hydroxyalkyl acrylate, based on the total weight of the reactants for the terpolymer. This terpolymer may be represented by the following formula:
wherein R u is an alkylene group such as ethylene or propylene; U1 is the proportion of the polymer derived from vinyl chloride that is from about 80 percent to about 90 percent by weight, based on the total weight of the reactants for the terpolymer; U2 is the proportion of the polymer derived from vinyl acetate that is from about 3 percent to about 15 percent by weight, based on the total weight of the reactants for the terpolymer; and U3 is the proportion of the polymer derived from hydroxyalkyl acrylate that is from about 6 percent to about 20 percent by weight, based on the total weight of the reactants for the terpolymer.
[0034] Of course, the polymer containing hydroxyl groups and/or carboxyl groups in the first CTL formulation may be the reaction product of at least vinyl chloride, vinyl acetate, a hydroxyalkyl acrylate, and maleic acid, which may also be prepared using conventional emulsion or suspension polymerization techniques. One embodiment of the copolymer may be formed from a reaction mixture comprising from about 80 percent to about 90 percent by weight vinyl chloride, from about 3 percent to about 15 percent by weight vinyl acetate, from about 6 percent to about 20 percent by weight hydroxyalkyl acrylate, and from about 0.1 percent to about 0.5 percent by weight maleic acid, based on the total weight of the reactants for the tetrapolymer. This tetrapolymer may be represented by the following formula:
wherein R u is an alkylene group such as ethylene or propylene; U1 is the proportion of the polymer derived from vinyl chloride that is from about 80 percent to about 90 percent by weight, based on the total weight of the reactants for the tetrapolymer; U2 is the proportion of the polymer derived from vinyl acetate that is from about 3 percent to about 15 percent by weight, based on the total weight of the reactants for the tetrapolymer; U3 is the proportion of the polymer derived from hydroxyalkyl acrylate that is from about 6 percent to about 20 percent by weight, based on the total weight of the reactants for the tetrapolymer; and U4 is the proportion of the polymer derived from maleic acid that is from about 0.1 percent to about 0.5 percent by weight, based on the total weight of the reactants for the tetrapolymer.
[0035] Similarly, the polymer containing hydroxyl groups and/or carboxyl groups may comprise a terpolymer of vinyl chloride, vinyl acetate and vinyl alcohol such as VAGH, available from Union Carbide.
[0036] In a specific embodiment, the polymer containing hydroxyl groups and/or carboxyl groups of the first CTL formulation is a polymeric reaction product of 81 weight percent vinyl chloride, 4 weight percent vinyl acetate and 15 weight percent hydroxyethyl acrylate (VAGF, available from Union Carbide). VAGF is a terpolymer having a weight average molecular weight of about 33,000.
[0037] In another specific embodiment, the polymer containing hydroxyl groups and/or carboxyl groups of the first CTL formulation may be UCARMAG-527 available from Dow Chemical. UCARMAG-527 comprises a tetrapolymer reaction product of 81 weight percent vinyl chloride, 4 weight percent vinyl acetate, 0.28 weight percent maleic acid and 15 weight percent hydroxyethyl acrylate having a number average molecular weight (Mn) of about 35,000 and inherent viscosity 0.56.
[0038] Based on the total weight of the first CTL formulation, the amount of the first polymeric film forming binder material present in the first CTL formulation in accordance with the present disclosure is from about 100 to about 0.1 wt %, including from about 90 to about 10 wt %, and from about 80 to about 25 wt %. In a specific embodiment, the first CTL formulation comprises 4.0 g TTA (39.7%), 6.0 g Makrolon® 5705 (59.5%), and 0.08 g UCARMAG-527 (0.8%).
[0039] Optionally, a suitable antioxidant may be added in the first CTL formulation of the disclosure. Typically, the antioxidants used comprise a hindered phenol, hindered amine, thioether or phosphite. An antioxidant is effective for improvement of potential stability and image quality in environmental variation.
[0040] Exemplary hindered phenol antioxidants include, but are not limited to, Sumilizer BHT-R, Sumilizer MDP-S, Sumilizer BBM-S, Sumilizer WX-R, Sumilizer NW, Sumilizer BP-76, Sumilizer BP-101, Sumilizer GA-80, Sumilizer GM and Sumilizer GS (the above are manufactured by Sumitomo Chemical Co., Ltd.), IRGANOX 1010, IRGANOX 1035, IRGANOX 1076, IRGANOX 1098, IRGANOX 1135, IRGANOX 1141, IRGANOX 1222, IRGANOX 1330, IRGANOX 1425WL, IRGANOX 1520L, IRGANOX 245, IRGANOX 259, IRGANOX 3114, IRGANOX 3790, IRGANOX 5057 and IRGANOX 565 (the above are manufactured by Ciba Specialty Chemicals), and Adecastab AO-20, Adecastab AO-30, Adecastab AO-40, Adecastab AO-50, Adecastab AO-60, Adecastab AO-70, Adecastab AO-80 and Adecastab AO-330 (the above are manufactured by Asahi Denka Co., Ltd.).
[0041] Exemplary hindered amine antioxidants include, but are not limited to, Sanol LS2626, Sanol LS765, Sanol LS770, Sanol LS744, Tinuvin 144, Tinuvin 622LD, Mark LA57, Mark LA67, Mark LA62, Mark LA68, Mark LA63 and Sumilizer TPS. Exemplary thioether antioxidants include, but are not limited to, Sumilizer TP-D. Exemplary phosphite antioxidants include, but are not limited to, Mark 2112, Mark PEP 8, Mark PEP 24G, Mark PEP 36, Mark 329K and Mark HP 10 etc.
[0042] Based on the total weight of the first CTL formulation, the amount of antioxidant present in the first CTL formulation in accordance with the present disclosure is from about 50 to about 0.01 wt %, including from about 20 to about 0.1 wt %, and from about 10 to about 0.5 wt %.
[0043] If desired, other optional additives may be incorporated into the first CTL formulation of the present disclosure. The additives may be selected from the group consisting of a curing catalyst, a stabilizer, silane coupling agent, a deletion control agent, a surface energy control agent, inorganic and/or organic fillers, and mixture thereof. Based on the total weight of the first CTL formulation, the amount of the additive(s) present in the first CTL formulation in accordance with the present disclosure may be from about 20 to about 0.001 wt %, including from about 15 to about 0.01 wt %, and from about 10 to about 0.1 wt %.
[0044] Any suitable solvent may be used for the first CTL formulation. Typical solvents include, for example, methylene chloride, tetrahydrofuran, toluene and monochloro benzene, and the like. Generally, the solvent selected should dissolve all of the charge transport components and polymeric film forming binder used to form the first charge transport layer. In a specific embodiment, the solvent of the first CTL formulation is methylene chloride.
[0045] Generally, the amount of solvent used depends upon the type of coating technique employed to fabricate the imaging member. For example, less solvent is used for dip or immersion coating than for extrusion coating.
[0046] In a variety of exemplary embodiments, the aromatic monoamine and other optional charge transporting compound(s) are dissolved or molecularly-dispersed in the first polymeric film forming binder material. The term “dissolved” is defined herein as forming a solution in which the molecules are dissolved in the polymer to form a homogeneous phase. The expression “molecularly dispersed” used herein is defined as charge transporting molecule dispersed in the polymer, the small molecules being dispersed in the polymer on a molecular scale.
[0047] Depending on specific imaging member to be fabricated, the thickness of the first charge transport layer may be from about 50 to about 0.01 micron, including from about 35 to about 1 micron, and from about 25 to about 5 micron. In a specific embodiment, the first charge transport layer is a 15 micron layer.
[0048] As described above, also disclosed herein is a second CTL formulation which comprises an aromatic diamine and a second polymeric film forming binder material.
[0049] In a variety of exemplary embodiments, aromatic diamine of the present disclosure may be represented by the following formula I D :
in which n D is independent of each other an integral number and 1≦n D ≦5; and R D is independent of each other selected from the group consisting of hydrogen, C 1 -C 6 alkyls, halo groups, and mixture thereof.
[0050] Exemplary aromatic diamines include, but are not limited to, compounds with the following formulas:
[0051] In a specific embodiment, aromatic diamine of the second CTL formulation is the compound of formula D1 (m-TBD) as shown below:
[0052] Optionally, one or more of other charge transporting compounds may be combined with the aromatic diamine. Examples of such charge transporting compounds include, bur are not limited to, pyrene, carbazole, hydrazone, oxazole, oxadiazole, pyrazoline, arylmethane, benzidine, thiazole, stilbene and butadiene compounds; for example, pyrazolines such as 1-phenyl-3-(4′-diethylaminostyryl)-5-(4′-diethylamino phenyl)pyrazoline; hydrazones such as N-phenyl-N-methyl-3-(9-ethyl)carbazyl hydrazone and 4-diethyl amino benzaldehyde-1,2-diphenyl hydrazone; oxadiazoles such as 2,5-bis (4-N,N′-diethylaminophenyl)-1,2,4-oxadiazole; and the like.
[0053] Optionally, one or more of charge transporting polymers may be combined with the aromatic diamine. Examples of charge transporting polymers include, but are not limited to, poly-N-vinylcarbazole, poly-N-vinylcarbazole halide, polyvinyl pyrene, polyvinylanthracene, polyvinylacridine, a pyrene-formaldehyde resin, polysilylenes, an ethylcarbazole-formaldehyde resin, polymeric arylamine compounds a triphenylmethane polymer and polysilane, and the like. More examples are described in U.S. Pat. Nos. 4,806,443, 4,806,444, 4,801,517, 4,818,650, 4,935,487 and 4,956,440, the disclosures of which are incorporated herein by reference in their entirety.
[0054] Based on the total weight of the second CTL formulation, the amount of aromatic diamine and other optional charge transporting compound(s) present in the second CTL formulation in accordance with the present disclosure is from about 5 to about 95 wt %, including from about 70 to about 15 wt %, and from about 60 to about 25 wt %.
[0055] Any suitable binder material may be employed as the second polymeric film forming binder material to form the matrix for the second charge transport layer. Although selection of the second polymeric film forming binder material is independent of the first polymeric film forming binder material, typically they are the same. General polymeric film forming materials include those described, for example, in U.S. Pat. No. 3,121,006. Thus, the second polymeric film forming binder material may be thermoplastic and thermosetting resins which include, but are not limited to, polycarbonates, polyesters, polyamides, polyurethanes, polystyrenes, polyarylethers, polyarylsulfones, polybutadienes, polysulfones, polyethersulfones, polyethylenes, polypropylenes, polyimides, polymethylpentenes, polyphenylene sulfides, polyvinyl acetate, polysiloxanes, polyacrylates, polyvinyl acetals, polyamides, polyimides, amino resins, phenylene oxide resins, terephthalic acid resins, phenoxy resins, epoxy resins, phenolic resins, polystyrene and acrylonitrile copolymers, polyvinylchloride, vinylchloride and vinyl acetate copolymers, acrylate copolymers, alkyd resins, cellulosic film formers, poly(amideimide), styrenebutadiene copolymers, vinylidenechloride-vinylchloride copolymers, vinylacetate-vinylidenechloride copolymers, styrene-alkyd resins, polyvinylcarbazole, and the like. These polymers may be block, random or alternating copolymers.
[0056] In a variety of exemplary embodiments, the second polymeric film forming binder material of the present disclosure may comprise a polycarbonate. Exemplary polycarbonates include poly(4,4′-isopropylidene-diphenylene)carbonate (also referred to as bisphenol-A-polycarbonate); poly(4,4′-cyclohexylidinediphenylene)carbonate (referred to as bisphenol-Z polycarbonate); poly(4,4′-isopropylidene-3,3′-dimethyl-diphenyl)carbonate (also referred to as bisphenol-C-polycarbonate); and the like. An example of Bisphenol A polycarbonate is Makrolon® 5705 as described supra.
[0057] If desired, the second CTL formulation may also comprise a second polymeric film forming binder material that not only functions as a binder, but also functions to improve electrical prosperities of the photoreceptor. Such material may include a polymer containing hydroxyl groups and/or carboxyl groups. In a variety of exemplary embodiments, the polymer containing hydroxyl groups and/or carboxyl groups may comprise a polymeric film forming reaction product of at least vinyl chloride, vinyl acetate and hydroxyalkyl acrylate. One embodiment of the polymer may be formed from a reaction mixture comprising from about 80 percent to about 90 percent by weight vinyl chloride, from about 3 percent to about 15 percent by weight vinyl acetate, and from about 6 percent to about 20 percent by weight hydroxyalkyl acrylate, based on the total weight of the reactants for the terpolymer.
[0058] In a variety of exemplary embodiments, the polymer containing hydroxyl groups and/or carboxyl groups in the second CTL formulation may be the reaction product of at least vinyl chloride, vinyl acetate, a hydroxyalkyl acrylate, and maleic acid. One embodiment of the copolymer may be formed from a reaction mixture comprising from about 80 percent to about 90 percent by weight vinyl chloride, from about 3 percent to about 15 percent by weight vinyl acetate, from about 6 percent to about 20 percent by weight hydroxyalkyl acrylate, and from about 0.1 percent to about 0.5 percent by weight maleic acid, based on the total weight of the reactants for the tetrapolymer.
[0059] Similarly, the polymer containing hydroxyl groups and/or carboxyl groups may comprise a terpolymer of vinyl chloride, vinyl acetate and vinyl alcohol, such as VAGH available from Union Carbide; or a polymeric reaction product of 81 weight percent vinyl chloride, 4 weight percent vinyl acetate and 15 weight percent hydroxyethyl acrylate (VAGF, available from Union Carbide).
[0060] In another specific embodiment, the polymer containing hydroxyl groups and/or carboxyl groups of the first CTL formulation may be UCARMAG-527 as described supra.
[0061] Based on the total weight of the second CTL formulation, the amount of the second polymeric film forming binder material present in the second CTL formulation in accordance with the present disclosure is from about 100 to about 0.1 wt %, including from about 90 to about 10 wt %, and from about 80 to about 25 wt %.
[0062] Optionally, a suitable antioxidant may be added in the second CTL formulation of the disclosure. Typically, the antioxidants used comprise a hindered phenol, hindered amine, thioether or phosphite. Examples of antioxidants have been described supra. An antioxidant is effective for improvement of potential stability and image quality in environmental variation.
[0063] In a specific embodiment, the antioxidant in the second CTL formulation is tetrakis[methylene(3,5-di-tert-butyl-4-hydroxy hydrocin namate)]methane (Irganox®-1010), which is commercially available from Ciba-Geigy Corporation.
[0064] Based on the total weight of the second CTL formulation, the amount of antioxidant present in the second CTL formulation in accordance with the present disclosure is from about 50 to about 0.01 wt %, including from about 20 to about 0.1 wt %, and from about 10 to about 0.5 wt %.
[0065] If desired, other optional additives may be incorporated into the second CTL formulation of the present disclosure. The additives may be selected from the group consisting of a curing catalyst, a stabilizer, silane coupling agent, a deletion control agent, a surface energy control agent, inorganic and/or orgqanic fillersand mixture thereof. Based on the total weight of the second CTL formulation, the amount of the additive(s) present in the second CTL formulation in accordance with the present disclosure may be from about 20 to about 0.001 wt %, including from about 15 to about 0.01 wt %, and from about 10 to about 0.1 wt %. In a specific embodiment, the second CTL formulation comprises 4.66 g m-TBD (46.6%),4.56 g Makrolon® 5705 (45.6%), 0.1 g UCARMAG-527 (1.0%), and 0.68 g Irganox®-1010 (6.8%).
[0066] Any suitable solvent may be used for the second CTL formulation. Typical solvents include, for example, methylene chloride, tetrahydrofuran, toluene and monochloro benzene, and the like. Generally, the solvent selected should dissolve all of the components used to form the second charge transport layer. In a specific embodiment, the solvent of the second CTL formulation is methylene chloride.
[0067] Generally, the amount of solvent used depends upon the type of coating technique employed to fabricate the imaging member. For example, less solvent is used for dip or immersion coating than for extrusion coating.
[0068] In a variety of exemplary embodiments, the aromatic diamine and other optional charge transporting compound(s) are dissolved or molecularly dispersed in the second polymeric film forming binder material.
[0069] Depending on specific imaging member to be fabricated, the thickness of the second charge transport layer may be from about 50 to about 0.01 micron, including from about 35 to about 1 micron, and from about 25 to about 5 micron. In a specific embodiment, the second charge transport layer is a 15 micron layer, for example, a 15 micron standard Galaxy SMTL.
[0070] Combination of the first charge transport layer and the second charge transport layer gives a design commonly called “two-pass CTL” or “dual CTL structure”. As a skilled artisan can understand, two-pass coating process may be employed to fabricate such a device.
[0071] It was found that the charge transport layer (CTL) plays a big role in curling the device.
[0072] On one hand, it is known that belt photoreceptors with aromatic monoamine hole transport material such as tri(3-methylphenyl)amine (TTA) and a binder such as polycarbonate in CTL do not exhibit curling problems. However, a CTL based solely on TTA/polycarbonate possesses electrical problems such as cycle-up and high residual voltage as well as a low T g . It is believed that these problems are related to the chemical property of TTA. As such, few photoreceptor devices use TTA alone as charge transport material in the CTL.
[0073] On the other hand, if a CTL contains an aromatic diamine hole transport material such as N,N′-diphenyl-N,N′-bis(3-methylphenyl)-(1,1′-biphenyl)-4,4′-diamine (m-TBD) and a binder such as polycarbonate, the photoreceptor device tends to curl badly. But this kind of device has very good electrical properties.
[0074] Therefore, the present disclosure providing a photoconductive imaging member comprising two charge transport layers, the first of which is formed from a an aromatic monoamine such as TTA, and the second of which is formed from aromatic diamine such as m-TBD.
[0075] This is a new charge transport layer design for flexible xerographic photoreceptors. The design eliminates the need for an anti-curl backing coating (ACBC) coating layer to compensate for the stress imbalance caused by thermal expansion and residual solvent mass transport differences between the substrate and SMTL layers. The design gives less internal stress imbalance resulting in little or no upward curling of the photoreceptor. The design solves the curl problem while the device maintains excellent electrical and physical properties by using dual CTL structure. Additionally, this new design does not need any change in current manufacturing process. All additives to the CTL can be maintained.
[0076] In a specific embodiment, a two-pass coating process is used to make the TTA and SMTL layers combined with use of an acid such as UCARMAG-527 to achieve the desired electrical performance. For example, the first CTL is a 15 micron layer of TTA with a polycarbonate binder between a 15 micron standard Galaxy SMTL and a substrate (PEN).
[0077] In a specific embodiment, the first charge transport layer, which is typically a low T g layer, is kept away from the photoreceptor surface and the addition of an acid such as UCARMAG-527 improves its electrical performance.
[0078] The present disclosure also relates to a method of preparing an imaging member such as photoreceptor. The method comprises (i) providing a substrate, (ii) coating a charge generation layer above the substrate, (iii) coating a first charge transport layer above the charge generation layer, (iv) coating a second charge transport layer above the first charge transport layer, and (v) optionally coating an overcoat layer above the second charge transport layer. As describe supra, the first charge transport layer is formed from a first CTL formulation comprising an aromatic monoamine and a first polymeric film forming binder material. As describe supra, the second charge transport layer is formed from a second CTL formulation comprising aromatic diamine and a second polymeric film forming binder material.
[0079] An imaging member may be prepared by any suitable techniques that are well known in the art. Although rigid substrate may be contemplated within the scope of the present disclosure, typically a flexible substrate layer is provided. The flexible substrate support layer can be formed of a conductive material. Alternatively, a conductive layer can be formed on top of a nonconductive flexible substrate support layer.
[0080] The charge generation layer is then applied to the electrically conductive surface. A charge blocking layer or undercoat layer may optionally be applied to the electrically conductive surface prior to the application of the charge generation layer, for example, when an organic photoreceptor is to be fabricated. If desired, an adhesive layer may be utilized between the charge blocking layer and the charge generation layers. Usually the charge generation layer is applied onto the blocking layer and the charge transport layers of the present disclosure are formed on the charge generation layer. This structure may have the charge generation layer on top of or below the charge transport layers. For example, a charge generation layer may be sandwiched between conductive surface and charge transport layer; or a charge transport layer may be sandwiched between a conductive surface and a charge generation layer. This structure may be imaged in the conventional xerographic manner which usually includes charging, optical exposure and development.
[0081] The substrate may be opaque or substantially transparent and may comprise any suitable material having the required mechanical properties. Accordingly, the substrate may comprise a layer of an electrically non-conductive or conductive material such as an inorganic or an organic composition. As electrically non-conducting materials, there may be employed various resins known for this purpose including polyesters, polycarbonates, polyamides, polyurethanes, and the like, which are flexible as thin webs. An electrically conducting substrate may be any metal, for example, aluminum, nickel, steel, copper, and the like; or a polymeric material, as described above, filled with an electrically conducting substance, such as carbon, metallic powder, and the like; or an organic electrically conducting material. The electrically insulating or conductive substrate may be in the form of an endless flexible belt, a web, a rigid cylinder, a sheet, and the like.
[0082] The thickness of the substrate layer depends on numerous factors, including strength desired and economical considerations. For an electrophotographic imaging member such as a drum, this layer may be of substantial thickness of, for example, up to many centimeters or of a minimum thickness of less than a millimeter. Similarly, a flexible belt may be of substantial thickness, for example, about 250 micrometers, or of minimum thickness less than 50 micrometers, provided there are no adverse effects on the final electrophotographic device.
[0083] In embodiments where the substrate layer is not conductive, the surface thereof may be rendered electrically conductive by an electrically conductive coating. The conductive coating may vary in thickness over substantially wide ranges depending upon the optical transparency, degree of flexibility desired, and economic factors. Accordingly, for a flexible photoresponsive imaging device, the thickness of the conductive coating may be generally from about 20 angstroms to about 750 angstroms, and typically from about 100 angstroms to about 200 angstroms for an optimum combination of electrical conductivity, flexibility and light transmission. The flexible conductive coating may be an electrically conductive metal layer formed, for example, on the substrate by any suitable coating technique, such as a vacuum depositing technique or electrodeposition. Typical metals include aluminum, zirconium, niobium, tantalum, vanadium, hafnium, titanium, nickel, stainless steel, chromium, tungsten, molybdenum, and the like. For example, a continuous metal film can be attained on a suitable substrate, e.g. a polyester web substrate such as Mylar available from E. I. DuPont de Nemours & Co. with magnetron sputtering.
[0084] If desired, an alloy of suitable metals may be deposited. Typical metal alloys may contain two or more metals such as zirconium, niobium, tantalum, vanadium, hafnium, titanium, nickel, stainless steel, chromium, tungsten, molybdenum, and the like, and mixtures thereof. A typical electrical conductivity for conductive layers for electrophotographic imaging members in slow speed copiers is about 10 2 to 10 3 ohms/square.
[0085] In a specific embodiment of the present disclosure, the substrate support is comprised of a flexible 3½ mil thick biaxially polyethylene naphthalate (PEN Kaladex, available from DuPont). The substrate may be metallized to provide a 100 angstrom conductive titanium surface.
[0086] An optional hole blocking layer or undercoat may be applied to the substrate. Any suitable and conventional blocking layer capable of forming an electronic barrier to holes between the adjacent photoconductive layer and the underlying conductive surface of a substrate may be utilized. The blocking layer may comprise nitrogen containing siloxanes or nitrogen containing titanium compounds, such as trimethoxysilyl propylene diamine, hydrolyzed trimethoxysilyl propyl ethylene diamine, N-β-(aminoethyl)γ-amino-propyl trimethoxy silane, isopropyl 4-aminobenzene sulfonyl, di(dodecylbenzene sulfonyl)titanate, isopropyl di(4-aminobenzoyl)isostearoyl titanate, isopropyl tri(N-ethylaminoethylamino)titanate, isopropyl trianthranil titanate, isopropyl tri(N,N-dimethylethylamino)titanate, titanium-4-amino benzene sulfonate oxyacetate, titanium 4-aminobenzoate isostearate oxyacetate, [H 2 N(CH 2 ) 4 ]CH 3 Si(OCH 3 ) 2 , (γ-aminobutyl)methyl diethoxysilane, and [H 2 N(CH 2 ) 3 ]CH 3 Si(OCH 3 ) 2 , (γ-aminopropyl)methyl diethoxysilane, as disclosed in U.S. Pat. Nos. 4,338,387, 4,286,033 and 4,291,110, the disclosures of which are incorporated herein in their entirety. An exemplary blocking layer comprises a reaction product between a hydrolyzed silane and the oxidized surface of a metal ground plane layer. The blocking layer may be applied by any suitable conventional technique such as spraying, dip coating, draw bar coating, gravure coating, silk screening, air knife coating, reverse roll coating, vacuum deposition, chemical treatment and the like. The blocking layer should be continuous and have a thickness of less than about 0.2 micrometer because greater thicknesses may lead to undesirably high residual voltage.
[0087] Any suitable adhesive layer well known in the art may optionally be applied to the hole blocking layer or undercoat layer. Typical adhesive layer materials include, for example, polyesters, polyurethanes, and the like. Satisfactory results may be achieved with adhesive layer thickness from about 0.05 micrometer (500 angstroms) to about 0.3 micrometer (3,000 angstroms). Conventional techniques for applying an adhesive layer coating mixture to the charge blocking layer include spraying, dip coating, roll coating, wire wound rod coating, gravure coating, Bird applicator coating, and the like. Drying of the deposited coating may be effected by any suitable conventional technique such as oven drying, infra red radiation drying, air drying and the like.
[0088] At least one electrophotographic imaging layer is formed on the adhesive layer, hole blocking layer or substrate. The electrophotographic imaging layer may be a single layer that performs both charge generating and charge transport functions as is well known in the art or it may comprise multiple layers such as a charge generation layer and a charge transport layer.
[0089] Charge generation layers may comprise amorphous selenium, triggonal selenium, and alloys of selenium and arsenic, tellurium, germanium and the like, hydrogenated amorphous silicon and compounds of silicon and germanium, carbon, oxygen, nitrogen, and the like fabricated by, for example, vacuum evaporation or deposition. The charge generation layers may also comprise inorganic pigments of crystalline selenium and its alloys; Group II-VI compounds; and organic pigments and dyes such as quinacridones, polycyclic pigments such as dibromo anthanthrone pigments, perylene and perinone diamines, polynuclear aromatic quinones, azo pigments including bis-, tris- and tetrakis-azos; quinoline pigments, indigo pigments, thioindigo pigments, bisbenzimidazole pigments, phthalocyanine pigments, quinacridone pigments, lake pigments, azo lake pigments, oxazine pigments, dioxazine pigments, triphenylmethane pigments, azulenium dyes, squalium dyes, pyrylium dyes, triallylmethane dyes, xanthene dyes, thiazine dyes, cyanine dyes, and the like dispersed in a film forming polymeric binder and fabricated by solvent coating techniques.
[0090] In an embodiment, phthalocyanines may be employed as photogenerating materials for use in laser printers utilizing infrared exposure systems. Infrared sensitivity is required for photoreceptors exposed to low cost semiconductor laser diode light exposure devices. The absorption spectrum and photosensitivity of the phthalocyanines depend on the central metal atom of the compound. Many metal phthalocyanines have been reported and include, for example, oxyvanadium phthalocyanine, chloroaluminum phthalocyanine, copper phthalocyanine, oxytitanium phthalocyanine, chlorogallium phthalocyanine, hydroxygallium phthalocyanine magnesium phthalocyanine and metal-free phthalocyanine. The phthalocyanines exist in many crystal forms which have a strong influence on photogeneration.
[0091] Any suitable polymeric film forming binder material may be employed as the matrix in the charge generating (photogenerating) binder layer. Typical polymeric film forming materials include those described, for example, in U.S. Pat. No. 3,121,006, the entire disclosure of which is incorporated herein by reference. Thus, typical organic polymeric film forming binders include thermoplastic and thermosetting resins such as polycarbonates, polyesters, polyamides, polyurethanes, polystyrenes, polyarylethers, polyarylsulfones, polybutadienes, polysulfones, polyethersulfones, polyethylenes, polypropylenes, polyimides, polymethylpentenes, polyphenylene sulfides, polyvinyl acetate, polysiloxanes, polyacrylates, polyvinyl acetals, polyamides, polyimides, amino resins, phenylene oxide resins, terephthalic acid resins, phenoxy resins, epoxy resins, phenolic resins, polystyrene and acrylonitrile copolymers, polyvinylchloride, vinylchloride and vinyl acetate copolymers, acrylate copolymers, alkyd resins, cellulosic film formers, poly(amideimide), styrene-butadiene copolymers, vinylidenechloride-vinylchloride copolymers, vinylacetate-vinylidenechloride copolymers, styrene-alkyd resins, polyvinylcarbazole, and the like. These polymers may be block, random or alternating copolymers.
[0092] A photogenerating composition or pigment may be present in the resinous binder composition in various amounts. Generally, however, from about 5 percent by volume to about 90 percent by volume of the photogenerating pigment is dispersed in about 10 percent by volume to about 95 percent by volume of the resinous binder, and typically from about 20 percent by volume to about 30 percent by volume of the photogenerating pigment is dispersed in about 70 percent by volume to about 80 percent by volume of the resinous binder composition. The photogenerator layers can also fabricated by vacuum sublimation in which case there is no binder.
[0093] Any suitable and conventional technique may be utilized to mix and thereafter apply the photogenerating layer coating mixture. Typical application techniques include spraying, dip coating, roll coating, wire wound rod coating, vacuum sublimation and the like. For some applications, the generator layer may be fabricated in a dot or line pattern. Removing of the solvent of a solvent coated layer may be effected by any suitable conventional technique such as oven drying, infrared radiation drying, air drying and the like.
[0094] Any suitable and conventional technique may be utilized to mix and thereafter apply the first and second CTL formulations as described supra, to the charge generation layer. Typical application techniques include spraying, dip coating, roll coating, wire wound rod coating, and the like. Drying of the deposited coating may be effected by any suitable conventional technique such as oven drying, infra red radiation drying, air drying and the like.
[0095] In general, the thickness ratio between the sum of the first and the second charge transport layers of the present disclosure and the charge generation layer is typically maintained from about 2:1 to 200:1 and in some instances as great as 400:1. Typically, a charge transport layer is substantially non-absorbing to visible light or radiation in the region of intended use but is electrically “active” in that it allows the injection of photogenerated holes from the photoconductive layer, i.e., charge generation layer, and allows these holes to be transported through itself to selectively discharge a surface charge on the surface of the active layer.
[0096] Optionally, other layers may also be used such as conventional electrically-conductive ground strip along one edge of the belt or drum in contact with the conductive layer, blocking layer, adhesive layer or charge generation layer to facilitate connection of the electrically conductive layer of the photoreceptor to ground or to an electrical bias. Ground strips are well known and usually comprise conductive particles dispersed in a film forming binder.
[0097] Optionally, an overcoat layer (OCL) may also be utilized to improve resistance to abrasion. OCL has been shown to increase the mechanical life of an OPC by as much as 10-fold. The overcoat layer is well known in the art and may comprise thermoplastic organic polymers or inorganic polymers that are electrically insulating or slightly semi-conductive.
[0098] The thickness of the overcoat layer depends upon the abrasiveness of the charging (e.g., bias charging roll), cleaning (e.g., blade or web), development (e.g., brush), transfer (e.g., bias transfer roll), etc., in the electrophotographic imaging system employed. Generally, the overcoat layer thickness may range up to about 10 micrometers. A typical thickness is from about 1 micrometer to about 5 micrometers.
[0099] Any suitable and conventional technique may be utilized to mix and thereafter apply the overcoat layer coating mixture to the charge transport/generating layer. Typical application techniques include spraying, dip coating, roll coating, wire wound rod coating, and the like. Drying of the deposited coating may be effected by any suitable conventional technique such as oven drying, infrared radiation drying, air drying and the like.
[0100] The dried overcoat should transport holes during imaging and should not have too high free carrier concentration. Free carrier concentration in an overcoat increases the dark decay. It is desirable that the dark decay of the overcoated layer is about the same as, or is close to, that of an unovercoated counterpart.
[0101] According to the present disclosure, a method of imaging is provided. The imaging method comprises generating an electrostatic latent image on an imaging member comprising a first charge transport layer and a second charge transport layer as described supra, developing the latent image, and transferring the developed electrostatic image to a suitable substrate.
[0102] The imaging member such as photoreceptor according to the present disclosure may be incorporated into various imaging systems such as those conventionally known as xerographic imaging devices or electrophotographic image forming devices. Additionally, the imaging members may be selected for imaging and printing systems with visible, near-red and/or infrared light. In this embodiment, the imaging members may be negatively or positively charged, exposed to light having a wavelength of from about 700 to about 900, such as generated by solid state layers, e.g., arsenide-type lasers, either sequentially or simultaneously, followed by developing the resulting image and transferring it to a print substrate such as transparency or paper. Additionally, the imaging members may be selected for imaging and printing systems with visible light. In this embodiment, the imaging members may be negatively or positively charged, exposed to light having a wavelength of from about 400 to about 700 nanometers, followed by development with a known toner, and then transferring and fixing of the image on a print substrate.
[0103] In an embodiment, an image forming device may comprise the imaging member as discussed above, a charging device, an electrostatic image forming station, an image developing station, and an image transfer station.
[0104] In an embodiment, the image forming device may be used to generate images with the photoreceptor disclosed herein. Generally, the imaging member may be first charged with a corona charging device such as a corotron, dicorotron, scorotron, pin charging device, bias charging roll (BCR) or the like. Then, an electrostatic image is generated on the imaging member with an electrostatic image forming device. Subsequently, the electrostatic image is developed by known developing devices at one or more developing stations that apply developer compositions such as, for example, compositions comprised of resin particles, pigment particles, additives including charge control agents and carrier particles, etc., reference being made to, for example, U.S. Pat. Nos. 4,558,108; 4,560,535; 3,590,000; 4,264,672; 3,900,588 and 3,849,182, the disclosures of each of these patents being totally incorporated herein by reference. The developed electrostatic image is then transferred to a suitable print substrate such as paper or transparency at an image transfer station, and affixed to the substrate. Development of the image may be achieved by a number of methods, such as cascade, touchdown, powder cloud, magnetic brush, and the like.
[0105] Transfer of the developed image to a print substrate may be by any suitable method, including those wherein a corotron or a biased roll is selected. The fixing step may be performed by means of any suitable method, such as flash fusing, heat fusing, pressure fusing, vapor fusing, and the like.
[0106] Following transfer of the developed image from the imaging member surface, the imaging member may be cleaned of any residual developer remaining on the surface, and also cleaned of any residual electrostatic charge prior to being subjected to charging for development of a further or next image.
[0107] Specific embodiments of the disclosure will now be described in detail. These examples are intended to be illustrative, and the disclosure is not limited to the materials, conditions, or process parameters set forth in these embodiments. All parts and percentages are by weight unless otherwise indicated.
EXAMPLE 1
Formulations
[0108] All the materials in this new proposal were used directly as received. m-TBD was purchased from Sankio Ltd., TTA was purchased from Eastman Kodak Co. Polycarbonate (Makrolon® 5705) from Bayer Co. has weight average molecular weight (M w ) 170,000. Vinyl chloride copolymer [poly(vinyl chloride-co-vinyl acetate-co-hydroxypropyl acrylate-co-maleic acid)], with number average molecular weight (Mn) 35,000 and inherent viscosity 0.56, was purchased from Dow Chemical with brand name UCARMAG-527. Methylene chloride in HPLC grade was purchased from Fisher Scientific. Tetrakis[methylene(3,5-di-tert-butyl-4-hydroxy hydrocinnamate)]methane (Irganox®-1010) was purchased from Ciba-Geigy Corporation. The first CTL formulation and the second formulation are shown in Table 1 below.
TABLE 1 HTGPC Analysis of Polywax samples Samples Description M n M w PDI Unpurified Polywax 2000 1890 2746 1.45 Purified Polywax 2000 (the 2 nd portion) 2694 3418 1.27 Residue removed from Polywax 2000 1557 1999 1.28 by extraction process (the 1 st portion) Unpurified Polywax 1000 1154 1243 1.08 Purified Polywax 1000 (the 2 nd portion) 1259 1325 1.05 Residue removed from Polywax 2000 840 872 1.04 by extraction process (the 1 st portion)
[0109] All samples were stirred at room temperature until clear solutions were obtained. Because TTA has the inherent cycle-up problem, UCARMAG-527 was added t o overcome this problem in the 1 st CTL formulation. Because the m-TBD/polycarbonate CTL (the 2 nd CTL formulation) was designed to be on the top of the device, so antioxidant Irganox-1010 was added to minimize the deletion problem, and UCARMAG-527 was added to control the electrical properties of the upper layer also.
EXAMPLE 2
Coating
[0110] The solutions of Example 1 were coated as charge transport layer (CTL) on standard Xerox belt photoreceptor substrate coated up to charge generation layer (CGL) [HOGaPC/PcZ, Constellation generator layer] respectively. First, the solution comprising the 1 st CTL formulation was coated on the CGL to be about 15 micrometers thick. The device was dried at 110° C. for 30 minutes, and cooled to room temperature. Then the solution comprising the 2 nd CTL formulation was coated on this device to be about 15 micrometers thick. The full finished photoreceptor device was dried at 110° C. for another 30 minutes. So the total thickness of the CTL was about 30 micrometers. The structure of this new designed photoreceptor device is shown in FIG. 1 , except that the optional overcoat layer 18 is omitted.
EXAMPLE 3
Electrical Test
[0111] According to standard Constellation belt photoreceptor test in Xerox photoreceptor product, the full photoreceptor devices prepared from Example 2 were measured for electrical properties on a drum scanner which was the same method described in U.S. Pat. No. 6,875,548, herein incorporated by reference.
[0112] The essential characteristic of the photoreceptor is the photoinduced discharge curve (PIDC), which relates the voltage on the photoreceptor to the light exposure. The shape of this curve is governed by an electric-field-dependent quantum efficiency, the mobility of the photogenerated carriers, and charge trapping. The PIDC of the photoreceptor prepared from Example 2 is shown in FIG. 2 .
[0113] The electrical properties summary of this new designed device is tabulated in Table 2.
TABLE 2 Electrical analysis of Gyricon devices made using unpurified and purified Polywax AA531, XRCC531 60 V 80 V 100 V 125 V Unpurified PW2000 Time zero 2.13 3.45 4.31 4.49 48 hours 1.16 1.34 1.55 1.86 AA569, XRCC94 60 V 80 V 100 V 125 V Purified PW2000 Time zero 3.67 3.91 3.76 3.57 48 hours 3.55 3.64 3.56 3.40 120 hours 3.26 3.60 3.60 3.50
In Table 2, V0 is the dark voltage after scorotron charging; S is the initial slope of the PIDC, which is a measurement of sensivity; Vc is the surface potential at which PIDC slope is S/2; Vr is the residual voltage; V depl is the difference between applied voltage and V0; V dd is 0.2 s duration dark decay voltage; V cyc-up is the residual change after 10000 cycling test
[0114] From the above, this new designed photoreceptor device had excellent electrical performance. When this belt device was heated at 135° C. for 30 minutes, and then was cooled to room temperature, it showed negligible curling. So even without ACBC, this new designed photoreceptor device still can solve the curling problem by dual-CTL coatings.
[0115] While particular embodiments have been described, alternatives, modifications, variations, improvements, and substantial equivalents that are or may be presently unforeseen may arise to applicants or others skilled in the art. Accordingly, the appended claims as filed and as they may be amended are intended to embrace all such alternatives, modifications variations, improvements, and substantial equivalents.
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Provided is an imaging member such as photoreceptor comprising a substrate, a charge generation layer, a first charge transport layer, a second charge transport layer, and an optional overcoat layer. The first charge transport layer is formed from a first CTL formulation comprising an aromatic monoamine and a first polymeric film forming binder material. The second charge transport layer is formed from a second CTL formulation comprising aromatic diamine and a second polymeric film forming binder material. The imaging member has gained improved properties such as removal of anti-curl layer, desirable structural flatness, electrical properties, mechanical robustness, flexibility, longevity, and copy image qualities over extended use, among others.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to power tools for treating and shaping concrete. More particularly, the present invention relates to portable, hand operated power tools for shaping green concrete into curbs.
2. Description of the Related Art
Concrete curbs form structural borders upon peripheries of concrete streets or parking lots where aesthetics are important. Appropriate concrete curbing is often integral with gutter structures that contribute to proper drainage. Additionally, residential property owners often employ decorative edging along borders to enhance the appearance of their landscaping. Properly formed curb and gutter designs add valuable structural and functional attributes to modern concrete structures as well. In many communities properly designed curbs and gutter arrangements are required by zoning ordinances.
A wide variety of curb forming techniques thus exist. Concrete shaping systems and curb forming devices can contact freshly placed concrete directly, while still green in a slab, or concrete curbing can be extruded with a variety of placement devices.
Some large scale, motor driven curb forming devices store concrete in a hopper, and pump it outwardly through shaping dies, molds or extruder equipment that preshapes the curb. Some larger, wheeled systems used to strike-off or screed large slabs traverse forms or rails for support. Many include ancillary curb installers that shape slab edges as concrete is laid.
So-called slip-forming machines have been adapted to lay concrete curbing or curb and gutter arrangements during slab pouring and screeding. Typical slip forming machines follow the length of the slab and store wet concrete in a hopper. Concrete discharged from or forced out of the hopper is shaped by a form proximate the hopper that moves with the machine. As the form compresses and shapes the concrete edges, a properly shaped curb or curb and gutter combination is formed in place.
For example, U.S. Pat. No. 4,544,346 issued Oct. 1, 1985 illustrates curb forming apparatus associated with a screed. The screed treats plastic concrete and forms a curb along one or both sides of the slab as the screed travels the slab length. The triangular truss concrete screed has first and second sides supported by rollers which engage spaced apart forms. The screed traverses the entire width of the slab, and is supported upon forms, and is not hand operated by a single worker. A curb form is coupled to one side of the finishing machine.
U.S. Pat. No. 4,217,065 issued Aug. 12, 1980 discloses a slip-form curb and gutter machine with a wheeled chassis that travels along tracks. A concrete receiving hopper discharges green concrete that is shaped by suitable forms affixed to the chassis. A hand winch above the hopper attaches to a cable for pulling the machine along its tracks. An operator can stand on a platform disposed above the form.
U.S. Pat. No. 5,803,656 issued Sep. 8, 1998 discloses a motorized concrete screed with a roller attached to a chassis. A pair of handles extending from the chassis are independently adjustable. A throttle attached to one of the handles is electrically connected to the motor. A pair of wheel assemblies permit the apparatus to be easily moved to and from a worksite without damaging the roller.
Slip-form machines and large screeding devices involve expensive, heavyweight equipment, and they are too expensive and cumbersome for smaller contractors to set up and use economically, particularly on smaller jobs. Because of the disadvantages with large slip form machines and screeds, smaller hand operated machines have evolved for treating concrete and shaping it into gutters or curbs. Some use motor driven carriages that, like slip form machines, include hoppers that discharge concrete into molds or shapers that compress the concrete into a desired shape. Some analogous devices use a U-shaped handle arrangement, that journals a rotatable roller whose periphery contacts the concrete for shaping.
For example, U.S. Pat. No. 3,910,738 issued Oct. 7, 1975 discloses a concrete finishing roller rotatably mounted on an axle that is controlled by a handle. Indicia formed on the outer periphery of the roller imprints the concrete surface. Workers can manipulate the handle so that the roller may be pushed across green concrete. The depth of the impression made in the concrete surface may be varied by the addition or the removal of weights on the handle and by vibrating the roller in a vertical plane as it moves across the concrete surface.
U.S. Pat. No. 5,354,189 issued Oct. 11, 1994 discloses a concrete forming device for extruding curb, barrier, wall, gutter or the like from concrete or cement. Cement stored within a vibrating hopper falls onto tapered, counter rotating augers which compact and force the concrete through an adjacent extrusion mold for shaping.
U.S. Pat. No. 5,846,176 issued Dec. 8, 1998 also shows a hand-operated roller tool for concrete finishing. A hollow, cylindrical, roller secured journalled to a U-shaped frame has protrusions or nubs defined about its outer surface to produce a desired texture on the green concrete. A single worker can operate the device with a handle coupled to the frame.
U.S. Pat. No. 6,474,906 issued Nov. 5, 2002 discloses a concrete finishing machine wherein a roller extends between a primary motorized unit and a secondary unmotorized unit disposed on each side of a slab to be paved. An engaging lever must be pressed to initiate tube rotation, driving the primary and secondary units forward.
U.S. Pat. No. 6,863,470 issued Mar. 8, 2005 provides a curbing apparatus for shaping green concrete by pushing it through a channel defined by a mold.
U.S. Pat. Application No. 20020021938 published Feb. 21, 2002 discloses a curb forming and extruding machine includes a plunger that forces raw concrete via lower hopper into and through a curb extrusion mold.
U.S. Pat. No. 7,621,694 issued Nov. 24, 2009 discloses a curb forming machine using a single, rotatable curb-forming roller. A handle assembly is utilized for pulling and maneuvering the roller, and a motor rotates the roller to shape and smooth wet concrete into curbing.
U.S. Pat. No. 5,449,406 issued Sep. 12, 1995 discloses a machine for applying grout mortar to a tiled surface. A frustroconical shroud having a plurality of generally radially extending blades rotates about an axis that is perpendicular to the surface being treated.
U.S. Pat. Application No. 20050238745 discloses an apparatus for impressing three-dimensional patterns in a slip-formed concrete wall. Impression rollers include outer peripheries provided with three-dimensional patterns. One roller coats a side of an exposed wall, and an ancillary roller coats the top of the wall.
Despite the advantages of relatively recently develop portable curb forming devices, they suffer from well known disadvantages. Often they have to be made flush with available forms, and hand controlled designs with large rollers are difficult to guide and control. Irregular patterns and misshapen concrete edges can thus result. Changing the operating direction is difficult, because handles and frames, including wheeled carriages where used, are designed to move in only one direction. Further, where rollers are placed horizontally to help propel the apparatus, and rotate in an axis parallel with the plane of the slab, curb deformation and uneven spots can occur when the unit suddenly jerks in response to tight turns in smaller pours.
BRIEF SUMMARY OF THE INVENTION
This invention provides an improved, portable, hand controlled concrete curbing machine. Curb shaping is effectuated by a specially shaped head that rotates about an axis that is perpendicular to the slab. The head projects downwardly from a self propelled, wheeled carriage whose width and dimensions can be user adjusted or configured by the user to fit many diverse curbing applications faced by the small contractor.
The curb forming machine comprises a rectangular frame comprising inturned edges that slidably receive an adjustable subframe supporting a pair of wheels that can ride on a form. The subframe is user adjustable, so machine width can be selected to best fit the job application. A roller on the opposite frame side rides on the opposite curb form. Concrete is formed by a shaping head rotating beneath the frame driven by an electric motor. The motor is adjustably secured to the frame by a mounting plate secured beneath the frame by fasteners received within follower slots in the frame that slidably adjust position.
An optional, removable adaptor plate is disposed on an opposite frame end to support the machine when in transit or storage. It is removed for normal curb work. Te adaptor plate can raise the machine from for monolithic curbs without rebar by supporting the normal wheels, an effectively lowering them to ride o the ground. A roller behind the adaptor plate is exposed when the plate is removed, and it rides along forms when normal curb and gutter work is undertaken. Preferably the handle assembly is “offset” from the machine center to aid in operator control.
It is therefore a primary object of the present invention to provide a portable, one-man, self-propelled curb forming device that is ideal for smaller jobs.
It is also important to provide a curb-forming machine of the character described that is highly stable.
It is also an object to provide a transformable curb forming machine that can be user switched between jobs of different dimensions, and which can be switched between normal curb-and-gutter applications and monolithic curb jobs.
Another object is to provide a curb former of the character described that finishes and shapes plastic concrete and forms a curb with a desired size and shape.
Another important object is to enable contractors to use a single adjustable machine for either finishing normal curb and gutter work, or for finishing monolithic curbs.
A further object is to provide a powered, self propelled curb-forming apparatus which can easily be reversed in the direction of travel.
Another object of the present invention is to provide a motor-powered, curb-forming machine which is inexpensive, relatively lightweight, easy to use, and ideal for smaller contractors.
Yet another object is to provide a transformable curb and gutter machine that can be quickly and easily switched between job applications in the field without special tools or equipment.
These and other objects and advantages of the present invention, along with features of novelty appurtenant thereto, will appear or become apparent in the course of the following descriptive sections.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
In the following drawings, which form a part of the specification and which are to be construed in conjunction therewith, and in which like reference numerals have been employed throughout wherever possible to indicate like parts in the various views:
FIG. 1 is a rear isometric view showing the best mode of my new concrete curb forming machine;
FIG. 2 is a frontal isometric view thereof;
FIG. 3 is a rearward bottom isometric view thereof;
FIG. 4 is a partially exploded, fragmentary isometric view thereof, with portions thereof broken away for clarity or omitted for brevity;
FIG. 5 is an enlarged, partially exploded, fragmentary isometric view showing the preferred adjustable subframe and the wheels;
FIG. 6 is an enlarged, partially exploded, isometric view showing the preferred handle assembly;
FIG. 7A is an enlarged, fragmentary, sectional view taken generally along line 7 - 7 of FIG. 4 , with the adaptor plate removed, and showing the machine forming a curb and riding a two inch by six inch form on the left, and a two inch by twelve inch form on the right for normal curb and gutter work;
FIG. 7B is an enlarged, fragmentary, sectional view similar to FIG. 7A , with the adaptor plate removed, showing the machine in use with a monolithic curb with rebar;
FIG. 7C is an enlarged, fragmentary, sectional view similar to FIGS. 7A and 7B , with the adaptor plate removed, showing the machine in use with a monolithic curb without rebar;
FIG. 8 is an enlarged, partially exploded, fragmentary isometric view showing the adaptor plate end of the frame; and,
FIG. 9 is a rear elevational view thereof.
DETAILED DESCRIPTION OF THE INVENTION
With initial reference directed now to FIGS. 1-3 and 9 of the appended drawings, a concrete curb forming machine constructed generally in accordance with the best mode of the invention has been generally designated by the reference numeral 10 . The curb former machine 10 is adapted to traverse wet or freshly laid concrete, preferably disposed between parallel and slightly elevated forms, for shaping edges or boundary regions of the slab into arcuate curbs of appropriate shape and dimensions. The machine 10 can be used by a single workman, and it is portable, enabling quick transportation between job sites.
The curb forming machine comprises a rigid, generally rectangular frame 12 somewhat in the form of a flat parallelepiped. The frame 12 has downwardly depending front and rear edges 14 ( FIG. 1) and 16 ( FIG. 2 ) respectively. (Since the handle can be adjusted to face either direction, these edges 14 and 16 can each be referred to as either “font” or rear.“) Various components are mounted on the upper surface 18 ( FIGS. 1 , 2 , 5 ) atop the frame 12 . A handle assembly 20 is pivotally and adjustably mounted to the frame 12 at opposite frame ends, as will later be described in detail. An electric drive motor 22 ( FIGS. 1 , 2 ) secured to frame 12 is powered by a conventional electrical cord 24 ( FIGS. 1 , 2 ) that is secured to the handle assembly 20 and controlled by a conventional switch 25 . Conventional 120 V.A.C. power is supplied by plug 27 .
As described in detail hereinafter, a rigid, subframe 30 supporting a pair of main wheels 32 is adjustably, slidably coupled to the right side of the frame 12 . In use, these wheels normally ride on a two inch by six inch toe board form, which is used in normal curb and gutter work. The opposite end of the frame supports a removable and adjustable adaptor plate 36 ( FIGS. 2 , 3 ) that normally supports the machine 10 when not in use.
Concrete is contacted by and formed by a replaceable shaping head 40 operationally disposed beneath frame 12 . Motor 22 is amounted atop frame 12 proximate surface 18 . As best seen in FIGS. 3 and 4 , the shaping head 40 is a hollow, hat-like structure, preferably molded from plastic. Head 40 has a body 41 ( FIG. 3 ) substantially shaped like an inverted, truncated cone, and an integral, convex cap portion 42 that projects downwardly. An integral, circular ridge portion 44 transitions between body 41 and an integral, ring shaped flange 45 that includes a plurality of radially spaced-apart mounting orifices 46 ( FIG. 4 ). A circular drive plate 48 above head 40 is concentrically secured to flange 45 on head 40 by fasteners 49 that penetrate orifices 50 and the aligned orifices 46 in head flange 45 . Plate 48 has a central, cylindrical drive hub 52 that is reinforced by a plurality of webs 54 .
A rigid, square motor mounting plate 55 above drive plate 48 has a central orifice 56 through which hub 52 rotatably projects. The hub key orifice 53 is penetrated by motor output shaft 58 ( FIG. 4 ) that is coaxially aligned with orifices 53 and 56 and hub 52 . Shaft 58 thus establishes an axis of rotation for itself and the shaping head 40 that is perpendicular to the slab surface. Motor 22 is attached to mounting plate 55 with suitable fasteners (not shown) that penetrate orifices 59 in mounting plate 55 ( FIG. 4 ). Importantly, motor mounting plate 55 can be adjusted lengthwise across frame 12 (i.e., towards or away from the ends of the machine frame 12 . To this effect there are a plurality of standoffs 60 ( FIG. 4 ) that project upwardly, generally from the corners of mounting plate 55 , and register with elongated adjustment slots 62 defined in the surface 18 of frame 12 . Suitable fasteners 64 ( FIG. 1 ) penetrate frame adjustment slots 62 and secure the head 40 and motor 22 in a desired position. Widthwise adjustment in head placement is thus possible, by loosening fasteners 64 , shifting the motor and the head 40 below along the frame 12 , and then retightening the fasteners 64 .
With joint reference now to FIGS. 5 and 6 , the preferred subframe 30 is also adjustably attached to the frame 12 . The edges 14 , 16 of the frame 12 have inwardly turned lip portions 66 ( FIG. 5 ), forming a generally C-shaped cross section. Subframe 30 has a generally rectangular top 68 , bounded by spaced apart, parallel end rails 69 , 70 , that ride within and are captivated between frame edges 14 and 16 in assembly ( FIG. 5 ). A subframe reinforcement 71 extends between a side strut 73 and a generally U-shaped wheel mounting plate 75 . The main wheels 32 previously described can be secured to plate 75 with bolts 77 that penetrate the wheels and mounting orifices 78 in plate 75 , being secured with nuts 79 . Preferably there are elongated mounting slots 81 formed in the legs of plate 75 above wheel orifices 78 that slidably accommodate extra large wheels for clearance where necessary.
Subframe 30 is moved relative to frame 12 by a hand-operated adjustment knob 84 . As seen in FIG. 5 for example, there is a U-shaped flange 86 projecting upwardly from the end of frame 12 . An elliptical orifice 82 ( FIGS. 2 , 4 , 5 ) in the arcuate flange 86 provides a connection point for lifting. One end of a threaded shaft 88 ( FIG. 7A ) penetrates flange 86 and is secured to drive knob 84 , and the opposite end rotatably terminates in an L-bracket 90 ( FIG. 7A ) that is secured to frame surface 18 by a fastener 91 . A downwardly projecting traveler 93 has a threaded collar 94 threadably mated to shaft 88 , so that rotation of the knob 84 moves the traveler 93 . The lower shank 96 of the traveler 93 penetrates an elongated slot 98 ( FIGS. 4 , 5 ) formed in frame 12 , and is attached to subframe 30 to move main wheels 32 inwardly or outwardly relative to the motor 22 . Specifically, traveler shank 96 penetrates and is fastened to a selected orifice 99 ( FIG. 5 ) in the subframe reinforcement strut 71 . Thus the main wheels 32 can be move inwardly or outwardly to change or adjust the effective width of the curb former 10 , adapting it for use in diverse situations of varying dimensions and width.
With reference now to FIGS. 1 , 2 and 8 , 9 , there is an adaptor plate 36 disposed on the frame end 101 ( FIGS. 2 , 8 ) opposite wheels 32 . The adaptor plate 36 is shaped generally “U-shaped” and when installed, it is mated to a bell shaped plate 102 ( FIG. 8 ) secured at end 101 of the frame 12 ( FIG. 8 ). Plate 102 has a curved top 104 bordering a curved follower slot 105 that is used by the handle assembly 20 , as later described. A plurality of threaded studs 107 projecting outwardly from the plate 102 ( FIG. 8 ) penetrate upper orifices 109 and aligned slots 111 in the legs 110 of adaptor plate 36 . Hand-operable wing nuts 114 engage studs 107 to secure adaptor plate 36 to bell shaped plate 102 . The elliptical orifice 103 provides a lifting point when used with similar orifice 82 in flange 86 ( FIG. 4 ). Optional wheels can be attached to plate 36 with orifices 112 .
The bell-shaped plate 102 also mounts a roller 120 ( FIGS. 7A , 8 ) that is used with normal curb and gutter work with adaptor plate 36 removed from the machine. Roller 120 is secured to stud 122 on bell shaped plate 102 , being journalled with bearing 124 and fastener 125 ( FIG. 8 .
The adaptor plate 36 has several functions. First, as illustrated in FIGS. 1 and 2 it supports the machine in a stable position for transportation or stowage. It is removed in use (i.e., FIG. 7A ) for normal curb and gutter work. Finally, it can be raised or adjusted in position to support an auxiliary wheel for monolithic curb installations, (i.e., FIG. 7B ).
The handle assembly 20 can tilt in either direction, fore or aft of the motor 22 , so that the curbing machine is easily reversible, from the point of reference of an operator, who pushes” forwardly” along an intended direction of travel with the handle assembly 20 . As best appreciated from FIGS. 1 , 2 , 6 , and 9 , the handle assembly is “offset,” in that the handlebar 127 and hand grips 128 are positioned towards the adaptor plate side 101 , away from the motor 22 . As best seen in FIG. 9 , the handle assembly comprises an angled rod 130 extending angularly upwardly from a turned end portion 132 that is penetrated by shaft 88 ( FIGS. 7A and 9 ) and rotatably secured within pivot bracket 134 ( FIG. 9 ). A vertical handle portion 136 extends downwardly from junction 138 , where it connects to handle rod 130 , to another pivot bracket 138 ( FIG. 7A ) within which end 137 ( FIG. 6 ) is journalled by pin 140 ( FIG. 7A ) and secured by fastener 142 . The handle orientation is fixed by tightening an adjustment knob 144 that is threaded to carriage bolt 145 ( FIG. 7A ) that penetrates and tracks within follower slot 105 in bell-shaped plate 102 previously described. The head 147 ( FIG. 7A ) of carriage bolt 145 prevents axial escape of the bolt and insures proper tracking within the follower slot.
FIGS. 7A and 7B illustrate actual use. In FIG. 7A the wheels 32 are riding upon a two-by-six inch toe board 150 that is substantially parallel with and spaced-apart from a two-by-twelve form member 152 . Shaping head 40 penetrates downwardly into the concrete 153 and a concrete mass 154 is shaped by the rotating head 40 that creates a curb between itself and the form 152 . It will be noted that for normal curb and gutter work, the adaptor plate 36 previously discussed has been removed, exposing the roller 120 mounted to plate 102 ( FIG. 8 ) that rides atop form member 152 . It should be appreciated that the head 40 is removable and selectable; differently shaped heads can be used for differently shaped curbs.
In FIG. 7B a monolithic curb is being formed. Here roller 120 rides atop a form member 161 . Adaptor plate 36 is uninstalled. Within the raw concrete are rebar chairs 162 and a rebar mat 164 . A form member 167 ( FIG. 7B ) contacts the rebar mat 164 and supports wheels 32 .
In FIG. 7C a monolithic curb without rebar is being formed. Here roller 120 rides atop a higher form member 169 . Adaptor plate 36 is uninstalled from frame side 101 and placed on the opposite, “wheeled” side. Wheels 32 ride directly on surface 171 , without a form on the left side ( FIG. 7C ). Referencing FIG. 5 , for the application of FIG. 7C , the wheels 32 may need to be elevated. To do this they are removed from plate 75 and attached to adaptor plate 36 . With the adaptor plate 36 removed from side 101 (i.e., exposing roller 120 ) and coupled instead to wheel mounting plate 75 (i.e., FIG. 5 ) to form an extension as shown, ( FIG. 7C ), machine 10 easily traverses the work site surface 171 without a form on the left (i.e., like form 152 in FIG. 7A or form 167 in FIG. 7B ) that are no longer needed.
From the foregoing, it will be seen that this invention is one well adapted to obtain all the ends and objects herein set forth, together with other advantages which are inherent to the structure.
It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.
As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.
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A hand-controlled, curb forming machine that is transformable between different widths and geometries, and between different wheel configurations, to accommodate different concrete curbing. A downwardly projecting, rotating head that rotates about an axis perpendicular to the slab shapes raw concrete into appropriately styled and contoured curbs. A machine frame slidably receives an adjustable, wheeled subframe. A roller on the opposite frame side rides on an opposite curb form. A pivoted handle is reversible. The electric motor is adjustably secured to the frame by a mounting plate movable within follower slots in the frame. A removable adaptor plate disposed on an opposite frame end supports the machine when not in use, but can be removed for normal curb work exposing a form riding roller. When the machine is deployed with monolithic curbs without rebar, the adaptor plate can mount to the subframe to raise the machine by lowering the wheels.
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BACKGROUND OF THE INVENTION
Several methods and types of knitting machines are known which can be used to knit courses alternatingly from one of at least two pile threads together with one base thread.
According to German Patent No. 671,333, two pile threads are successively fed to one of two alternate sets of needles, while the base thread is fed to all needles. As a result, the pile thread, which is fed first of all, will be arranged in a wave-like manner in front of and behind the needles. This will strain the pile thread in an uncontrollable manner during the knitting action. As a consequence of this tensioning, special requirements of the pile-yarns, such as requiring a high tenacity yarn, are necessary. Also, the different tension of the pile threads will effect the pile forming ability of each pile thread to form different pile lengths.
The wave-like arrangement of the first pile thread is approximately realized by an extraordinary adjustment of the feeding tubes, using needles with plating angle hooks and a constant feeding speed of the pile thread which results from the preferred stitch construction. If an individual needle selection is preformed, the feeding speed of the pile thread is extraordinarily different according to pile knitting or missing so that vibrations of the pile thread will occur and will prevent a regular feeding to the predetermined needles only. Also, each negligible deviation from the position of the needles or the feeding tubes will damage these parts and leads to additional faults in the fabric.
By a method according to FIG. 18 to 21 of U.S. Pat. No. 4,633,683 (based on German Patent No. 30 24 705) the feeding of the pile threads is improved by the presence of a larger space between the alternate needle sets. Nonetheless, undesirable straining or tensioning of the first fed pile thread still exists because of the wave-like arrangement established in the yarn due to its being positioned before and behind the needles until the thread is knitted. Similarly, the depending disadvantages of such tensioning of the pile yarn, as described before, still exist.
In U.S. Pat. No. 4,307,586 (based on the German Patent Specification No. 23 43 886) it is proposed to feed pile threads in a way that is analogous to the distribution of pile fibers on sliver knit machines. In succeeding feeders only a pile thread is fed to selected needles raised to their clearing position and which are then retracted to an intermediate (feeding) position until at the last feeder of a knitting cycle base thread is fed to all needles which are subsequently retracted to the knock over position.
The method described in this '586 patent is, however, characterized by the same disadvantages as German Patent No. 671,333 and U.S. Pat. No. 4,633,683. In these a correct arrangement of the pile threads before selected and behind undelected needles is impossible. Also, after feeding a pile thread to the raised selected needles and the retraction of these needles with their hooks to the intermediate position of all needles, the pile thread will rest on the hooks of the unselected needles and can slip uncontrollably before or behind these hooks. This result is sometimes assisted by the vibrations of the pile thread depending on its shortly changing feeding speed. Sinkers to control the arrangement of the pile threads are not provided. The wave-like arrangement of the pile threads from the feeding to the knitting action will also strain these threads uncontrollably so that breakage may occur. Contrary to the described feeding of a base thread during the production of sliver knit fabrics, the base thread for a pile or plush fabric must be fed underneath the sinker nebs.
Nowhere does the U.S. '586 patent set forth a way in which the base thread is fed underneath of the sinker nebs and it is simultaneously avoided that the previously fed pile threads will remain in place over of the nebs of the retracted sinkers, so that pile loops are drawn from the pile threads simultaneously to the knitting action of the needles.
To avoid the above referred disadvantages of these foregoing methods German Patent Specification No. 23 22 384 suggests that each pile thread be knit to stitches subsequent to the feeding. This method is practiced on a machine having a cylinder and dial, and the base thread is fed at first to all dial and cylinder needles. While the dial needles are knitting preferably longer stitches, the cylinder needles are retracted to an intermediate position, in which the base yarn is looped, but the clearing of the previously knitted stitches is prevented ("tuck on the latch"-position). In at least two subsequent steps in each case selected needles are raised to engage a pile thread and are retracted to their knock over position, knitting stitches from the base and pile thread and simultaneously drawing pile loops. Additional base thread for the stitches of the cylinder needles is robbed from the enlarged dial stitches. The advantages of this method are that the base thread is prelooped in the first feeder for subsequent knitting actions together with one of the pile threads and that the pile threads are knit to stitches in the same feeder in which they are fed.
The disadvantages of this approach is that the resulting fabric is characterized by a rib-construction, which reduces the pile density, and that the pile loops must protrude between the wales of the cylinder needles.
The method according to U.S. Pat. No. 4,612,784 (based on German Patent No. 31 45 307) will transfer the fundamental steps of the German Patent Specification No. 23 22 384, under consideration of U.S. Pat. No. 3,406,538, in which also all threads knitted to a course are pre-looped and which is an improvement of U.S. Pat. No. 2,094,180 in which part of threads knitted to a course are pre-looped, to a multifeed circular knitting machine with cylinder and sinker ring.
Analogous to the foregoing referred specifications the base thread and at least two pile threads are fed and prelooped in succeeding feeders by retracting the needles to the "tuck on the latch" position. All needles are raised for clearing and after feeding the base thread the needles are retracted, prelooping the base thread over the ledges of the loop sinking plates. In subsequent feeders selected needles are raised for engaging a pile thread, without clearing the loops of the base thread from the latches, and are then retracted again to the "tuck on the latch" position, prelooping the pile threads over the ledges of the knock-over plates which are also operating as holding down sinkers for the loops of the base thread. Subsequent to the feeding and pre-looping of the pile threads both sinkers ("plates") are actuated outwardly to clear the loops of the base and the pile threads from the ledges, and the knock over action of the needle is completed.
The advantages of this method are the reliable feeding of all threads with controllable tension and the pre-looping of all threads immediately following the feeding. The disadvantages are the great extent of a knitting cycle based on the prelooping actions of all threads which reduces the production capacity and the necessarily coordinated adjustment of the prelooping cams to the stitch cam.
The pre-looping of the ground thread is indispensible in this concept since it is only through the higher position of the loops of the base thread that, without clearing the base thread from the latches, the needles may be raised sufficiently to have the pile thread fed into their hooks. Therefore, extended raising and retracting movements of the needles are stipulated and a reduced number of feeders will result.
A further fundamental disadvantage of this method is that the pre-looped loops of the base and pile threads must be cleared from the corresponding sinker ledges during knitting by retracting the sinkers with their nebs in front of the needles, and, for that reason, the formation of the pile loops cannot be controlled in this decisive and critical moment. Immediately after the knock-over action of the needles, the pile loops are engaged by the sinker nebs of the sinking plates and post-tensioned to obtain a satisfactory uniformity of the pile loops while the needles remain in idle position. This process, however, necessitates a certain minimum length of the pile loops and, therefore, excludes the production of short pile loops.
During knock-over it is also possible that pile loops which are directly connected with the feeder by floats can be deformed or distorted by irregular tensioning of the pile threads.
SUMMARY OF THE INVENTION
It is the object of the invention to produce a fabric as referred to in U.S. Pat. No. 4,307,586 by an improved method in which the pile loops are controlled during the knock-over action of the needles and the space of a knitting cycle is reduced which will thereby increase the production rate of a knitting machine.
The solution is achieved by feeding and positioning the base thread (without prelooping) in a usual way underneath the nebs of the retracted sinkers by controlling the movement of the base thread to the knock-over action in the throats of the sinkers which are subsequently positioned with their looping ledges between the needle stems, actuation in at least two succeeding, of steps, of alternatively predetermined needles to an upper position. These needles are retracted after they have engaged, exclusively; a pile thread to the "tuck on the latch" position and clearing the pile threads from the looping ledges prior to the knock over action. The pile loops are controlled or reformed from the pile forming ledges of the sinkers. If the pile thread were guided in the sinker throats, so as to be able to knit in a conventional and well established manner without the necessity of fine adjustment between prelooping and looping (knitting) and without the increased extent of the knitting cycle in view of pre-looping, the needle could only be raised until such a level in which the tip of the opened latch is not raised above the knitting ledge of the sinker. In this position the tips of the needle hooks are spaced only slightly above the looping ledges of the sinkers so that the pile threads must be positively located in the needle hooks by feeding sinkers.
In a multifeed circular knitting machine according to the present invention, the needles are individually controllable by one of two butts of combined pattern jacks which can be actuated by a conventional pattern device so that they will be operable with predetermined movements by associated cams. Cooperating with the needles are a plurality of pile sinkers each having loop forming ledges, holding or pile forming ledges and knitting ledges. All of these ledges are preferably formed as a part of a unitary sinker. The sinkers can be comprised of two independently movable sinkers, pile and feeding sinkers, respectively, that are controlled by associated cams. The second or feeding sinker has a feeding ledge and in its relative movement to the pile sinker serves to push a fed pile thread into a needle hook raised over or above the loop forming ledge of the pile sinker. The loop forming ledges serve to form loops in a pile thread substantially instantaneously after the pile thread is fed to the needles. Preferably a straining ledge is positioned on the pile sinker between the looping and pile forming ledges.
The advantages of the invention are achieved by the pile forming action of the last fed pile thread simultaneously to the knock-over action so that a prelooping of the base thread and one pile thread is avoided. The control of the pile loops by the pile forming ledges of the sinkers simultaneously to the knock-over action of the needles assures an equal pile forming process and also allows the production of short pile loops. By the short space of the two feeding positions one to the other the necessary movements of the needles are reduced and, therefore, the number of knitting cycles will be increased.
Other objects, features, and characteristics of the present invention, as well as the methods and operation and functions of the related elements of the structure, and to the combination of parts and economies of manufacture, will become apparent upon consideration of the following description and the appended claims with reference to the accompanying drawings, all of which form a part of this specification, wherein like reference numerals designate corresponding parts in the various Figures.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now further be explained with reference to the drawings which are as follows:
FIG. 1 is a schematic partial cross-sectional view of a circular knitting machine according to the invention;
FIGS. 2 and 3 are side views of two alternatively formed pile sinkers;
FIG. 4 and 15 are alternate control diagrams and cam sections corresponding to a first embodiment;
FIGS. 5 to 14 are side view sketches of the knitting elements respectively corresponding to the positions V to XIV in FIGS. 4 and 15;
FIG. 16 is a control diagram and cam section corresponding to a second embodiment;
FIGS. 17 to 22 are side view sketches of the knitting elements respectively corresponding to the positions XVII to XXII in FIG. 16;
FIG. 23 is a control diagram and cam section corresponding to a third embodiment; and
FIG. 24 shows a stitch construction of a two colored patterned pile fabric knit in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Turning first to FIG. 1, the main construction of a multifeed circular knitting machine according to the invention is illustrated in a cross-sectional view of part of the needle cylinder and the sinker ring. Needles 1 are arranged in cuts formed in the cylinder Z. For collective movements the needles will be actuated via butts 1a by cams A. The jacks 2 are pivotally combined with needles 1 and are turnable or pivotable, by selectors 3, between a base position, depicted in full lines, and a selected position which is in turn depicted in dashed lines. The selectors 3 are actuated by one of the usual pattern devices which, for example, cooperate with different arranged butts 3a. If a jack 2 remains in its base position that jack and the cooperating needle will be actuated by butt 2a via cams C while butt 2b is withdrawn into the cylinder Z. When jack 2 is pivoted into its selected position by the operation of a selector 3, butt 2b will then project from the cylinder Z and will be in a position where it and the corresponding needle will be actuatable by cams B. Butt 2a would then be withdrawn into the cylinder Z.
Movements of the needles and jacks by one of the butts 2a and 2b, respectively, are independent one to the other and may be executed reciprocally.
The pile sinkers 4 and the feeding sinkers 5 are arranged side by side in the slots of a sinker ring R and are actuated coherently by cams D of the sinker cam arrangement on butt 4a or 5a.
The pile sinkers 4 may be alternatively shaped, either as shown in FIG. 2 or FIG. 3.
FIG. 2 shows a pile sinker 4 with a knitting ledge 4d, for knitting the base thread, and a pile forming ledge 4e on the upper part of the sinker neb 4b.
In front of the pile ledge 4e an inclined part 4h is arranged on the sinker neb 4b, so that the tip of the neb is near the throat 4c. Further, the pile sinker 4 has a looping ledge 4f and a vertical straining ledge 4g.
The alternative pile sinker 41 of FIG. 3 shows a diverging shape for the sinker neb 41b. The tip of neb 41b is arranged so as to slope toward the pile forming ledge 41e. The knitting ledge 41d, the looping ledge 41f and the vertical straining ledge 41g are equivalent to the same ledges of the pile sinker 4 shown in FIG. 2.
Each of the alternative pile sinkers, 4 or 41, can be employed in any of the embodiments even if a particular embodiment shows the other as the preferred alternative. The advantage of sinker 41 is that it provides a shorter pile forming ledge and, consequently, a shorter way for retraction to clear the knitted pile loops from the sinker nebs. This further reduces the knitting cycle.
In each slot of the sinker ring R a pile sinker 4 or 41 is preferably arranged side by side with a feeding sinker 5, having a feeding ledge 5b. As shown in FIG. 1 pile sinkers 4 are being used.
With reference to the first embodiment shown in FIG. 4, sinkers 4 are used. The knitting cycle starts by raising all needles 1, via cam A1, to the clearing position. The pile sinkers 4 are controlled by cam D1. The presser cam PC1 will move all butts 2b of the jacks 2 into the cylinder Z thereby placing all jacks 2 and selectors 3 into their base positions. As soon as the previously knitted stitches are cleared from the latches, the pile sinkers 4 are actuated inwardly by cam D2, so that the previously knitted pile loops are strained by ledges 4g and the corresponding needle stitches of the pile threads are tightened to the needle stems. This is performed in position V of FIG. 4 and shown in FIG. 5.
Simultaneously, needles 1 are retracted by cam A2 to a lower feeding position and the pile sinkers 4 and the feeding sinkers 5 are actuated with their nebs positioned outwardly of the needle stems by cam D3 or D4, respectively, so that at position VI of FIG. 4 the feeding of the base thread occurs as shown in FIG. 6.
As is additionally shown in FIG. 6, the base thread G1 is fed by feeder F1 underneath of the nebs 4b of the pile sinkers 4 to the needles 1. Immediately after feeding the base thread G1 the pile sinkers 4 are actuated inwardly by cam D5 so that the base thread is controlled from within the throat 4c. Simultaneously, the nebs 4b will penetrate the previously knitted pile loops which will slide on the inclined part 4hupward onto the pile forming ledge 4e as in FIG. 7. The inward movement of the pile sinkers 4 will position the looping ledges 4f between the needle stems of needles 1. In a coordinated fashion with the inward movement of the pile sinkers a conventional pattern device S1 will actuate certain predetermined selectors 3, which in turn will move the corresponding jacks 2 into their selected position. The cooperating needles 1 of the remaining non-selected jacks 2 are then raised to an upper feeding position via butts 2a by cam C1 so that at VII of FIG. 4, as shown in FIG. 7, a first pile thread P1 can be fed to those raised needles.
As shown in FIG. 7 the looping ledges 4f of pile sinkers 4 will cover the needle hooks of those needles 1 remaining still in a lower feeding position, while the needle hooks of the selected needles will project over or above the looping ledges 4f. Feeder F2 will feed the first pile thread P1 exclusively to the raised needles which are in the upper feeding position. At this same time the feeding sinkers 5 start a coordinated inward movement actuated by cam D6. This action is performed at VIII of FIG. 4, as shown in FIG. 8. This will assure the pile thread P1 is definitely inserted into the needle hooks by feeding ledge 5b of the feeding sinkers 5.
Immediately with the insertion of the pile thread P1, cam C2 will retract the selected needles, via butts 2a of the cooperating jacks 2 ,from the upper feeding position to the "tuck on the latch" position, shown at position IX and in FIG. 9. This will draw the pile thread P1 to predetermined loops over the looping ledges 4f without clearing the previously knitted stitches from the needles.
As visible in FIG. 9 the base thread G1 will further move in the throat of the sinkers and in the hooks of the retracted needles without handicapping the succeeding knock-over action, while the pile thread P1 after looping has no relative movement to the needles and sinkers. Simultaneously with the looping of the pile thread P1 the feeding sinkers 5 are actuated outwardly by cam D7. Subsequent to the looping action of the pile thread P1, the turned or selected jacks 2 and the cooperating needles 1 are raised via butts 2b by cam B1 from the lower to the upper feeding position. At position X of FIG. 4, and with reference to FIG. 10, the feeding sinkers 5 are actuated outwardly by cam D7 so far that feeder F3 can feed a second pile thread P2 to the newly raised or selected needles which now project over or above the looping ledges 4f. The feeding sinkers 5 are subsequently actuated inwardly by cam D8, inserting the pile thread P2 into the needle hooks at position XI in FIG. 4, as exhibited in FIG. 11.
Thereafter the raised needles 1 are retracted from the cooperating jacks 2 via butts 2b by cam B2 to the "tuck on the latch" position, forming alternatively loops from pile threads P2 over the looping ledges 4f at position XII of FIG. 4, as shown in FIG. 12. The pile thread P1 will miss the looping ledge 4f when pile thread P2 is looped and vice versa. Immediately after looping the pile thread P2 the pile sinkers 4 and the feeding sinkers 5 are actuated outwardly by cams D9 and D10, respectively, to clear the pile loops and floats from the looping ledges 4f as detailed at position XIII of FIG. 4, and shown in FIG. 13.
Subsequently all needles are retracted to the knock-over position and the sinkers 4 start with their holding down action by cam D1a of the succeeding knitting cycle. Therefore at position XIV of FIG. 4, see FIG. 14, a complete course is knitted from the base thread G1 and one or the other of the pile threads P1 or P2, alternatively, thereby forming pile loops and floats, respectively.
At the knock-over action of the needles the pile loops rest on the pile forming ledges 4e. Any unverifiable deformation of the pile loops is avoided. If pile loops according to the needle selection are directly connected with the feeder a deformation is also avoided by the postforming action over the pile forming ledges 4e of the sinkers. Therefore, it is possible that the pile loops of the last fed pile thread are formed simultaneously with the knitting action of the needles and the previous prelooping process is avoided.
In FIG. 15 a modification of FIG. 4 is shown in which two pile threads are also alternatively knit with a base thread, but divergent to FIG. 4 from predetermined needles. The additional presser cam PC2 will move all butts 2b into the cylinder Z simultaneously to the knock-over action of the needles. Therefore, a selection is realized by an additional selecting device S1a prior to the raising of the predetermined needles. Jacks 2 remaining in base position and the cooperating needles are raised on butts 2a by cam C3 to the clearing position. Other needles will be cooperating with the turned or selected jacks 2. After retraction of the raised needles by cam A2, the cooperating selecting jacks 2 are subdivided by a pattern device S1 and a part of the butts 2b previously withdrawn in cylinder Z, will project into cam 3 for further control. The subsequent movements of the needles and sinkers 4 and 5 are identical as described previously in accordance with FIGS. 4 to 14.
A second embodiment using pile sinkers 41 (FIG. 3) is shown in FIGS. 16 to 22. Because of the reduced length of the sinker nebs 41b, as opposed to the nebs 4b of sinkers 4, the extent of the sinker movement is reduced.
According to FIG. 16 all needles are raised from cam A5 to clearing. Simultaneously presser cam PC3 moves all butts 2b into the cylinder, so that subsequently predetermined jacks 2 are pivotable into the selected position by pattern device S2. When the latches are cleared from the previously knitted stitches cam D11 actuates the pile sinkers 4 inwardly, so that ledges 41g will strain the pile loops. Cam B3 acting on butts 2b of selected jacks 2 will additionally raise their cooperating needles (a first set) while cam C4 will retract via butts 2a, the remaining jacks with cooperating needle (a second set) to a lower feeding position, so that at position XVII of FIG. 16 a first pile thread can be fed.
As is visible from FIG. 17, the pile thread P3 is directly fed from feeder F4 to the additional raised needles. The space between the divided needles is sufficient for feeding pile thread P3 into the needle hooks by feeder F4.
Simultaneously the pile sinkers 41 and the feeding sinkers 5 are moved outwardly by cams D12 or D13. While the second set of needles remain in the lower feeding position cam B4 will cause the retraction of the selected first set of needles to an upper feeding position in which feeder F5 will feed a base thread G2 to all raised needles, as shown in FIG. 17a, thus including the needles at both upper and lower feeding positions. When the base thread G2 is fed, the pile sinkers 41 are immediately actuated inwardly by cam D14 until the looping ledges 41f are moved underneath of the pile thread P3 in position between the needle stems.
Subsequently the first set of needles needles controlled in the upper feeding position are retracted via butts 2b of the jacks 2 by cam B6 to the "tuck on the latch" position at location XVIII of FIG. 16. By the simultaneous inward movement of feeding sinkers action by cam D15 the insertion of the pile thread is ensured. As shown in FIG. 18 the pile thread P3 is prelooped over the looping ledges 41f, while the base thread G2 is further controlled in the throats without any effort to the knitting action.
The feeding sinkers 5 are then actuated outwardly by cam D16, while cam C5 will raise the remaining needles second set of from the lower to an upper feeding position. It should be understood that feeding sinkers 5 need not necessarily be actuated outwardly or retracted. They could already be positioned outwardly or in a retracted position. The inward and subsequent outward movement have been shown for clarity and may be avoided in practice to avoid unnecessary movements. It is actually preferred to omit the inward movement of the feeding sinkers to allow earlier feeding of the second pile thread and further reduce the extent of the knitting cycle.
At position XIX of FIG. 16 a second pile thread is fed exclusively to these needles (the second set) F6. As shown in FIG. 19 feeder F6 will position the pile thread P4 in front of the opened needle hooks. Immediately thereafter, the feeding sinkers 5 are actuated inwardly by cam D17, inserting the pile thread P4 into the needle hooks at position XX of FIG. 16 and as shown in FIG. 20. When the needles of the second set start to retract on cam A7, simultaneously cam D18 and D19 will actuate the pile sinkers 41 and feeding sinkers 5 outward, clearing the pile threads P3 and P4 from the looping ledges 41f at XXI of FIG. 21. As shown in FIG. 16 the last fed pile thread P4 remains unlooped from the looping ledges of the sinkers.
The pile sinkers 41 are subsequently actuated inwardly by cam D20 while the needles are being retracted into their knock-over position by cam A7 as described at position XXII of FIG. 16.
Simultaneously with the knitting action all needles which had engaged pile thread P4 will draw pile loops over the pile forming ledges 41e directly, as shown in FIG. 22.
Floats of the pile thread P4 will rest on the pile ledge 41e of the sinker nebs which are holding pile loops of pile thread P3 in place.
It is obvious from the description of the foregoing embodiment that the width of a knitting cycle is reduced and their number can be increased, if the last fed pile thread is looped simultaneously with the knitting action.
In FIG. 23 an embodiment is shown in which three pile threads are alternatively knitted together with a base thread. It is realized principally as referred in the embodiments before. All needles 1 are raised for clearing by cam A8 and retracted by cam A9 to the feeding position. Simultaneously, the previously knitted pile loops are strained from straining ledges 4g by a movement actuated from cam D22 (analogous to FIG. 5). After actuating all sinkers outwardly by cam D23 and D24 the feeding of a base thread by feeder F7 is executed (analogous to feeder F1 at FIG. 6). Simultaneously a selection of the jacks 2 by pattern device S3 is performed which previously were positioned in base position by presser cam PC4. Selected jacks 2 and their cooperating needles are raised to an upper feeding position by cam B7 acting on butts 2b and subsequent to the movement of the pile sinkers 4 with their looping ledges 4f between the needle stems by cam D25, feeder F8 will feed a first pile thread to the selected needles (analogous to FIG. 7). By cams D26 and D27 the feed sinkers 5 will insert the pile thread with their feeding ledges 5b into the needle hooks (analogous to FIG. 8) whereupon the selected needles are retracted by cam B8 to the "tuck on the latch" position (analogous to FIG. 9).
Subsequently all needles remaining in the lower feeding position are raised by cam C6 to the upper feeding position in which the jacks 2 of these needles are divided by a pattern mechanism S4. Non-actuated jacks 2 remaining in their base position and the cooperating needles are retracted to the lower feeding position again by cam C7. Butts 2b of jacks 2 will protrude after passing cam B8 from the cylinder. As the feeding sinkers 5 are actuated by cam D28 outwardly, a second pile thread is fed by feeder F9 (analogous to FIG. 10). The second pile thread is thereupon inserted by feeding ledges 5b of the feeding sinkers which are actuated inwardly by cam D29 (analogous to FIG. 11) and subsequently these needles are retracted from the upper feeding position to the "tuck on the latch" position by cam B9 (analogous to FIG. 12). The feeding sinkers 5 are again actuated outwardly by cam D30. Those needles previously lowered by cam C7 and which had not engaged a pile thread in the prior actions are raised by cam C8 to the upper feeding position.
A third pile thread is fed to these needles by feeder F10 (analogous to FIG. 10) which is inserted into the needle hooks by the feeding ledges 5b of the feeding sinkers 5 which are again actuated inwardly by cam D31 (analogous to FIG. 11). As the needles start to retract on stitch cam A11 all the cams D32 and D33 actuate the pile sinkers 4 and the feeding sinkers 5 outwardly for clearing all pile threads from the looping ledges 4f.
Simultaneously with the retraction of the needles, cam D34 will position the pile sinkers 4 with their pile forming ledges 4e between the needle stems and all needles are retracted to the knock over position.
During the knitting action all pile loops of the first and second pile thread are controlled by the pile forming ledges 4e for a reliable formation of the pile loops. The pile loops of the third pile thread are directly drawn over the pile forming ledges 4e simultaneously with the knitting action without any prelooping. The foregoing described action of the pile sinkers is one of the most essential advantages of the invention.
It should be noted, that in place of jacks 2, needles with additional needle butts replacing one of the butts 2a or 2b may be alternatively used to accomplish this invention.
With respect to the foregoing embodiments, the base thread G1 or G2, respectively, is fed by the base thread thread feeder F1, F5 or F7, respectively, at the level of the sinker throats 4c or 41c, respectively, and is fed at this level to the needles 1 with opened needle latches. It is, however, also easily possible in the scope of the present invention to feed the base thread G1 or G2, respectively, at a level above the sinker nebs 4b or 41b, respectively, and then to pull it downwardly by a retraction movement of needles 1 to the level of the sinker throats 4c or 41c, respectively. The space requirement for each system is indeed somewhat increased, compared to the minimum obtainable space requirement, but a simplification of the apparatus can be achieved more easily as then the needles have to be arranged in one single feeding position and in one tuck on the latch position only, so that no opposite control movements of individual needles occur; thus, a pattern device positioned below the needle butt can only produce the rise movements, whereas the needle butt controls the reraction movements. A simplified construction and apparatus for the pattern control thus results.
In FIG. 24 a stitch construction of a two colored pile fabric is shown as produced by the present invention, specifically as set forth in conjunction with FIGS. 4, 16 and 23. In a first course all stitches are knit from a base thread G11 and alternatively from a first pile thread P11 and a second pile thread P21.
The predetermined non-knitting pile thread is formed as a float which projects over the pile loops of the knitting pile thread. In the same way as described before a second course is knit from a base thread P22, also a third course from a base thread G13 and a first pile thread P13 and a second pile thread P23. If a third pile thread, per course, is fed in accordance with the embodiment of FIG. 23, alternatively two of the three pile threads will spread over and cover the pile loops of the knitting and pile forming thread.
In the subsequent finishing operations the pile loops are opened by shearing. Simultaneously, the floats of the pile threads are removed and the fabric gets its final appearance.
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 are equivalent arrangements included within the spirit and scope of the appended claims.
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A method and apparatus for forming pile fabric where the pile loops are controlled during the knock-over action of the needles. The sinker ring mounted sinkers include separate pile and loop forming ledges. The base thread is fed into the throat of the sinker, and with the sinker positioned with their loop forming ledges between adjacent needle stems, the alternate raising different sets of needles to feeding positions and the subsequent retraction to a tuck on the latch position and the subsequent clearing of the pile threads from the loop forming ledges assures that in the knock-over action of the needles the pile loops remain under the control of the pile forming ledges.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of U.S. patent application Ser. No. 12/858,339 filed on Aug. 17, 2010 now abandoned, the contents of which is incorporated herein by reference.
FIELD OF THE INVENTION
The invention relates to toilet water reservoirs and, more particularly, to a secondary water shutoff apparatus and method of use for toilet reservoirs.
BACKGROUND OF THE INVENTION
The failure of toilet flappers to properly seal toilet tanks wastes a tremendous amount of water, often going undetected indefinitely. Water conservation is a critical global obligation, especially when the waste of water is due to flapper valve malfunction. The majority of residential toilets and commercial toilets utilize a flapper valve that is mechanically lifted, releasing water from an elevated reservoir to forcingly move the contents of a toilet bowl into a sewer system. Should the flapper valve malfunction, the flapper allows water to continuously move from the reservoir into the toilet bowl and subsequently flow uncontrolled to the sewer system. The use of the flapper valve is well known it is not a matter of whether the flapper valve will fail, it is a matter of when the flapper valve will fail. The flapper valve is submerged in water at all times and will eventually degrade which results in leakage. If the water is off balance, pH is not neutral; failure of the flapper valve can accelerate.
The basic operation of a conventional toilet has not changed in many years. The conventional toilet flush raises a toilet flapper valve during the flush cycle wherein water stored within the reservoir flows past the flapper valve, draining the contents of the bowl. Once the reservoir is lowered, the flapper valve returns to a normally closed position. Emptying of the reservoir further opens an inlet water valve operated by a float; the lowered water level causes the float to lower resulting in the opening of the inlet water valve for purposes of refilling the reservoir. The water valve stays open until the water flowing into the reservoir lifts the float up causing the inlet water valve to close thereby shutting of the water flow. Depending on the size of the reservoir, it may take a few minutes to fully refill the reservoir. When failure occurs, it is unlikely that the individual who last used the toilet is still in the area. It is possible that the flapper value never returned to position due to valve failure, valve misalignment, or blockage such as when a chain that pulls the flapper valve is wedged in the drain opening. Even if one waits, the inside of a toilet reservoir is not typically visible to the owner or operator.
Moreover, as water enter the reservoir, the weight of the water increases to better seal the flapper valve in an effort to prevent leakage. The flapper valve is the only mechanism employed in a conventional toilet to prevent water from exiting the reservoir. When the flapper valve does not return to a sealed position, the water flowing from the open inlet water valve flows through the reservoir and to the sewer system. A homeowner or business owner may not know of the problem for a period of time, particularly for guest bathrooms that are not operated often. An unsealed flapper in mechanical failure results in large amounts of wasted water, as well as an expensive water bill. Moreover, in this type of failure, an owner may only realize that a failed flapper valve exists when an attempt is made to re-flush the toilet.
In another common failure, the inlet valve or pipe bursts. In this case, the flapper valve may be properly sealed and the reservoir my overflow. Conventional toilets have an elongated conduit proximal to the bottom of the reservoir, the elongated conduit extending vertically allowing for the receipt and passage of water at the distal end. The purpose of the conduit is to prevent water damage to the immediate area should the toilet reservoir continue to fill with water. The conduit protects homeowners and business owners from flooding due to the overflow of water from the reservoir. However, the owner or operator of the toilet may not realize that the water flow is exiting directly to the sewer system because the toilet would continue to flush.
U.S. Pat. No. 6,088,846 and related U.S. Pat. No. 5,125,120 disclose a toilet water regulator which can be mechanically inserted in a flush system to provide variably control of the amount of water that enters a flush operation. The operation is controlled by a cam member in operative mechanical communication a turbine member, the inlet water flow is initiated by a front arm setting of the cam to a high point to set an inlet valve to an open position to establish a water inlet regulation through turbine rotation and an adjustable valve in the outlet and simultaneously setting an outlet valve through the movement of a rear arm and both arms fall away thereby preventing the replenishment of water to a leaking tank.
U.S. Pat. No. 7,293,583 discloses an electronically controlled electro-mechanical device designed to limit a finite amount of water per flush to a tank reservoir. The toilet is flushed, the flush lever activates an attached tilt switch, the tilt switch actuates the countdown timer by means of electrical linkage, and the countdown timer in turn activates the solenoid valve by means of electrical connection. The Countdown timer then resets itself to the time set in memory for the next flush operation.
U.S. Pat. No. 4,058,858 discloses a water storage tank used in a flush toilet is disclosed wherein a timer is provided on the tank for manually adjusting the flush time to automatically control the volume of water required for flush purpose. And the contact area between a closure member and an outlet tube of the tank is made linear to reduce wearing there-between and prevent water leakage.
U.S. Pat. No. 7,509,973 discloses a mechanical timed secondary shut-off valve which is automatically disposed into an initialized configuration upon completion of a normal flush cycle and disposed into a closed configuration in the event of a failed flush cycle.
U.S. Pat. No. 7,654,281 discloses a gauge assembly that includes an indicator for providing an indication of an amount of fluid in a tank and a stop-fill assembly for stopping the flow of fluid flowing into the tank once the fluid reaches a particular level. The gauge assembly has a shaft that rotates as the fluid level changes in the tank. The indicator translates the rotational position of the shaft into a fluid level. The stop-fill assembly moves from an open position, where fluid can flow into the tank, to a closed position, where fluid is prohibited from flowing into the tank, depending on the rotational position of the shaft.
U.S. Pat. No. 4,189,795 discloses an improved ball valve for toilet flush tanks for regulating the quantity of water released from a tank in a flush includes a gauged or adjustable water inlet hole at the bottom of the ball valve and an air bleed hole at the top of the ball valve. The water inlet hole at the bottom of the ball valve is adjustable in size for selectively setting the flow rate of water entering the ball valve during a flush action, and thereby determining the time the ball valve remains open to allow flush water to drain from the tank.
U.S. Pat. No. 6,321,395 discloses by depressing a push button (42), a toilet user opens a valve (44) that permits pressure holding a flush valve (12) seated to be exhausted through a pressure-relief line (48). The pressure in the flow path by which liquid thereby leaves the outlet (46) of the remote valve (44) tends to hold that remote valve's valve member (100) open after the user releases the push button (42). But pressure from the pressure-relief line (48) slowly builds up in a seating-pressure chamber (110) by fluid flow through a high-flow-resistance path provided by a passage containing a fluted pin (114). After a resultant delay sufficient to permit the toilet's tank (16) to empty through the outlet (22) controlled by the flush valve (12), the pressure within the seating-pressure chamber (80) reaches a point at which the force exerted by it on the valve member (110) exceeds the flow-path-pressure force tending to keep that valve member unseated. The remote valve (44) therefore closes and as a result causes the flush valve to close.
U.S. Pat. No. 3,733,618 discloses a water saver attachment for toilet tank flush valves is presented. The attachment includes an automatic one-way vent valve mounted in an opening through the wall of the flush valve. The vent valve may be preset to control the rate of flow therethrough. As the buoyant flush valve vents water replaces the vented air to decrease the buoyancy of the valve causing it to close before all water has drained from the tank. The rate of flow through the vent then is proportional to the amount of water retained in the tank when the flush valve closes.
U.S. Pat. No. 5,920,919 discloses a toilet system which minimizes water usage, provides improved flushing, includes a water volume control device and provides flushing when the supply water pressure is below desired levels. The toilet system includes a source of water, a feed valve which is opened by an flush activation device and closes when the water supply flow rate falls below a predetermined flow rate. The toilet system also includes a sealed flush tank with a water volume control for pre-setting the desired water volume, and a flush valve which is activated when the flow rate of supply water falls below a pre-determined minimum level.
U.S. Publication No. 2008/0120770 discloses a water-conserving blowout toilet (10) includes a valve (14), such as a globe valve, connected to a timing mechanism (16) for determining a volume of water flowing to a toilet bowl (32) independent of water flow, a bowl (32) having a lower portion (36) defining a volume of space such that a minimal amount of the water is sufficient to cover and seal a waste outlet (34), and a distribution manifold (22) for distributing the water into the bowl (32) for maximum effect.
U.S. Pat. No. 4,014,050 discloses an apparatus for controlling the quantity of water flowing through a water outlet in the tank of a toilet comprising a timer including a rotatable output shaft, the timer being responsive to the angular rotation of the shaft from an initial position and operative to return the shaft to the initial position after a time duration corresponding to the amount of angular rotation of the shaft, a crank coupled to the shaft and being capable of rotating the shaft through a predetermined angle when a force is applied to it, a mounting assembly for mounting the timer to the tank, and a mechanical linkage coupled between the shaft and a lift rod in the tank for moving the lift rod a dimension such that a valve is unseated when the shaft is not in the initial position, and the valve is seated when the shaft is in the initial position, whereby when a force applied to the crank rotates the angle the linkage is moved a dimension sufficient to unseat the valve from the water outlet causing water to flow through the water outlet, and whereby the return of the shaft to said initial position causes the linkage to seat the valve on the water outlet after a time duration corresponding to the predetermined angle, the time duration serving to control the quantity of water flowing out of the tank.
U.S. Pat. No. 3,787,902 discloses the volume of water supplied to flush a toilet bowl is selected by setting a handle mounted externally on a flush tank, which handle swings a support lever between a nonlimiting position and a position for limiting downward travel of an auxiliary float. A float-actuated lever carries adjacent to its pivot a link for engaging the flush tank discharge valve to limit upward travel of such valve. The valve thereby remains close to its valve seat so that the valve is closed more quickly by pressure of the water on its upper surface and suction created by water flowing through the valve port, thereby substantially reducing the volume of water supplied to the bowl.
U.S. Pat. No. 3,902,201 discloses a control which may be used for the filling of a flush tank of a commode, depending upon the amount of fluid passing through a fluid flow controlling device including a housing containing a turbine wheel. The control includes a valve actuating cam surface which is driven, through a reducer mechanism, by the rotation of the turbine wheel. The rotation of the turbine wheel is caused by the flow of fluid past the turbine wheel. After flowing past the turbine wheel, the fluid flows into a flush tank and commode. The relationship between the turbine wheel and the valve actuating cam surface is such that after a predetermined amount of fluid flows past the turbine wheel, the cam surface is rotated so as to cause the inlet valve to close.
U.S. Pat. No. 3,619,821 discloses a control for the filling of a flush tank for a commode depending on the weight of a proportionate part of the water flowing into the flush tank. The control includes a three-way valve allowing water, when the valve is open, to flow into three separate conduits. One conduit leads to the flush tank, one to the commode, and the third to a relatively small auxiliary weight tank. The valve has its control stem connected to and operated by the relatively small auxiliary weight tank (which is sometimes herein designated as a water weight control box) into which a relatively small proportion of the water flowing through the valve flows. The amount of water flowing through the third conduit is controlled by a needle valve.
U.S. Pat. No. 3,713,558 discloses a liquid metering and dispensing attachment for dispensing given amounts of fluid when the unit price varies. The amount of flow in value as measured in dollars and cents is translated into degrees of rotation by means of an extensible and retractable computing means. The flow of liquid through the device spins a turbine and the amount of liquid dispensed is also translated thereby into degrees of rotation. When the two are equal, a snap action valve is released thereby shutting off the flow of liquid.
U.S. Pat. No. 7,617,949 discloses a turbine wheel and gear system rotate an output shaft in response to flow, where the output shaft is connected to a clutch cup that engages a clutch and valve disk. The disk cooperates with a valve seat formed on a piston to permit/prevent flow within the piston. During flow, the clutch clamps to the disk, and the piston and disk move downstream until an associated control member hits a stop, opening the valve (as the disk stops), while the piston continues downstream. The clutch rotates the disk and control member, and if a maximum flow volume occurs, the control member rotates to an interrupt position and is released from the stop, closing the valve. Passages allow restricted flow to disengage the clutch and permit a spring to move the piston and valve upstream until engaging a reset cam that rotates the control member back to an initial position.
U.S. Pat. No. 5,125,120 discloses a toilet water regulator device which prohibits water flow into the toilet system after a predetermined amount of water has entered the system comprising a valve at the water inlet to the system, said valve having a water outlet to the system, wherein the flow of water through said valve is controlled by turbine means associated with the water outlet of the valve and the amount of water predetermined necessary to fill the tank is controlled by adjustable valve means.
U.S. Pat. No. 5,134,729 discloses a device for metering the flow of water into the tank and bowl of any currently known tank toilet and providing a positive shut-off of the flow. When the toilet handle is turned, a linkage rotates a cam to force a stopper from its seat thereby commencing water flow. Water flows through a flow channel to be directed by a flow nozzle past a water wheel imparting a rotation thereto. The water wheel is gearably linked to the cam thereby rotating the cam. When the cam has rotated to position a cam repeat over the stopper stem, the stopper is reseated by the pressure of the water and water flow ceases. The distribution of flowing water between tank and bowl can be changed by altering the structure of a bowl fill assembly. The bowl fill assembly and a tank fill tube are attached to the outlet by a right angle manifold. The amount of water flow permitted is a function of the number of cam notches and flow nozzle size.
U.S. Pat. No. 7,171,702 discloses a metered water control system inlet tube (24) receiving water conducting water into the interior of the tank to a diverter. A diverter (48) channels the flow to cause mechanical motion responsive to the channeled flow. A control valve (66 and 60), responsive to a mechanical switch, opens and closes access of the water from the inlet tube to the diverter. A mechanical switch (124, 112, and 114), responsive to flow of water from the diverter, closes the control valve automatically when a predeterminable volume of water flows through the diverter. A discharge tube (20 and 24) receives water from the diverter to discharge the water into the tank. An actuator (158 and 162) linked to a flush arm of the toilet and linked to the mechanical switch causes the switch to open the control valve to allow the pre-determined volume of water to flow into the discharge tube.
Accordingly, a need exists to provide a back-up to the conventional flapper valve shutoff and, more particularly, to a system and method that provides a safety control for water before it enters the toilet reservoir.
SUMMARY OF THE INVENTION
The present invention provides a system and method for a secondary toilet reservoir water shutoff for water conservation. According to one aspect of the present invention, a mechanical water timer is provided for toilet reservoir water shutoff providing a timing device to automatically shut off the flow of water based on an ‘x’ amount of time, where ‘x’ is determined by the amount rotation of the timing mechanism. Once the water shuts off, an operator may again open the valve.
It is an objective of the instant invention to provide a water timer that preferably shall be rotated counter clockwise relative to the timer body.
It is yet another objective of the instant invention to provide a disc with a notch, the disc formed or secured about a rotating timing device, the notch allowing an elongated pin to movingly enter the notch cavity, the elongated pin secured at a proximal end to a plunger valve, a spring exerting downward force against the plunger towards the notch cavity causing a sealing engagement of the plunger valve against a conduit when the notch is aligned with the elongated pin.
It is a still further objective of the instant invention to provide a conduit for the flow of water when a timing valve is open.
It is a still further objective of the instant invention to provide a completed kit for releasing water into a toilet reservoir.
Other objectives and advantages of this invention will become apparent from the following description taken in conjunction with any accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention. Any drawings contained herein constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a side perspective view of the toilet water shutoff kit;
FIG. 2 is a side view of the timing mechanism;
FIG. 3 is a side view opposite of FIG. 2 of the timing mechanism;
FIG. 4 is a cross-sectional side view of the timing mechanism;
FIG. 5 is a cross-sectional view of the timing mechanism of FIG. 4 taken along the line 5 - 5 .
DETAILED DESCRIPTION OF THE INVENTION
Referring now to FIG. 1 , an embodiment of a toilet water system and method of use comprising a flush handle 56 situated outside of the toilet reservoir, the flush handle allows for an operator to engage the handle 56 causing the release of water into a toilet reservoir. The flush handle is connected to first arm 60 , capable of moving when an operator engages the flush handle 56 . A toilet flapper 38 capable of hingedly opening and closing, closing of the toilet flapper may cause a sealing fit, preferably the toilet flapper will not allow the passage of water until intentionally activated. A mechanical connection 40 exists between the toilet flapper 38 and the first arm 60 . The connection may formed from a chain, flexible line, or similar connection capable of placing vertical force on the toilet flapper 38 when an operator engages the flush handle 56 . Once a toilet reservoir has emptied, the toilet flapper 38 may hingedly return to the closed position. Emptying of the reservoir allows a toilet reservoir float 36 to hingedly fall, resulting in the opening of a valve 52 . The opening of the valve 52 allows water to refill the reservoir. The valve 52 stays open until the water flowing into the reservoir lifts the float 36 causing the water valve 52 to close and shutting of the water flow, taking upward from a few seconds to a few minutes to fully fill the tank. Moreover, as water enters the reservoir, the weight of the water increases, the flapper 38 is typically sealed tighter against the reservoir preventing leakage, though sealing does not always occur.
An elongated conduit 68 proximal 66 to the bottom 70 of the reservoir, the elongated conduit 68 extending vertically allowing for the receipt and passage of water at the distal end 70 . The purpose of the conduit is to allow for the disposal of water when the toilet reservoir continues to fill with water. The conduit protects homeowners and business owners of flooding resulting from the overflow of water from the reservoir. The owner or operator of the toilet would not be alarmed to the water flow overflow exiting the conduit to the sewer system because the toilet would continue to flush.
A second elongated conduit 67 having a proximal end 58 securable to the bottom 70 of the reservoir for receiving water passage therethrough, the second elongated conduit 67 extending vertically allowing the dispensing of water at a distal end 54 . The second elongated conduit 67 is preferably made from PVC plastic. In one preferred embodiment, the proximal end 58 is constructed with a threaded end about the outside wall. In another preferred embodiment, the proximal end 58 is constructed with a threaded end about the inside of the wall. In a preferred embodiment, the distal end 54 constructed having a threaded end about the outside wall. In another preferred embodiment, the distal end 54 having a threaded end about the inside wall. At a point about the second elongated conduit 67 exists a secondary toilet reservoir shutoff 10 .
The shutoff 10 is based on a timer design. The secondary toilet reservoir shutoff prevents the flow of water when time ‘x’ equals zero. The shutoff 10 is formed having a timing arm 44 . A mechanical connection 42 exists between the timing arm and the first arm 60 .
Operator activation and engagement of the flush handle 56 increases the time ‘x’ that water may flowingly pass through the secondary toilet reservoir shutoff 10 . In one embodiment, increasing ‘x’ means the turning of the rotating timing device 28 . Preferably, the timing mechanism shall be turned counter-clock wise. The timer is composed of a disc 32 with a notch 34 and a gear assemblage 24 , the disc 32 formed or secured about a rotating timing device, the notch 34 allowing an elongated pin 22 to movingly enter the notch cavity 34 at the distal end 30 of the elongated pin 22 , seen in FIG. 5 , the elongated pin secured at a proximal end 70 to a plunger valve 20 , a spring 72 exerting downward force against the plunger towards the notch cavity causing a sealing engagement of the plunger valve against a conduit when the notch is aligned with the elongated pin.
Activation of the flush handle 56 causes, for ‘x’ amount of time, an intentional misalignment of the notch with the elongated pin 22 . The misalignment forces the elongated pin to move away from the notch. The result of the elongated pin movement in relation to the notch causes the opening of the plunger valve 20 for time ‘x’, where ‘x’ is determined by the rotational displacement of the rotating timing device 28 . Subsequent to the opening of the plunger valve, water shall flow through the secondary toilet water reservoir shutoff 10 .
When ‘x’ equals zero, the timing mechanism closes, thereby closing the plunger 20 . Activating the flush handle 56 increases time ‘x’ and allows the passage of water to the toilet reservoir.
In one preferred embodiment, the rotating timing device 28 has a gear and spring system. After rotation of the rotating timing device 28 , the gear and spring system moves the rotating timing device 28 to the starting position where ‘x’ shall equal zero.
All patents and publications mentioned in this specification are indicative of the levels of those skilled in the art to which the invention pertains. All patents and publications are herein incorporated by reference to the same extent as if each individual publication was specifically and individually indicated to be incorporated by reference.
It is to be understood that while a certain form of the invention is illustrated, it is not to be limited to the specific form or arrangement herein described and shown. It will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not to be considered limited to what is shown and described in the specification and any drawings/figures included herein.
One skilled in the art will readily appreciate that the present invention is well adapted to carry out the objectives and obtain the ends and advantages mentioned, as well as those inherent therein. The embodiments, methods, procedures and techniques described herein are presently representative of the preferred embodiments, are intended to be exemplary and are not intended as limitations on the scope. Changes therein and other uses will occur to those skilled in the art which are encompassed within the spirit of the invention and are defined by the scope of the appended claims. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention which are obvious to those skilled in the art are intended to be within the scope of the following claims.
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A secondary toilet reservoir water shutoff system and method for use in the water tank of a toilet assembly. The secondary toilet reservoir water shutoff having a beneficial use with toilets to prevent the wasting of water in a failing system. The secondary toilet reservoir water shutoff being activated by a toilet flush handle causing rotation of a timing device thereby opening of a secondary valve for a period of time allowing for the passage of water, the time determined by the degree of rotation of the timing device.
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CROSS REFERENCE TO RELATED APPLICATIONS
Provisional application for patent No. 60/405,674 of Aug. 24, 2002 with the same title: “Equalizing Flow From Pressure Compensated Pumps, With or Without Load Sensing, in a Multiple Pump Circuit” which is hereby incorporated by reference. Applicant claims priority pursuant to 35 U.S.C. Par. 119 (e) (I).
Statement as to rights to the invention made under federally sponsored research and development: not applicable.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to improving the performance of two or more pressure compensated pumps, with or without load sensing, that supply fluid to a single driven circuit. The invention uses a rotary type flow divider operating in reverse to make fluid flow through the pumps at the same rate of flow even when the pumps are limited to different output pressures.
2. Background Information
It is often necessary to use more than one pressure compensated pump, with or without load sensing, to supply a hydraulic circuit's highest flow demand. A prior art hydraulic system might use separate pumps, with separate drive motors for each pump, to feed into a common manifold that supplies pressurized hydraulic fluid to a circuit. In such a prior art arrangement there is an attempt to set each pump so that they will operate at the same sensed pressure level such that when there is a need for pressurized flow that both pumps will supply at least part of the flow. The main problem with such a prior art arrangement is that no matter how closely the pumps are set, one pump will almost always start first and the other pump or pumps sensing the increased pressure will not operate. Even when it is possible to set the pumps to supply flow simultaneously, contamination, wear, spring deterioration and other variations will soon change such that one pump will start off supplying flow and the other pump or pumps will not start until the system requirements exceed the capacity of the first pump. The concept can be implemented with two or more pumps.
The prior art multiple pump system allows one pump to lead and the other pumps to start flowing when pressure drops due to a flow demand higher than the first pump can supply. One pump starts and the others start as needed. Some pump manufacturers recommend their pumps be set with triggering pressures 100–150 PSI apart so that they will not try to start flowing at the same time. The problem with starting the prior art system pumps at nearly the same pressure is that the first pump can be forced to no flow when the second pump flow reaches the manifold. In this situation the pumps can oscillate on and off so fast that they suffer mechanical damage.
Thus it can be seen that there is a need for a multi-pump system that will allow for multiple pumps to supply hydraulic fluid to a single hydraulic circuit.
SUMMARY OF THE INVENTION
A rotary flow divider is normally used to divide the flow from a single pump to two or more separate circuits. Operating in reverse of normal installation, the rotary flow divider can become a rotary flow combiner, combining two or more flows instead of dividing them. Normally hydraulic fluid from a pump is fed into a single inlet of a rotary flow divider, is ported to two or more identically sized hydraulic motors in the rotary flow divider and flows out two or more outlets to supply hydraulic fluid in equal volume to two or more circuits. The hydraulic motors of the rotary flow divider have a common shaft so they must turn at the same rate and since they are equal in size they pass the same flow. Equal flow leaving each hydraulic motor outlet of the rotary flow divider is sent to devices needing the same flow even though the devices may operate at different pressures.
In this invention the rotary flow divider's normal outlets become inlets for the rotary flow combiner receiving flow from multiple pump sources and combines them into a common flow output. Since the hydraulic motors of the rotary flow combiner perform like pumps when driven it does not matter if the pressure compensating pumps with or without load sensing have exactly the same pressure setting. When the circuit needs flow the pressure drop at the rotary flow combiner outlet also gives a pressure drop at both inlets causing the pump compensators to shift both pumps on flow and to maintain them on flow. With both pumps flowing pressure at the outlet of the flow combiner equalizes.
In another aspect of the invention, when the system requires more fluid than the pumps are capable of producing, pressure drops below compensator setting of both pumps and they will go to full flow. If one pump has less flow than required to meet the demand it will see a vacuum at its outlet since the rotary flow combiner acts as a pump, at this point hydraulic fluid will be drawn directly from a reservoir to make up the required flow difference. This differential flow is powered by the pump with the larger flow through the rotary flow combiner.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates the preferred embodiment of the present invention prior to actuation of any actuator in the driven circuit;
FIG. 2 illustrates the operation of the preferred embodiment of the present invention when the embodiment is functioning with identical pumps at low pressure;
FIG. 3 illustrates the operation of the preferred embodiment of the present invention when the embodiment is operating with pumps of different flows at less than maximum pressure;
FIG. 4 illustrates the operation of the preferred embodiment of the present invention when the embodiment is operating with pumps of different flows near maximum pressure;
FIG. 5 illustrates the operation of the preferred embodiment of the present invention when the embodiment is operating with pumps at different pressures while an actuator is moving at a pressure higher than the low pressure pump can reach;
FIG. 6 illustrates the operation of a second embodiment of the present invention including three input pumps.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates the preferred embodiment of the present invention. As shown in FIG. 1 a hydraulic system 100 comprises two pressure compensated pumps 1 A and 1 B powered by drives 3 which can be electrical or can be internal combustion engines or a combination of one electrical motor and one engine. The system 100 supplies fluid power to any number of actuators such as fluid driven rotating actuators 12 , 13 or a fluid driven linear actuator 14 in driven circuit 200 . Three position solenoid controlled valves 8 can be used to control the operation of the rotating actuators 12 , 13 and linear actuator 14 while the meter out flow controls 9 can set the flow requirements for each actuator 12 , 13 , 14 . Filter 10 filters the flow of hydraulic fluid back to reservoir 6 . Anti-cavitation check valves 5 A and 5 B, have 1 PSI springs in them so they can open and keep the rotary flow combiner 7 from starving for hydraulic fluid from a either pump 1 A, 1 B. Flow meters 2 can show the flow of each pump 1 A, 1 B and pressure gauges 24 and 25 can show pressure from the pumps 1 A and 1 B in supply lines 20 and 23 . Pressure gauge 27 shows the pressure in line 26 , which is the outlet of the rotary flow combiner 7 and the supply for the driven circuit 200 .
FIG. 2 illustrates the hydraulic system 100 with the hydraulic motor 12 using, for example, 22 gallons per minute (GPM) flow as set by the meter out flow controls 9 . The rotary flow combiner 7 accepts fluid from the first pump 1 B that starts flowing and immediately the operation of the rotary flow combiner 7 will lower the pressure in line 23 enough to trip the pump 1 A making it flow as well. Check valve 5 A connected parallel to pump 1 A, keeps the left rotary motor 7 C of the rotary flow combiner from cavitating by allowing hydraulic fluid to flow to it from the reservoir 6 until pump 1 A produces flow. Pressure on gauges 24 , 25 and 26 will read at or near the same pressure (750 PSI) while the rotary motors 7 C and 7 D are running. Flow meters 2 A and 2 B will show identical flow when both pumps 1 A and 1 B are operating. Both pumps 1 A and 1 B will give equal flow until reaching set flow of meter out flow control 9 , thus the system makes continual effective use of both pumps 1 A and 1 B.
Rotary flow dividers have a characteristic referred to as ‘intensification’ when used in the conventional manner. If there is resistance to flow out of one outlet of a rotary flow divider, then pressure in that outlet will intensify as the rotary flow divider will attempt to maintain the same volume of flow to each outlet. In this invention, with the rotary flow divider reversed to be a rotary flow combiner 7 , fluid entering the inlets 7 A and 7 B is deintensified so if one pump 1 A is at 1000 PSI and the other pump 1 B is at 0 PSI, then the outlet line 26 will be at 500 PSI. (1000+0/2=500).
FIG. 3 . Illustrates the hydraulic system 100 of the hydraulic motor actuator 12 using hydraulic fluid at a rate again of 22 GPM as set by meter out flow controls 9 . In this arrangement of the driven circuit 200 the left pump 1 A is set to pump no more than 8 GPM so anti-cavitation check valve 5 A is forced open by atmospheric pressure which pushes an extra 3 GPM into line 23 . The same result would occur if left pump were replaced with a pump only capable of producing 8 GPM flow. Because of the vacuum, gauge 25 will actually read a pressure slightly below zero such as −2 PSI. Pump 1 B is at 11 GPM and 1200 PSI. Note that pump 1 B is actually capable of pumping 15 GPM at 1500 PSI and that pump 1 B provides the extra power that allows the rotary flow combiner 7 to pull additional hydraulic fluid through the check valve 5 A. Since only one pump 1 B is at pressure, hydraulic fluid going to the hydraulic motor actuator 12 is only at half pressure 600 PSI; (1200 psi+0 psi)/2=600 PSI. Flow meter 2 A is showing 8 GPM while flow meter 2 B is showing 11 GPM with the flow through the check valve 5 A making up the rest of the 22 GPM flow.
FIG. 4 illustrates the hydraulic system 100 with said driven circuit 200 with the hydraulic motor actuator 12 still requiring hydraulic fluid at the same 22 GPM rate as set by meter out flow control 9 . In this case the left pump 1 A is only capable of pumping 8 GPM and the pressure required to operate the hydraulic motor actuator 12 is higher than half the set pressure of pump 1 B. The pump 1 B will go to full pressure and the flow from pump 1 B will be reduced (a characteristic of pressure compensated pumps). When pump 1 B flow has dropped to 8 GPM, flow from pump 1 A will push into the left inlet 7 A of the rotary flow combiner 7 at 500 PSI and the rotary flow combiner will push 16 GPM at 1000 PSI into the driven circuit 200 . This flow is not enough to meet the full requirements of the driven circuit 200 but will keep the driven circuit 200 working. In all cases, flow into the inlets 7 A and 7 B of the rotary flow combiner 7 will be equal when any flow is present.
FIG. 5 illustrates the driven circuit 200 with the hydraulic motor actuator 12 still requiring hydraulic fluid at a rate of 22 GPM as set by meter out flow control 9 . In this case the hydraulic motor actuator can use 22 GPM at a pressure above what the lowest pressure pump 1 A or 1 B can supply. The pump 1 A can produce 15 GPM at 1300 PSI and the pump 1 B can produce 15 GPM at 1500 PSI. The rotary flow combiner 7 in this case will produce output flow of hydraulic fluid to the driven circuit 200 at 22 GPM and 1400 PSI maximum and 15 GPM up to 1500 PSI. Again although pump 1 A is not fully capable of meeting the load requirement both pumps will operate at capacity. Without a rotary flow combiner 7 this combination of pumps, with flows into a manifold, could only produce 15 GPM at pressures above 1300 PSI because the lower pressure pump 1 A would compensate to no flow above this pressure.
FIG. 6 illustrates the driven circuit 200 with the hydraulic motor actuator 12 still requiring hydraulic fluid at a rate of 22 GPM as set by meter outflow controls 9 . This hydraulic system 300 for example uses the same driven circuit 200 but uses three pressure compensated pumps without load sensing 1 A, 1 B and 1 C that feed into the inlets 70 A, 70 B, 70 C of a three motor rotary flow combiner 70 . The operation of the three motor rotary flow combiner 70 is similar to that of the two motor rotary flow combiner 7 in that each rotary motor 70 D, 70 E and 70 F must turn at the same speed and allow for the same flow rates from each inlet 70 A, 70 B and 70 C regardless of flow or pressure settings. The rotary motors 70 D, 70 E and 70 F can be gear motors for example sharing a common shaft (not shown) that keeps them rotating at a proportional rotary speed such as the same speed. Fluid from the third pump 1 C is supplied through line 29 to inlet 70 C and gauge 28 can monitor pressure in line 29 .
Using a rotary flow combiner with motors having different ratio flows (not shown) would allow different flow rated pumps to use all their flow output at a pressure without restricting the higher flow ones.
A specific example of a useful application is when separate internal combustion engines are driving pumps of the same or different volumes at the same or different pressures. Each internal combustion engine would give its required portion of flow and operate at a comparable horsepower rating for any flow requirement. Without the equal flow provided by the rotary flow combiner, one engine would do all the work most of the time, while the other burns fuel and does no useful work. Neither engine would be operating efficiently. Adding the rotary flow combiner 7 as shown above causes both engines to do a significant portion of the work at all times resulting in even wear on the engines and in more efficient operation.
A benefit of this invention is that the pumps in a multi-pump system can be set as closely as possible to the same pressure without causing the pumps to override each other. An additional benefit of this invention is that a conventional multiple pressure compensated pump with or without load sensing circuit can have a noticeable pressure drop as the lead pump reaches its maximum flow and the next pump starts flowing. This pressure drop will be at least as much as the pumps pressures are set differently and even more for a short period of time as the lagging pump or pumps respond and start flowing.
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A rotary flow combiner allows flow from multiple pressure compensated hydraulic pumps; with or without load sensing to be combined into a single outlet. The flows are combined in such a way that each input to the rotary flow combiner has equal flow. The flow from each pump is optimized in such a way that the output from the rotary flow combiner can achieve the maximum range of flow and pressure and so that all the pumps in the multiple pump system are supplying fluid flow at all times. A check valve can allow the rotary flow combiner to pull hydraulic fluid direct from a reservoir in parallel to a lower flow pump such that the volume of flow from the lower pump combined with the fluid drawn directly from the reservoir will match the flow from the higher flow pump.
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CROSS-REFERENCE TO RELATED PATENT APPLICATIONS
The applicant filed a patent application on Mar. 30, 2001 in the United States Patent and Trademark Office, which was assigned Ser. No. 09/823,020. That patent application was abandoned.
STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT
This invention was developed entirely with private funds and there was no federal assistance.
REFERENCE TO A “MICROFICHE APPENDIX”
This section is not applicable to this patent application.
BACKGROUND OF THE INVENTION
1. Field of the Invention
Brooms, brushes, mops and the like pick up particulate matter such as dust, dirt, lint and hair from a floor. After a while, the brooms, brushes, mops and the like do not effectively pick up the particulate matter. It is necessary to remove the particulate matter from the brooms, brushes, mops and the like. It is desirable to have an apparatus and method for cleaning the brooms, brushes, mops, and the like of the particulate matter. This invention is directed to the removal of the particulate matter from the brooms, brushes, mops, and the like at the place of activity. The apparatus is portable and can be moved from location to location so as to be available for removing particulate matter from brooms, brushes, mops, and the like.
2. Description of the Related Art, Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.99
Kramer, U.S. Pat. No. 2,197,869, teaches of a mop cleaning device or deduster for cleaning or removing the dust and dirt from dry mops, dusters, and the like.
Ulrich, U.S. Pat. No. 3,015,121, relates to a vacuum type of cleaner for brooms, brushes, mops, and the like.
Clarke, U.S. Pat. No. 1,253,939, discloses an invention relating to pneumatics and more especially to fluid tanks for removing dust from the air collected on the nozzle of a vacuum cleaner. Clarke is more directly related to a vacuum cleaner than to a device for cleaning a mop or a broom or a duster.
Hildreth, U.S. Pat. No. 1,381,553, is directed to a cleaning machine to provide a simple, inexpensive, and efficient machine for cleaning garments, cloths, pieces of fabric, and the like. Hildreth uses two rotary brushes. One of the brushes is employed to remove dust from the article and the other is to remove sports or stains from the article.
Leaycraft, U.S. Pat. No. 279,572, is directed to a vacuum apparatus that can be used for cleaning rugs, floors, upholstery, and the like. Leaycraft teaches of a pneumatic system that operates by suction, whereby the dirt and dust can be conveniently removed from any place desired, such as floors of stores and buildings, without causing the dust to rise, as is the case where brooms are used, or with the sweepers now ordinarily in use.
Cudy, U.S. Pat. No. 2,625,704, provides a mop cleaner for dry mops and dusters that is clean and sanitary in operation. This mop cleaner effectively shakes a mop clean, and employs a removable container for receiving dirt, dust and lint shaken from the mop and which also includes means for settling dirt, dust and lint into the removable container.
Jones, U.S. Pat. No. 2,642,600, is directed to providing a readily portable housing with means therein for loosening dirt from a standard floor dust mop in an efficient manner and discharging the dirt from the housing through a suitable outlet.
Hayter, U.S. Pat. No. 2,849,746, provides a cleaning machine having means that will clean a mop, or similar article, with only the necessary amount of fabric agitation or beating and which will also cause an air blast to pass through the fabric concurrently to insure a thorough cleaning job.
Mills, U.S. Pat. No. 3,411,175, provides an improved industrial dust-mop apparatus that comprises an enclosure or console. The enclosure is provided with an adjustable dust mop receiving channel that has a pair of counter-rotating brushes moving downwardly at the bite zone formed between.
Walter, U.S. Pat. No. 1,014,027, is directed to a pneumatic carpet-sweeper and not to an apparatus for cleaning dust cloths and dust mops.
Riley, U.S. Pat. No. 1,914,295, teaches of a dust mop cleaning machine having means for loosening the dust and dirt from the articles being cleaned. Riley describes a novel means for picking up the dust and dirt and carrying it to a place of deposit.
BRIEF SUMMARY OF THE INVENTION
The invention is directed to a portable cleaning apparatus for cleaning a dry mop, cleaning cloth and/or a duster that carries particulate matter, such as dust, dirt, lint and/or hair, to name a few. The dry mop and the cleaning cloth and/or the duster can be cleaned of the particulate matter and used again. In order to remove the particulate matter from the dry mop or the cleaning cloth or the duster, the invention includes a number of resilient, radial fingers that amount to a brush. These radial fingers are rotated and contact the dry mop or the cleaning cloth or the duster to knock loose the particulate matter. The particulate matter is carried by air to the interior of a housing. In the interior of the housing small drops of water are sprayed onto the particulate matter. Then the air and the wet particulate matter are passed through at least one filter so as to remove the wet particulate matter and to allow the moisture and air to escape from the housing. The filter with the wet particulate matter can be discarded or can be cleaned and used again.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
In the drawings, it is seen that:
FIG. 1 is a block diagram of the method for separating particulate matter from a dust mop or cleaning cloth or duster;
FIG. 2 is a first side elevational view of the apparatus for removing the particulate matter from the dry mop of the cleaning cloth or duster;
FIG. 3 is a first end elevational view of said apparatus;
FIG. 4 is a second, opposite end elevational view of said apparatus;
FIG. 5 is a top plan view of said apparatus;
FIG. 6 is a first side elevational view of said apparatus illustrating some of the components of said apparatus;
FIG. 7 is a top plan view of the spray nozzle arrangement of said apparatus;
FIG. 8 is a perspective view of the apparatus awaiting the introduction of a mop (depicted in phantom outline).
Similar numerals designate similar component parts of the invention throughout the several views.
DETAILED DESCRIPTION OF THE INVENTION
In FIG. 1 there is illustrated, in a block diagram, the method steps involved for cleaning particulate matter from a dry mop or a cleaning cloth. Reference numeral 20 refers to an agitator and separator for removing particulate matter such as dust, dirt, line and hair from a dry mop, cleaning cloth or a duster. With the particulate matter removed, the particulate matter is moved by the flow of air under the decreased air pressure 22 . The particulate matter in the flow of air is introduced to a liquid mist or fine spray of liquid. Liquid mist or fine spray settles on the particles in step 24 . Then the combination of the liquid mist and particulate matter flows to a collector for the combination of these particles and liquid at step 26 . The combination of the mist and the particulate matter of step 26 flow to an exit separator such as a filter for removing the combination of the particulate matter and the mist and also for removing the particulate matter at step 28 . Again, a filter may be used for removing the particulate matter at step 28 so as to produce clean air at the exit of the apparatus.
In summary, the invention includes an agitator and separator for separating the particulate matter from the dry mop or cleaning cloth. Due to the decreased air pressure, the particulate matter flows from the agitator and separator and into the apparatus. A liquid mist is applied at 24 to the particulate matter. The combination of the particulate matter and the liquid mist goes to a collector. Then the combination of the air and particulate matter and mist pass through a filter so as to remove the particulate matter such as dust, dirt, hair and lint. The air and the mist can flow through the filter and out into the atmosphere.
A frame 30 comprises two laterally spaced-apart, lower longitudinal beams 32 and two longitudinally spaced-apart, lower lateral beams 34 that connect opposite first and second ends of the two lower longitudinal beams. This provides support for the components of the apparatus. Attached to each of the four junctions of the lower longitudinal beams 32 with the lower lateral beams 34 is an upright support 36 —so that there are four upright supports 36 in all. Two laterally spaced-apart upright members 70 are disposed intermediate the upright supports 36 and have lower ends attached to the lower longitudinal beams 32 . A support shelf 72 connects with the two upright members 70 and also with the upright members 36 .
In FIG. 2 , it is seen that, on each of the opposite sides of the apparatus, there are laterally spaced-apart upper beams 38 , 42 that connect upper ends of the upright supports 36 to upper ends of the upright members 70 . Near the first end of the apparatus, a first lateral upper beam 44 has opposite ends attached to upper ends of the adjacent upright supports 36 . At the second end of the apparatus, a second lateral upper beam 46 has opposite ends attached to upper ends of the adjacent upright supports 36 . This provides rigidity and strength to the frame 30 . At the four corners of the frame 30 , and underneath the frame, are four spaced-apart, caster wheels 52 to facilitate wheeled motion of the apparatus from location to location. As may be seen in FIG. 5 , longitudinally spaced-apart, lateral supports 54 , 56 have opposite ends attached to the upper beams 42 . On the lateral support 54 there is a bearing 58 , and on the lateral support 56 there is another bearing 58 . The two bearings 58 are aligned for receiving a drum shaft 60 . Mounted on the shaft 60 is a drum 62 . On the exterior of the drum 62 there are a plurality of flexible, resilient bristles 64 . An electric motor 74 is mounted on the support shelf 72 . The electric motor has an output shaft 76 upon which is mounted a pulley 78 . A belt 80 runs around the pulley 78 and also around a pulley 66 mounted to the shaft 60 for rotating the drum 62 . A drum housing 92 substantially surrounds the drum 62 to confine the particulate matter to the interior of the apparatus, but has an access opening at the top to permit a dry mop, cleaning cloth and the like to contact the fibers 64 . The electric motor 74 by means of the pulley 66 and the drive belt 80 , causes the drum 62 with its flexible, resilient fibers 64 to rotate and to dislodge the particulate matter from any dry mop, cleaning cloth, and the like that is placed adjacent to the rotating fibers 64 . In the bottom of the drum housing 92 is an outlet passageway 94 to allow the particulate matter to move down through a top opening of a shroud 108 that is disposed below the passageway 94 . Within the shroud 108 and below the outlet passageway 94 is an electric fan 100 that has fan blades 102 mounted to an upstanding fan blade shaft 104 for rotation about a vertical axis. The shroud 108 also has an open passageway 112 that faces toward the first end of the apparatus and through which it discharges air and particulates into a substantially closed chamber 118 to which it is attached and by which it is supported; see FIG. 6 . The chamber 118 has a floor 116 supported on beams 32 and 34 . Exiting gas from the apparatus containing particulate matter passes through a filter 120 that is mounted within the chamber 118 , thereby removing the particulate matter from the gas. The exit gas is mainly air and some fine water mist. In FIG. 8 , it is seen that there is a first side panel 122 ; an upper portion of this panel has an air vent 124 that communicates with a fan compartment 106 that houses the fan motor below the shroud 108 to cool the fan motor. On the opposite side of the apparatus there is a second side panel 126 and a first end panel 130 covers the first end of the apparatus; see FIG. 2 . In the first end panel 130 there is an exit opening 132 to allow air to escape from the apparatus. From the foregoing it is seen that a chamber 118 is defined by side panel 126 , floor 116 , end panel 128 , side panel 122 , exit end panel 130 , first end panel 132 , and support shelf 72 .
A removable water tank 140 with a filler cap 144 rests in a cradle disposed at the first end of the apparatus and has a liquid outlet. Referring to FIGS. 2 and 7 , a water line 146 conducts water from the liquid outlet of the tank 140 to a water pump 142 that is mounted to the top of the chamber 118 near the first end of the apparatus. A water pipe 148 has a first end connected to the outlet of the water pump 142 and an opposite, second end connected to a tee-pipe 150 . A water pipe 152 is connected to a first outlet of the tee 150 and also with a first spray nozzle 154 . Further, a second outlet of the tee 150 is connected to a water pipe 156 that in turn connects to a tee 159 . A water line 160 is connected to a first outlet of the tee 158 and also with a second spray nozzle 162 . Further, the tee 158 is connected to a water pipe 164 that in turn is connected to a third spray nozzle 166 .
The three spray nozzles 154 , 162 , and 166 are in the chamber 118 . These spray nozzles are so positioned that they can spray a fine mist of water 180 or other liquid on the particulate matter 178 being moved by the air from the fan 100 and the fan blades 102 . The fine mist of water 180 adheres to the particulate matter 178 so as to form a combination 182 of particulate matter and water of a size larger than the particulate matter 178 by itself. This makes it possible to more completely remove the particulate matter from the flow of air. The particulate matter 178 becomes heavy and settles to the bottom of a removable tray 190 that is housed within a lower portion of the chamber 118 . An electrical plug inlet 200 is mounted to the first side panel 122 and is wired to the electric motor 74 , water pump 142 and electric fan motor 106 .
FIG. 8 is a schematic illustration of a dry mop 172 being introduced to the apparatus and to the flexible, resilient fibers 64 of the drum 62 . The symbolic mop 172 denotes a dry mop, a cloth or a duster. The mop 172 or the like can be introduced to the top access opening of the housing 92 of the apparatus and the flexible, resilient fibers 64 on the drum 62 will agitate the mop or cloth or duster so as to separate particulate matter from the cloth or mop or duster. Outside of the drum 62 and also outside of the apparatus 20 the air is at ambient atmospheric pressure P- 1 . The electric motor 106 rotates the fan blade shaft 104 and the fan blades 102 . The air pressure P- 2 at the fan blades 102 is less than the ambient atmospheric pressure P- 1 —that is, there is a differential air pressure between P- 1 and P- 2 . As a result, the atmospheric pressure P- 1 forces the particulate matter 178 toward the fan blades 102 . Then the fan blades force the air and particulate matter through the open passageway 112 and into the chamber 118 . The air pressure of P- 3 in the chamber 118 is greater than the air pressure P- 2 of the fan blades. However, the fan blades 102 force the air into the chamber 118 so as to increase the air pressure to that of P- 3 . There is a filter means 120 . The pressure P- 4 outside of the apparatus 20 is atmospheric pressure or substantially atmospheric pressure. The pressure P- 1 and P- 4 are substantially the same as they are substantially atmospheric pressure. Since the gaseous pressure P- 3 is greater than the gaseous pressure P- 4 the flow of particulate matter 178 and of the combination 182 with gas is to the filter 120 ; that is there is a differential air pressure between P- 3 and P- 4 . Most of the particulate matter 178 is removed by the spray nozzles 154 , 162 , and 166 to form the combination 182 . To ensure greater removal of the particulate matter there is a mist or spray from the spray nozzle 154 , 162 , and 166 . The fine spray of water 180 lands on the particulate matter 178 making the combination 182 heavier and making it possible to more completely remove particulate matter. An exit filter 202 , which may be a solid filter, removes the smallest particulate matter 182 .
In use, the apparatus is switched on and the mop 172 with particulate matter 178 attached is introduced to the rotating drum 62 through the access opening at the top of the housing 92 . The flexible, resilient fibers 64 on the rotating drum 62 agitate the mop 172 and the particulate matter 178 so as to dislodge the particulate matter from the mop 172 . The descending air from the drum 62 carries the particulate matter 178 through the shroud 108 to the chamber 118 . In the chamber 118 a fine mist of water 180 is introduced and combines with some of the particulate matter 178 to form a combination 182 of the particulate matter 178 and the water 180 . To repeat, the pressure P- 3 is greater than the pressure P- 4 , which is ambient atmospheric pressure. The combination of the particulate matter 178 and water mist 180 is directed to the filter 120 . The particulate matter 178 does not pass through the filter 120 . The combination 182 of the mist and particulate matter 178 is filtered out the air stream by the filter 120 . The air and water mist 180 pass through the filter 120 . When the filter 120 is saturated or near saturated with particulate matter 178 the filter 120 can be removed and cleaned or discarded. In this manner the particulate matter 178 can be collected in one area or one place so as not to be distributed over a wide area. In particular, at the bottom of the chamber 118 there is a water tray that collects particulate matter 178 , water mist 180 and the combination 182 of the particulate matter and the water mist. The material collected by the tray or container 190 can be discarded. The exit filter 202 may also be discarded and replaced after being used.
From the foregoing description it will be clear that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. Thus, the presently disclosed embodiment is to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims, and not limited to the foregoing description. In the appended claims, the term “mop” will be understood generically to refer to any broom, mop, cloth, brush, duster or other article used for cleaning purposes, regardless of where or how they are used; and, the term “liquid” will be understood to refer to water as well as to any cleaning fluid or other liquid known to persons of ordinary skill in the cleaning arts as efficacious for the removal of particulate matter from a mop, cloth, brush, duster or other article used for cleaning purposes, provided that said liquid is capable of being spray misted onto particulate matter to form a combination 182 of particulate matter and liquid mist.
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A mobile machine for removing dry particulate matter from a mop, cloth or duster by agitation. A drum with flexible, resilient fingers rotates and agitates the mop, cloth or duster to loosen the particulate matter. An electric fan sucks ambient air and the particulate matter to a chamber wherein it is wetted by a liquid mist introduced by spray nozzles. The mist combines with the particulate matter to form larger particulates. The particulate matter and larger particulates are passed through a filter to remove the particulate matter and larger particulates, which drop onto a removable tray.
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FIELD OF THE INVENTION
The field of this invention is tools used in a subterranean formation that have a movable component that is subjected to shock loading and the use of a field to cushion impact loads and more particularly using a magnetic field to control shock loading on a flapper of a subsurface safety valve.
BACKGROUND OF THE INVENTION
Magnets have been used to act as dampeners such as in the context of exercise equipment as illustrated in U.S. Pat. No. 5,752,879. Magnets have been used in fluid flow systems to hold a position of a moving component such as for example in an open or a closed position. Illustrative of a gas line and a medical device application are U.S. Pat. No. 5,209,454 and U.S. Pat. No. 5,970,801. In a similar vein is U.S. Pat. No. 7,527,069. The use of magnets to control the fixation of a movable member in a level control application is seen in U.S. Pat. No. 4,436,109. These disparate applications seek to use the force of a magnetic field for fixation to a given position. Some of them release the component when the magnetic field is deactivated.
In downhole applications and most particularly in valves where large pressure differentials can build in an instant as a valve member such as a flapper moves against a seat, there can be serious damage from the impact force that can be severe enough to deform the valve member or the mating seat. In the case of subsurface safety valve flappers, when opened but more so when allowed to close, there is a risk of flapper or seat damage or damage to both from a severe impact loading. Accordingly the present invention seeks to cushion or even eliminate the shock contact while still allowing the movable member to reach its intended ultimate position. In the context of a flapper, the preferred embodiment locates at least one magnet on the flapper and magnets in the housing adjacent the location of the flapper when it reaches its ultimate open or closed position. In this manner the application of a magnetic field to the pivoting flapper damps any impact with the seat in the closed position and any travel stop for the open position. These and other features of the present invention will be more apparent to those skilled in the art from a review of the description of the preferred embodiment and the associated FIGS. while recognizing that the full scope of the invention is given by the appended claims.
SUMMARY OF THE INVENTION
A flapper in a subsurface safety valve has at least one magnet that comes in close proximity with another magnet mounted in a fixed position on the valve body. There is a fixed magnet on the body adjacent to the fully open and the fully closed positions of the flapper. In each case like poles on the flapper magnet and the housing magnet come in close proximity as the flapper reaches its fully open and fully closed positions. The orientation of like poles adjacent each other creates a repelling force that damps or eliminates shock loading.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a section view of a flapper in a safety valve just about to close;
FIG. 2 is the view of FIG. 1 with the flapper in the fully open position; and
FIG. 3 is the view of FIG. 2 with the flapper in the fully closed position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The basic structure of a downhole subsurface safety valve is known to those skilled in the art. Basically, a hydraulic control line runs from the surface to the valve to operate a piston that is biased against the applied pressure in the control line. Pressurizing the control line moves the piston which is linked for tandem movement with a flow tube 10 . The flow tube 10 rides inside seat assembly 12 the lower end of which has a seat 14 . A flapper 16 is pivoted at 18 and the pivot shaft can have a spring to bias the flapper 16 into the closed position of FIG. 3 when the pressure on the control line is removed and a closure spring pushes the piston in an opposed direction which has the effect of retracting the flow tube 10 at which point the spring on the pivot 18 initiates movement of the flapper 16 toward seat 14 . The flow trying to come uphole as represented by arrow 20 helps to get the flapper 16 moving toward its seat 14 . The seat 14 and the corresponding portion of the flapper 16 that lands on seat 14 are complex contoured shapes that are expensive to produce in computer controlled milling machines. It is very undesirable to get any deformation in the seat 14 or in the mating portion of the flapper 16 .
Those skilled in the art will see that as the flow tube 10 is retracted and the flapper starts movement from the FIG. 2 to the FIG. 1 to the FIG. 3 positions, the velocity of the fluid represented by arrow 20 can result in slamming the conforming shapes of the seat 14 and the flapper 16 against each other. In the preferred embodiment, the use of a force of a magnetic field is designed to reduce the velocity of the rotating flapper 16 as it reaches the fully closed FIG. 3 position and the fully open FIG. 2 position.
The way the dampening is accomplished in the preferred embodiment is to fixedly mount a permanent magnet 22 and 24 in the housing 26 and a magnet 27 to the flapper 16 on an extending tab 28 . Tab 28 is preferably diametrically opposed from the location of the pivot connection 18 . The opposing surfaces of magnets 24 and 27 are of the same polarity so that they repel each other as they get closer together. The same can be said for magnets 22 and 27 as they approach each other when the flapper 16 goes toward the open position of FIG. 2 . The end tab 28 is used to allow the magnets 24 and 27 to be away from the specially machined complementary surfaces that engage when the flapper 16 engages the seat 14 . It is cheaper to do it this way than to drill blind bores in the flapper and seat sealing surfaces although to do so can be an alternative way to use the magnets 24 and 27 to provide a dampening of the velocity and the resulting momentum force as the flapper 16 goes to the closed position of FIG. 3 . As shown in FIG. 3 magnet 24 is on a longer radius from pivot 18 than magnet 27 which still allows taking advantage of like poles repelling each other. The orientation can also be changed to position magnet 27 on the same arc as magnet 24 to create the dampening effect of magnets repelling each other. However, the offset orientation allows taking advantage of the repelling force when magnets 24 and 27 get close enough to each other, as shown in FIG. 1 , and then deliberately reducing or eliminating the repelling force having already slowed the flapper 16 when the magnets 24 and 27 go side by side as shown in FIG. 3 . In this configuration the flapper can seat within 5 seconds as required in Standard 14A of the American Petroleum Institute (API). The relative positions can be varied to take into account ease of assembly, cost, power of the magnets to repel each other and the size and weight of the flapper 16 . The overarching concept is the use of a field to reduce the velocity of a moving component in a downhole tool. From there the focus can get more specific to the use of a magnetic field and on down to permanent magnets and their relative positions in the open position of FIG. 2 and the closed position of FIG. 3 .
It should also be noted that introducing high pressure and high velocity gas in a downhole direction which is the reverse of arrow 20 from above a closed flapper 16 can accelerate the flapper 16 to the open position of FIG. 2 with enough force to also cause potential damage. Clearly there is greater risk of damage in the flapper 16 going to the closed position of FIG. 3 . However, magnet pair 22 and 27 serves to slow down the flapper 16 as it starts to slam to the fully open position. Again with this magnet pair there can be an axial offset between them in the direction of arrow 20 or the arc of magnet 27 can coincide with the location of magnet 22 .
Magnet pair 22 and 27 also prevent another problem. Sometimes when the flow tube 10 is raised by the control system (not shown) high velocity gas gets behind the flapper 16 in the open position and creates a low pressure zone behind the flapper 16 that in extreme cases holds the flapper in the open position where it needs to go to the closed position. The magnet pair 22 and 27 can provide a repelling force to drive the flapper 16 toward the closed position. To do this the preferred orientation of this pair of magnets is alignment. The flow tube 10 will push the flapper out of the way when going to the open position so alignment of this magnet pair is not an issue even if the repelling force does not diminish since the force behind the moving flow tube will overcome the repelling force in any event. The magnet 22 can optionally be eliminated.
While more complicated, one or more of the magnets can be powered electromagnets that can be selectively powered or turned off from a location removed from the valve. Other electrical fields are contemplated that can create a repelling force. It should be noted that the flapper momentum by definition overcomes the repelling force while it is being decelerated with the repelling force diminishing or going to zero when the magnets 24 and 27 get toward a radially aligned position shown in FIG. 3 , so that the force of pressure on the flapper 16 in the closed position will tightly hold the closed position of FIG. 3 . It is even possible to have the magnets attract in the FIG. 3 position by having opposite poles close enough to each other to aid in holding flapper 16 in the closed position. In the open position the flow tube 10 holds back the flapper 16 and overcomes any repelling force as magnets 22 and 27 get close to each other.
The above description is illustrative of the preferred embodiment and many modifications may be made by those skilled in the art without departing from the invention whose scope is to be determined from the literal and equivalent scope of the claims below:
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A flapper in a subsurface safety valve has at least one magnet that comes in close proximity with another magnet mounted in a fixed position on the valve body. There is a fixed magnet on the body adjacent to the fully open and the fully closed positions of the flapper. In each case like poles on the flapper magnet and the housing magnet come in close proximity as the flapper reaches its fully open and fully closed positions. The orientation of like poles adjacent each other creates a repelling force that damps or eliminates shock loading.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a United States National Phase application of International Application PCT/EP2010/002198 and claims the benefit of priority under 35 U.S.C. §119 of German Patent Application DE 10 2009 017 627.6 filed Apr. 9, 2009, the entire contents of which are incorporated herein by reference.
FIELD OF THE INVENTION
The invention relates to a locking apparatus for a vehicle seat, particularly for a motor vehicle seat, comprising a locking mechanism for mechanically locking a moveable catch of the locking mechanism with a counter element, and comprising an actuator device for actuating the catch by means of a drive, and comprising a housing in which the locking mechanism is arranged and housed.
BACKGROUND OF THE INVENTION
In particular locking and unlocking components for backseat systems often have a manually operable locking and unlocking mechanism, by which a locking of a backseat backrest of the backseat system with a vehicle structure can be created and released. To increase the comfort, such backseat systems are being provided increasingly more often with an electrically driven actuator, by which an unlocking of the locking mechanism can also be triggered in a motor-driven manner. Generally here, already existing, purely mechanical locking components are additionally provided with an electrical actuation. By means of transmission elements, such as angles, levers, linkages, gears and suchlike, which are also fastened on the adapter plate, a coupling takes place between the actuator and the locking mechanism for the transmission of the drive movement of the actuator to the locking mechanism.
Backseat backrests of the second or third row of seats are generally able to be turned over, in order to make a greater loading volume possible. For this, the backseat backrests can be unlocked from the vehicle structure and turned over towards the front. The resetting generally takes place in the manner that the passenger straightens up the backrest manually and with a particular expenditure of force carries out the locking of the backrest in the vehicle structure. The required expenditure of force is necessary in order to overcome the cushion pressure and the adjusting forces of the catches within the locking apparatus. The completed locking of the backrest with the vehicle structure is currently displayed by an indicator. The indicator is mechanically coupled with the locking apparatus such that it indicates to the passenger the status of the locking apparatus as a function of the position of a mechanical element of the locking apparatus which is responsible for the locking. In such backseat backrests, however, under different circumstances it is possible that nevertheless a correct locking does not take place, for example due to carelessness of the user. In this case, the backseat system is nevertheless not locked, but able to be sat in. In the case of an accident (frontal impact), it can then occur that the backseat backrest can not fulfil the requirement of “protection from load” as a separation of the passenger compartment from the luggage compartment. Thereby, the passengers in the passenger compartment are in certain circumstances under considerable risk; severe injuries to the passengers can then be the result.
SUMMARY OF THE INVENTION
The invention is therefore based on the problem of creating a locking apparatus of the type mentioned in the introduction, by which an improved safety is enabled against injuries to vehicle passengers that occur due to non-locked backseat backrests.
This problem is solved in a locking apparatus of the type mentioned in the introduction in accordance with the invention by motor-driven means for creating a lock of the locking mechanism. Locking apparatuses with a motor drive in fact already exist. However, these are used exclusively for the unlocking of the catch from its counter element, usually a bolt. Within the framework of the invention, it has now been found that a motor-generated locking movement of the catch can contribute to a greater security to the effect that an intended locking is in fact completed. If the locking apparatus has a motor-driven actuating device for the motor-driven unlocking of the catch, basically the locking can take place with the same actuator device with which the motor-driven drive movement is also produced for the unlocking. In a preferred embodiment of the invention, however, for the production of a drive movement for a locking of the locking device a separate actuating device, in particular only associated with the locking function, can be provided.
The actuator device can be integrated into the locking apparatus and its housing. In addition, in the case of an electrically adjustable backrest, the drive of the backrest device can be used as the actuator device for the locking device. If an electric backrest inclination adjustment is present, this can undertake the function of the drive production for the locking. This can take place for example in that the backrest is adjusted in its inclination until the locking of the backrest into the (vehicle) structure has taken place. In this case, the locking takes place purely mechanically, the catch itself does not have its own, i.e. separate, drive associated with it. The force for overcoming the cushion pressure and the locking forces is produced here by the backrest adjustment drive. In this embodiment, the functionality of a driven locking can be achieved, without having to undertake the expenditure of an additional drive.
In a preferred embodiment of the invention, a sensor device can be provided, by which a lockable position of the backrest of the seat system is able to be detected. As a function of a position recognition of the backrest, an activation can take place of the motor-driven drive movement produced by the actuator device. For this purpose, a corresponding signal of the sensor device can be used, which on recognition of a particular backrest position and/or of a particular relative position between the catch and its counter-bolt generates a corresponding signal which is fed to a control, which thereupon triggers the actuator unit, in order to thereby carry out the locking of the catch of the locking apparatus with the counter element.
Also in the variant in which the drive of the backrest inclination is used for the locking, a sensor device can be provided and an exchange of information between the sensor device of the locking apparatus and the backrest inclination adjuster is advantageous in an analogous manner to the variant with a separate actuator device. In this preferred embodiment according to the invention, it is possible that the sensor system of the locking apparatus and its electronic evaluation unit undertakes at least partially the function of a control of the backrest drive and carries out a data exchange with the backrest drive. Through the data exchange, the drive of the backrest can remain switched on until the backrest has reached a locking position and/or a locking of the backrest has taken place by means of the locking apparatus.
To further increase the security for producing a locking, in a further preferred embodiment of the invention, the sensor device can also comprise means by which (relative) positions of components of the locking apparatus are detected by sensor and monitored during the locking. When the components reach their respective final position, this can be signalled by a corresponding signal of the sensor device to the control or to another evaluation device. The control interprets these signals and can switch off the actuator device on reaching of end positions of the monitored components, which corresponds to a completed locking between the catch and its counter element. In addition, means can be provided in particular for the visual display of the completed locking.
In a further preferred configuration of the invention, a visual display can be provided for the locking status of the locking apparatus which is determined by the sensor device. Hereby, a visual monitoring of the locking status is possible, whereby the security can be further increased. The visual display can be arranged on the locking apparatus itself or in the vicinity thereof. Likewise, it is possible to indicate the locking status visually and/or acoustically on an instrument panel of the vehicle, in particular, a locking which has not been completed, in the form of a warning signal. For this, a processing of the signal of the sensor device can take place through the control.
It is advantageous if the actuator device acts with its motor-driven movement directly onto the catch itself, in order to transfer the latter into a locking position. In addition, expediently at least one securing element should be present, by which the catch can be secured in its locking position against an unintentional opening. This makes it possible to construct a locking mechanism which is particularly reliable in operation. In addition, such a structural solution also facilitates arranging the actuator device outside a flux of force, which in the case of a crash acts on the locking mechanism. The actuator device itself therefore does not imperatively have to be designed for crash forces.
In further preferred embodiments of the invention, the actuator device can be provided with a gear, in particular with a spindle gear, by which a reduction of the motor-driven drive movement of the actuator device is able to be produced. A spindle gear is one of several possibilities, in order to convert a rotary drive movement of the motor into an at least substantially translatory movement. By means of such a preferred rectilinear movement, the actuator device can act on the locking mechanism in order to achieve a locking pivoting movement of the catch of the locking mechanism with the counter element. Preferably here, a stop of the actuator device can act on a carrier of the catch arranged at a distance from a rotation axis of the catch, in order to hereby achieve a pivoting movement of the catch.
In order to achieve an even greater reduction and hence to further increase the torque, in addition a second gear can be provided, in particular a planetary gear upstream of the spindle gear. Advantageously, on the output side the planetary gear and the electric motor of the actuator device can be constructed identically, for example in the form of identical gearwheels. Thereby it is possible in a particularly simple manner to form a system of locking apparatuses in which for example different gears or respectively a different number of gears can be provided depending on which torque is required. Furthermore, different electric motors can also be integrated hereby in a simple manner into the modular system.
To achieve the locking, the actuator device advantageously carries out a lifting movement. In order to return one or more elements carrying out the lifting movement of the actuator device, after completion of the locking, into a position again which they have occupied before the locking, the locking apparatus can be provided with a resetting element. The resetting element can be constructed here as an energy store, in particular as an energy store which is able to be charged with energy by the drive movement during locking. The stored energy can then be released and used subsequently for the resetting of the actuator device. In a favourable embodiment of the invention, the resetting element can be a spring element. Advantageously, the resetting element brings the stored energy into the actuator device for its resetting in the region of the gear of the actuator device.
Further preferred configurations of the invention will emerge from the claims, the description and the drawings. The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which preferred embodiments of the invention are illustrated.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a cutout view of a backseat of a motor vehicle with a locking apparatus according to the invention and with a counter element fastened to a vehicle structure;
FIG. 2 is a perspective view of the locking apparatus of FIG. 1 ;
FIG. 3 is a partial perspective view of the locking mechanism of FIG. 2 in an unlocked position;
FIG. 4 is a partial perspective view of the locking mechanism of FIG. 2 in a locked position;
FIG. 5 is a partially schematic view of the locking apparatus according to the invention of FIG. 1 together with a control.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings in particular, an example embodiment is shown for a locking apparatus 1 according to the invention, as can be integrated for example in a pivotably articulated backrest 2 of a backseat system 3 . With such a locking apparatus 1 , an upright position of the backrest 2 can be arrested or respectively secured by cooperation of the locking apparatus 1 with a counter element B. By means of a possibility, which is not illustrated, for the actuation of the locking apparatus 1 , this arresting is releasable, for example in order to fold down the backseat backrest 2 in the direction of a seat surface, which is not illustrated, of the backseat system 3 . The locking apparatus 1 can be integrated here into the backseat backrest 2 , and the counter element B, for example a bolt, can be arranged fixed to the vehicle or respectively in a stationary manner on the vehicle structure 4 . In principle, however, it is also possible to provide the counter element B on the backseat backrest 2 and the locking apparatus 1 on the vehicle structure 4 . On pivoting movements of the backrest 2 , the counter element B and a locking mechanism 23 of the locking apparatus move close to each other or respectively move apart from each other.
The locking apparatus 1 is provided with a multiple-part housing 20 ( FIG. 2 ). In the latter a locking mechanism 23 known per se (cf. FIG. 3 ) is arranged and a first actuator unit 24 ( FIG. 2 ), not illustrated more closely in detail, for an electrically generated drive movement of the locking mechanism for its unlocking, and mounted on the housing 20 . In addition to the automated drive movement, the locking mechanism 23 can also be actuated manually with the aid of a pivotably articulated operating handle 25 ( FIG. 2 ), in order to thereby cancel an arresting between the locking mechanism 23 and the counter element B. Embodiments are also possible in which no operating handle 25 is provided and the unlocking always takes place with the actuator unit 24 . The locking mechanism 23 can be constructed in a manner known per se with regard to its mechanical components, their articulation and interactions with each other. Principles of such locking mechanisms are disclosed for example in DE 10 2004 056 086 B3, DE 103 04 574 B4 and DE 103 177 A1, the respective disclosure content of which is herewith included by reference. Therefore, the structure of the locking mechanism is only entered into in a rudimentary manner in the following.
As is represented in FIGS. 3 and 4 , a catch 31 of the locking mechanism 23 is pivotably mounted on a first bearing bolt 33 , which in turn is arranged securely on and between two housing shells and hence on the housing 20 . The catch 31 could, however, also be mounted movably in a different manner. For cooperating with the counter element B, the catch 31 has a groove-shaped hook jaw 35 , which in a locked state of the locking apparatus 1 crosses at least approximately perpendicularly a mount 29 and surrounds the counter element B by three sides, whilst in an opened state it opens obliquely towards the mount 29 . A second bearing bolt 43 is arranged parallel to the first bearing bolt 33 and is arranged in the same way as the latter on the housing. On the second bearing bolt 43 , as first securing element, a catching eccentric 45 is pivotably mounted, which is prestressed towards the catch 31 by a spring, not represented in further detail, acting between the housing and the catching eccentric 45 . The tensioning eccentric 51 is mounted as a second securing element alongside the catching eccentric 45 and likewise pivotably on the second bearing bolt 43 . In the locked state, both the catching eccentric 45 and also the tensioning eccentric 51 have engaged into the catch, as is illustrated in FIG. 4 . The tensioning eccentric 51 exerts a closing moment onto the catch 31 here by means of a clamping surface 49 which is curved eccentrically to the second bearing bolt 43 .
In addition, the catching eccentric 45 in its closure position closes the hook jaw 46 , which is open on one side, with a closing extension 46 . For this purpose, the catching eccentric 45 has a catching surface, which is situated in the vicinity of the clamping surface 49 of the tensioning eccentric 51 , but in the locked state does not imperatively have to be in contact with the catch 31 . The catching surface of the catching eccentric 45 can be constructed as a surface curved centrically around the second bearing bolt 43 . The catching eccentric 45 serves as security against unintentional opening from the locked state. In the case of a crash, when the catch 31 possibly undergoes an opening moment and presses the tensioning eccentric 51 away, the catching surface of the catching eccentric 45 arrives in abutment against the catch 31 , without the catch 31 being able to exert a moment on the catching eccentric 45 . The catching eccentric 45 therefore serves both for supporting the catch 31 and for preventing the opening thereof and also for load bearing in the case of a crash. The tensioning eccentric 51 , which is for example prestressed with a spring, not illustrated, towards the catch 31 , undertakes the function in the locked position that it exerts a closing moment onto the catch 31 , whereby a position free of play and a tolerance compensation to the vehicle body is realized. Both securing elements, the catching eccentric 45 and also the tensioning eccentric 51 , therefore secure the locked state of the catch 31 .
Both from the catching eccentric 45 and also from the tensioning eccentric 51 respectively an arm, integrally formed onto the respective eccentric, projects in the form of an unlocking lever 45 a , 51 a for the unlocking of the locking device 1 . By the moving of at least one of these unlocking levers 45 a , 51 a —in the illustration of FIGS. 3 and 4 —, starting from the locked state in a clockwise direction, for example by means of a Bowden cable, the catching eccentric 45 and hence the catching surface pivots away from the catch 31 . For example, by means of a carrier, which is not illustrated in further detail, the catching eccentric 45 , if applicable after a short idle stroke, entrains the tensioning eccentric 51 and draws up the catch 31 by means of a tension spring which is not illustrated, so that it frees the counter element B. By suitable geometric relationships, the catching eccentric 45 and/or the tensioning eccentric 51 , in the positions which they have taken up after the movements relative to the catch 31 , exert an opening moment on the catch 31 or hold the latter opened otherwise. In this position, by a pivoting movement of the backseat backrest, the counter element B can now be guided through the relative movement of the locking apparatus 1 in relation to the counter element B out from the hook jaw 35 and hence the locking can be completely cancelled.
As is shown in FIGS. 3 and 4 , the locking apparatus 1 has an actuator device 50 associated exclusively with the catch 31 for its locking, said actuator device being fastened on the housing 20 . In the effective direction of the actuator device 50 , the latter is provided with a direct current electric motor 52 , which is functionally connected on the output side with an optionally provided planetary gear 53 . In other embodiments of the invention a different type of gear can be provided or the gear can be dispensed with. Likewise, a motor could be provided as drive of the actuator device 50 , which apart from the actuator device 50 also provides drive movements for other components. The planetary gear 53 in turn is functionally connected on the output side with a spindle gear 54 , which in a manner known per se converts a rotary movement on the input side into a rectilinear movement on the output side. For this purpose, such a spindle gear has a spindle provided with a thread, and a spindle nut, arranged on the thread, which is driven by the planetary gear. With this rectilinear movement of the spindle, a fork-shaped stop 58 arranged on the spindle is moved to and fro in accordance with the arrow 55 in a straight line between two end regions. With the motor-generated forward movement, the stop 58 strikes onto a pin-shaped carrier 59 , which is arranged on the catch 31 at a distance from the rotation axis of the catch 31 defined by the bearing bolt 33 . With its lifting movement, the stop 58 receives and entrains the carrier between its forks, whereby a rotary movement of the catch 31 about the rotation axis of the bearing pin 33 is produced owing to a movement acting directly from the actuator device 50 onto the catch 31 . In the illustration of FIG. 3 , this rotary movement takes place in an anti-clockwise direction. With this rotary movement, carried out due to the stroke of the stop 58 , the catch 31 engages the bolt B and locks with the latter.
During this process, the position of one or of several components of the locking mechanism can be monitored by means of one or more sensors for the reaching of their end position, and on reaching of the end position a corresponding signal can be generated. In the embodiment which is shown, only the position of the catching eccentric 45 is determined by sensor 67 . The at least one signal is fed to an electronic control 62 . The control 62 interprets this signal and switches off the motor 52 of the actuator device 50 in the presence of predetermined conditions. In the example embodiment of FIGS. 3 and 4 , for example a Hall sensor, not illustrated in further detail, fastened to the inner side of the housing 20 , can be provided as sensor, by which a position of a magnet, likewise not illustrated, is detected, which can basically be fastened to the catching eccentric 45 or to the tensioning eccentric 51 . With locking movements of the catch 31 , without an engaging of the bolt B by the catch 31 , the catching eccentric 45 reaches a different end position than with a correct locking between the catch 31 and the bolt B. This difference in the possible end position of the catching eccentric 45 can therefore serve as the basis for the information which is determined by sensor as to whether the backrest 2 is locked on the vehicle structure 4 or not. The Hall sensor therefore generates signals corresponding to this information, which is fed via lines 61 to the control 62 shown in FIG. 5 . A display 68 is provided to display a locking final position. In a possible further development of the embodiment according to the invention which is shown, the position of the tensioning eccentric 51 can also be detected by sensor. This position information does not, however, enter into the information taken into consideration by a control 62 for the activation of the actuator device 50 , but can be used to establish a faulty locking (misuse), i.e. a locking of the catch 31 without the bolt B being engaged.
The movement of the actuator device 50 is triggered by the backrest 2 arriving, from a folded down position, in its upright end position as locking position, as is represented in FIG. 1 . In the example embodiment, a microswitch 60 is provided, preferably arranged externally on the locking apparatus 1 , which is connected with the control 62 by means of lines 63 . On reaching the lockable position, the microswitch 60 is triggered, owing to its contact with the vehicle structure 4 , whereby a signal of the microswitch 60 for signalling the reaching of the lockable position of the backrest is fed to the control 62 shown in FIG. 5 . This triggers a switching on of the motor 52 by the control 62 , the drive movement of which pivots the catch 31 by means of the carrier 58 , as already discussed. The signal of the Hall sensor is likewise fed to the control 62 and hence the motor 52 is switched off when the locking is completed. Differently from that illustrated in FIG. 5 , the control 62 of the motor 52 can also be integrated into the locking apparatus 1 . The control 62 is connected to a voltage supply 64 and on the basis of the sensor signals supplied to it determines the switching on and off of the motor 52 . If applicable, the control can also undertake further functions, such as for example a voltage/current monitoring, which in the case of an overload switches off the motor independently of signals of the sensors for determining position.
The flux of force on the locked components runs from the counter element B via the catch 31 towards the tensioning eccentric 51 , so that the actuator device 50 does not have to bear any loads such as e.g. crash loads.
In this embodiment, after the locking is completed, the stop 58 is reset again, so that it occupies the initial position again, shown in FIG. 3 , but the catch 31 continues to be arranged in the position represented in FIG. 4 . The spindle gear 54 can also be designed so that it is passively entrained with the opening catch 31 and in this way a resetting takes place. A resetting element 65 is provided for resetting the actuator device 50 into an initial position after a locking of the catch 31 has been completed. The resetting element 65 may be an energy store 66 , which is able to be charged by a drive movement of the actuator device 50 . Alternatively, as is the case in the example embodiment, after the switching off of the motor 52 , a spring (e.g. spiral spring), which is not illustrated in further detail, can act on the actuator device 50 (motor, gear and/or spindle) such that hereby the stop 58 is actively drawn back again into its initial position. Thereby, on unlocking, no additional forces become necessary for overcoming retention forces of the actuator device 50 , and the unlocking process can take place quickly and with less expenditure of force. For this purpose, the spring can be arranged for example between the planetary gear 53 and the spindle gear 54 and can be tensioned by the motor-driven locking movement. As soon as the motor 52 of the actuator device 50 is switched off, the spring can relax. As the motor 52 now no longer produces a force directed against a relaxing of the spring, and the torque introduced from the spring onto the spindle gear 54 exceeds the restoring torque of the actuator device 50 , the spring now relaxes, which leads to a movement of the stop into its initial position, as shown in FIG. 3 . The spring therefore turns the spindle gear 54 and the planetary gear 53 back into their positions which they had occupied before the production of the locking.
In other embodiments, a resetting of the actuator device 50 can also take place by a movement of the motor 52 , the drive shaft of which, for this purpose, rotates in the opposite direction compared with the drive movement for the production of the locking.
In further possible embodiments of the invention, the actuator device 50 can use the rotation movement of an electric motor as such and without transformation into a rectilinear movement for action on the catch 31 in its closure movement. In this case, the motor can be coupled to the catch 31 such that its rotary movement is transferred to the catch 31 directly or via a gear which likewise provides a rotary movement on the output side. For example, provision can be made that the motor is arranged on the bearing bolt 33 and its rotary movement as such is transferred to the catch 31 . In particular in connection with such solutions, electric motors with a particularly flat structural shape can be advantageous, as is the case for example in electronically commutated motors (ECM).
While specific embodiments of the invention have been described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.
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A locking apparatus for a vehicle seat, particularly for a motor vehicle seat, includes a locking mechanism ( 23 ) for mechanically locking a moveable catch ( 31 ) of the locking mechanism ( 23 ) with a counter element (B), and an actuator device ( 24, 50 ) for actuating the catch ( 31 ) via a drive. A housing ( 20 ) is provided in which the locking mechanism ( 23 ) is arranged and housed. Improved safety against injuries of vehicle passengers that occur due to non-locked backseat backrests is provided with a motor-driven device for creating a lock of the locking mechanism ( 23 ).
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BACKGROUND OF THE INVENTION
The present invention generally relates to a safety control mechanism for a reciprocating press brake assembly of the type used to bend sheet metal or the like. In particular, the present invention is directed to a safety control mechanism requiring both of an operator's hands to actuate movement of a ram member toward a workpiece. After the ram comes within a predetermined distance of the workpiece, movement of the ram is automatically stopped, with a foot pedal being actuable for controlling further movement of the ram, thereby freeing the operator to grasp and position the workpiece during the actual work operation without fear of his hands being caught between the ram and workpiece.
While press brake assemblies for bending sheet metal are well known, safety control devices for such assemblies have generally proven unsatisfactory with regard to allowing an operator to control the placement of the workpiece during the work operation. It would be most desirable for an operator to be able to hold and place the workpiece as the ram assembly makes actual contact therewith, thereby allowing the operator to position the workpiece against guide stops and further allowing the operator to feel and recognize possible slippage of the workpiece during the bending operation.
The Occupational Safety and Health Administration (OSHA) requires than an operator's fingers be at least 12 inches from a ram and associated bending die as they approach one another, but the fingers can be placed much closer to the ram after the gap is reduced to 1/4 inch or less.
An assembly which is typical of the prior art and which meets the OSHA requirements is disclosed in U.S. Pat. No. 2,199,501, issued May 7, 1940 to MacBlane, which suggests two hand controls and a foot control, wherein both hand controls must always be depressed to actuate movement of the ram assembly. This safety control mechanism does not allow for the handling of the workpiece and is difficult to precisely position the workpiece with respect to the ram.
As will be discussed in detail hereafter, applicant's new and useful invention solves the problems confronting the prior art, by providing a safety control mechanism which positively assures an operator's safety, while still allowing hand contact with the workpiece during the actual work operation.
OBJECTS AND SUMMARY OF THE PRESENT INVENTION
An object of the present invention is to provide a safety control mechanism for a press brake assembly capable of preventing injury to an operator's hands during reciprocating operation.
A further object of the present invention is to provide a safety control mechanism for a press brake assembly which allows an operator to contact and precisely position a workpiece during the actual work operation.
Another object of the present invention is to provide a safety control mechanism for a press brake, wherein actuation of the control system requires both of an operator's hands until the ram has come within a predetermined distance of the bending die at which time movement of the ram is automatically stopped, with a foot pedal being actuated to control further movement of the ram.
A further object of the present invention is to provide a safety control mechanism adaptable for easy attachment to a conventional press brake assembly or the like.
These and other objects of the present invention are achieved in a preferred enbodiment of the present invention wherein a plurality of interconnected valves are selectively actuated to control the reciprocal movement of the press brake ram.
During operation, an operator is required to continuously depress a pair of separate control buttons with each of his hands to initiate and maintain downward movement of the ram toward the workpiece, thereby preventing the operator from extending his hands between the ram and workpiece. When the press brake ram comes within a predetermined distance of a support die which is preferably 1/4 inch or less, the safety control mechanism automatically actuates a foot pedal member for controlling further movement of the ram, thereby allowing the operator to grasp and maneuver the workpiece during the actual work operation. After the work operation has been completed, continued depression of the foot pedal causes the ram to reciprocate upwardly toward its top dead center position, at which time the ram is stopped with control being automatically transferred to the control buttons. In this manner, a new work cycle can only be initiated by depression of the pair of control buttons.
The safety control assembly of the present invention is not limited to use with a press brake described herein, but is intended for use with any device employing a reciprocating work member wherein it is desired to prevent accidental injury to an operator while at the same time, allowing the operator to grasp the workpiece during the actual work operation.
A clearer understanding of the present invention will become apparent from a reading of the following specification and claims, together with the accompanying drawings, wherein similar elements are referred to and are indicated by similar reference numerals.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention can be best understood with reference to the accompanying drawings, wherein:
FIG. 1 shows a front view of a press brake assembly including a safety control mechanism constructed according to a preferred embodiment of the present invention;
FIG. 2 shows a side view of the press brake assembly of FIG. 1;
FIG. 3 shows a blow up view of a portion of FIG. 2 including a cam actuable valve assembly positioned on the press brake assembly;
FIG. 4 shows a blow up view of a section taken along line AA of FIG. 1 including a further cam valve assembly positioned according to the present invention; and
FIG. 5 shows a schematic representation of a safety control valve mechanism formed in accordance with the preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings, and FIGS. 1 and 2 in particular, a press brake assembly including a safety control system formed according to the present invention is generally indicated at 10. Press brake assembly 10 comprises a housing 11 which supports a conventional motor and belt drive assembly that has been deleted from the drawings for purposes of clarity.
A clutch and brake mechanism generally designated at 12 is mounted within housing 11 and functions to selectively transfer driving torque from a belt drive assembly to a ram member in a well-known manner. A control rod 13 is positioned within a housing 11 and is pivotally attached at a lower end to a connecting link 14 which, in turn, is pivotally attached to housing 11. An upper end of a control rod 13 is pivotally attached to a cam member 15 mounted in housing 11 and including a cam surface 16 which selectively contacts clutch mechanism 12. During operation, movement of control rod 13 causes cam surface 16 to contact and force clutch mechanism 12 into torque transmitting engagement. The precise manner in which control rod 13 is actuated will be described hereafter.
A ram assembly 20 is mounted on housing 11 for reciprocating movement relative to a fixed die support member 21 axially spaced therefrom. Ram 20 is powered by torque transferred from the drive motor through an associated belt drive and the clutch and brake mechanism 12 in a conventional manner, the details of which have been deleted for purposes of clarity. A workpiece placed on die 21 is deformed by the pressing contact of ram 20 and die 21. The vertical position of supporting die 21 relative to ram 20 can be adjusted by rotating threaded shafts 22 and 23, which are mounted on housing 11 and extend into similarly threaded bores formed in die 21. Rotation of crank member 24 and connecting member 25 functions to rotate shafts 22 and 23 to raise or lower die 21 respective to ram 20.
The safety control mechanism according to the preferred embodiment will now be described in detail.
Referring to FIGS. 1 and 5 in particular, a source of pressurized fluid, such as air, is generally designated at 30. A fluid passageway 31 extends from source 30 to inports formed in plunger valves 32a and 32b, respectively. Each plunger valve 32a and 32b also includes a push button actuator 33a and 33b, respectively, with each valve being initially biased to a closed position via attached spring members 34a and 34b. Fluid passageways 35a and 35b extend between outports of valves 32a and 32b, respectively, and separate inports of a combining valve member 36 which is mounted on housing 11.
A single fluid passageway 37 extends from an outport of combining valve 36 to an inport of cam valve assembly 38, with valve 38 being biased to a closed position by attached spring member 39. A fluid passageway 40 extends from passageway 37 to an inport of a control valve 41 which is biased by a spring member 42 into an initially closed position.
A separate fluid passageway 43 joins passageway 31 and extends to an inport of a cam valve assembly 44. A further passageway 45 extends between passageway 43 and an inport of valve 41, with an outport of valve 41 being in fluid communication with a hollow cylinder 46 via passageway 47. Cylinder 46 may be mounted on frame 11 and encloses a piston and rod assembly, wherein the rod is fastened to control rod 13 providing joint motion therewith.
Similarly shaped cam valve assemblies 38 and 44 are each mounted on opposite sides of housing 11. Referring to FIG. 3, cam valve 44 includes a cam actuator 50 extending toward ram 20, with a cam member 51 attached to a lower end portion of ram 20, and including a wedge shaped end surface 52. Cam valve 38 includes a similarly shaped cam actuator 51 and a separate cam member, not shown.
Referring again to FIG. 5, a fluid passageway 52 extends between an outport of cam valve 44 and a first end of plunger control valve 53. A further fluid passageway 54 connects a second end of valve 53 with an outport of a cam valve assembly 55, which is spring biased to an initially closed position. A fluid passageway 57 connects an inport of cam valve 55 with fluid passageway 43. An inport of control valve 53 is also connected to passageway 57 via passageway 58, while an output of valve 53 is connected to an inport of foot controlled valve 59 via passageway 60. Finally, an outport of foot valve 59 is connected to a cylinder 61 through a separate passageway 62.
Cylinder 61 is similar in structure to cylinder 46 in that it is attached to frame 11 and includes a piston and rod assembly fastened to control rod 13. Likewise, cam valve 55 is similar to cam valves 38 and 44 and, as shown in FIG. 4, includes a cam actuator 63 extending therefrom. A cam member 64 may be attached to a vertically upper end of ram 20 for contact with actuator 63 as will be described hereafter. Furthermore, a conventional foot pedal actuator 65 is mounted in housing 11 and is attached to foot control valve 59.
The operation of the safety control device of the present invention will now be described with reference to the drawings, and in particulr to FIG. 5. At the beginning of an operating cycle, it is assumed that ram 20 is at a top dead center position, with only cam valve 55 being forced into an open position against its biasing spring, to allow fluid flow therethrough. The fluid then passes through valve 55, passageway 54 and acts against the second control end of valve 53 thereby closing valve 53 and removing the pressure against foot control valve 59.
An operator grasps and depresses push buttons 33a and 33b with each of his hands to open valves 32a and 32b, respectively. A pressurized fluid, such as air, is then allowed to flow from souce 30, through passageway 31, to open valves 32a and 32b, and into passageways 35a and 35b leading to valve 36. Valve 36 is only opened by a combination of fluids from flow paths 35a and 35b, which ensures that an operator must continuously depress both button members 33a and 33b to maintain valve 36 in an open position.
As a further safety control, valve 36 is designed to be actuated only when push buttons 33a and 33b are depressed within a predetermined time. In a preferred embodiment, push buttons 33a and 33b must be depressed within 0.5 seconds of each other to open valve 36. If a longer time passes between depression of the first and second buttons, valve 36 will remain closed. The time control forces an operator to depress both push buttons 33a and 33b at substantially the same time, thereby reducing the chances of injury to the operator.
After valve 36 is forced into an open position, fluid flows into and through passageway 37 until it reaches the initially closed inport of cam valve 38. The pressurized fluid in passageway 37 also flows through passageway 40 to force valve 41 into its open position. The opening of valve 41 allows pressurized fluid to flow from source 30, through passageways 31, 43, 45 and valve 41 into passageway 47 and cylinder 46. As pressurized fluid fills a chamber in cylinder 46, piston 48 and its attached rod move and force attached control rod 13 to move therewith.
As control rod 13 moves, it causes cam member 15 to pivot with cam portion 16 engaging clutch mechanism 12. Further movement of rod 13 forces cam portion 16 to engage clutch 12, resulting in the rotative torque from the drive motor being transferred to the belt drive assembly, causing ram 20 to being a downward movement toward fixed support die 21 and a workpiece mounted thereon. It is noted that movement of ram 20 continues only as long as both buttons 33a and 33b remain depressed. If either button is released, valve 36 will automatically close, reducing pressure in passageway 37, which allows valve 41 to close and cut off the flow of pressurized fluid to cylinder 46, with the fluid in passageway 47 being exhausted through valve 41 to stop movement of cylinder 46.
After ram 20 has moved within a predetermined distance of the support die 21, preferably 1/4 inch or less to meet OSHA requirement, the wedge shaped cam members attached to ram 20 will simultaneously contact and deflect actuators 51 and 50 of cam valves 38 and 44, respectively. As cam actuator 51 is deflected, it moves valve 38 to its open position allowing the pressurized air in passageway 37 to flow through valve 38 and dissipate into the atmosphere. As a result, the fluid pressure within passageways 37 and 40 is reduced and valve 41 is then biased by attached spring 42 to its closed position. The pressurized air within passageway 47 and cylinder 46 can exhaust through closed valve 41, which removes the drive force from rod 13 and allows the clutch portion mechanism 12 to disengage, with the brake portion being automatically actuated to prevent any movement of ram 20. This stops the downward movement of ram 20 and frees the operator to remove his hands from buttons 33a and 33b and grasp and position the workpiece as desired.
Because both cam valves 38 and 44 are deflected by movement of ram 20, a fluid passage through initially closed valve 44 is now opened via deflection of cam actuator 50. Pressurized fluid flows from source 30 through passageways 31, 43, valve 44 and into passageway 52, striking the first end of control 53, and causing initially closed control valve 53 to move to its open position. Fluid in passageway 43 flows through passageways 57, 58, open valve 53 and into passageway 60.
The operator can now control further downward movement of ram 20 by stepping on foot pedal actuator 65, which causes foot control valve 59 to move from a closed position to an open position. As valve 59 opens, fluid passes from passageway 60, through valve 59, and through further passageway 62 into cylinder 61. Cylinder 61 operates in a manner similar to cylinder 46, with the pressurized fluid causing the piston rod and attached control rod 13 to move and engage clutch mechanism 12 to cause movement of ram 20. The speed of reciprocating ram 20 is directly controllable by the amount of depression of pedal 65 which directly affects the size of the flow path through valve 59.
After the ram 20 has completed its downward motion, it begins reciprocating in an upwardly direction. As ram 20 approaches top dead center, cam member 64 contacts and deflects actuator 63, forcing cam valve 55 which is biased closed to move to an open position. This allows fluid within passageway 57 to flow through valve 55 and passageway 54. Fluid contacts the second end valve 53, moving valve 53 to a closed position, which allows fluid in passageways 62 and 60 to exhaust through valve 53 into the atmosphere and making further foot controlled operation of ram 20 impossible. To initiate a further cycle of ram member 20, buttons 33a and 33b must be again continuously depressed by the operator.
The preferred embodiment of the present invention has been described with the use of pressurized air as the control fluid. It would, of course, be possible to substitute other fluids for pressurized air, with the exhaust ports of the various valves being connected to a sump for collecting the fluid in a well-known manner, rather than dissipating the pressurized fluid into the atmosphere. Furthermore, the cam members 51 and 64 can be positioned on housing 11 to stop the movement of ram 20 at any predetermined position, with the distances chosen in the preferred embodiment meeting the outstanding OSHA requirement.
In the preferred embodiment, a pressurized fluid control assembly controls movements of the ram member. It is within the scope of the present invention to substitute either an electrical control assembly or a combination of electrical and fluid control assembly for the fluid control assembly described hereabove.
The present invention is not limited to the above-described embodiment, but is limited only by the scope of the following claims.
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A safety control mechanism for a press brake assembly or the like, wherein an operator is required to continuously depress two hand control buttons to initiate movement of a ram from a top dead center position toward the workpiece. When the ram has come within a predetermined distance of a support die on which the workpiece is positioned, a foot pedal is actuable for controlling movement of the ram during actual contact with the workpiece and until the ram reaches top dead center. The operator is then free to grasp and position the workpiece during the actual work operation.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is the U.S. national phase of PCT Application No. PCT/EP2014/059147 filed on May 6, 2014, and claims priority to EP13166852.7 filed on May 7, 2013, the entire disclosures of which are herein incorporated by reference herein.
TECHNICAL FIELD
[0002] The invention relates to an apparatus for the fabrication of containers, specifically by the process of blow molding. The invention also relates to a method for employing such an apparatus to fabricate containers, as well as the containers so produced.
BACKGROUND OF THE INVENTION
[0003] It is generally well known in the art to fabricate containers by the process of blow molding, wherein a plastic parison known as a “preform” is molded into a container. This preform is generally in the form of an elongated tube which defines a preform cavity and which is provided with a closed distal end and a mouth at an open proximal end in communication with said preform cavity. The preform may be fabricated from any polymer resin which has appropriate deformation characteristics; polyethylene terephthalate (PET) and polypropylene (PP) are particularly favored for their deformation properties and suitability for use with alimentary products.
[0004] The preform is first placed in a mold which defines a mold cavity in the form of a container. The mold is usually provided in at least two segments, ideally configured such that the open proximal end of the preform protrudes from the mold while a majority of the preform remains within the mold cavity. A pressurized fluid is then injected into the preform cavity, which induces it to expand and assume the contours of the mold, thereby forming a container.
[0005] When forming a container by the blow molding process, it is necessary to ensure that the segments of the mold are held together tightly at the end of the forming process where the preform is in contact with the interior of the mold and is exerting an outward force upon the mold surfaces. Otherwise, the force exerted by the preform on the surface of the mold cavity as it is formed will cause the mold segments to separate and result in the undesirable formation of prominent parting lines in the container.
[0006] In known embodiments of the blow molding process, the expansion of the preform is made by the injection of compressed air. To maintain tight closure of the mold segments, one or several compensation chambers, for instance pneumatic cylinders, are provided in one or more of the mold segments to press or clamp the mold segments together, the compensation chambers being fed from the same compressed air supply as the molding apparatus. Preferably, one mold segment is held stationary while the other is pressed against it by the pneumatic cylinder.
[0007] However, it has recently become known to make the expansion of the preform by the injection of a liquid, in particular the liquid which is ultimately to be packaged in the container thereby fabricated. In a blow molding apparatus so configured, there is thus no supply of compressed air, requiring an alternate means for ensuring the closure of the mold segments to be furnished so as to avoid the formation of parting lines on the containers being produced.
[0008] In particular, the international patent application publication WO 2012/0170517 describes a system wherein there is provided a means for driving a hydraulic cylinder placed in abutment to one of the mold segments, thereby ensuring the proper closure of the mold during the injection step. In one embodiment, the injection liquid and the hydraulic cylinder are bridged by an isolator device. The isolator device comprises a diaphragm or piston disposed in an injection head of the apparatus and acted upon directly by the injection liquid, thereby pressurizing the hydraulic fluid and driving the hydraulic cylinder. This embodiment is particularly appealing in that only one pressure source is employed. In an alternate embodiment, the hydraulic circuit is isolated from the injection liquid and driven by a separate pressure source.
[0009] However, the systems described in the prior art do not satisfactorily resolve the problem of ensuring the proper closure of the mold segments.
[0010] Specifically, the apparatus of the prior art reference is constrained in that the pressure for driving the compensation mechanism is limited by the pressure of injection of the liquid into the preform. Thus, in order to generate a sufficient force on the mold segments to hold the mold closed during injection, the principle of hydraulic force multiplication dictates that the area of the isolator upon which the pressure of the injection fluid acts must necessarily be greater than the area of the projection of the container onto the plane normal to the direction of motion of the mold segment. In practice, this means that the surface area of the plunger, piston, or diaphragm of the isolator must exceed the area of the longitudinal section of the container being formed for the compensation mechanism to provide enough force to keep the mold closed during the forming process. The isolator unit and injection head are very large and unwieldy as a result.
[0011] It is therefore an object of the invention to provide an apparatus which employs a single pressure source to ensure the closure of a mold during the blow molding of a container within, and which is compact and reliable.
SUMMARY OF THE INVENTION
[0012] In a first aspect of the invention, there is provided an apparatus for fabricating containers, comprising a plurality of mold segments, said plurality of mold segments defining a mold cavity substantially in the form of a container and configured to accommodate a substantially tubular preform having a preform cavity communicating with an open end; an injection cylinder, said injection cylinder comprising a chamber with a piston mobile therein and being disposed in fluid communication with said injection head, and further configured to inject a volume of liquid into said preform when said piston is advanced into said chamber; and a closure cylinder, said closure cylinder being configured to exert a force on at least one of the mold segments so as to maintain said mold segments in a closed disposition.
[0013] According to the invention, the apparatus further comprises a motor cylinder, the piston of said motor cylinder driving said piston of said injection cylinder, the motor cylinder and closure cylinder being concurrently driven by a single pressure source.
[0014] Thanks to the provision of the motor cylinder driving the injection cylinder, and the closure cylinder holding the mold closed during the molding process, the molding apparatus is rendered more compact while achieving a high level of quality in the containers produced therein.
[0015] Specifically, the provision of a motor cylinder to drive the injection cylinder means that rather than the injection liquid being pressurized and driving the closure cylinder indirectly through an isolator, the injection of the liquid into the preform and the closure of the mold are effectuated separately by a single hydraulic pressure source. There is thus no need to provide an isolator in the injection head of the apparatus to bridge the pressurized injection liquid and the hydraulic fluid driving the closure cylinder, thereby rendering the apparatus simpler and more compact.
[0016] In a preferred embodiment, said injection cylinder and said motor cylinder are provided as two separate components.
[0017] This is advantageous in that providing the motor cylinder and the injection cylinder as two separate components will maintain the hydraulic fluid and the injection liquid in perfect isolation from each other. Specifically, when the motor cylinder and the injection cylinder are provided as separate components, there will necessarily be a physical separation between the two that, when properly configured, will eliminate the possibility of cross-contamination between the hydraulic fluid and the injection liquid such as would occur across a piston ring seal or through a cracked or otherwise damaged diaphragm in an isolator according to the prior art. The integrity of the fluids within the apparatus is thereby maintained with maximal effectiveness.
[0018] Advantageously, the piston of said motor cylinder is directly connected to the piston of said injection cylinder.
[0019] This is advantageous in that it will result in an efficient transfer of power between the motor cylinder and the injection cylinder, while simultaneously reducing the complexity and cost of the apparatus.
[0020] As a practical embodiment, said motor cylinder and said closing cylinder are double-acting cylinders.
[0021] This is advantageous in that by furnishing the appropriate hydraulic control mechanisms, the apparatus is quickly and easily reset to an initial position following the fabrication of a container, facilitating the rapid and continuous production of containers. In particular, it may be advantageous to utilize the return stroke of the motor cylinder to cause the injection cylinder to draw in another volume of liquid for injection in a subsequent container fabrication cycle.
[0022] In a second aspect of the invention, the invention is directed to a method for the fabrication of a container, comprising the steps of providing a substantially tubular preform having a preform cavity communicating with an open end; disposing said preform at least partially within a mold cavity substantially in the form of a container, said mold cavity defined by a plurality of mold segments; pressurizing a motor cylinder, a piston thereof driving a piston of an injection cylinder and thereby pressurizing a quantity of liquid within said injection cylinder, while concurrently pressurizing a closing cylinder adapted to exert a force upon at least one of said mold segments and thereby maintain said mold segments in a closed disposition; and injecting said quantity of liquid within said injection cylinder into said preform cavity of said preform, said preform being thereby induced to deform and assume the shape of the mold cavity.
[0023] This is advantageous in that it realizes the advantages of the apparatus as described above in the production of containers.
[0024] According to a possible embodiment, the method is further characterized in that after the injecting step, there is a retracting step for retracting the pistons of said motor cylinder and closing cylinder.
[0025] This is advantageous in that such a step will reset the apparatus, readying it to fabricate another container from a subsequent preform. This will reduce the amount of time during each cycle where a container is not being fabricated, thereby maximizing the production of containers and rendering the implementation of the method more efficient.
[0026] Preferably, during said retraction step a volume of liquid is drawn into said injection cylinder.
[0027] This is advantageous in that the injection cylinder is thereby primed for the forming and filling of a container in a subsequent cycle.
[0028] In a possible embodiment, the method is further characterized in that initiating prior and taking place concurrent to the injecting step there is a step for advancing a stretching rod into said preform cavity of said preform, said stretching rod being urged against the surface of said preform cavity so as to induce said preform to deform along a longitudinal axis.
[0029] This is advantageous in that the provision of the stretching rod and the advancement thereof into the preform during the injecting step will promote the longitudinal expansion of the preform. This enables the production of more varied forms of containers by the method of the invention, while permitting a greater degree of control over the process by the user.
[0030] In a third aspect of the invention, the directed to a container fabricated by the method described above.
[0031] This is advantageous in that such a container embodies the advantages of the invention as previously detailed.
BRIEF DESCRIPTION OF THE FIGURE
[0032] FIG. 1 is a schematic depiction of an apparatus for fabricating containers according to an exemplary embodiment of the invention.
DETAILED DESCRIPTION
[0033] For a complete understanding of the present invention and the advantages thereof, reference is made to the following detailed description of the invention.
[0034] It should be appreciated that various embodiments of the present invention can be combined with other embodiments of the invention and are merely illustrative of the specific ways to make and use the invention and do not limit the scope of the invention when taken into consideration with the claims and the following detailed description.
[0035] In the present description, the following words are given a definition that should be taken into account when reading and interpreting the description, examples and claims:
[0036] “Closure Cylinder” is a piston-like device acting upon a mold, the closure cylinder being disposed so as to compress or otherwise hold together the mold halves during the deformation of a preform within said mold;
[0037] “Injection Liquid” is the liquid which is injected at pressure into the preform so as to induce it to deform into the shape of a container, and which is generally edible and intended to be packaged within the container so formed; and
[0038] “Pressure Source” is any machine or mechanism which is configured to provide a flow of liquid under pressure.
[0039] As used in this specification, the words “comprises”, “comprising”, and similar words, are not to be interpreted in an exclusive or exhaustive sense. In other words, they are intended to mean “including, but not limited to.
[0040] Any reference to prior art documents in this specification is not to be considered an admission that such prior art is widely known or forms part of the common general knowledge in the field.
[0041] The invention is further described with reference to the following example. It will be appreciated that the invention as claimed is not intended to be limited in any way by this example.
[0042] FIG. 1 is a schematic depiction of an apparatus for fabricating containers according to an exemplary embodiment of the invention. The molding apparatus 100 is broadly comprised of three sections: a mold section 101 , a liquid injection section 102 , and a hydraulic power section 103 .
[0043] The mold section 101 comprises the mold 104 , here comprised of a base mold segment 104 A and the right and left lateral mold segments 104 B & 104 C. The mold segments 104 A, 104 B, & 104 C are disposed in the mold carriers 104 D & 104 E. The mold carriers 104 D & 104 E serve to maintain the mold segments 104 A, 104 B, & 104 C in a pre-determined relation to each other, as well as to permit a controlled motion of the lateral mold segments 104 B & 104 C relative to each other during the insertion of the preform 107 at the start of the molding cycle and the extraction of a finished container at its conclusion.
[0044] The mold segments 104 A, 104 B, & 104 C are thus disposed so as to be mobile in a first type of motion relative to the overall structure of the apparatus (e.g. a pedestal). This type of motion and the articulation mechanisms employed to create it are generally well-known in the art, and so are not discussed here.
[0045] However, the left lateral mold segment 104 C is also mobile in a second type of motion relative to the other two mold segments 104 A & 104 B, in that it is mobile between a position where the two lateral mold segments 10413 & 104 C are pressed together tightly (depicted here by the left lateral mold segment 104 C in solid lines) and another where they are not (depicted here by the left lateral mold segment 104 C′ in dashed lines). The separation d between the two positions of the left lateral mold segment 104 C is the gap that is necessary to avoid the lateral mold segments 10413 & 104 C binding against each other during operation of the apparatus 100 . The means for creating this motion are discussed infra.
[0046] While in this embodiment only the left lateral mold segment 104 C is mobile, it should be understood that in other embodiments any or all of the mold segments may be configured to be mobile, depending on the size and shape of the containers being fabricated and the other particular demands of the installation in question, with additional closure cylinders and other such devices furnished as appropriate.
[0047] Each of the mold segments 104 A, 104 B & 104 C has a mold surface 105 A, 105 B, & 105 C, respectively, which collectively define the mold cavity 106 . Disposed within the mold cavity 106 is the preform 107 . The preform 107 encloses a preform cavity 108 , which communicates with an open end 109 of the preform 107 . The preform 107 is disposed such that the majority of its length is within the mold cavity 106 , with only a small portion of the open end 109 protruding through top of the mold 104 .
[0048] The mold section 101 further comprises the injection head 110 , which comprises an internal channel 111 that flares out into the nozzle 112 . The nozzle 112 is disposed about the open end 109 of the preform 107 and pressed into the mold 104 , creating a sealed fluid connection between the preform cavity 108 of the preform 107 and the internal channel 111 of the injection head 110 .
[0049] The liquid injecting section 102 of the molding apparatus 100 is comprised primarily of the injection cylinder 113 . The chamber 114 of the injection cylinder 113 is in communication with the liquid supply 115 through the supply line 116 , and with the internal channel 111 of the injection head 110 through the injection line 117 .
[0050] When the injection piston 118 is withdrawn from the injection cylinder 113 , a quantity of liquid 119 is drawn from the liquid supply 115 through the supply check valve 120 and into the chamber 114 . Backflow from the injection head 110 is prevented by the piloted injection valve 121 , which opens when a pre-determined positive pressure is reached in the chamber 114 .
[0051] When the injection piston 118 is subsequently advanced into the injection cylinder 113 , the piloted injection valve 121 opens and the liquid 119 within the injection cylinder 113 is expelled at great pressure via the injection line 117 and the internal channel 111 of the injection head 110 through the nozzle 112 and into the preform cavity 108 of the preform 107 . The preform 107 is thereby induced to expand, assuming the form of the mold cavity 106 as defined by the mold faces 105 A, 105 B, & 105 C.
[0052] In certain embodiments, it may also be advantageous to provide a means for inducing a longitudinal stretching of the preform. In particular, it is advantageous to furnish a stretching rod which is advanced into the preform and urged against an internal surface thereof. This will induce and accelerate the longitudinal deflection of the preform during the injection of the injection liquid, optimizing the process for the production of elongated containers. The precise configuration of the injection head will thus vary according to the size and shape of the containers being produced by it.
[0053] The hydraulic section 103 of the molding apparatus 100 broadly comprises the hydraulic pump 122 , the control valve 123 , the motor cylinder 124 , and the closure cylinder 125 . In this embodiment, the closure cylinder 125 is incorporated within the left mold holder 104 E. Also, in this embodiment the hydraulic pump 122 is an ordinary constant-displacement pump, drawing hydraulic fluid from the reservoir 126 and sending it to the control valve 123 .
[0054] The control valve 123 is a standard four-port closed-center directional control valve, having three positions: a closed center section 127 , a forward section 128 , and a reversing section 129 . The center section 127 is the default position of the control valve 123 , maintained there by the centering springs 130 A and 130 B. The control valve 123 is deflected to side by the solenoids 130 C and 130 D, thereby placing either of the forward or reversing sections 128 and 129 in the hydraulic circuit as desired.
[0055] To the ports of the control valve 123 are connected four hydraulic lines: the pressure line 131 , the return line 132 , the extension line 133 , and the retraction line 134 . The extension line splits into two branches: the motor branch 133 A which is connected to the motor cylinder 124 ; and the closure branch 133 B, which is connected to the closure cylinder 125 . Likewise, the return line 132 splits into the motor branch 134 A and the closure branch 134 B.
[0056] When the control valve 123 is disposed in the center position as shown here, the center section is configured to block off the extension and retraction lines 133 and 134 , while connecting the extension and return lines 131 and 132 so as to redirect the pressurized hydraulic liquid issuing from the hydraulic pump 122 back to the reservoir 126 .
[0057] When the control valve 123 is disposed in the forward position the forward section 128 is connected, pressurizing the extension line 131 and the associated motor and closure branches 133 A & 13313 thereof. As a result, the closure piston 137 within the closure cylinder 125 is advanced from the closure cylinder 125 , urging the left lateral mold segment 104 C against the right lateral mold segment 10413 by way of the closure cylinder piston rod 138 . Continued pressurization of the closure cylinder 125 holds the left lateral mold segment 104 C against the right lateral mold segment 1048 and thus maintains the mold 104 in a closed disposition.
[0058] As stated above, in this embodiment the right lateral mold segment 104 B is fixed relative to the right mold holder 104 D and the left lateral mold segment 104 C is mobile relative to the left mold holder 104 E by way of the action of the closure cylinder 125 .
[0059] However, in certain embodiments it may be desirable to provide a second closure cylinder operating on the right lateral mold segment, to provide an augmented mold closure force. The exact configuration of the apparatus may be chosen according to the particularities of each application.
[0060] Concurrently to the pressurization of the closure cylinder 125 , the motor cylinder 124 is also pressurized. This causes the motor piston 135 of the motor cylinder 124 to be advanced therefrom. The motor piston 135 is linked to the injection piston 118 of the injection cylinder 113 by the linkage 136 , which pressurizes the liquid 119 for injection into the preform 107 as described above.
[0061] The preform 107 is thereby expanded into the mold cavity 106 , forming a container (omitted from this diagram for clarity), while at the same time the force exerted on the lateral mold segments 104 B & 104 C by the closure cylinder 125 ensures that the force of the expanding preform 107 upon the mold surfaces 105 A, 105 B, & 105 C does not result in the separation of the mold segments 104 A, 104 B, & 104 C. The formation of a mold separation line on the resulting container is thereby avoided.
[0062] Furthermore, the provision of the closure cylinder 125 in the manner described will ensure that the lateral mold segments 1048 & 104 C are completely and tightly closed during each molding cycle as they undergo normal wear and tear over the course of their service life.
[0063] Preferably, the motor cylinder 124 and the injection cylinder 113 are provided as two separate components, to isolate the liquid injecting section 102 from the hydraulic section 103 and thereby eliminate the possibility of contamination due to leakage, seal wear, or other compromise of the mechanical integrity of the apparatus. Furthermore, it should be noted that, while in this embodiment the linkage 136 is a solid rod connecting the motor piston 135 to the injection piston 118 , it may in other embodiments be advantageous to furnish a more complex means for linking the motor cylinder 124 to the injection cylinder 113 . For instance, it may be advantageous to provide a limited-travel prismatic joint in the linkage, permitting one to vary the travel of the injection piston for a given travel of the motor piston and thereby utilize the apparatus to fabricate differently-sized containers. The precise configuration of the linkage between motor cylinder and injection cylinder for each application may be determined by one skilled in the art of mechanics.
[0064] At the conclusion of injection of the liquid 119 into the preform 107 , the container is fully formed and must be removed from the mold 104 . To achieve this, the control valve 123 is disposed in the reversing position, connecting the reversing section 129 to the hydraulic circuit. Since the motor cylinder 124 and closure cylinder 125 are here provided as double-acting cylinders, the motor cylinder 124 and closure cylinder 125 will reverse, thereby retracting the motor and closure pistons 135 and 137 into their respective cylinders 124 and 125 .
[0065] Alternately, the motor and closure cylinders may be provided as single-acting hydraulic cylinders, being retracted at the conclusion of the injecting step by a spring force or the like. This will simplify the design of the hydraulic control circuit of the molding apparatus in that it eliminates the need for a reversing section and the associated return lines from the cylinders, and may thus be advantageous in certain other embodiments of the invention.
[0066] The retraction of the closure cylinder 125 will displace a portion of the mold 104 into a position where the two lateral mold segments 104 B and 104 C are no longer compressed against each other; an exaggerated depiction of this is shown in hatched lines by the left lateral mold segment 104 C′, the closure piston 137 ′, and the closure piston rod 138 ′. This permits the lateral mold segments 104 B & 104 C to be separated and the mold cavity 106 opened to remove the container therein, preventing the mold segments 104 A, 104 B, & 104 C from binding upon the container or upon each other. The retraction of the motor cylinder 124 will cause the injection piston 118 to be partially withdrawn from the injection cylinder 113 , creating a vacuum and drawing a quantity of the liquid 119 from the liquid supply 115 into the chamber 114 . Another preform 107 may be placed in the mold cavity 106 and the injection head 110 disposed thereupon, and the process repeated to fabricate another container in a subsequent cycle.
[0067] Of course, the invention is not limited to the embodiments described above and in the accompanying Figure. In particular, it will be readily understood that the hydraulic circuit described herein is merely exemplary and not in any way limiting or suggestive of a necessary arrangement of components. One skilled in the art will be readily able to configure the hydraulic components and hydraulic circuit so as to be optimized for any particular application or operating mode.
[0068] Although the invention has been described by way of example, it should be appreciated that variations and modifications may be made without departing from the scope of the invention as defined in the claims. Furthermore, where known equivalents exist to specific features, such equivalents are incorporated as if specifically referred in this specification.
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An apparatus for fabricating containers. The apparatus including a plurality of mold segments, an injection cylinder, a closure cylinder and a motor cylinder. The injection cylinder defining a mold cavity substantially in the form of a container and accommodating a substantially tubular preform having a preform cavity in communication with an open end. The injection head establishes fluid communication with the preform and the injection cylinder is in fluid communication with the injection head and configured to inject a volume of liquid into the preform The closure cylinder is configured to exert a force on at least one of the mold segments to maintain them in a closed disposition. The motor cylinder is configured to drive the injection cylinder and being itself concurrently driven with the closure cylinder by a single pressure source.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a continuous process and apparatus for the bleaching of triglyceride oils with a bleaching adsorbent.
2. Description of the Prior Art
In the processing of oils and fats for purposes of producing salad and cooking oils, and other edible oil products such as margarines and shortenings, it is necessary to bleach the oil with an adsorbent substance such as an adsorbent clay. The purpose of the bleaching process is to remove coloured materials from the oil, such as chlorophyll and chlorophyll breakdown products, brown-coloured compounds and other materials which may be sufficiently polar for removal from the oil by adsorption on the clay. If these compounds are not removed, the desired light colours cannot be achieved in the various oil and fat products mentioned above. Equally importantly, the chemical activity of these compounds can lead to the formation of additional coloured material, and to the formation of compounds which impart unacceptable flavours to the oil products. They must therefore be removed to very low levels.
It is generally not intended to remove carotene, which is a major contributor to the colour of most oils in the crude state, by this process. Carotene does not readily adsorb on bleaching clay, but it breaks down on heating to near-colourless (yellow) compounds. Hence, the high temperatures to which oils are exposed in the course of deodorizing after bleaching are relied upon to eliminate the strong carotene (red) colour of many oils.
The complexity and variety of the compounds to be removed by bleaching are such that it is not practical to analyze the bleached oil for them in detail to determine the effect of the process. Instead, it is customary to determine the colour of the oil after bleaching by comparison with Lovibond-Red standards as described in Bailey's Industrial Oil and Fat Products, Third Edit., (1964), pages 132 and 133. Because of the difficulties with colour comparisons in the presence of carotene, it is often desirable to determine the amount of chlorophyll left in the oil by analysis and to determine the peroxide value (PV) as a measure of primary oxidation products, and the anisidine value (AV) as a measure of secondary oxidation products in the bleached oil. If bleaching is performed inefficiently, or without proper protection from oxygen, it can be expected that coloured materials of a non-carotenoid nature such as chlorophyll are inadequately removed and that oxidation values will be relatively higher in the bleached oil.
Because of this complexity in evaluating bleached oils, the ultimate test must be an evaluation of the oil after deodorizing. At that stage, it is possible to assess the effect of the bleaching process properly with respect to colour since there is no longer any interference from carotenoid compounds. Also, the effect on flavour and flavour stability can be evaluated at this stage.
In a typical process of bleaching as carried out in the industry, adsorbent clay is mixed with the oil or liquified fat (hereinafter designated generically as oil) which usually has been subjected to a refining operation, the mixture is adjusted to the desired bleaching temperature and is held at this temperature for a sufficient length of time for adsorption of coloured material to take place to the maximum extent. At the end of this period the oil is filtered to remove the clay.
It is usually preferable to protect the oil from contact with air throughout the process, and particularly during that phase of the process when the oil is at maximum temperature and in contact with the bleaching clay. Usually, this is accomplished by processing under vacuum either in batch kettles or continuously in stirred, flow-through tanks which may be compartmented to achieve a degree of control over the residence-time of the oil/clay mixture. The use of vacuum also performs the important function of removing any air from the oil/clay mixture and of removing moisture. It is, however, important to avoid complete drying of the oil/clay mixture, since this reduces the adsorptive capacity of the clay according to many investigators (see, for example, Bailey's Industrial Oil and Fat Products, Third Edit., p. 780).
A bleaching process in which the bleaching action takes place under atmospheric or greater pressure is described in Harris et al, U.S. Pat. No. 3,673,228. In this process, there is a preliminary vacuum treatment which serves only to deaerate and to moisture-adjust the oil/clay mixture for optimum bleaching efficiency. This can be achieved by putting the oil/clay mixture through a vacuum-dryer rather than having the entire bleaching section of the process under vacuum. With this arrangement, more precise control of the moisture-adjusting phase of the process is possible, since there is no need to have the oil/clay mixture under vacuum during the entire bleaching phase of the process in order to maintain protection from air.
With conventional bleaching processes there are two serious difficulties. First, it is difficult to meter the bleaching clay, which is a fine powder, from ambient pressure into the evacuated vessel in which the oil/clay mixture is to be dried, or, in which both drying and bleaching are to take place. Usually this can be done by installing devices which measure-out a small quantity of clay and transfer it from ambient pressure into the evacuated vessel. This means that the bleaching operation must be semi-continuous, which is more complex mechanically. Another method, as suggested in Harris et al, U.S. Pat. No. 3,673,228, is to slurry the clay in a small quantity of the oil in a separate tank, and then meter this slurry continuously into the main oilstream. The disadvantage of this method is that changes in the oil-stocks to be bleached require also a change in slurry-stock, if contamination between oil-stocks is to be avoided, which complicates the process considerably. Also contact of a portion of the oil with the clay is far in excess of the optimum time and amount of clay, for bleaching.
The second difficulty arises with respect to the contact-time of the oil with the clay during bleaching. The selected residence-time of the oil-clay mixture in the bleaching zone in the usual conventional processes employed in the industry is in the range of about 5 to 30 minutes, depending on the type of oil and type of clay. Agitated tanks allow considerable short-circuiting and back-mixing with the result that the actual residence-time of the increments of the oil/clay mixture varies widely. The use of a packed column, as described in Harris et al U.S. Pat. No. 3,673,228, provides some improvement, but there is still considerable variation in residence time between different portions of the mixture. The result of this variation is that bleaching vessels are sized for rather long average-residence times. This makes it inevitable that portions of the oil are exposed to bleaching conditions for so long that certain reactions which produce coloured material in the course of bleaching can assume significant proportions. Consequently the bleaching process is then correspondingly less efficient. Also, packed columns do not allow for efficient oil/clay mixing and hence longer bleaching times must be allowed to achieve proper clay-utilization. The object of the present process is to overcome these disadvantages.
SUMMARY OF THE INVENTION
It has been found that in a process for continuous bleaching of oils the bleaching adsorbent can be added to the oil without having the oil under vacuum and still achieve protection from contact with air. Further it has been found that the contact of bleaching adsorbent with the oil can be reduced from the customary 5-30 minutes in a bleaching zone to about one minute. In the process, the oil is first heated to bleaching temperature in a heat-exchanger. It is then discharged into a mixing vessel under conditions to provide for vigorous swirling of the surface of the oil in the vessel. Preferably, the mixing vessel has a section or zone of conical configuration, such as a cyclone. The adsorbent, which invariably will contain some moisture, is dropped from a metering device onto the swirling oil-surface in the vessel where it is rapidly wetted by the heated oil. As the adsorbent comes in contact with the hot oil some of the water present in the adsorbent is volatilized. An atmosphere of water vapor or steam is produced in the head-space of the vessel over the surface of the oil. This atmosphere of steam or water vapor is constantly renewed and provides effective protection from air of the oil in the vessel.
The oil/adsorbent mixture may then be pumped directly into a bleaching zone or station which comprises a series of static mixers designed for rapid and efficient mixing as described below.
Alternatively, the oil/adsorbent mixture may be discharged continuously from the mixer into a vacuum dryer where any air entrained in the feed oil or introduced into the oil with the adsorbent is removed and where the oil/adsorbent mixture is dried to the desired moisture content. The desired moisture content is achieved by adjusting the vacuum in the dryer and, in addition, by adjusting the average residence-time of the oil/adsorbent mixture in the dryer. The dried mixture is then pumped to the bleaching zone or station.
The residence time in the bleaching zone is in the order of about 1 minute instead of the conventional 5-30 minutes in other bleaching processes. Efficient bleaching is achieved in this contact-time because of the excellent mixing and the very narrow residence-time distribution achieved in the static mixers. The oil/adsorbent mixture is then filtered.
BRIEF DESCRIPTION OF THE INVENTION
FIG. 1 is a diagrammatic illustration of the process steps and apparatus utilized in carrying out the preferred combination features of applicants' invention.
FIG. 2 is a detailed elevational view, partially in section, illustrating the preferred oil/clay mixing features of applicants' invention.
FIG. 3 is a fragmentary sectional view showing one embodiment of a static mixing device which may be used in the bleaching zone of applicants' process.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the drawings, and in particular to FIG. 1, a triglyceride oil, which may be, for example, an alkali-refined oil, hydrogenated oil, or phosphoricacid pretreated crude oil, is pumped from tank 1 by pump 2 through flow control device 3 to a heat-exchanger 4 where it is heated to bleaching temperature.
Bleaching tempertures may vary widely, depending on preference and upon the type of oil, but for the purposes of this invention the temperature should not be below 70° C. (160° F.). The preferred temperature range is from about 95° C. to about 105° C. (205° F.-220° F.).
The heated oil is discharged through pipe 7 into a mixing vessel 5, having a lower section 6 of conical configuration, e.g. a cyclone, at a pressure of at least 5 psig, trangentially to the wall of the vessel. The oil-level in the vessel 5 is controlled so as to submerge the oil discharge pipe. See FIG. 2 wherein the discharge end of the oil discharge pipe is below the surface 8 of the swirling oil. This avoids any spraying effect, and transmits the flow energy to the mass of oil contained in the cyclone to produce the swirling action which wets the adsorbent.
The amount of oil in the vessel 5 is preferably equivalent to approximately 10 seconds' flow of oil. In this instance the total capacity of the vessel 5 may be equal to about 40 seconds' flow of oil. It will be seen that the residence time of the oil in this vessel is less than one minute and is usually in the order of about 10 seconds.
As shown in FIGS. 1 and 2, a solid bleaching adsorbent in powder form, such as bleaching clay, is metered into the vessel 5 from a metering device 9. This device may comprise a screw type conveyor 10 (FIG. 2) driven at a controlled rate by any conventional means as shown schematically at 11. The solid adsorbent, as shown in FIG. 2, is continuously showered upon the surface 8 of the hot oil, is drawn into the vortex of the swirling oil and is rapidly and thoroughly mixed with the oil in its downward passage through the conical lower section 6 of the vessel 5. The oil/adsorbent mixture is then withdrawn from vessel 5 through the outlet 12 which is located in a lower region of the section 6.
The bleaching adsorbent used in the process can be any of those conventionally used in the art of bleaching triglyceride oils. Bleaching clays and, in particular, acid-activated bleaching clays such as those manufactured by the Filtrol Corporation of E. Washington Blvd., Los Angeles, Calif., are suitable for the process. These adsorbents, as supplied, usually contain about 10 to 15% of free moisture. Where the word "Filtrol" is used hereinafter, it will be understood to be the registered trademark of the Filtrol Corporation. However, any solid bleaching adsorbent which contains an amount of free moisture greater than about 3% can be used in the present process. This includes all of the presently known bleaching clays. This amount of moisture will be sufficient to provide the protective layer of water vapor or steam above the hot oil in the mixing vessel. When the moist adsorbent from the metering device 10 contacts the surface of the hot oil, water vapor or steam is substantially instantaneously generated to provide the protective atmosphere in the upper part of vessel 5 above the surface of the oil.
The amount of adsorbent may also be that conventionally used in known processes and will vary in accordance with the specific adsorbent and the type of oil being processed. In general, the amount of adsorbent will be within the range of about 0.2 to 3.0% by weight, based on the weight of the oil.
The vessel 5 may be entirely open at the top as shown in FIG. 1. However, the top of the vessel 5 may be provided with a hood, such as shown at 14 in FIG. 2, to confine dust and steam. It is not necessary that this hood be air tight and it may be vented as at 15 to the atmosphere or to an exhaust system. It will be understood that, while substantially atmospheric conditions as exist in an open top vessel are preferred, the mixing system may also be operated with slightly negative or positive pressures above the oil in the mixing vessel.
The oil/adsorbent mixture flows from the mixing vessel 5 through a level-control valve 16 which maintains the desired level of oil in the mixer 5. It may then be pumped directly through open valves 17 and 18 by pump 19 to the bleaching zone 20. The level-control valve may be responsive to level sensing means, shown diagrammatically by line 16a, to provide automatic level control.
Alternatively, the oil/adsorbent mixture may flow from the mixing vessel 5 through the level-control valve 16 into a conventional vacuum-dryer 21. This is accomplished by proper manipulation of valves 17, 22 and 23. The oil-level in the vessel 5 seals the vacuum-dryer 21 against the atmosphere. Any air entrained in the feed-oil and in the bleaching adsorbent is removed in the vacuum dryer 21, and the moisture content of the oil/adsorbent mixture may be adjusted to the desired concentration. The residence time of the oil/adsorbent mixture in the vacuum dryer 21 can be adjusted in the range of from a few seconds to about 1 minute depending on the amount of moisture to be removed. The pressure in the dryer can also be adjusted from ambient pressure (760 mm Hg absolute) to 50 mm Hg (about 2 inches Hg). The optimum moisture content for best bleaching efficiency varies with the type of oil to be processed. It is generally in the range of about 0.05 to 0.25% by weight. However, for many oils the preferred concentration is about 0.1% as measured in the bleached, filtered oil. Since the oil entering the process usually contains no more than about 0.2% moisture (as little as 0.03 to 0.05% in many instances) and much of the moisture added with the adsorbent has been vaporized in mixer 5, little or in many instances no moisture need be removed in the dryer 21. Therefore, residence time in this unit is very short or the unit is omitted entirely. It has been found that little or no air is entrained in the oil/adsorbent mixture during the described mixing procedure.
The deaerated and moisture-adjusted oil/adsorbent mixture is then pumped by means of pump 19 through the bleaching zone or section 20 which consists of a series of static mixers 24. If necessary, the oil/adsorbent mixture prior to entering the bleaching zone 20 may be pumped through a heat exchanger 25 for temperature adjustment to ensure that the temperature in the bleaching zone 20 is in the 70° C. to 180° C. range. This is accomplished by appropriate manipulation of valves 18, 26 and 27.
The static mixers 24 are preferably designed to provide for an average residence-time of about 1 minute, and for a residence-time distribution such that no more than 10% of the flow is less than 0.5 minutes in the bleaching section, and no more than 10% of the flow longer than 1.5 minutes. To achieve this residence-time distribution it is important that the static mixers be substantially free of elements that would cause back mixing and short circuiting such as would take place in the agitated tank or packed tower, i.e. that the forward flow of the oil-adsorbent mixture be substantially unimpeded. In addition it is of course necessary to choose the flow velocity such that no significant settling of clay can occur. This will depend on the type of clay used and on the arrangement of the bleaching section. Lower flow-velocities can be chosen without settling if the static mixers are arranged vertically. Higher velocities are required to prevent settling in a horizontal arrangement. These velocities, which can be calculated easily by one skilled in the art, depend on the particle-size of the bleaching clay and on the particle density. The flow may be laminar or turbulent.
Static mixers of a variety of designs, including empty pipe sections, may be used provided the proper residence-time distribution is achieved. A preferred design is the "Kenics" static mixer which has helical mixing elements approximately 1.5 pipe-diameters in length. A device utilizing helical mixing elements is shown in FIG. 3. A plurality of such elements arranged to provide sequential reversal in the direction of helical flow may be employed. Other designs available are those known as the "Ross"-mixer, the "Lightnin" mixer, the "Komax" mixer and the "Sulzer" (Koch) mixer.
After passing through the static mixers 24 of the bleaching zone 20, the oil-adsorbent mixture is filtered through a conventional filter 28. Filtering temperatures may vary widely. When filter-presses are used the heat-tolerance of the cloth may present a limitation. "Open-discharge" filter-presses require low filtering temperatures to protect the bleached, filtered oil from oxidation. In such instances the oil-adsorbent mixture may be passed through a heat exchanger 29 for cooling to appropriate temperature before filtering. This may be accomplished by suitable adjustment of valves 30, 31 and 32.
No temperature limitations exist with tank-filters provided the oil is passed through a heat-exchanger before contact with the atmosphere to cool the oil sufficiently to prevent oxidation. Therefore, it is preferred that filter 28 be of the tank-filter type and that the oil then be cooled in heat exchanger 33. Valves 34 and 35 can be manipulated to provide flow through heat exchanger 33.
The invention will be further illustrated by the following representative examples of practice:
EXAMPLE 1
Alkali-refined rapeseed oil was bleached at a rate of 420 pounds per hour (about 200 kg/hour) with 1.5% of an activated bleaching clay (Filtrol 105) according to the invention. The oil was first heated to 107° C. (225° F.) by passing it through a heat-exchanger. The heated oil was discharged into the mixing cyclone while simultaneously feeding the appropriate amount of clay into the top of the cyclone. The level of the oil/clay mixture in the cyclone was controlled to provide a seal for the vacuum-dryer, and to keep the oil discharge pipe into the cyclone submerged. This was equivalent to about 10 seconds average residence-time of the oil/clay mixture in the cyclone. The oil/clay mixture was discharged into the vacuum-dryer which was under about 50 mm Hg absolute pressure, and in which the level of the oil/clay mixture was controlled to allow about 1 minute adjusting of average residence time for deaeration and moisture. The oil/clay mixture was then pumped through the bleaching section which consisted of a series of static mixer modules sized to allow an average residence-time of 1 minute. After passing through the bleaching section the oil temperature was 100° C. (212° F.). Filtration took place at that temperature in a tank-filter. After filtration, the oil was cooled to 55° C. (130° F.) before discharging to atmosphere. The bleached oil was evaluated with respect to colour, peroxide value (PV) and anisidine value (AV). It was then deodorized and the deodorized oil was evaluated with respect to colour, anisidine value, flavour and Schaal-oven stability at 46° C. (115° F.). For comparison, a quantity of the same oil was batch-vacuum bleached for 15 minutes at 105° C. (220° F.) and filtered (conventional process), and similarly evaluated. The results from these test-runs are given in Table I.
TABLE I__________________________________________________________________________BLEACHING OF ALKALI-REFINED RAPESEED OIL Unbleached Oil Bleached Oil Deodorized Oil Col. Colour Colour PV R PV R R Flav. Flav. Stab. me/kg AV (1") me/kg AV (51/4") (51/4") AV 7→1 Schaal Days__________________________________________________________________________Novel Process 5.0 1.6 4.3 0.6 3.5 2.7 0.4 1.9 4-5 6-7Conventional 5.0 1.6 4.3 0.4 6.1 2.3 0.5 2.7 5 6-7Process (Slightly green)__________________________________________________________________________
The above data show that the deodorized oil colour achieved with the oil bleached by the novel process was slightly better, particularly as far as removal of "green" compounds was concerned. Flavour and flavour stability were essentially equal from both processes, but the concentration of secondary oxidation products (as measured by AV) was lower from the novel process.
EXAMPLE 2
A second lot of alkali-refined rapeseed oil was bleached with 1.5% Filtrol 105 clay under the same conditions as described in Example 1, except that in one test-run no vacuum-drying was done and in a second test-run vacuum-drying was done at 500 mm Hg absolute pressure and with a residence time of only 20 seconds rather than 1 minute. A conventional, 15-minute batch vacuum-bleach (200 mm Hg absolute pressure) was done with the same oil for comparison. The results of these test-runs are given in Table II.
TABLE II__________________________________________________________________________BLEACHING OF ALKALI-REFINED RAPESEED OIL Unbleached Oil Bleached Oil Deodorized Oil Col. Colour Colour PV R PV R R Flav. Flav. Stab. me/kg AV (1") me/kg AV (51/4") (51/4") AV 7→1 Schaal Days__________________________________________________________________________Novel Proc. 8.4 1.9 4.5 0.4 3.6 1.5 0.5 1.9 5 10(No Vacuum)Novel Proc. 8.4 1.9 4.5 0.2 3.8 1.4 0.5 1.5 5 11(500 mm Hg)Conv. Proc. 8.4 1.9 4.5 0.7 4.7 1.7 0.4 2.1 4-5 8(200 mm Hg)__________________________________________________________________________
The data show that the deodorized oil colours from the two processes were equal. Flavour and flavour stability of the oils from the novel process were slightly better. Performing the process with or without vacuum-drying made no significant difference.
EXAMPLE 3
Alkali-refined soybean oil was bleached with 0.5% of an activated clay, as described in Example 1, except that the clay was different (Filtrol 4), the bleaching temperature was 105° C. (221° F.) and the pressure in the vacuum-dryer was 500 mg Hg absolute with an average residence-time of 20 seconds for moisture adjustment. A conventional, 15-minute batch-vacuum bleach was done at 200 mm Hg absolute pressure for comparison. The results are given in Table III.
TABLE III__________________________________________________________________________BLEACHING OF ALKALI-REFINED RAPESEED OIL Unbleached Oil Bleached Oil Deodorized Oil Colour Colour Colour PV R PV R R Flav. Flav. Stab. me/kg AV (51/4") me/kg AV (51/4") (51/4") AV 7→1 Schaal Days__________________________________________________________________________Novel Process 8.5 1.3 9.0 0.8 8.7 4.0 0.6 3.1 5 7Conventional 8.5 1.3 9.0 4.8 5.0 6.4 0.6 3.3 6 5Process__________________________________________________________________________
The colour, AV, flavour and flavour stability of the deodorized oils from the two processes were essentially equal.
EXAMPLE 4
Alkali-refined peanut oil was bleached by the process of the invention substantially as described in Example 1, except that 1.3% Filtrol 4 was used and the temperature of the oil was 105° C. (221° F.). In one test 20 seconds residence time with 50 mm Hg absolute pressure was used in the vacuum-dryer. In a second test no vacuum drying was employed. The pressure in the vacuum dryer in this test was 760 mm Hg absolute. The same oil was also bleached by the conventional 15-minute batch-vacuum process at 105° C. (221° F.) at 100 mm Hg absolute pressure and at ambient pressure. The results are listed in Table IV.
TABLE IV__________________________________________________________________________BLEACHING OF ALKALI-REFINED PEANUT OIL Unbleached Oil Bleached Oil Deodorized Oil Colour Colour Colour PV R PV R R Flav. me/kg AV (51/4") me/kg AV (51/4") (51/4") AV 7→1__________________________________________________________________________Novel Proc. 22 4.0 4.0 0.8 18.0 1.5 1.0 7.1 6(50 mm Hg)Novel Proc. 22 4.0 4.0 0.0 15.1 1.6 1.0 5.7 6(No Vacuum)Conv. Proc. 22 4.0 4.0 2.8 15.3 1.5 1.0 7.3 6(100 mm Hg)Conv. Proc. 22 4.0 4.0 2.8 10.7 1.5 1.2 7.1 5(No vacuum)__________________________________________________________________________
The colours and flavours of the deodorized oils bleached by the novel process were identical to those achieved with the conventional vacuum-bleaching process. Conventional atmospheric bleaching gave slightly poorer colour and flavour. This shows that in conventional bleaching the use of vacuum is important for the protection of the oil during the process. It also shows that the method of clay addition used in the new process does not allow air-contact with the oil.
EXAMPLE 5
Alkali-refined corn oil was bleached with 0.8% Filtrol 4 clay with conditions substantially as described in Example 1. The temperature used was 105° C. (221° F.) and the pressure in the vacuum-dryer was 50 mm Hg absolute with a residence time of 20 seconds. For comparison, the same oil was also bleached by the conventional 15-minute batch-vacuum process at the same temperature and pressure. The results are listed in Table V.
TABLE V__________________________________________________________________________BLEACHING OF ALKALI-REFINED CORN OIL Unbleached Oil Bleached Oil Deodorized Oil Colour Colour Colour PV R PV R R Flav. me/kg AV (51/4") me/kg AV (51/4") (51/4") AV 7→1__________________________________________________________________________Novel Process 6.0 1.2 9.5 1.8 2.6 2.5 0.7 1.4 5Conventional 6.0 1.2 9.5 4.0 3.5 4.0 0.8 1.9 5-6Process__________________________________________________________________________
The deodorized oils from both bleaching processes were of similar quality with respect to colour, oxidation values and flavour.
EXAMPLE 6
Alkali-refined cottonseed oil was bleached with 2.0% Filtrol 105 under conditions substantially as described in Example 1. The bleaching temperature was 105° C. (221° F.) and in one test-run the pressure in the vacuum-dryer was 50 mm Hg, absolute, and in another test-run the pressure was 760 mm Hg. The residence-time in the vacuum-dryer was 1 minute in both tests. The same oil was also bleached by the conventional 15-minute batch-vacuum process. The bleached oils were analyzed for moisture content, in addition to the usual evaluation. Table VI gives the results.
TABLE VI__________________________________________________________________________BLEACHING OF ALKALI-REFINED COTTONSEED OIL* Unbleached Oil Bleached Oil Deodorized Oil Colour Colour Colour PV R PV Moisture R R Flav. me/kg (1") me/kg % (51/4") (51/4") 7→1__________________________________________________________________________Novel Proc. 3.6 5.5 0.2 0.065 6.9 3.4 5-6(50 mm Hg)Novel Proc. 3.6 5.5 0.6 0.120 3.9 2.0 5-6(No Vacuum)Conv. Proc. 3.6 5.5 0.0 0.025 11.0 4.7 4-5(100 mm Hg)__________________________________________________________________________ *- Moisture content of the unbleached oil 0.07%
The data show that bleaching of alkali-refined cottonseed oil was very sensitive to the amount of moisture present in the system, as indicated by the moisture content of the bleached oil. The lower the moisture level in the oil the poorer the colour. In the conventional process there is an obvious difficulty to achieve optimum moisture adjustment while protecting the oil/clay mixture from air. In the process of the invention, this is easily achieved, since the use of vacuum is only required to obtain the optimum moisture level, but not to give protection from air. In the test-run using no vacuum a deodorized oil colour of 2.0R was achieved. This is an excellent result compared to 4.7R obtained in conventional 15-minute vacuum bleaching.
EXAMPLE 7
Crude, rendered lard was bleached as described in Example 1. Three different levels of Filtrol 4 bleaching clay were used, 0.76%, 0.9% and 1.5%. The bleaching temperature was 105° C. (221° F.) and the pressure in the vacuum-dryer was 50 mm Hg absolute. The residence time in the dryer was 1 minute. The same oil was bleached at all three clay-levels by the conventional batch-vacuum process for comparison, using a pressure of 100 mm Hg absolute. The results are given in Table VII.
TABLE VII__________________________________________________________________________BLEACHING OF RENDERED, CRUDE LARD Unbleached Oil Bleached Oil Deodorized Oil Colour Colour Colour PV R PV R R Flav. me/kg AV (51/4") me/kg AV (51/4") (51/4") AV 7→1__________________________________________________________________________Novel Proc. 11.0 3.0 -- -- 4.6 1.4 1.2 2.8 5-6(0.76% Clay)Novel Proc. 11.0 3.0 -- 2.8 5.6 1.3 0.8 2.8 6(0.90% Clay)Novel Proc. 11.0 3.0 -- 0.6 5.0 0.8 0.7 1.9 6(1.50% Clay)Conv. Proc. 11.0 3.0 -- 2.8 -- 2.2 2.2 -- 5-6(0.76% Clay)Conv. Proc. 11.0 3.0 -- 2.0 4.2 1.7 1.8 2.3 4-5(0.90% Clay)Conv. Proc. 11.0 3.0 -- 2.0 4.4 1.3 1.1 2.3 6(1.50% Clay)__________________________________________________________________________
The data show that the process of the invention achieved significantly lower bleached oil and deodorized oil colours at each level of clay usage than those achieved with the conventional bleaching process. AV's and flavours did not differ significantly with the two processes.
EXAMPLE 8
Crude palm oil was bleached, after a phosphoric acid pretreatment. The pretreatment with the acid was done continuously, also, and the bleaching-step followed immediately. The bleaching was done with 2.1% Filtrol 105 at 105° C. (221° F.) with the vacuum-dryer at a pressure of 50 mm Hg absolute. Residence-time in the vacuum-dryer was 1 minute and average residence-time in the bleaching zone was 1 minute. For comparison, the same oil was pretreated and immediately bleached by the conventional 15-minute batch-vacuum process at 75 mm Hg absolute pressure. Table VIII gives the results.
TABLE VIII__________________________________________________________________________BLEACHING OF CRUDE, PHOSPHORIC ACID PRETREATED PALM OIL Crude Oil Pretreat.,Bl. Oil Steam Ref./Deod. Oil Col. Col. PV R PV R Colour Flav. me/kg AV (1") me/kg AV (1") (51/4") AV 7→1__________________________________________________________________________Novel Proc. 9.0 30.4 13.5 0 16.4 5.2 2.6 5.0 6(2.1% Clay)Novel Proc. 9.0 30.4 13.5 0 19.4 5.5 2.7 7.1 6(Dupl. above)Conv. Proc. 9.0 30.4 13.5 0 21.4 6.0 3.0 8.6 5-6(2.1% Clay)__________________________________________________________________________
Oils bleached by the process of the invention had lower colours and anisidine values after deodorizing than those of the oil bleached by the conventional process. Flavours were not significantly different.
A wide variety of oils, fats and waxes, as are customarily subjected to bleaching processes may be bleached by the method of the present invention. Where the word "oil" is used in the claims, it is intended that it include such substances. The bleaching process is particularly applicable to refined and/or hydrogenated edible oils and fats, such as rapeseed, soybean, peanut, corn, cottonseed, palm, and palm kernel oils, lard and edible tallow. However, the invention is not limited to these substances and may be used with advantage in those processes in which adsorbent bleaching of oils, and fats, whether edible or inedible, refined or unrefined, has been practiced.
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Triglyceride oils are bleached rapidly and efficiently in a continuous system wherein a stream of the oil is preheated to bleaching temperature and is introduced into a mixing zone in such manner as to provide a swirling motion, bleaching adsorbent containing moisture is added to the surface of the swirling hot oil and water vapor or steam derived from the moisture in the adsorbent forms a protective atmosphere above the surface of the oil to protect it from oxidation. The oil-adsorbent mixture is pumped continuously from the mixer to a bleaching zone consisting of one or more static mixers, which may be unobstructed pipe sections, under flow conditions providing an average residence time of approximately one minute. The flow regime in the bleaching zone may be laminar or turbulent. Optionally, the oil-adsorbent mixture may flow continuously from the mixing zone to a vacuum dryer where it is deaerated and dried to optimum moisture content for bleaching prior to being pumped to the bleaching zone. Total time through the system may be in the order of less than three minutes. The advantages include simplicity of the operation, savings in time and ease of changing feedstocks.
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TECHNICAL FIELD
[0001] The present invention relates to an emulsion composition for vibration damping materials. Specifically, the present invention relates to an emulsion composition for vibration damping materials used to prevent vibration or noise of various structures, thereby to insure sustained quietude.
BACKGROUND ART
[0002] Vibration damping materials are used to prevent vibration or noise of various structures to insure sustained quietude. The vibration damping materials have been widely used for, for example, underfloor spaces of automobile interior, or for railway vehicles, ships, aircrafts, electric devices, buildings, or construction machinery. Such vibration damping materials have been conventionally made from materials having vibration absorbing performance or sound absorbing performance, and molded products such as plate products or sheet products have been used as vibration damping materials. Such molded products are however difficult to use at vibration- or noise-generation positions having complicated shapes. Therefore, various methods for improving the workability and maintaining sufficient vibration damping property have been examined. For example, an inorganic powder-containing asphalt sheet has been used for underfloor spaces of automobile interior. However, since the sheet must be bonded by thermal fusion, the workability and the like need to be improved. Therefore, studies have been made on various compositions or polymers for forming vibration damping materials.
[0003] Application type vibration damping materials (coating materials) have been developed as an alternative to such molded products. For example, vibration damping coating materials have been suggested which can absorb vibration or sound in the form of a coating formed by spraying a vibration damping coating material onto or applying a vibration damping coating material to target areas by an optional method. Specifically, aqueous vibration damping coating materials with improved coating hardness have been developed, which are obtained by blending a vehicle such as asphalt, rubber, or synthetic resin with synthetic resin powders. In addition, for interior parts of automobiles, vibration damping coating materials have been developed, which are prepared by dispersing activated carbon as a filler into a resin emulsion. However, these conventional items still do not reach the sufficient level of vibration damping performance. Therefore, a technique for achieving sufficient vibration damping performance has been required.
[0004] As conventional compositions or the like used for vibration damping materials, for example, Patent Literature 1 discloses a copolymer emulsion for vibration damping materials prepared by copolymerizing a monomer mixture essentially including an acrylic monomer.
CITATION LIST
Patent Literature
[0005] Patent Literature 1: JP 2003-42223 A
SUMMARY OF INVENTION
Technical Problem
[0006] However, the above-described copolymer emulsion for vibration damping materials does not provide sufficient vibration damping property required for practical use, and there is room for developing a composition for vibration damping materials which exhibits higher vibration damping property.
[0007] The present invention has been made in view of the state of the art, and aims to provide a composition for vibration damping materials which exhibits excellent vibration damping property.
Solution to Problem
[0008] The present inventors have performed various studies on a composition for vibration damping materials which exhibits excellent vibration damping property in the practical temperature range, and have found that a compound having 7 or more carbon atoms, a boiling point of 190° C. or higher, and at least two ether groups or at least two ester groups in the molecule acts as a vibration damping modifier for a polymer emulsion. Further, the present inventors have found that a composition prepared by adding such a compound to a polymer emulsion provides a coating that can exhibit excellent vibration damping property. Thus, the present inventors admirably solved the above problems, thereby completing the present invention.
[0009] That is, the present invention includes an emulsion composition for vibration damping materials including:
[0010] a vibration damping modifier including a compound that has 7 or more carbon atoms, a boiling point of 190° C. or higher, and at least two ether groups or at least two ester groups in the molecule; and
[0011] a polymer emulsion.
[0012] The present invention is described in more detail below.
[0013] Preferred embodiments according to the present invention include a combination of two or more of the preferred embodiments according to the present invention described below.
[0014] The emulsion composition for vibration damping materials of the present invention comprises a vibration damping modifier including a compound (hereinafter, also referred to as a compound A) that has 7 or more carbon atoms, a boiling point of 190° C. or higher, and at least two ether groups or at least two ester groups in the molecule; and a polymer emulsion. The emulsion composition may contain one or more species of compounds having 7 or more carbon atoms, a boiling point of 190° C. or higher, and at least two ether groups or at least two ester groups in the molecule, and one or more species of polymer emulsions.
[0015] The emulsion composition for vibration damping materials of the present invention may contain one or more species of compounds A as a vibration damping modifier.
[0016] The number of carbon atoms of the compound A is not particularly limited as long as the compound A has 7 or more carbon atoms in the molecule. The number of carbon atoms is preferably 7 to 50, more preferably 7 to 40, and still more preferably 7 to 35.
[0017] The compound A contains at least two ether groups or at least two ester groups. This means that the compound A contains two or more ether groups or two or more ester groups. The compound A may have other group(s) as long as the compound A has two or more ether groups or two or more ester groups.
[0018] The boiling point in the present invention refers to a boiling point at 1 atm. As for a compound that decomposes under boiling point at 1 atm, the boiling point is determined as the following: boiling points under reduced pressure of the compound are measured, and converted into the boiling point at 1 atm based on a nomograph (boiling-point conversion chart) or using the Antoine equation.
[0019] The Antoine equation is represented by the following formula (1) in which p represents a vapor pressure and T represents a temperature. A, B, and C represent constants specific to a compound. A boiling point at atmospheric pressure can be determined by calculating the Antoine constants (A, B, C) from three or more actual measurement values of vapor pressure.
[0000]
[
Formula
1
]
log
10
p
=
A
-
B
T
+
C
(
1
)
[0020] As for the compound that has 7 or more carbon atoms, a boiling point of 190° C. or higher, and at least two ether groups or at least two ester groups, a compound (A-1) that has a boiling point of 190° C. or higher and a solubility of 3 to 120 g in 100 g of water, or a compound (A-2) that has a boiling point of 260° C. or higher and ester group in the molecule is preferably used. Or both compounds may be used together as a vibration damping modifier.
[0021] Use of the compound (A-1) as the compound A enables more sufficient improvement in vibration damping property in the temperature range of 20° C. to 60° C. Usually, addition of a solvent to the emulsion composition for vibration damping materials causes a decrease in Tg of a coating of the composition to degrade the vibration damping performance in the high temperature range of 40° C. to 60° C., or to narrow the temperature range in which vibration damping property are exhibited. However, addition of the compound (A-1) causes no decrease in Tg of a coating of the composition, or only a small decrease in Tg. Therefore, no degradation of the vibration damping performance is observed in the high temperature range, or the degradation thereof is sufficiently small. Thus, the sufficient vibration damping performance can be exhibited even in the high temperature range. The compound (A-1), which is water-soluble, does not penetrate into polymer particles, and the effect of plasticization (decrease in Tg) is therefore small. However, it is presumed that, after a coating is dried, the compound (A-1) exists on the surface of the polymer particles and imparts flexibility to the coating.
[0022] Further, the formation of bubbles during baking of a coating is likely to be prevented (the porosity of the coating is reduced) by adding the compound (A-1) or (A-2). Thereby, the strength of the coating and the adhesion of the coating to a base are improved. Therefore, even when the emulsion composition for vibration damping materials of the present invention is used for automobiles or railway vehicles, which are likely to be subjected to vibration or impacts, break or peel off of a coating is restricted, and the coating exhibits favorable vibration damping property.
[0023] The compound (A-1) has a solubility of preferably 5 to 100 g in 100 g of water, more preferably a solubility of 6 to 80 g in 100 g of water, and still more preferably a solubility of 10 to 80 g in 100 g of water.
[0024] Examples of the compound (A-1) include dipropylene glycol-n-butyl ether, dipropylene glycol monopropyl ether, dipropylene glycol methyl ether acetate, propylene glycol methyl ether acetate, and propylene glycol diacetate.
[0025] The compound (A-2) has a boiling point of 260° C. or higher, preferably has a boiling point of 300° C. or higher, more preferably has a boiling point of 400° C. or higher.
[0026] The compound (A-2) preferably has a diester structure. Examples of such a compound include dibutyl phthalate, dioctyl phthalate, diisononyl phthalate, dimethyl phthalate, diethyl phthalate, diisodecyl phthalate, dioctyl adipate, diisononyl adipate, and diisodecyl adipate. In particular, a compound containing an aromatic ring in the molecule is still more preferred.
[0027] The amount of the vibration damping modifier is preferably 0.1% to 40% by mass based on 100% by mass of a monomer component which is a raw material of the polymer emulsion in the emulsion composition for vibration damping materials. The composition containing such an amount of the vibration damping modifier exhibits more sufficient effects obtained by comprising the vibration damping modifier. The amount of the vibration damping modifier is more preferably 0.5% to 30% by mass, still more preferably 0.5% to 20% by mass, and particularly preferably 0.5% to 15% by mass, based on 100% by mass of the monomer component.
[0028] The phrase “amount of the vibration damping modifier” herein means, when the emulsion composition for vibration damping materials contains only one compound as the vibration damping modifier, the amount of the one compound, and when the emulsion composition for vibration damping materials contains two or more compounds as the vibration damping modifier, the total amount of the two or more compounds.
[0029] The polymer emulsion of the emulsion composition for vibration damping materials of the present invention preferably includes an aqueous medium and a polymer (hereinafter, also referred to as a polymer (A)) in the polymer emulsion.
[0030] The monomer component which is a raw material of the polymer (polymer A) in the polymer emulsion in the present invention is not particularly limited as long as the monomer component provides the effects of the present invention. The monomer component preferably includes an unsaturated carboxylic acid monomer. More preferably, the monomer component includes an unsaturated carboxylic acid monomer and other monomer(s) copolymerizable with the unsaturated carboxylic acid monomer. The unsaturated carboxylic acid monomer may be any compound that contains an unsaturated bond and a carboxyl group in the molecule. The unsaturated carboxylic acid monomer preferably contains an ethylenically unsaturated carboxylic acid monomer.
[0031] Examples the ethylenically unsaturated carboxylic acid monomer include, but are not particularly limited to, unsaturated carboxylic acids such as (meth)acrylic acid, crotonic acid, itaconic acid, citraconic acid, fumaric acid, maleic acid, maleic anhydride, monomethyl fumarate, monoethyl fumarate, monomethyl maleate, or monoethyl maleate, and derivatives thereof. One or more of these may be used. Among these, a (meth)acrylic acid monomer such as (meth)acrylic acid is preferred. That is, the preferred embodiments of the present invention include an embodiment in which the polymer (polymer (A)) in the polymer emulsion is a (meth)acrylic polymer in which the monomer component includes at least one (meth)acrylic acid monomer.
[0032] In particular, the (meth)acrylic polymer obtained from a monomer component that includes a (meth)acrylic acid monomer is preferred. Further, the (meth)acrylic polymer of the present invention is preferably obtained from a monomer component that includes at least one monomer represented by C(R 4 ) 2 =CH—COOR 5 or C(R 6 ) 2 =C(CH 3 )—COOR 7 (R 4 , R 5 , R 6 , and R 7 are the same as or different from one another, and each represent hydrogen atom, a metal atom, ammonium group, or an organic amine group).
[0033] The (meth)acrylic acid monomer herein is a monomer containing a —COOH group, and an acryloyl group, a methacryloyl group, or a group obtained by replacing a hydrogen atom of an acryloyl group or a methacryloyl group with another atom or another atomic group. The (meth)acrylic monomer herein is a monomer containing an ester or salt of a —COOH group, and an acryloyl group, a methacryloyl group, or a group obtained by replacing a hydrogen atom of an acryloyl group or a methacryloyl group with another atom or another atomic group. The (meth)acrylic monomer also includes a derivative of such a monomer.
[0034] It is preferable that the monomer component which is a raw material of the (meth)acrylic polymer includes 0.1% to 20% by mass of a (meth)acrylic acid monomer and 80% to 99.9% by mass of other copolymerizable ethylenically unsaturated monomer(s), based on 100% by mass of the entire monomer component. Using the (meth)acrylic acid monomer improves the dispersibility of a filler such as inorganic powders in the emulsion composition for vibration damping materials of the present invention that includes the polymer emulsion. Thereby, the vibration damping property are further improved. Furthermore, using the other copolymerizable ethylenically unsaturated monomer(s) enable(s) easy adjustment of an acid value, a Tg, physical property, and the like, of the polymer. The monomer component in which the amount of the (meth)acrylic acid monomer is adjusted within the range of from 0.1% to 20% by mass can be stably copolymerized. Monomer units formed from these monomers generate synergistic effects in the (meth)acrylic polymer in the polymer emulsion. Therefore, a resulting aqueous vibration damping material can show excellent coating appearance and sufficiently exhibit vibration damping property.
[0035] More preferably, the monomer component includes 0.5% to 3% by mass of a (meth)acrylic acid monomer and 97% to 99.5% by mass of other copolymerizable ethylenically unsaturated monomer(s) based on 100% by mass of the entire monomer component.
[0036] Examples of the other copolymerizable ethylenically unsaturated monomer(s) include (meth)acrylic monomers other than the (meth)acrylic acid monomer, aromatic ring-containing unsaturated monomers, nitrogen-containing unsaturated monomers, and other monomers copolymerizable with the (meth)acrylic acid monomer.
[0037] Examples of the (meth)acrylic monomers other than the (meth)acrylic acid monomer include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, isopropyl acrylate, isopropyl methacrylate, butyl acrylate, butyl methacrylate, isobutyl acrylate, isobutyl methacrylate, tert-butyl acrylate, tent-butyl methacrylate, pentyl acrylate, pentyl methacrylate, isoamyl acrylate, isoamyl methacrylate, hexyl acrylate, hexyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate, octyl acrylate, octyl methacrylate, isooctyl acrylate, isooctyl methacrylate, nonyl acrylate, nonyl methacrylate, isononyl acrylate, isononyl methacrylate, decyl acrylate, decyl methacrylate, dodecyl acrylate, dodecyl methacrylate, tridecyl acrylate, tridecyl methacrylate, hexadecyl acrylate, hexadecyl methacrylate, octadecyl acrylate, octadecyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, vinyl formate, vinyl acetate, vinyl propionate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, diallyl phthalate, triallyl cyanurate, ethylene glycol diacrylate, ethylene glycol dimethacrylate, 1,4-butanediol diacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, diethylene glycol diacrylate, diethylene glycol dimethacrylate, allyl acrylate, allyl methacrylate, and salts and esterified products thereof. One or more of these may be preferably used.
[0038] Preferred examples of the salts include metal salts, ammonium salts, and organic amine salts. Preferred examples of the metal atom of the metal salts include monovalent metal atoms such as alkali metal atoms (e.g. lithium, sodium, potassium); divalent metal atoms such as alkaline-earth metal atoms (e.g. calcium, magnesium); and trivalent metal atoms such as aluminum or iron. Preferred examples of the organic amine salts include alkanolamine salts such as an ethanolamine salt, a diethanolamine salt, or a triethanolamine salt; and a triethylamine salt.
[0039] The monomer component which is a raw material of the (meth)acrylic polymer preferably includes the (meth)acrylic monomer in an amount of 20% by mass or more and more preferably 30% by mass or more, based on 100% by mass of the entire monomer component.
[0040] Examples of the aromatic ring-containing unsaturated monomer include divinylbenzene, styrene, α-methyl styrene, vinyl toluene, and ethyl vinyl benzene. Styrene is preferred.
[0041] That is, the preferred embodiments of the present invention further include an embodiment in which the polymer (polymer (A)) in the polymer emulsion is a styrene-(meth)acrylic polymer obtained from a monomer component including styrene.
[0042] When the polymer (polymer (A)) in the polymer emulsion includes a styrene-(meth)acrylic polymer, the monomer component preferably includes the aromatic ring-containing unsaturated monomer in an amount of preferably 1% to 70% by mass, more preferably 5% to 60% by mass, and still more preferably 10% to 40% by mass, based on 100% by mass of the entire monomer component. The monomer component which is a raw material of the polymer (A) may not include an aromatic ring-containing unsaturated monomer.
[0043] Examples of the nitrogen-containing unsaturated monomer include acrylonitrile, methylacrylonitrile, 2-vinyl pyrrolidone, acryloylmorpholine, acrylamide, methacrylamide, and diacetone acrylamide. Acrylonitrile is preferred.
[0044] The polymer (polymer (A)) in the polymer emulsion may preferably be obtained from a monomer component including a polar group-containing monomer.
[0045] A group generally regarded as a polar group of an organic compound may be used as the polar group of the polar group-containing monomer, and the polar group is preferably at least one selected from the group consisting of a hydroxyl group, a nitrile group, a carboxyl group, and a pyrrolidone group. A nitrile group and/or a carboxyl group are more preferred.
[0046] When the monomer component which is a raw material of the polymer (polymer (A)) in the polymer emulsion includes the polar group-containing monomer, the amount of the polar group-containing monomer is preferably 0.1% to 10% by mass, more preferably 0.3% to 5% by mass, and still more preferably 0.5% to 2% by mass, based on 100% by mass of the entire monomer component.
[0047] The monomer component which forms the (meth)acrylic polymer may further include a functional group-containing unsaturated monomer. Examples of the functional group of the functional group-containing unsaturated monomer include an epoxy group, a glycidyl group, an oxazoline group, a carbodiimide group, an aziridinyl group, an isocyanate group, a methylol group, a vinyl ether group, a cyclocarbonate group, and an alkoxysilane group. One or more of these functional groups may be present in one molecule of the unsaturated monomer. Examples of the functional group-containing unsaturated monomer include glycidyl group-containing unsaturated monomers such as glycidyl (meth)acrylate or acrylic glycidyl ether. Each of these may be used alone, or two or more of these may be used in combination.
[0048] Examples of the polyfunctional unsaturated monomer containing two or more functional groups include divinylbenzene, ethylene glycol di(meth)acrylate, N-methoxymethyl(meth)acrylamide, N-methxoyethyl(meth)acrylamide, N-n-butoxymethyl(meth)acrylamide, N-i-butoxymethyl(meth)acrylamide, N-methylol(meth)acrylamide, diallyl phthalate, diallyl terephthalate, polyethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, tetramethylene glycol di(meth)acrylate, polytetramethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, and neopentyl glycol di(meth)acrylate.
[0049] The monomer component which is a raw material of the polymer (polymer (A)) in the polymer emulsion preferably includes a (meth)acrylic acid monomer and/or a (meth)acrylic monomer, in terms of vibration damping property and workability.
[0050] Thus, the polymer emulsion is preferably a (meth)acrylic polymer emulsion obtained by emulsion polymerization of a monomer component including a (meth)acrylic acid monomer and/or a (meth)acrylic monomer.
[0051] The polymer emulsion preferably includes a polymer emulsion obtained by emulsion polymerization of a monomer component that includes a monomer whose homopolymer has a glass transition temperature of 100° C. or higher. Such a polymer emulsion can be sufficiently improved in vibration damping property in a wide temperature range by adding thereto the above-described vibration damping modifier, particularly, the compound (A-1) and/or the compound (A-2).
[0052] The polymer emulsion obtained by emulsion polymerization of the monomer component that includes a monomer whose homopolymer has a glass transition temperature of 100° C. or higher contains the monomer whose homopolymer has a glass transition temperature of 100° C. or higher in an amount of preferably 20% to 80% by mass and more preferably 30% to 70% by mass, based on 100% by mass of the monomer component.
[0053] In the emulsion composition for vibration damping materials which contains the vibration damping modifier and the polymer emulsion obtained by emulsion polymerization of the monomer component that includes a monomer whose homopolymer has a glass transition temperature of 100° C. or higher, the amount of the vibration damping modifier is preferably 0.1% to 50% by mass based on 100% by mass of the monomer whose homopolymer has a glass transition temperature of 100° C. or higher. The coating obtained from the emulsion composition for vibration damping materials which contains such an amount of the vibration damping modifier is excellent in strength, adhesion to a base material and it can exhibit more favorable vibration damping property. The amount of the vibration damping modifier is more preferably 1% to 40% by mass, still more preferably 2% to 35% by mass, particularly preferably 3% to 30% by mass, and most preferably 3% to 20% by mass.
[0054] The meaning of the phrase “the amount of the vibration damping modifier” is the same as described above.
[0055] In the emulsion composition for vibration damping materials of the present invention, the monomer component which is a raw material of the polymer emulsion preferably includes butyl acrylate and/or 2-ethylhexyl acrylate, more preferably includes butyl acrylate and 2-ethylhexyl acrylate.
[0056] The total amount of butyl acrylate and 2-ethylhexyl acrylate in the monomer component is preferably 20% to 60% by mass and more preferably 30% to 50% by mass, based on 100% by mass of the monomer component which is a raw material of the polymer emulsion.
[0057] The phrase “the total amount of butyl acrylate and 2-ethylhexyl acrylate in the monomer component” means, when the monomer component only includes butyl acrylate, the amount of butyl acrylate, and when the monomer component only includes 2-ethylhexyl acrylate, the amount of 2-ethylhexyl acrylate.
[0058] In the present invention, as described above, the polymer (polymer (A)) in the polymer emulsion may include one or two or more polymers. Further, the polymer (A) may include two or more polymers in the form of a composite. When the polymer (A) is in the form of a below-described core-shell structure, the polymer (A) may include two polymers in which one polymer forms a core part and the other forms a shell part. For example, the unsaturated carboxylic acid monomer and the other monomer(s) copolymerizable therewith may be contained in a core-forming monomer component or a shell-forming monomer component, or may be contained in both.
[0059] The polymer in the polymer emulsion preferably includes at least one polymer in the form of core-shell emulsion particles. By using the polymer in the form of core-shell emulsion particles, the interface among polymers can be increased to enhance the effects of improving the vibration damping property and the like.
[0060] In the core-shell composite structure, a core part surface is preferably covered with a shell part. In this case, the core part surface is preferably completely covered with a shell part, or may not be completely covered therewith. For example, the core part surface may be covered in a mesh pattern or covered to be partly exposed.
[0061] When the polymer (polymer (A)) in the polymer emulsion includes at least one polymer in the form of core-shell emulsion particles, the difference in glass transition temperature (Tg) between a polymer obtained from a core part-forming monomer component and a polymer obtained from a shell part-forming monomer component is preferably 5° C. to 60° C. When a polymer having such a difference in glass transition temperature (Tg) is used for a vibration damping material, higher vibration damping property can be exhibited in a wide temperature range, and in particular, the vibration damping property are further improved in the practical range of from 20° C. to 60° C. The difference in glass transition temperature (Tg) is more preferably 5° C. to 50° C. and still more preferably 5° C. to 40° C.
[0062] The Tg of the polymer obtained from the monomer component including the core part-forming monomer component and the shell part-forming monomer component is preferably −20° C. to 40° C., more preferably −15° C. to 35° C., and still more preferably −10° C. to 30° C.
[0063] The core-shell emulsion particles can be prepared by the emulsion polymerization (multi-stage polymerization) as described below.
[0064] When the polymer (polymer (A)) in the polymer emulsion of the present invention is a (meth)acrylic polymer and is in the form of a core-shell structure, the (meth)acrylic acid monomer and the ethylenically unsaturated monomer copolymerizable with the (meth)acrylic acid monomer may be contained in any of a monomer component forming a core part of the emulsion and a monomer component forming a shell part of the emulsion, or may be contained in both. The proportion of each monomer in the core part-forming monomer component and the proportion of each monomer in the shell part-forming monomer component are the same as described above.
[0065] When the polymer (polymer (A)) in the polymer emulsion includes at least one polymer in the form of core-shell emulsion particles, the mass ratio of the core part-forming monomer component to the shell part-forming monomer component (core part-forming monomer component/shell part-forming monomer component) is preferably 30/70 to 70/30. The polymer having such a mass ratio exhibits the effects obtained from a core-shell structure more sufficiently. The mass ratio of a core part-forming monomer component to a shell part-forming monomer component is more preferably 35/65 to 65/35 and still more preferably 35/65 to 55/45.
[0066] The polymer (polymer (A)) in the polymer emulsion preferably has a weight average molecular weight of 20,000 to 800,000. For exhibiting vibration damping property, it is preferable to convert energy due to vibration applied to the polymer into frictional thermal energy, and the polymer needs to be movable when vibration is applied thereto. The polymer (A) having such a weight average molecular weight is sufficiently movable when vibration is applied thereto, and can exhibit high vibration damping property. The weight average molecular weight of the polymer (A) is more preferably 30,000 to 400,000.
[0067] The weight average molecular weight (Mw) can be measured by gel permeation chromatography (GPC) under the following conditions. Measuring equipment: HLC-8120GPC (trade name, produced by Tosoh Corporation)
[0068] Molecular-weight column: TSK-GEL GMHXL-L and TSK-GEL G5000HXL (both produced by Tosoh Corporation) connected in series
[0069] Eluent: tetrahydrofuran (THF)
[0070] Calibration curve reference material: polystyrene (produced by Tosoh Corporation)
[0071] Measuring method: A measurement object was dissolved in THF to a solids content of about 0.2% by mass, and the resulting solution was filtered through a filter. The filtrate was measured for the molecular weights as a measurement sample.
[0072] The preferred embodiments of the present invention include an embodiment in which the polymer (polymer (A)) in the polymer emulsion is a (meth)acrylic polymer having a number average molecular weight of 25,000 or less.
[0073] The composition comprising such a polymer emulsion provides a coating having excellent vibration damping property and high strength.
[0074] That is, the preferred embodiments of the present invention include an embodiment in which the emulsion composition for vibration damping materials of the present invention includes a (meth)acrylic polymer emulsion prepared by emulsion polymerization of a monomer component, and the number average molecular weight of the (meth)acrylic polymer is 25,000 or less.
[0075] For exhibiting vibration damping property, it is preferable that the vibration energy applied to the polymer is converted into the frictional thermal energy, and the polymer needs to be movable when vibration is applied thereto. The (meth)acrylic polymer having such a number average molecular weight is sufficiently movable when vibration is applied thereto, and can exhibit high vibration damping property. Further, the emulsion composition for vibration damping materials containing the (meth)acrylic polymer having such a number average molecular weight provides a coating with high strength.
[0076] Use of the emulsion of a (meth)acrylic polymer having a number average molecular weight of 25,000 or less in the emulsion composition for vibration damping materials is technically important in the present invention. The present invention includes all of the emulsion composition for vibration damping materials which contains a (meth)acrylic polymer having a number average molecular weight of 25,000 or less, a coating formed from the emulsion composition for vibration damping materials, and a method for producing the emulsion composition for vibration damping materials using a (meth)acrylic polymer having a number average molecular weight of 25,000 or less.
[0077] The number average molecular weight of the (meth)acrylic polymer having a number average molecular weight of 25,000 or less is preferably 22,000 or less. The acrylic polymer having such a number average molecular weight provides an emulsion composition for vibration damping materials having better vibration damping property. The number average molecular weight is more preferably 20,000 or less. Further, the number average molecular weight is preferably 10,000 or more and more preferably 15,000 or more.
[0078] The number average molecular weight can be measured by gel permeation chromatography (GPC) under the same conditions as those in measurement of the weight average molecular weight (Mw) of the polymer (A).
[0079] The (meth)acrylic polymer preferably has a molecular weight distribution of 3.0 or less. Most of polymers included in the (meth)acrylic polymer having such a molecular weight distribution have a number average molecular weight near the preferred one, and the vibration energy applied to the polymer can be effectively converted into the frictional thermal energy. Therefore, better vibration damping property can be exhibited. The molecular weight distribution is more preferably 2.5 or less and still more preferably 2.3 or less.
[0080] The molecular weight distribution is represented by weight average molecular weight/number average molecular weight. [0050]
[0081] The polymer (polymer (A)) in the polymer emulsion preferably has a glass transition temperature of −20° C. to 40° C. Use of the polymer (A) having such a glass transition temperature can effectively impart the vibration damping performance in the practical temperature range of the vibration damping material. The glass transition temperature of the polymer (A) is more preferably −15° C. to 35° C. and still more preferably −10° C. to 30° C.
[0082] The glass transition temperature (Tg) may be determined based on already acquired knowledge, or may be controlled depending on the species or used amounts of the respective monomer components described below. However, the Tg can be calculated from the following formula (2), theoretically.
[0000]
[
Formula
2
]
1
Tg
′
=
[
W
1
′
T
1
+
W
2
′
T
2
+
…
+
W
n
′
T
n
]
(
2
)
[0083] In the formula, Tg′ represents a Tg (absolute temperature) of the polymer; W 1 ′, W 2 ′, and . . . Wn′ each represent a mass fraction of each monomer relative to the entire monomer component; and T 1 , T 2 , and . . . Tn each represent a glass transition temperature (absolute temperature) of the homopolymer of each monomer component.
[0084] When the polymer (polymer (A)) in the polymer emulsion of the present invention is a (meth)acrylic polymer and is in the form of a core-shell structure, the glass transition temperature of the polymer as a core part is preferably 0° C. to 60° C. and more preferably 10° C. to 50° C.
[0085] The glass transition temperature of the polymer as a shell part is preferably −30° C. to 30° C. and more preferably −20° C. to 20° C.
[0086] The difference in glass transition temperature between the polymer as a core part and the polymer as a shell part is preferably 5° C. to 60° C. When a polymer having such a difference in glass transition temperature is used for a vibration damping material, higher vibration damping property can be exhibited in the wide temperature range, and in particular, the vibration damping property are further improved in the practical range of from 20° C. to 60° C. The difference in glass transition temperature is more preferably 5° C. to 50° C. and still more preferably 5° C. to 40° C.
[0087] The average particle size of the emulsion particles in the polymer emulsion is preferably 80 to 450 nm.
[0088] Use of the emulsion particles having an average particle size in the above range can achieve better vibration damping property as well as sufficient basic performances required for the vibration damping material, such as coating appearance or coating formability. The upper limit of the average particle size is more preferably 400 nm or less and still more preferably 350 nm or less. When the average particle size of the emulsion particles is within such a range, the effects of the emulsion composition for vibration damping materials are more effectively exhibited. The lower limit of the average particle size thereof is more preferably 100 nm or more.
[0089] The average particle size (volume average particle size) can be measured in the following way, for example: the emulsion is diluted with distilled water and then sufficiently mixed by stirring, and about 10 ml of the mixture is then put into a glass cell and subjected to measurement by a dynamic light scattering method with a particle size distribution analyzer (NICOMP Model 380, produced by Particle Sizing Systems).
[0090] The emulsion particles with the above average particle size have a particle size distribution, which is defined as a value obtained by dividing a standard deviation by a volume average particle size thereof (standard deviation/volume average particle size×100), of preferably 40% or less and more preferably 30% or less. The emulsion particles having a particle size distribution in the above range do not contain coarse particles. As a result, the emulsion composition for vibration damping materials can provide sufficient heat-drying property.
[0091] The emulsion composition for vibration damping materials of the present invention may contain other component(s) as long as it contains a vibration damping modifier and a polymer emulsion.
[0092] When the emulsion composition for vibration damping materials contains other component(s), the amount of the other component(s) is preferably 10% by mass or less and more preferably 5% by mass or less, based on the entire emulsion composition for vibration damping materials. The other component(s) herein refer(s) to a nonvolatile component (solids content) left in a coating obtained by applying the emulsion composition for vibration damping materials and heating and drying the applied composition. The other component(s) do/does not include an aqueous medium.
[0093] The solids content of the emulsion composition for vibration damping materials of the present invention is preferably 40% to 80% by mass and more preferably 50% to 70% by mass, in the entire emulsion composition for vibration damping materials.
[0094] The amount of the (meth)acrylic polymer in the emulsion composition for vibration damping materials is set so that, for example, the solids content of the (meth)acrylic polymer is preferably 10% to 60% by mass and more preferably 15% to 60% by mass, in 100% by mass of the solids content of the emulsion composition for vibration damping materials.
[0095] The solids content herein refers to components contained in the emulsion composition for vibration damping materials, excluding an aqueous medium.
[0096] The pH of the emulsion composition for vibration damping materials is not particularly limited, and preferably 2 to 10, more preferably 3 to 9.5, and still more preferably 7 to 9. The pH of the polymer emulsion can be adjusted by adding ammonia water, a water-soluble amine, an alkali hydroxide aqueous solution, or the like, to the polymer emulsion.
[0097] The pH herein can be measured with a pH meter. For example, the pH at 25° C. is preferably measured with a pH meter (“F-23” produced by HORIBA, Ltd.).
[0098] The viscosity of the emulsion composition for vibration damping materials is not particularly limited, and preferably 1 to 10,000 mPa·s, more preferably 5 to 5,000 mPa·s, much more preferably 5 to 2,000 mPa·s, still more preferably 5 to 1500 mPa·s, still much more preferably 5 to 1,000 mPa·s, particularly preferably 5 to 500 mPa·s, more particularly preferably 10 to 500 mPa·s, more particularly preferably 20 to 500 mPa·s, and most preferably 50 to 500 mPa·s.
[0099] The viscosity can be measured under the conditions of 25° C. and 30 min −1 with a B type rotational viscometer.
[0100] The polymer emulsion is produced by emulsion polymerization of the monomer component in the presence of an emulsifier. The embodiment of the emulsion polymerization is not particularly limited. For example, the emulsion polymerization can be performed while appropriately adding the monomer component, a polymerization initiator, and an emulsifier to an aqueous medium. A polymerization chain transfer agent or the like is preferably used to control the molecular weight.
[0101] When the polymer emulsion is a core-shell emulsion, it is preferably obtained by a common emulsion polymerization method. Specifically, the core-shell emulsion is preferably produced by multi-stage polymerization in which a monomer component is emulsion polymerized in an aqueous medium to form a core part and a monomer component is further added and emulsion polymerized with an emulsion containing the core part to form a shell part, in the presence of an emulsifier and/or a protective colloid. Thus, the preferred embodiments of the present invention include an embodiment in which the polymer emulsion is a core-shell emulsion which is obtainable by multi-stage polymerization in which a core part is formed, followed by a shell part.
[0102] Examples of the aqueous medium include, but are not particularly limited to, water, a water-miscible solvent, a mixed solvent of two or more water-miscible solvents, and a mixed solvent containing water as a main component and the water-miscible solvent. Among these, water is preferred, considering the safety or influence on environment in application of the coating material containing the polymer emulsion of the present invention.
[0103] The amount of the emulsifier used is preferably 0.1% to 10% by mass based on 100% by mass of the entire compound containing a polymerizable unsaturated bond group in view of polymerization stability. Use of 0.1% by mass or more of the emulsifier provides favorable mechanical stability and polymerization stability. The amount of the emulsifier is more preferably 0.5% to 5% by mass and still more preferably 1% to 3% by mass. Use of the emulsifier in an amount in the above range sufficiently improves the mechanical stability and maintains the polymerization stability.
[0104] Examples of the emulsifier include anionic, cationic, nonionic, amphoteric, and polymeric surfactants. One or more of these may be used.
[0105] Examples of the anionic surfactant include, but are not particularly limited to, polyoxyalkylene alkyl ether sulfates, sodium polyoxyalkylene oleyl ether sulfates, polyoxyalkylene alkyl phenyl ether sulfates, alkyl diphenyl ether disulfonates, polyoxyalkylene (mono, di, tri) styryl phenyl ether sulfates, polyoxylalkylene (mono, di, tri) benzyl phenyl ether sulfates, and alkenyl disuccinates; alkyl sulfates such as sodium dodecyl sulfate, potassium dodecyl sulfate, or ammonium alkyl sulfate; sodium dodecyl polyglycol ether sulfate; sodium sulfolisinolate; alkyl sulfonates such as salts of sulfonated paraffin; alkyl sulfonates such as sodium dodecylbenzene sulfonate or alkali metal sulfates of alkali phenol hydroxyethylene; higher alkyl naphthalene sulfonates; a naphthalene sulfonic acid-formalin condensate; fatty acid salts such as sodium laurate, triethanol amine oleate, or triethanol amine abietate; polyoxyalkyl ether sulfates; polyoxyethylene carboxylate sulfates; polyoxyethylene phenyl ether sulfates; dialkyl sulfosuccinates; and polyoxyethylene alkyl aryl sulfates. One or more of these may be used.
[0106] Preferred examples of commercial products of the anionic surfactant include LATEMUL WX, LATEMUL 118B, PELEX SS-H, EMULGEN A-60, B-66, LEVENOL WZ, and EMAL O (product of Kao Corporation); NEWCOL 707SF, NEWCOL 707SN, NEWCOL 714SF, and NEWCOL 714SN (product of Nippon Nyukazai Co., Ltd.), ABEX-26S, ABEX-2010, 2020, 2030, and DSB (product of Rhodia Nikka Co., Ltd.); and HITENOL 18E and HITENOL NF-08 (product of DAI-ICHI KOGYO SEIYAKU CO., LTD.).
[0107] Further, nonionic surfactants corresponding to these surfactants can also be used.
[0108] A reactive surfactant may be used as the anionic surfactant. Examples of the reactive surfactant include reactive anionic surfactants, sulfosuccinate-type reactive anionic surfactants, and alkenyl succinate-type reactive anionic surfactants. One or more of these may be used.
[0109] Examples of commercial products of the sulfosuccinate-type reactive anionic surfactants include LATEMUL S-120, S-120A, S-180, and S-180A (trade name, product of Kao Corp.), ELEMINOL JS-2 (trade name, product of Sanyo Chemical Industries, Ltd.), and ADEKA-REASOAP SR-10, SR-20, and SR-30 (trade name, product of ADEKA Corp.).
[0110] Examples of commercial products of the alkenyl succinate-type reactive anionic surfactants include LATEMUL ASK (trade name, product of Kao Corp.).
[0111] Further, polyoxyethylene(meth)acrylate sulfonates (e.g. “ELEMINOL RS-30” product of Sanyo Chemical Industries, Ltd., ANTOX MS-60″ product of Nippon Nyukazai Co., Ltd.), allyl group-containing sulfates (salts) such as sulfonate salts of allyloxymethyl alkyloxy polyoxyethylene (e.g. “AQUALON KH-10” product of DAI-ICHI KOGYO SEIYAKU CO., LTD.), and polyoxyalkylene alkenyl ether ammonium sulfate (e.g. “LATEMUL PD-104” product of Kao Corp.) may also be used.
[0112] Further the following reactive surfactants may be used as the anionic surfactant.
[0113] Examples of the reactive surfactant include salts of sulfoalkyl (C1-C4) esters of C3-C5 aliphatic unsaturated carboxylic acids, such as salts of sulfoalky(meth)acrylate (e.g. sodium 2-sulfoethyl(meth)acrylate, ammonium 3-sulfopropyl(meth)acrylate); and salts of alkyl sulfoalkyl diesters of aliphatic unsaturated dicarboxylic acids (e.g. sodium alkyl sulfopropylmaleate, ammmonium polyoxyethylene alkyl sulfopropylmaleate, or ammonium polyoxyethylene alkyl sulfoethylfumarate).
[0114] Examples of the nonionic surfactant include, but are not particularly limited to, polyoxyethylene alkyl ethers; polyoxyethylene alkylaryl ethers; sorbitan aliphatic esters; polyoxyethylene sorbitan aliphatic esters; aliphatic monoglycerides such as glycerol monolaurate; a polyoxyethylene-oxypropylene copolymer; and a condensate of ethylene oxide with an aliphatic amine, amide, or acid. For example, EMULGEN 1118S (product of Kao Corporation) is commercially available as the nonionic surfactant. Also reactive nonionic surfactants such as allyloxymethyl alkoxy ethyl hydroxy polyoxyethylene (e.g. “ADEKA-REASOAP ER-20” product of ADEKA Corp.); and polyoxyalkylene alkenyl ether (e.g. “LATEMUL PD-420”, “LATEMUL PD-430”, product of Kao Corp.) may be used. One or more of these may be used.
[0115] Examples of the cationic surfactant include, but are not particularly limited to, dialkyl dimethyl ammonium salts, ester type dialkyl ammonium salts, amide type dialkyl ammonium salts, and dialkylimidazolinium salts. One or more of these may be used.
[0116] Examples of the amphoteric surfactant include, but are not particularly limited to, alkyl dimethyl aminoacetic acid betaine, alkyl dimethyl amine oxide, alkyl carboxymethyl hydroxyethyl imidazolinium betaine, alkyl amide propyl betaine, and alkyl hydroxy sulfobetaine. One or more of these may be used.
[0117] Examples of the polymeric surfactant include, but are not particularly limited to, polyvinyl alcohols and modified products thereof; (meth)acrylic water-soluble polymers; hydroxyethyl(meth)acrylic water-soluble polymers; hydroxypropyl(meth)acrylic water-soluble polymers; and polyvinyl pyrrolidone. One or more of these may be used.
[0118] Among the surfactants, an ethylene oxide chain-containing anionic surfactant is preferably used. Use of an ethylene oxide chain-containing anionic surfactant provides a coating excellent in coating appearance and vibration damping property, with favorable workability.
[0119] Among the surfactants, a non-nonylphenyl surfactant is preferably used in view of influence on environment.
[0120] The amount of the surfactant may be appropriately determined depending on, for example, the type of the surfactant or a monomer component to be used. As the minimum amount needed to obtain stability during polymerization or storage stability after polymerization, for example, the amount of the surfactant is preferably 0.1 to 10 parts by mass, more preferably 0.5 to 5 parts by mass, and still more preferably 1 to 3 parts by mass, based on 100 parts by mass of the entire monomer component for forming the polymer.
[0121] Examples of the protective colloid include polyvinyl alcohols such as partially saponified polyvinyl alcohols, completely saponified polyvinyl alcohols, or modified polyvinyl alcohols; cellulose derivatives such as hydroxyethyl cellulose, hydroxypropyl cellulose, and salt of carboxymethyl cellulose; and natural polysaccharides such as guar gum. One or more of these may be used. The protective colloid may be used alone or in combination with a surfactant.
[0122] The amount of the protective colloid is appropriately determined depending on use conditions. For example, the amount of the protective colloid is preferably 5 parts by mass or less and more preferably 3 parts by mass or less, based on 100 parts by mass of the entire monomer component for forming the polymer.
[0123] The polymerization initiator may be any substance as long as it decomposes by heating to generate radical molecules. A water-soluble initiator is preferably used. Examples of the water-soluble initiator include persulfates such as potassium persulfate, ammonium persulfate, or sodium persulfate; water-soluble azo compounds such as 2,2′-azobis(2-amidinopropane)dihydrochloride or 4,4′-azobis(4-cyanopentanoic acid); thermal decomposition initiators such as hydrogen peroxide; redox polymerization initiators such as a combination of hydrogen peroxide and ascorbic acid, a combination of t-butyl hydroperoxide and rongalite, a combination of potassium persulfate and a metal salt, and a combination of ammonium persulfate and sodium hydrogen sulfite. One or more of these may be used.
[0124] The amount of the polymerization initiator is not particularly limited and is appropriately determined depending on the type or the like of the polymerization initiator. For example, the amount of the polymerization initiator is preferably 0.1 to 2 parts by mass and more preferably 0.2 to 1 part by mass, based on 100 parts by mass of the entire monomer component for forming the polymer.
[0125] A reducing agent may be used in combination with the polymerization initiator, if necessary, in order to accelerate the emulsion polymerization. Examples of the reducing agent include reducing organic compounds such as ascorbic acid, tartaric acid, citric acid, or glucose; and reducing inorganic compounds such as sodium thiosulfate, sodium sulfite, sodium bisulfite, sodium metabisulfite, sodium hydrogen sulfite, or thiourea dioxide. One or more of these may be used.
[0126] The amount of the reducing agent is not particularly limited, and preferably, for example, 0.05 to 1 part by mass based on 100 parts by mass of the entire monomer component for forming the polymer.
[0127] Further, the mole ratio of the polymerization initiator to the reducing agent blended (polymerization initiator/reducing agent) is preferably 1.0 to 2.0, more preferably 1.2 to 1.9, and still more preferably 1.2 to 1.8.
[0128] Examples of the polymerization chain transfer agent include, but are not particularly limited to, alkyl mercaptans such as hexyl mercaptan, octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, n-hexadecyl mercaptan, or n-tetradecyl mercaptan; halogenated hydrocarbons such as carbon tetrachloride, carbon tetrabromide, or ethylene bromide; alkyl mercaptocarboxylates such as 2-ethylhexyl mercaptoacetate, 2-ethylhexyl mercaptopropionate, or tridecyl mercaptopropionate; alkoxy alkyl mercaptocarboxylates such as methoxybutyl mercaptoacetate or methoxybutyl mercaptopropionate; mercaptoalkyl carboxylates such as 2-mercaptoethyl octanoate; α-methylstyrene dimer, terpinolene, α-terpinene, γ-terpinene, dipentene, anisole, or allyl alcohol. Each of these may be used alone, or two or more of these may be used in combination. Among these, preferred are alkylmercaptans such as hexylmercaptan, octylmercaptan, n-dodecylmercaptan, t-dodecylmercaptan, n-hexadecylmercaptan, or n-tetradecylmercaptan.
[0129] The amount of the polymerization chain transfer agent is, for example, preferably 2.0 parts by mass or less, more preferably 1.0 part by mass or less, and still more preferably 0.8 parts by mass or less, based on 100 parts by mass of the entire monomer component. The amount of the polymerization chain transfer agent is preferably 0.1 parts by mass or more and more preferably 0.3 parts by mass or more, based on 100 parts by mass of the entire monomer component.
[0130] The emulsion polymerization may be performed, if necessary, in the presence of a chelating agent such as sodium ethylenediamine tetraacetate, a dispersant such as sodium polyacrylate, or an inorganic salt. The monomer component, the polymerization initiator, or the like may be added by, for example, en bloc addition, continuous addition, or multi-stage addition. These addition methods may be appropriately employed in combination.
[0131] Regarding the emulsion polymerization conditions in the production method, the polymerization temperature is not particularly limited, and preferably 0° C. to 100° C. and more preferably 40° C. to 95° C., for example. The polymerization time is not particularly limited, and preferably 1 to 15 hours and more preferably 5 to 10 hours, for example.
[0132] The method for adding the monomer component, the polymerization initiator, or the like is not particularly limited, and may be, for example, en bloc addition, continuous addition, or multi-stage addition. These methods may be appropriately employed in combination.
[0133] In the method for producing the polymer emulsion, the emulsion produced by emulsion polymerization is preferably neutralized with a neutralizer. As a result, the emulsion can be stabilized.
[0134] Examples of the neutralizer include, but are not particularly limited, tertiary amines such as triethanolamine, 2-methyl amino ethanol, dimethylethanolamine, diethylethanolamine, or morpholine; diglycol amine and ammonia water; and sodium hydroxide. Each of these may be used alone, or two or more of these may be used in combination. Among these, a volatile base which evaporates from a coating formed from the emulsion composition for vibration damping materials essentially containing the polymer emulsion by heating is preferably used because it improves the water resistance and the like of the coating. More preferably, an amine having a boiling point of 80° C. or higher, particularly 80° C. to 360° C. is used because it provides favorable heat-drying property and improves the vibration damping property. Preferred examples of the neutralizer include tertiary amines such as triethanolamine, dimethylethanolamine, diethylethanolamine, morpholine, or diglycolamine. More preferably, an amine with a boiling point of 130° C. to 280° C. is used. The above boiling point is a boiling point at normal pressure.
[0135] The molecular weight of the neutralizer is not particularly limited, and is preferably 130 to 280 in terms of its volatility.
[0136] Further, the amine is preferably added in an amount of 0.6 to 1.4 equivalents and more preferably 0.8 to 1.2 equivalents, per equivalent of an acid group of the polymer in the polymer emulsion.
[0137] The emulsion composition for vibration damping materials of the present invention can be prepared by adding the vibration damping modifier to the polymer emulsion prepared as described above and mixing them.
[0138] Another aspect of the present invention includes a thick-film coating composition for heat-drying that contains the emulsion composition for vibration damping materials of the present invention and at least one selected from the group consisting of pigments, fillers, foaming agents, and thickeners.
[0139] Such a thick-film coating composition for heat-drying essentially including the emulsion composition for vibration damping materials of the present invention has excellent heat-drying property and it provides a vibration damping material exhibiting particularly excellent vibration damping property.
[0140] In cases where the thick-film coating composition for heat-drying contains a foaming agent, a coating formed therefrom sometimes does not have sufficient strength. However, in cases where the emulsion composition for vibration damping materials of the present invention contains a (meth)acrylic polymer having a number average molecular weight of 25,000 or less, the vibration damping coating composition can provide a coating with excellent strength even when the composition contains a foaming agent.
[0141] Another aspect of the present invention includes the thick-film coating composition for heat-drying (vibration damping coating composition) including a foaming agent and the emulsion composition for vibration damping materials of the present invention which contains a (meth)acrylic polymer having a number average molecular weight of 25,000 or less.
[0142] The thick-film coating composition for heat-drying of the present invention can be produced by blending the polymer emulsion prepared as described above, the vibration damping modifier, and at least one selected from the group consisting of pigments, fillers, foaming agents, and thickeners.
[0143] Another aspect of the present invention includes a method for producing the thick-film coating composition for heat-drying which includes the step of blending the polymer emulsion, the vibration damping modifier, and at least one selected from the group consisting of pigments, fillers, foaming agents, and thickeners.
[0144] The method for producing the thick-film coating composition for heat-drying of the present invention may include the step of blending other component(s) (4), as long as the method includes the step of blending the polymer emulsion (1), the vibration damping modifier (2), at least one (3) selected from the group consisting of pigments, fillers, foaming agents, and thickeners. These components may be added at a time, or two or three of the components (1) to (4) are added first, and the rest of the components are then added.
[0145] The thick-film coating composition for heat-drying preferably has a solids content of 40% to 90% by mass, more preferably 50% to 90% by mass, and still more preferably 60% to 90% by mass, in 100% by mass of the entire thick-film coating composition for heat-drying.
[0146] As for the content of the emulsion composition for vibration damping materials in the thick-film coating composition for heat-drying, the solids content of the emulsion composition for vibration damping materials is for example, preferably 10% to 60% by mass and more preferably 15% to 60% by mass, in 100% by mass of the solids content of the thick-film coating composition for heat-drying.
[0147] The vibration damping coating composition including a foaming agent and the emulsion composition for vibration damping materials of the present invention which contains a (meth)acrylic polymer having a number average molecular weight of 25,000 or less can be produced by blending a foaming agent, the emulsion composition for vibration damping materials of the present invention which contains a (meth)acrylic polymer having a number average molecular weight of 25,000 or less, and if necessary other component(s). Another aspect of the present invention includes such a method for producing the vibration damping coating composition which includes a step of blending a foaming agent and an emulsion containing a (meth)acrylic polymer having a number average molecular weight of 25,000 or less which is prepared by emulsion polymerization of a monomer component.
[0148] The method for producing the vibration damping coating composition including a foaming agent and the emulsion composition for vibration damping materials of the present invention which contains a (meth)acrylic polymer having a number average molecular weight of 25,000 or less may include the step of blending other component(s) such as a filler, a pigment, or a thickener, as long as the method includes the step of blending a foaming agent and an emulsion containing a (meth)acrylic polymer having a number average molecular weight of 25,000 or less which is prepared by emulsion polymerization of a monomer component. In cases where the method includes the step of blending other component(s), a foaming agent and other component(s) may be added to the (meth)acrylic polymer emulsion in any order. The method for producing the vibration damping coating composition of the present invention may include the step of adding a foaming agent to the (meth)acrylic polymer emulsion first or the step of adding other component(s) to the (meth)acrylic polymer emulsion first.
[0149] The vibration damping coating composition including a foaming agent and the emulsion composition for vibration damping materials of the present invention which contains a (meth)acrylic polymer having a number average molecular weight of 25,000 or less contains the emulsion composition for vibration damping materials of the present invention in such an amount that the solids content of the emulsion composition for vibration damping materials is preferably 10% to 60% by mass and more preferably 15% to 60% by mass, in 100% by mass of the solids content of the vibration damping coating composition.
[0150] The thick-film coating composition for heat-drying has a pH of preferably 7 to 11 and more preferably 7 to 9. The pH can be measured by the same method as described above.
[0151] The thick-film coating composition for heat-drying has a viscosity of preferably 100 to 2,000 Pa·s and more preferably 200 to 1,000 Pa·s, under the condition of 2 min −1 (=2 rpm). The viscosity is preferably 10 to 500 Pa·s and more preferably 30 to 300 Pa·s, under the condition of 20 min −1 (=20 rpm).
[0152] The thick-film coating composition having such a viscosity is suitable as an application type composition for vibration damping materials, which is easily applied to a base material and free from liquid sagging.
[0153] The viscosity of the thick-film coating composition for heat-drying can be measured by the same method as in the following examples.
[0154] The vibration damping coating composition including a foaming agent and the emulsion composition for vibration damping materials of the present invention which contains a (meth)acrylic polymer having a number average molecular weight of 25,000 or less has any pH, but the pH is preferably 2 to 10, more preferably 3 to 9, and still more preferably 7 to 8. The pH of the vibration damping coating composition can be adjusted by adding ammonia water, a water-soluble amine, an aqueous alkali hydroxide solution, or the like, to the resin.
[0155] The pH of the vibration damping coating composition can be measured by the same method as in the measurement of the pH of the emulsion composition for vibration damping materials.
[0156] The vibration damping coating composition including a foaming agent and the emulsion composition for vibration damping materials of the present invention which contains a (meth)acrylic polymer having a number average molecular weight of 25,000 or less may have any viscosity, but the viscosity is preferably 100 to 2,000 Pa·s and more preferably 200 to 1,000 Pa·s, under the condition of 2 min −1 (=2 rpm). Further, the viscosity is preferably 10 to 500 Pa·s and more preferably 30 to 300 Pa·s, under the condition of 20 min −1 (=20 rpm).
[0157] The vibration damping coating composition having such a viscosity is suitable as an application type composition for vibration damping materials, which is easily applied to a base material and free from liquid sagging.
[0158] The viscosity can be measured under the condition of 25° C. with a B type rotational viscometer.
[0159] Examples of the other component(s) that may be added to the thick-film coating composition for heat-drying of the present invention include pigments; foaming agents; thickeners, aqueous cross-linking agents; fillers, gelling agents; dispersants; defoaming agents; colorants; rustproof pigments; plasticizers; stabilizers; wetting agents; antiseptic agents; foaming inhibitors; anti-aging agents; mildew-proofing agents; ultraviolet absorbers; and antistatic agents. One or more of these may be used.
[0160] The other component(s) can be mixed with the emulsion composition for vibration damping materials or the like, for example, by means of a butterfly mixer, planetary mixer, spiral mixer, kneader, or dissolver.
[0161] As the pigment, one or more of the colorants, antirust pigments, and the like listed below may be used. The amount of the pigment is preferably 0.2 to 700 parts by mass and more preferably 100 to 550 parts by mass, based on 100 parts by mass of the solids content of the emulsion composition for vibration damping materials.
[0162] Preferred examples of the foaming agent include a low-boiling point hydrocarbon-containing thermal expansion microcapsule, an organic foaming agent, and an inorganic foaming agent. One or more of these may be used. Examples of the thermal expansion microcapsule include Matsumoto Microsphere F-30, F-50 (product of Matsumoto Yushi-Seiyaku Co., Ltd.); and EXPANCEL WU642, WU551, WU461, DU551, DU401 (product of Japan Expancel Co., Ltd.). Examples of the organic foaming agent include azodicarbonamide, azobisisobutyronitrile, N,N-dinitrosopentamethylenetetramine, p-toluenesulfonylhydrazine, and p-oxybis(benzenesulfohydrazide). Examples of the inorganic foaming agent include sodium bicarbonate, ammonium carbonate, and silicon hydride.
[0163] The amount of the foaming agent is preferably 0.2 to 3.0 parts by mass and more preferably 0.3 to 2.0 parts by mass, based on 100 parts by mass of the solids content of the emulsion composition for vibration damping materials.
[0164] The amount of the foaming agent in the vibration damping coating composition including a foaming agent and the emulsion composition for vibration damping materials of the present invention which contains a (meth)acrylic polymer having a number average molecular weight of 25,000 or less is preferably 0.4% to 8.0% by mass and more preferably 0.6% to 7.0% by mass, based on 100% by mass of the solids content of the emulsion composition for vibration damping materials.
[0165] Examples of the thickener include, for example, polyvinyl alcohol, cellulose derivatives, and polycarboxylic acid resins. The amount of the thickener is preferably 0.01 to 2 parts by mass, more preferably 0.05 to 1.5 parts by mass, and still more preferably 0.1 to 1 part by mass, in terms of solids content, based on 100 parts by mass of the solids content of the emulsion composition for vibration damping materials.
[0166] Preferred examples of the aqueous cross-linking agent include oxazoline compounds such as EPOCROS WS-500, WS-700, K-2010, 2020, 2030 (trade name, product of NIPPON SHOKUBAI CO., LTD.); epoxy compounds such as ADEKA resin EMN-26-60, EM-101-50 (trade name, product of ADEKA Corp.); melamine compounds such as CYMEL C-325 (trade name, product of Mitsui Cytec Ind.); block isocyanate compounds; zinc oxide compounds such as AZO-50 (trade name, 50% by mass of zinc oxide aqueous dispersant, product of NIPPON SHOKUBAI CO., LTD.).
[0167] The amount of the aqueous cross-linking agent is preferably 0.01 to 20 parts by mass, more preferably 0.15 to 15 parts by mass, and still more preferably 0.5 to 15 parts by mass, in terms of solids content, based on 100 parts by mass of the solids content of the emulsion composition for vibration damping materials.
[0168] The aqueous cross-linking agent may be added to the emulsion composition for vibration damping materials or may be added together with other component(s) when the thick-film coating composition for heat-drying is prepared. Addition of the cross-linking agent to the emulsion composition for vibration damping materials or the thick-film coating composition for heat-drying can improve toughness of the resin. Thereby, sufficiently high vibration damping property are exhibited in a high temperature range. In particular, an oxazoline compound is preferably used.
[0169] Examples of the filler include inorganic fillers such as calcium carbonate, kaolin, silica, talc, barium sulfate, alumina, iron oxide, titanium oxide, glass powder, magnesium carbonate, aluminum hydroxide, talc, diatomaceous earth, or clay; flaky inorganic fillers such as glass flakes or mica; and filamentous inorganic fillers such as metal oxide whiskers or glass fibers.
[0170] The amount of the filler is preferably 50 to 700 parts by mass and more preferably 100 to 550 parts by mass, based on 100 parts by mass of the solids content of the emulsion composition for vibration damping materials.
[0171] Examples of the gelling agent include starch and agar.
[0172] Examples of the dispersant include inorganic dispersants such as sodium hexametaphosphate or sodium tripolyphosphate, and organic dispersants such as polycarboxylic acid-based dispersants.
[0173] Examples of the defoaming agent include silicone defoaming agents.
[0174] Examples of the colorant include organic and inorganic colorants such as titanium oxide, carbon black, red iron oxide, Hansa yellow, benzine yellow, phthalocyanine blue, or quinacridone red.
[0175] Examples of the rustproof pigments include metal salts of phosphoric acid, molybdic acid, and boric acid.
[0176] Examples of the antiseptic agent include isothiazoline compounds.
[0177] In addition to the above other components, a polyvalent metal compound may be used. Such a polyvalent metal compound improves stability, dispersibility, and heat-drying property of the thick-film coating composition for heat-drying, and vibration damping property of the vibration damping material formed from the thick-film coating composition for heat-drying. Examples of the polyvalent metal compound include, but are not particularly limited to, zinc oxide, zinc chloride, and zinc sulfate. One or more of these may be used.
[0178] The polyvalent metal compound may be in the form of, for example, a powder, aqueous dispersion, or emulsified dispersion. In particular, the polyvalent metal compound is preferably used in the form of an aqueous dispersion or emulsified dispersion, and more preferably in the form of an emulsified dispersion because the dispersibility of the compound in the thick-film coating composition for heat-drying is improved.
[0179] The amount of the polyvalent metal compound is preferably 0.05 to 5.0 parts by mass and more preferably 0.05 to 3.5 parts by mass, based on 100 parts by mass of the solids content of the thick-film coating composition for heat-drying.
[0180] Another aspect of the present invention includes a vibration damping material obtained by applying the thick-film coating composition for heat-drying and drying the applied composition. The resulting coating has a thickness of preferably 1 to 5 mm.
[0181] In cases where the thick-film coating composition for heat-drying is a vibration damping coating composition including a foaming agent and the emulsion composition for vibration damping materials of the present invention which contains a (meth)acrylic polymer having a number average molecular weight of 25,000 or less, a coating formed from the vibration damping coating composition preferably has a thickness of 1.5 to 4.5 mm because the coating with such a thickness is excellent in vibration damping property and peel strength.
[0182] The thick-film coating composition for heat-drying can provide a coating as a vibration damping material, for example, by applying the composition to a base material and drying the applied composition. The thick-film coating composition for heat-drying can be applied to a base material by means of, for example, a brush, spatula, air spray, airless spray, mortar gun, or texture gun.
[0183] The application amount of the thick-film coating composition for heat-drying may be appropriately determined depending on the intended application, desired performance, or the like. For obtaining sufficient functionality such as vibration damping property, for example, the amount is preferably enough to form a coating with a thickness after drying of preferably not less than 1 mm, more preferably not less than 1.5 mm. Further, in view of the drying property of the coating, the coating after drying preferably has a thickness of not more than 5 mm and more preferably not more than 4.5 mm.
[0184] After the thick-film coating composition for heat-drying is applied, the applied composition may be dried by heating or at atmospheric temperature to form a coating. The thick-film coating composition for heat-drying of the present invention is excellent in heat-drying property. Therefore, in view of the efficiency, the thick-film coating composition for heat-drying is preferably dried by heating. The lower limit of the temperature of drying by heating is preferably 110° C. or higher and more preferably 120° C. or higher. The upper limit of the temperature of drying by heating is preferably 210° C. or lower and more preferably 170° C. or lower.
[0185] The vibration damping property of the thick-film coating composition for heat-drying, when used for vibration damping materials, can be evaluated by determining the loss coefficient of a coating formed from the thick-film coating composition for heat-drying.
[0186] The loss coefficient is usually represented by η, and represents the degree of attenuation of vibration applied to the vibration damping material. A higher loss coefficient indicates that the coating has higher vibration damping performance.
[0187] The loss coefficient is commonly determined by a resonance method in which a loss coefficient at around the resonant frequency is measured, and is specifically determined by a half-width method, attenuation factor method, or mechanical impedance method. Regarding the thick-film coating composition for heat-drying of the present invention, the loss coefficient of a coating formed from the thick-film coating composition for heat-drying is favorably measured by a resonance method (3 dB method) using a cantilever method. Measurement using a cantilever method can be performed by means of, for example, a FFT analyzer (CF-5200) produced by ONO SOKKI CO., LTD.
[0188] The loss coefficient is preferably measured by forming a film in such a way that the vibration damping coating composition in a volume of 200 mm in length×10 mm in width×3.0 mm in thickness is applied to a cold rolling steel plate (SPCC-SD: 250 mm in length×10 mm in width×1.6 mm in thickness), and dried at 95° C. for 30 minutes, and subsequently dry baked at 130° C. for 60 minutes. The loss coefficient is preferably measured at, for example, 20° C., 30° C., 40° C., 60° C., and optionally at 50° C. by a resonance method (3 dB method), and evaluation is performed based on the highest values of the resulting loss coefficients. Further, since the practical temperature range of the coating formed from the thick-film coating composition for heat-drying is usually 20° C. to 60° C., the vibration damping performance may be evaluated based on the total value of the loss coefficients measured at the above temperatures 20° C. to 60° C. The coating formed from the thick-film coating composition for heat-drying preferably has a total of loss coefficient at 20° C., 40° C., and 60° C. of preferably 0.120 or more and more preferably 0.200 or more. Such a thick-film coating composition for heat-drying can be evaluated to exhibit sufficient vibration damping property in the range of 20° C. to 60° C. which is the practical temperature range of the coating formed from the composition.
[0189] The thick-film coating composition for heat-drying of the present invention can provide a coating that exhibits excellent vibration damping property, and can be used for structures such as automobiles, railway vehicles, ships, aircrafts, electrical devices, buildings, or construction machinery. In particular, the composition is preferably used for bake coating of a steel plate for vehicles such as automobiles or railway vehicles. The preferred embodiments of the present invention include use of the thick-film coating composition for heat-drying of the present invention for bake coating of a steel plate for vehicles.
[0190] As described above, the thick-film coating composition for heat-drying of the present invention provides a coating having improved strength and adhesion to a base material, and such a coating is less likely to break or peel off. Therefore, the coating composition is favorably used particularly for members for vehicles (bake coating of steel plate for vehicles) which are likely to be subjected to vibration or impacts.
Advantageous Effects of Invention
[0191] The above-mentioned features of the emulsion composition for vibration damping materials of the present invention provide excellent vibration damping property and allow its use for vibration damping materials.
BRIEF DESCRIPTION OF DRAWINGS
[0192] FIG. 1 is a schematic view showing how to measure the peel strength in the examples.
DESCRIPTION OF EMBODIMENTS
[0193] The present invention is described in more detail with reference to Examples below, but the present invention is not limited to only these Examples. The terms, “part(s)” and “%” represent “part(s) by weight” and “% by weight”, respectively, unless otherwise specified.
[0194] The physical characteristics and properties (the weight average molecular weight and glass transition temperature of polymers in polymer emulsions, the average particle size of emulsion particles, and the nonvolatile content, pH, and viscosity of emulsion compositions for vibration damping materials) were measured or calculated as described below in the examples and comparative examples.
<Weight Average Molecular Weight and Number Average Molecular Weight>
[0195] The weight average molecular weight and number average molecular weight were measured by gel permeation chromatography (GPC) under the following conditions.
[0196] Measuring equipment: HLC-8120GPC (trade name, product of Tosoh Corporation)
[0197] Molecular-weight column: TSK-GEL, GMHXL-L and TSK-GEL G5000HXL (all products of Tosoh Corporation) connected in series
[0198] Eluent: tetrahydrofuran (THF)
[0199] Calibration curve reference material: polystyrene (product of Tosoh Corporation)
[0200] Measuring method: A measurement object was dissolved in THF to a solids content of about 0.2% by mass, and the resulting solution was filtered through a filter. The filtrate was measured for the molecular weights as a measurement sample.
<Glass Transition Temperature (Tg)>
[0201] The Tg was determined from the following formula (2) based on the monomer composition used in each stage.
[0000]
[
Formula
3
]
1
Tg
′
=
[
W
1
′
T
1
+
W
2
′
T
2
+
…
+
W
n
′
T
n
]
(
2
)
[0202] Tg values calculated from the monomer compositions in all the stages were expressed as “total Tg”.
[0203] The following shows the glass transition temperature (Tg) values of homopolymers which were used to calculate the Tg values of the polymerizable monomer components from the formula (2).
Methyl methacrylate (MMA): 105° C. Styrene (St): 100° C. Butyl acrylate (BA): −56° C. 2-Ethylhexyl acrylate (2EHA): −70° C. Acrylic acid (AA): 95° C.
<Average Particle Size>
[0209] The volume average particle size was measured by a dynamic light scattering method using a particle size distribution analyzer (“NICOMP Model 380” product of Particle Sizing Systems).
<Nonvolatile Content (N.V.)>
[0210] An about 1 g of an emulsion composition was weighed out, and dried in a hot air dryer at 110° C. for one hour. The residue amount after drying was measured as its nonvolatile content and expressed as % by mass relative to the mass before drying.
[0000] <pH>
[0211] The pH at 25° C. was measured using a pH meter (“F-23” product of HORIBA, Ltd.).
<Viscosity>
[0212] The viscosity was measured at under the conditions of 25° C. and 30 min −1 using a B type rotary viscometer (“VISCOMETER TUB-10” product of Toki Sangyo Co., Ltd.).
COMPARATIVE EXAMPLE 1
[0213] A polymerization vessel equipped with a stirrer, a reflux condenser, a thermometer, a nitrogen inlet tube and a dropping funnel was charged with deionized water (285 parts). Then, the internal temperature was increased to 75° C. under stirring and nitrogen flow. The dropping funnel was charged with a monomer emulsion of the first step which was composed of styrene (180 parts), methyl methacrylate (180 parts), 2-ethylhexyl acrylate (130 parts), acrylic acid (10 parts), t-dodecyl mercaptan (3.0 parts), a previously adjusted 20% aqueous solution of HITENOL 18E (trade name, produced by Dai-ichi Kogyo Seiyaku Co., Ltd.) (75 parts) and deionized water (100 parts). While the internal temperature of the polymerization vessel was maintained at 80° C., a 50-part portion of the monomer emulsion, a 3% potassium persulfate aqueous solution (6.6 parts) and a 2% sodium hydrogen sulfite aqueous solution (5.0 parts) were added to initiate initial polymerization. After 20 minutes, the rest of the monomer emulsion was uniformly added dropwise over 120 minutes with the reaction system being maintained at 80° C. Simultaneously, a 3% potassium persulfate aqueous solution (80 parts) and a 2% sodium hydrogen sulfite aqueous solution (30 parts) were uniformly added dropwise over 120 minutes. After the completion of dropwise addition, the temperature was maintained for 60 minutes. The dropping funnel was then charged with a monomer emulsion of the second step which was composed of styrene (105 parts), methyl methacrylate (100 parts), 2-ethylhexyl acrylate (85 parts), butyl acrylate (200 parts), acrylic acid (10 parts), t-dodecyl mercaptan (4.0 parts), a previously adjusted 20% aqueous solution of HITENOL 18E (trade name, produced by Dai-ichi Kogyo Seiyaku Co., Ltd.) (75 parts) and deionized water (100 parts). The monomer emulsion was uniformly added dropwise into the reaction solution over 120 minutes. Simultaneously, a 3% potassium persulfate aqueous solution (80 parts) and a 2% sodium hydrogen sulfite aqueous solution (30 parts) were uniformly added dropwise over 120 minutes. After the completion of dropwise addition, the temperature was maintained for 90 minutes to complete the polymerization. The resulting reaction solution was cooled to room temperature, and 2-dimethylethanolamine (20 parts) and FINECIDE HS-10 (trade name, produced by Tokyo Fine Chemical CO., LTD., active component: 5%) (3 parts) were added. Thus, comparative emulsion composition 1 for vibration damping materials which had a nonvolatile content of 54.9%, a pH of 8.2, a viscosity of 410 mPa·s, a number average molecular weight of 16,000, and a molecular weight distribution of 3.0 was obtained. The polymer obtained in the first step had a Tg of 34° C., the polymer obtained in the second step had a Tg of −12° C., and the total Tg of these polymers of the first and second steps was 10° C.
COMPARATIVE EXAMPLE 2
[0214] Comparative emulsion composition 2 for vibration damping materials was prepared in the same manner as in Comparative Example 1, except that the monomer emulsion of the first step was composed of methyl methacrylate (300 parts), 2-ethylhexyl acrylate (75 parts), butyl acrylate (115 parts), acrylic acid (10 parts), t-dodecyl mercaptan (2.5 parts), a previously adjusted 20% aqueous solution of LATEMUL 118B (trade name, produced by Kao Corp.) (75 parts) and deionized water (100 parts), that the monomer emulsion of the second step was composed of methyl methacrylate (250 parts), 2-ethylhexyl acrylate (50 parts), butyl acrylate (190 parts), acrylic acid (10 parts), t-dodecyl mercaptan (2.5 parts), a previously adjusted 20% aqueous solution of LATEMUL 118B (trade name, produced by Kao Corp.) (75 parts) and deionized water (100 parts), and that the additive added instead of FINECIDE HS-10 (3 parts) to the reaction solution after cooling to room temperature was ROCIMA 553 (tradename, produced by Dow Chemical Co., active component: 12%) (1.5 parts). The emulsion composition had a nonvolatile content of 55%, a pH of 8.1, a viscosity of 500 mPa·s, a number average molecular weight of 24,000, and a molecular weight distribution of 2.1. The polymer obtained in the first step had a Tg of 18° C., the polymer obtained in the second step had a Tg of 3° C., and the total Tg of these polymers of the first and second steps was 10° C.
COMPARATIVE EXAMPLE 3
[0215] Comparative emulsion composition 3 for vibration damping materials was prepared in the same manner as in Comparative Example 1, except that the monomer emulsion of the first step was composed of 2-ethylhexyl acrylate (50 parts), butyl acrylate (90 parts), styrene (250 parts), acrylic acid (10 parts), t-dodecyl mercaptan (3.0 parts), a previously adjusted 20% aqueous solution of LATEMUL WX (trade name, produced by Kao Corp.) (60 parts) and deionized water (80 parts), that the sodium hydrogen sulfite aqueous solutions used after the initial polymerization were changed to 2.3% sodium hydrogen sulfite aqueous solutions, that the amount of the 3% potassium persulfate aqueous solution added dropwise together with the monomer emulsion was 64 parts, that the amount of the 2.3% sodium hydrogen sulfite aqueous solution used after the initial polymerization was 24 parts, that the monomer emulsion of the second step was composed of 2-ethylhexyl acrylate (290 parts), styrene (300 parts), acrylic acid (10 parts), t-dodecyl mercaptan (3.0 parts), a previously adjusted 20% aqueous solution of LATEMUL WX (trade name, produced by Kao Corp.) (90 parts) and deionized water (120 parts), that the amounts of the 3% potassium persulfate aqueous solution and the 2.3% sodium hydrogen sulfite aqueous solution simultaneously added dropwise were 96 parts and 36 parts, respectively, and that the additive added instead of FINECIDE HS-10 (3 parts) to the reaction solution after cooling to room temperature was PROXEL GXL (trade name, produced by Lonza, active component: 20%) (0.5 parts). The emulsion composition had a nonvolatile content of 54.6%, a pH of 8.0, a viscosity of 290 mPa·s, a number average molecular weight of 20,000, and a molecular weight distribution of 2.0. The polymer obtained in the first step had a Tg of 21° C., the polymer obtained in the second step had a Tg of −8° C., and the total Tg of these polymers of the first and second steps was 3° C.
COMPARATIVE EXAMPLE 4
[0216] Comparative emulsion composition 4 for vibration damping materials was prepared in the same manner as in Comparative Example 1, except that the monomer emulsion of the first step was composed of 2-ethylhexyl acrylate (75 parts), methyl methacrylate (300 parts), butyl acrylate (115 parts), acrylic acid (10 parts), t-dodecyl mercaptan (4.5 parts), a previously adjusted 20% aqueous solution of LATEMUL 118B and EMULGEN 1118S (trade names, both produced by Kao Corp., mass ratio between them: 1:1) (75 parts) and deionized water (100 parts), that the monomer emulsion of the second step was composed of 2-ethylhexyl acrylate (50 parts), methyl methacrylate (250 parts), butyl acrylate (190 parts), acrylic acid (10 parts), t-dodecyl mercaptan (4.5 parts), a previously adjusted 20% aqueous solution of LATEMUL 118B and EMULGEN 1118S (trade names, both produced by Kao Corp., mass ratio between them: 1:1) (75 parts) and deionized water (100 parts), and that the additives added instead of 2-dimethylethanolamine and FINECIDE HS-10 (3 parts) to the reaction solution after cooling to room temperature were triethylamine (22 parts) and PROXEL NBZ (trade name, produced by Lonza, active component: 10%) (1.0 part), respectively. The emulsion composition had a nonvolatile content of 55%, a pH of 8.0, a viscosity of 240 mPa·s, a number average molecular weight of 13,000, and a molecular weight distribution of 2.9. The polymer obtained in the first step had a Tg of 18° C., the polymer obtained in the second step had a Tg of 3° C., and the total Tg of these polymers of the first and second steps was 10° C.
COMPARATIVE EXAMPLE 5
[0217] A polymerization vessel equipped with a stirrer, a reflux condenser, a thermometer, a nitrogen inlet tube and a dropping funnel was charged with deionized water (285 parts). Then, the internal temperature was increased to 75° C. under stirring and nitrogen flow. The dropping funnel was charged with a monomer emulsion which was composed of styrene (285 parts), methyl methacrylate (280 parts), 2-ethylhexyl acrylate (215 parts), butyl acrylate (200 parts), acrylic acid (20 parts), t-dodecyl mercaptan (6 parts), a previously adjusted 20% aqueous solution of HITENOL 18E (trade name, produced by Dai-ichi Kogyo Seiyaku Co., Ltd.) (150 parts) and deionized water (200 parts). While the internal temperature of the polymerization vessel was maintained at 80° C., a 100-part portion of the monomer emulsion, a 3% potassium persulfate aqueous solution (6.6 parts) and a 7.5% sodium hydrogen sulfite aqueous solution (6.6 parts) were added to initiate initial polymerization. After 20 minutes, the rest of the monomer emulsion was uniformly added dropwise over 240 minutes with the reaction system being maintained at 80° C. Simultaneously, a 3% potassium persulfate aqueous solution (160 parts) and a 7.5% sodium hydrogen sulfite aqueous solution (60 parts) were uniformly added dropwise over 240 minutes. After the completion of dropwise addition, the temperature was maintained for 90 minutes to complete the polymerization. The resulting reaction solution was cooled to room temperature, and triethylamine (22 parts) and FINECIDE HS-10 (trade name, produced by Tokyo Fine Chemical CO., LTD., active component: 5%) (3 parts) were added. Thus, comparative emulsion composition 5 for vibration damping materials which had a nonvolatile content of 54%, a pH of 8.3, a viscosity of 320 mPa·s, a number average molecular weight of 31,000, and a molecular weight distribution of 2.3 was obtained. The polymer had a Tg of 10° C.
COMPARATIVE EXAMPLE 6
[0218] Comparative emulsion composition 6 for vibration damping materials was prepared in the same manner as in Comparative Example 5, except that the amount of t-dodecyl mercaptan was changed to 0.1 parts, that the 7.5% sodium hydrogen sulfite aqueous solution was changed to a 2.0% sodium hydrogen sulfite aqueous solution, and that the triethylamine (22 parts) was changed to 2-dimethylethanolamine (20 parts). The emulsion composition had a nonvolatile content of 54.6%, a pH of 7.8, a viscosity of 350 mPa·s, a number average molecular weight of 79,000, and a molecular weight distribution of 3.0.
COMPARATIVE EXAMPLE 7
[0219] Comparative emulsion composition 7 for vibration damping materials was prepared in the same manner as in Comparative Example 1, except that the 2% sodium hydrogen sulfite aqueous solution was not used neither in the initial reaction nor in the dropwise addition, and that the 2-dimethylethanolamine (20 parts) was changed to monoethanolamine (14 parts). The emulsion composition had a nonvolatile content of 56.5%, a pH of 8.3, a viscosity of 1200 mPa·s, a number average molecular weight of 34,000, and a molecular weight distribution of 2.4.
COMPARATIVE EXAMPLE 8
[0220] Comparative emulsion composition 8 for vibration damping materials was prepared in the same manner as in Comparative Example 6, except that the 2-dimethylethanolamine (20 parts) was changed to ammonia (10 parts), and that FINECIDE HS-10 was not used. The emulsion composition had a nonvolatile content of 55.1%, a pH of 8.0, a viscosity of 400 mPa·s, a number average molecular weight of 77,000, and a molecular weight distribution of 3.1.
COMPARATIVE EXAMPLE 9
[0221] Comparative emulsion composition 9 for vibration damping materials was prepared in the same manner as in Comparative Example 6, except that the 2-dimethylethanolamine (20 parts) was changed to ammonia (10 parts), and that formalin (0.5 parts) was used instead of FINECIDE HS-10 (3 parts). The emulsion composition had a nonvolatile content of 55.0%, a pH of 7.7, a viscosity of 350 mPa·s, a number average molecular weight of 78,000, and a molecular weight distribution of 3.1.
COMPARATIVE EXAMPLE 10
[0222] Comparative emulsion composition 10 for vibration damping materials was prepared in the same manner as in Comparative Example 1, except that the amount of t-dodecyl mercaptan used in the first step was 2.0 parts, that the sodium hydrogen sulfite aqueous solution used after the initial polymerization were changed to a 7.5% sodium hydrogen sulfite aqueous solution, that a 100-part portion of the monomer emulsion of the first step was added at the beginning of the initial polymerization, that the amount of t-dodecyl mercaptan used in the second step was 1.0 part, that the 2% sodium hydrogen sulfite aqueous solution used in the second step was changed to a 7.5% sodium hydrogen sulfite aqueous solution, that PROXEL GXL (0.25 parts) and FINECIDE HS-10 (1 part) were used instead of FINECIDE HS-10 (3 parts), and that diglycolamine (22 parts) was used instead of 2-dimethylethanolamine. The emulsion composition had a nonvolatile content of 54.7%, a pH of 7.8, a viscosity of 150 mPa·s, a number average molecular weight of 35,000, and a molecular weight distribution of 2.9. The polymer obtained in the first step had a Tg of 34° C., the polymer obtained in the second step had a Tg of −12° C., and the total Tg of these polymers of the first and second steps was 10° C.
COMPARATIVE EXAMPLE 11
[0223] Comparative emulsion composition 11 for vibration damping materials was prepared in the same manner as in Comparative Example 1, except that t-dodecyl mercaptan was not used in the first step, that a 100-part portion of the monomer emulsion of the first step was added at the beginning of the initial polymerization, that the amount of t-dodecyl mercaptan used in the second step was 0.1 parts, and that PROXEL GXL (0.25 parts) and FINECIDE HS-10 (1 part) were used instead of FINECIDE HS-10 (3 parts). The emulsion composition had a nonvolatile content of 54.6%, a pH of 7.8, a viscosity of 350 mPa·s, a number average molecular weight of 81,000, and a molecular weight distribution of 3.0. The polymer obtained in the first step had a Tg of 34° C., the polymer obtained in the second step had a Tg of −12° C., and the total Tg of these polymers of the first and second steps was 10° C.
COMPARATIVE EXAMPLE 12
[0224] Comparative emulsion composition 12 for vibration damping materials was prepared in the same manner as in Comparative Example 1, except that the amount of water charged in the polymerization vessel was 435 parts, that the 2% sodium hydrogen sulfite aqueous solution was not used neither in the initial reaction nor in the dropwise addition, that the amounts of 3% potassium persulfate used in the initial reaction, in the dropwise addition in the first step, and in the dropwise addition in the second step were 1.6 parts, 35 parts, and 35 parts, respectively, that 2.5 parts of t-dodecyl mercaptan was added dropwise both in the first and second steps, that a 100-part portion of the monomer emulsion of the first step was added at the beginning of the initial polymerization, and that monoethanolamine (14 parts) was used instead of 2-dimethylethanolamine. The emulsion composition had a nonvolatile content of 54.5%, a pH of 8.3, a viscosity of 350 mPa·s, a number average molecular weight of 29,000, and a molecular weight distribution of 2.8. The polymer obtained in the first step had a Tg of 34° C., the polymer obtained in the second step had a Tg of −12° C., and the total Tg of these polymers of the first and second steps was 10° C.
COMPARATIVE EXAMPLE 13
[0225] Comparative emulsion composition 13 for vibration damping materials was prepared in the same manner as in Comparative Example 1, except that the monomer emulsion of the first step was composed of methyl methacrylate (300 parts), 2-ethylhexyl acrylate (75 parts), butyl acrylate (115 parts), acrylic acid (10 parts), t-dodecyl mercaptan (1.0 part), a previously adjusted 20% aqueous solution of LATEMUL 118B (trade name, produced by Kao Corp.) (75 parts) and deionized water (100 parts), that a 100-part portion of the monomer emulsion of the first step was added at the beginning of the initial polymerization, that the monomer emulsion of the second step was composed of methyl methacrylate (250 parts), 2-ethylhexyl acrylate (50 parts), butyl acrylate (190 parts), acrylic acid (10 parts), t-dodecyl mercaptan (1.0 part), a previously adjusted 20% aqueous solution of LATEMUL 118B (trade name, produced by Kao Corp.) (75 parts) and deionized water (100 parts), and that the additive added instead of FINECIDE HS-10 (3 parts) to the reaction solution after cooling to room temperature was ROCIMA 553 (trade name, produced by Dow Chemical Co., active component: 12%) (1.5 parts). The emulsion composition had a nonvolatile content of 54.9%, a pH of 8.0, a viscosity of 440 mPa·s, a number average molecular weight of 45,000, and a molecular weight distribution of 3.1. The polymer obtained in the first step had a Tg of 18° C., the polymer obtained in the second step had a Tg of 3° C., and the total Tg of these polymers of the first and second steps was 10° C.
EXAMPLE 1
[0226] A polymerization vessel equipped with a stirrer, a reflux condenser, a thermometer, a nitrogen inlet tube and a dropping funnel was charged with deionized water (285 parts). Then, the internal temperature was increased to 75° C. under stirring and nitrogen flow. The dropping funnel was charged with a monomer emulsion of the first step which was composed of styrene (180 parts), methyl methacrylate (180 parts), 2-ethylhexyl acrylate (130 parts), acrylic acid (10 parts), t-dodecyl mercaptan (3.0 parts), a previously adjusted 20% aqueous solution of HITENOL 18E (trade name, produced by Dai-ichi Kogyo Seiyaku Co., Ltd.) (75 parts) and deionized water (100 parts). While the internal temperature of the polymerization vessel was maintained at 80° C., a 50-part portion of the monomer emulsion, a 3% potassium persulfate aqueous solution (6.6 parts) and a 2% sodium hydrogen sulfite aqueous solution (5.0 parts) were added to initiate initial polymerization. After 20 minutes, the rest of the monomer emulsion was uniformly added dropwise over 120 minutes with the reaction system being maintained at 80° C. Simultaneously, a 3% potassium persulfate aqueous solution (80 parts) and a 2% sodium hydrogen sulfite aqueous solution (30 parts) were uniformly added dropwise over 120 minutes. After the completion of dropwise addition, the temperature was maintained for 60 minutes. The dropping funnel was then charged with a monomer emulsion of the second step which was composed of styrene (105 parts), methyl methacrylate (100 parts), 2-ethylhexyl acrylate (85 parts), butyl acrylate (200 parts), acrylic acid (10 parts), t-dodecyl mercaptan (4.0 parts), a previously adjusted 20% aqueous solution of HITENOL 18E (trade name, produced by Dai-ichi Kogyo Seiyaku Co., Ltd.) (75 parts) and deionized water (100 parts), and the emulsion was uniformly added dropwise over 120 minutes. Simultaneously, a 3% potassium persulfate aqueous solution (80 parts) and a 2% sodium hydrogen sulfite aqueous solution (30 parts) were uniformly added dropwise over 120 minutes. After the completion of dropwise addition, the temperature was maintained for 90 minutes to complete the polymerization. The resulting reaction solution was cooled to room temperature, and 2-dimethylethanolamine (20 parts), propylene glycol diacetate (21 parts), and FINECIDE HS-10 (trade name, produced by Tokyo Fine Chemical CO., LTD., active component: 5%) (3 parts) were added. Thus, emulsion composition 1 for vibration damping materials which had a nonvolatile content of 54.8%, a pH of 8.2, a viscosity of 410 mPa·s, a number average molecular weight of 17,000, and a molecular weight distribution of 2.9 was prepared. The polymer obtained in the first step had a Tg of 34° C., the polymer obtained in the second step had a Tg of −12° C., and the total Tg of these polymers of the first and second steps was 10° C.
EXAMPLE 2
[0227] Emulsion composition 2 for vibration damping materials was prepared in the same manner as in Example 1, except that the monomer emulsion of the first step was composed of 2-ethylhexyl acrylate (50 parts), styrene (250 parts), butyl acrylate (90 parts), acrylic acid (10 parts), t-dodecyl mercaptan (3.0 parts), a previously adjusted 20% aqueous solution of LATEMUL WX (trade name, produced by Kao Corp.) (60 parts) and deionized water (80 parts), that 64 parts of the 3% potassium persulfate aqueous solution and 24 parts of a 2.3% sodium hydrogen sulfite aqueous solution were simultaneously added dropwise, that the monomer emulsion of the second step was composed of 2-ethylhexyl acrylate (290 parts), styrene (300 parts), acrylic acid (10 parts), t-dodecyl mercaptan (3.0 parts), a previously adjusted 20% aqueous solution of LATEMUL WX (trade name, produced by Kao Corp.) (90 parts) and deionized water (120 parts), that 96 parts of the 3% potassium persulfate aqueous solution and 36 parts of a 2.3% sodium hydrogen sulfite aqueous solution were simultaneously added, and that the additives added instead of propylene glycol diacetate (21 parts) and FINECIDE HS-10 (3 parts) to the reaction solution after cooling to room temperature were dipropylene glycol monopropyl ether (21 parts) and PROXEL GXL (trade name, produced by Lonza, active component 20%) (0.5 parts). The emulsion composition had a nonvolatile content of 54.5%, a pH of 8.1, a viscosity of 500 mPa·s, a number average molecular weight of 20,000, and a molecular weight distribution of 2.1. The polymer obtained in the first step had a Tg of 22° C., the polymer obtained in the second step had a Tg of −8° C., and the total Tg of these polymers of the first and second steps was 3° C.
EXAMPLE 3
[0228] Emulsion composition 3 for vibration damping materials was prepared in the same manner as in Example 1, except that diisodecyl phthalate (21 parts) was used instead of propylene glycol diacetate (21 parts). The emulsion composition had a nonvolatile content of 55.4%, a pH of 8.2, a viscosity of 410 mPa·s, a number average molecular weight of 16,000, and a molecular weight distribution of 3.2. The polymer obtained in the first step had a Tg of 34° C., the polymer obtained in the second step had a Tg of −12° C., and the total Tg of these polymers of the first and second steps was 10° C.
EXAMPLE 4
[0229] Emulsion composition 4 for vibration damping materials was prepared in the same manner as in Example 2, except that diisononyl phthalate (10 parts) and dipropylene glycol monopropyl ether (10 parts) were used instead of dipropylene glycol monopropyl ether (21 parts). The emulsion composition had a nonvolatile content of 54.9%, a pH of 8.0, a viscosity of 290 mPa·s, a number average molecular weight of 18,000, and a molecular weight distribution of 2.2. The polymer obtained in the first step had a Tg of 22° C., the polymer obtained in the second step had a Tg of −8° C., and the total Tg of these polymers of the first and second steps was 3° C.
EXAMPLE 5
[0230] Emulsion composition 5 for vibration damping materials was prepared in the same manner as in Example 1, except that FINECIDE HS-10 was not used, and that dipropylene glycol monobutyl ether (21 parts) was used instead of propylene glycol diacetate (21 parts). The emulsion composition had a nonvolatile content of 54.6%, a pH of 8.1, a viscosity of 360 mPa·s, a number average molecular weight of 20,000, and a molecular weight distribution of 2.5. The polymer obtained in the first step had a Tg of 34° C., the polymer obtained in the second step had a Tg of −12° C., and the total Tg of these polymers of the first and second steps was 10° C.
EXAMPLE 6
[0231] Emulsion composition 6 for vibration damping materials was prepared in the same manner as in Example 2, except that PROXEL GXL was not used, and that dipropylene glycol methyl ether acetate (21 parts) was used instead of dipropylene glycol monopropyl ether (21 parts). The emulsion composition had a nonvolatile content of 54.6%, a pH of 8.0, a viscosity of 280 mPa·s, a number average molecular weight of 18,000, and a molecular weight distribution of 2.2. The polymer obtained in the first step had a Tg of 22° C., the polymer obtained in the second step had a Tg of −8° C., and the total Tg of these polymers of the first and second steps was 3° C.
EXAMPLE 7
[0232] Emulsion composition 7 for vibration damping materials was prepared in the same manner as in Example 2, except that PROXEL GXL was not used, and that propylene glycol diacetate (21 parts) was used instead of dipropylene glycol monopropyl ether (21 parts). The emulsion composition had a nonvolatile content of 54.3%, a pH of 8.0, a viscosity of 280 mPa·s, a number average molecular weight of 18,000, and a molecular weight distribution of 2.2. The polymer obtained in the first step had a Tg of 22° C., the polymer obtained in the second step had a Tg of −8° C., and the total Tg of these polymers of the first and second steps was 3° C.
EXAMPLE 8
[0233] Emulsion composition 8 for vibration damping materials was prepared in the same manner as in Example 2, except that PROXEL GXL was not used. The emulsion composition had a nonvolatile content of 54.5%, a pH of 8.0, a viscosity of 280 mPa·s, a number average molecular weight of 19,000, and a molecular weight distribution of 2.1. The polymer obtained in the first step had a Tg of 22° C., the polymer obtained in the second step had a Tg of −8° C., and the total Tg of these polymers of the first and second steps was 3° C.
EXAMPLE 9
[0234] Emulsion composition 9 for vibration damping materials was prepared in the same manner as in Example 2, except that PROXEL GXL was not used, and that dipropylene glycol monobutyl ether (21 parts) was used instead of dipropylene glycol monopropyl ether (21 parts). The emulsion composition had a nonvolatile content of 54.5%, a pH of 8.0, a viscosity of 280 mPa·s, a number average molecular weight of 19,000, and a molecular weight distribution of 2.1. The polymer obtained in the first step had a Tg of 22° C., the polymer obtained in the second step had a Tg of −8° C., and the total Tg of these polymers of the first and second steps was 3° C.
EXAMPLE 10
[0235] Emulsion composition 10 for vibration damping materials was prepared in the same manner as in Example 2, except that PROXEL GXL was not used, and that dipropylene glycol methyl ether acetate (90 parts) was used instead of dipropylene glycol monopropyl ether (21 parts). The emulsion composition had a nonvolatile content of 54.6%, a pH of 8.0, a viscosity of 230 mPa·s, a number average molecular weight of 20,000, and a molecular weight distribution of 2.2. The polymer obtained in the first step had a Tg of 22° C., the polymer obtained in the second step had a Tg of −8° C., and the total Tg of these polymers of the first and second steps was 3° C.
EXAMPLE 11
[0236] Emulsion composition 11 for vibration damping materials was prepared in the same manner as in Example 2, except that PROXEL GXL was not used, and that propylene glycol diacetate (11 parts) was used instead of dipropylene glycol monopropyl ether (21 parts). The emulsion composition had a nonvolatile content of 54.5%, a pH of 8.0, a viscosity of 290 mPa·s, a number average molecular weight of 19,000, and a molecular weight distribution of 2.1. The polymer obtained in the first step had a Tg of 22° C., the polymer obtained in the second step had a Tg of −8° C., and the total Tg of these polymers of the first and second steps was 3° C.
COMPARATIVE EXAMPLE 14
[0237] Comparative emulsion composition 14 for vibration damping materials was prepared in the same manner as in Example 2, except that PROXEL GXL was not used, and that diethylene glycol monoethyl ether (21 parts) was used instead of dipropylene glycol monopropyl ether (21 parts). The emulsion composition had a nonvolatile content of 54.5%, a pH of 8.0, a viscosity of 280 mPa·s, a number average molecular weight of 19,000, and a molecular weight distribution of 2.2. The polymer obtained in the first step had a Tg of 22° C., the polymer obtained in the second step had a Tg of −8° C., and the total Tg of these polymers of the first and second steps was 3° C.
COMPARATIVE EXAMPLE 15
[0238] Comparative emulsion composition 15 for vibration damping materials was prepared in the same manner as in Example 2, except that PROXEL GXL was not used, and that ethylene glycol mono-n-butyl ether (21 parts) was used instead of dipropylene glycol monopropyl ether (21 parts). The emulsion composition had a nonvolatile content of 54.4%, a pH of 8.1, a viscosity of 290 mPa·s, a number average molecular weight of 19,000, and a molecular weight distribution of 2.2. The polymer obtained in the first step had a Tg of 22° C., the polymer obtained in the second step had a Tg of −8° C., and the total Tg of these polymers of the first and second steps was 3° C.
COMPARATIVE EXAMPLE 16
[0239] Comparative emulsion composition 16 for vibration damping materials was prepared in the same manner as in Example 2, except that PROXEL GXL was not used, and that ethylene glycol monobutyl ether acetate (21 parts) was used instead of dipropylene glycol monopropyl ether (21 parts). The emulsion composition had a nonvolatile content of 54.4%, a pH of 8.0, a viscosity of 290 mPa·s, a number average molecular weight of 19,000, and a molecular weight distribution of 2.2. The polymer obtained in the first step had a Tg of 22° C., the polymer obtained in the second step had a Tg of −8° C., and the total Tg of these polymers of the first and second steps was 3° C.
EXAMPLE 12
[0240] Emulsion composition 12 for vibration damping materials was prepared in the same manner as in Example 1, except that FINECIDE HS-10 was not used, and that diisodecyl phthalate (21 parts) was used instead of propylene glycol diacetate (21 parts). The emulsion composition had a nonvolatile content of 55.4%, a pH of 8.1, a viscosity of 430 mPa·s, a number average molecular weight of 17,000, and a molecular weight distribution of 2.8. The polymer obtained in the first step had a Tg of 34° C., the polymer obtained in the second step had a Tg of −12° C., and the total Tg of these polymers of the first and second steps was 10° C.
EXAMPLE 13
[0241] Emulsion composition 13 for vibration damping materials was prepared in the same manner as in Example 2, except that PROXEL GXL was not used, and that diisodecyl phthalate (21 parts) was used instead of dipropylene glycol monopropyl ether (21 parts). The emulsion composition had a nonvolatile content of 55.1%, a pH of 8.0, a viscosity of 290 mPa·s, a number average molecular weight of 18,000, and a molecular weight distribution of 2.2. The polymer obtained in the first step had a Tg of 22° C., the polymer obtained in the second step had a Tg of −8° C., and the total Tg of these polymers of the first and second steps was 3° C.
EXAMPLE 14
[0242] Emulsion composition 14 for vibration damping materials was prepared in the same manner as in Example 2, except that PROXEL GXL was not used, and that diisononyl phthalate (21 parts) was used instead of dipropylene glycol monopropyl ether (21 parts). The emulsion composition had a nonvolatile content of 55.1%, a pH of 8.0, a viscosity of 290 mPa·s, a number average molecular weight of 19,000, and a molecular weight distribution of 2.2. The polymer obtained in the first step had a Tg of 22° C., the polymer obtained in the second step had a Tg of −8° C., and the total
[0243] Tg of these polymers of the first and second steps was 3° C.
EXAMPLE 15
[0244] Emulsion composition 15 for vibration damping materials was prepared in the same manner as in Example 2, except that PROXEL GXL was not used, and that dioctyl adipate (21 parts) was used instead of dipropylene glycol monopropyl ether (21 parts). The emulsion composition had a nonvolatile content of 55.1%, a pH of 8.0, a viscosity of 2760 mPa·s, a number average molecular weight of 19,000, and a molecular weight distribution of 2.2. The polymer obtained in the first step had a Tg of 22° C., the polymer obtained in the second step had a Tg of −8° C., and the total Tg of these polymers of the first and second steps was 3° C.
EXAMPLE 16
[0245] Emulsion composition 16 for vibration damping materials was prepared in the same manner as in Example 2, except that PROXEL GXL was not used, and that diisononyl phthalate (10 parts) and dipropylene glycol monopropyl ether (10 parts) were used instead of dipropylene glycol monopropyl ether (21 parts). The emulsion composition had a nonvolatile content of 55.0%, a pH of 8.0, a viscosity of 290 mPa·s, a number average molecular weight of 19,000, and a molecular weight distribution of 2.2. The polymer obtained in the first step had a Tg of 22° C., the polymer obtained in the second step had a Tg of −8° C., and the total Tg of these polymers of the first and second steps was 3° C.
COMPARATIVE EXAMPLE 17
[0246] Comparative emulsion composition 17 for vibration damping materials was prepared in the same manner as in Example 2, except that PROXEL GXL was not used, and that dimethyl fumarate (21 parts) was used instead of dipropylene glycol monopropyl ether (21 parts). The emulsion composition had a nonvolatile content of 55.1%, a pH of 8.0, a viscosity of 590 mPa·s, a number average molecular weight of 19,000, and a molecular weight distribution of 2.2. The polymer obtained in the first step had a Tg of 22° C., the polymer obtained in the second step had a Tg of −8° C., and the total Tg of these polymers of the first and second steps was 3° C.
EXAMPLE 17
[0247] Emulsion composition 17 for vibration damping materials was prepared in the same manner as in Example 2, except that PROXEL GXL was not used, and that diisononyl adipate (21 parts) was used instead of dipropylene glycol monopropyl ether (21 parts). The emulsion composition had a nonvolatile content of 55.1%, a pH of 8.1, a viscosity of 640 mPa·s, a number average molecular weight of 19,000, and a molecular weight distribution of 2.2. The polymer obtained in the first step had a Tg of 22° C., the polymer obtained in the second step had a Tg of −8° C., and the total Tg of these polymers of the first and second steps was 3° C.
EXAMPLE 18
[0248] Emulsion composition 18 for vibration damping materials was prepared in the same manner as in Example 2, except that PROXEL GXL was not used, and that diisononyl phthalate (130 parts) was used instead of dipropylene glycol monopropyl ether (21 parts). The emulsion composition had a nonvolatile content of 57.6%, a pH of 8.0, a viscosity of 560 mPa·s, a number average molecular weight of 18,000, and a molecular weight distribution of 2.3. The polymer obtained in the first step had a Tg of 22° C., the polymer obtained in the second step had a Tg of −8° C., and the total Tg of these polymers of the first and second steps was 3° C.
EXAMPLE 19
[0249] Emulsion composition 19 for vibration damping materials was prepared in the same manner as in Example 1, except that diisononyl phthalate (10 parts) and dipropylene glycol monopropyl ether (10 parts) were used instead of propylene glycol diacetate (21 parts). The emulsion composition had a nonvolatile content of 55.1%, a pH of 8.2, a viscosity of 410 mPa·s, a number average molecular weight of 17,000, and a molecular weight distribution of 2.9. The polymer obtained in the first step had a Tg of 34° C., the polymer obtained in the second step had a Tg of −12° C., and the total Tg of these polymers of the first and second steps was 10° C.
EXAMPLE 20
[0250] Emulsion composition 20 for vibration damping materials was prepared in the same manner as in Example 1, except that a 100-part portion of the monomer emulsion of the first step was added at the beginning of the initial polymerization, and that the monomer emulsion of the first step was free from t-dodecyl mercaptan, and that the amount of t-dodecyl mercaptan in the monomer emulsion of the second step was changed from 4.0 parts to 0.1 parts. The emulsion composition had a nonvolatile content of 54.5%, a pH of 7.8, a viscosity of 340 mPa·s, a number average molecular weight of 84,000, and a molecular weight distribution of 3.0. The polymer obtained in the first step had a Tg of 34° C., the polymer obtained in the second step had a Tg of −12° C., and the total Tg of these polymers of the first and second steps was 10° C.
EXAMPLE 21
[0251] Emulsion composition 21 for vibration damping materials was prepared in the same manner as in Example 1, except that a 100-part portion of the monomer emulsion of the first step was added at the beginning of the initial polymerization, that the monomer emulsion of the first step was free from t-dodecyl mercaptan, and the amount of t-dodecyl mercaptan in the monomer emulsion of the second step was changed from 4.0 parts to 0.1 parts, and that dipropylene glycol monobutyl ether (21 parts) was used instead of propylene glycol diacetate (21 parts). The emulsion composition had a nonvolatile content of 54.6%, a pH of 7.8, a viscosity of 350 mPa·s, a number average molecular weight of 83,000, and a molecular weight distribution of 3.0. The polymer obtained in the first step had a Tg of 34° C., the polymer obtained in the second step had a Tg of −12° C., and the total Tg of these polymers of the first and second steps was 10° C.
EXAMPLE 22
[0252] A polymerization vessel equipped with a stirrer, a reflux condenser, a thermometer, a nitrogen inlet tube and a dropping funnel was charged with deionized water (285 parts). Then, the internal temperature was increased to 75° C. under stirring and nitrogen flow. The dropping funnel was charged with a monomer emulsion of the first step which was composed of methyl methacrylate (300 parts), 2-ethylhexyl acrylate (75 parts), butyl acrylate (115 parts), acrylic acid (10 parts), t-dodecyl mercaptan (1.0 part), a previously adjusted 20% aqueous solution of LATEMUL 118B (trade name, produced by Kao Corp.) (75 parts) and deionized water (100 parts). While the internal temperature of the polymerization vessel was maintained at 80° C., a 100-part portion of the monomer emulsion, a 3% potassium persulfate aqueous solution (6.6 parts) and a 2% sodium hydrogen sulfite aqueous solution (5.0 parts) were added to initiate initial polymerization. After 20 minutes, the rest of the monomer emulsion was uniformly added dropwise over 120 minutes with the reaction system being maintained at 80° C. Simultaneously, a 3% potassium persulfate aqueous solution (80 parts) and a 2% sodium hydrogen sulfite aqueous solution (30 parts) were uniformly added dropwise over 120 minutes. After the completion of dropwise addition, the temperature was maintained for 60 minutes. The dropping funnel was charged with a monomer emulsion of the second step which was composed of methyl methacrylate (250 parts), 2-ethylhexyl acrylate (50 parts), butyl acrylate (190 parts), acrylic acid (10 parts), t-dodecyl mercaptan (1.0 part), a previously adjusted 20% aqueous solution of LATEMUL 118B (trade name, produced by Kao Corp.) (75 parts) and deionized water (100 parts), and the emulsion was uniformly added dropwise over 120 minutes. Simultaneously, a 3% potassium persulfate aqueous solution (80 parts) and a 2% sodium hydrogen sulfite aqueous solution (30 parts) were uniformly added dropwise over 120 minutes. After the completion of dropwise addition, the temperature was maintained for 90 minutes to complete the polymerization. The resulting reaction solution was cooled to room temperature, and 2-dimethylethanolamine (20 parts), dipropylene glycol methyl ether acetate (21 parts), and ROCIMA 553 (trade name, produced by Dow Chemical Co., active component 12%) (1.5 parts) were added. Thus, emulsion composition 22 for vibration damping materials which had a nonvolatile content of 54.9%, a pH of 8.0, a viscosity of 430 mPa·s, a number average molecular weight of 42,000, and a molecular weight distribution of 3.0 was obtained. The polymer obtained in the first step had a Tg of 18° C., the polymer obtained in the second step had a Tg of 3° C., and the total Tg of these polymers of the first and second steps was 10° C.
EXAMPLE 23
[0253] Emulsion composition 23 for vibration damping materials was prepared in the same manner as in Example 22, except that propylene glycol diacetate (21 parts) was used instead of dipropylene glycol methyl ether acetate (21 parts). The emulsion composition had a nonvolatile content of 54.7%, a pH of 8.0, a viscosity of 430 mPa·s, a number average molecular weight of 44,000, and a molecular weight distribution of 3.1. The polymer obtained in the first step had a Tg of 18° C., the polymer obtained in the second step had a Tg of 3° C., and the total Tg of these polymers of the first and second steps was 10° C.
EXAMPLE 24
[0254] Emulsion composition 24 for vibration damping materials was prepared in the same manner as in Example 22, except that dipropylene glycol monopropyl ether (21 parts) was used instead of dipropylene glycol methyl ether acetate (21 parts). The emulsion composition had a nonvolatile content of 54.8%, a pH of 8.0, a viscosity of 420 mPa·s, a number average molecular weight of 46,000, and a molecular weight distribution of 3.2. The polymer obtained in the first step had a Tg of 18° C., the polymer obtained in the second step had a Tg of 3° C., and the total Tg of these polymers of the first and second steps was 10° C.
EXAMPLE 25
[0255] Emulsion composition 25 for vibration damping materials was prepared in the same manner as in Example 22, except that the amount of dipropylene glycol methyl ether acetate was increased from 21 parts to 90 parts. The emulsion composition had a nonvolatile content of 54.9%, a pH of 8.0, a viscosity of 400 mPa·s, a number average molecular weight of 46,000, and a molecular weight distribution of 3.2. The polymer obtained in the first step had a Tg of 18° C., the polymer obtained in the second step had a Tg of 3° C., and the total Tg of these polymers of the first and second steps was 10° C.
EXAMPLE 26
[0256] Emulsion composition 26 for vibration damping materials was prepared in the same manner as in Example 22, except that propylene glycol diacetate (11 parts) was used instead of dipropylene glycol methyl ether acetate (21 parts). The emulsion composition had a nonvolatile content of 54.8%, a pH of 8.0, a viscosity of 440 mPa·s, a number average molecular weight of 49,000, and a molecular weight distribution of 3.1. The polymer obtained in the first step had a Tg of 18° C., the polymer obtained in the second step had a Tg of 3° C., and the total Tg of these polymers of the first and second steps was 10° C.
COMPARATIVE EXAMPLE 18
[0257] Comparative emulsion composition 18 for vibration damping materials was prepared in the same manner as in Example 22, except that diethylene glycol monoethyl ether (21 parts) was used instead of dipropylene glycol methyl ether acetate (21 parts). The emulsion composition had a nonvolatile content of 54.3%, a pH of 8.0, a viscosity of 390 mPa·s, a number average molecular weight of 47,000, and a molecular weight distribution of 3.0. The polymer obtained in the first step had a Tg of 18° C., the polymer obtained in the second step had a Tg of 3° C., and the total Tg of these polymers of the first and second steps was 10° C.
COMPARATIVE EXAMPLE 19
[0258] Comparative emulsion composition 19 for vibration damping materials was prepared in the same manner as in Example 22, except that ethylene glycol mono-n-butyl ether (21 parts) was used instead of dipropylene glycol methyl ether acetate (21 parts). The emulsion composition had a nonvolatile content of 54.7%, a pH of 8.1, a viscosity of 420 mPa·s, a number average molecular weight of 44,000, and a molecular weight distribution of 3.2. The polymer obtained in the first step had a Tg of 18° C., the polymer obtained in the second step had a Tg of 3° C., and the total Tg of these polymers of the first and second steps was 10° C.
COMPARATIVE EXAMPLE 20
[0259] Comparative emulsion composition 20 for vibration damping materials was prepared in the same manner as in Example 22, except that ethylene glycol monobutyl ether acetate (21 parts) was used instead of dipropylene glycol methyl ether acetate (21 parts). The emulsion composition had a nonvolatile content of 54.6%, a pH of 8.0, a viscosity of 400 mPa·s, a number average molecular weight of 46,000, and a molecular weight distribution of 3.1. The polymer obtained in the first step had a Tg of 18° C., the polymer obtained in the second step had a Tg of 3° C., and the total Tg of these polymers of the first and second steps was 10° C.
EXAMPLE 27
[0260] Emulsion composition 27 for vibration damping materials was prepared in the same manner as in Example 1, except that t-dodecyl mercaptan was not used in the first step, that the amount of t-dodecyl mercaptan used in the second step was changed to 0.1 parts, and that diisodecyl phthalate (21 parts) was used instead of propylene glycol diacetate (21 parts). The emulsion composition had a nonvolatile content of 55.4%, a pH of 8.2, a viscosity of 410 mPa·s, a number average molecular weight of 79,000, and a molecular weight distribution of 2.9. The polymer obtained in the first step had a Tg of 34° C., the polymer obtained in the second step had a Tg of −12° C., and the total Tg of these polymers of the first and second steps was 10° C.
EXAMPLE 28
[0261] Emulsion composition 28 for vibration damping materials was prepared in the same manner as in Example 22, except that diisodecyl phthalate (21 parts) was used instead of dipropylene glycol methyl ether acetate (21 parts). The emulsion composition had a nonvolatile content of 55.4%, a pH of 8.0, a viscosity of 400 mPa·s, a number average molecular weight of 43,000, and a molecular weight distribution of 3.2. The polymer obtained in the first step had a Tg of 18° C., the polymer obtained in the second step had a Tg of 3° C., and the total Tg of these polymers of the first and second steps was 10° C.
EXAMPLE 29
[0262] Emulsion composition 29 for vibration damping materials was prepared in the same manner as in Example 22, except that dioctyl phthalate (21 parts) was used instead of dipropylene glycol methyl ether acetate (21 parts). The emulsion composition had a nonvolatile content of 55.4%, a pH of 8.0, a viscosity of 400 mPa·s, a number average molecular weight of 44,000, and a molecular weight distribution of 3.1. The polymer obtained in the first step had a Tg of 18° C., the polymer obtained in the second step had a Tg of 3° C., and the total Tg of these polymers of the first and second steps was 10° C.
EXAMPLE 30
[0263] Emulsion composition 30 for vibration damping materials was prepared in the same manner as in Example 22, except that diisononyl phthalate (21 parts) was used instead of dipropylene glycol methyl ether acetate (21 parts). The emulsion composition had a nonvolatile content of 55.4%, a pH of 8.0, a viscosity of 400 mPa·s, a number average molecular weight of 42,000, and a molecular weight distribution of 3.3. The polymer obtained in the first step had a Tg of 18° C., the polymer obtained in the second step had a Tg of 3° C., and the total Tg of these polymers of the first and second steps was 10° C.
EXAMPLE 31
[0264] Emulsion composition 31 for vibration damping materials was prepared in the same manner as in Example 22, except that dioctyl adipate (21 parts) was used instead of dipropylene glycol methyl ether acetate (21 parts). The emulsion composition had a nonvolatile content of 55.4%, a pH of 8.0, a viscosity of 1700 mPa·s, a number average molecular weight of 45,000, and a molecular weight distribution of 3.2. The polymer obtained in the first step had a Tg of 18° C., the polymer obtained in the second step had a Tg of 3° C., and the total Tg of these polymers of the first and second steps was 10° C.
EXAMPLE 32
[0265] Emulsion composition 32 for vibration damping materials was prepared in the same manner as in Example 22, except that dioctyl phthalate (10 parts) and dipropylene glycol monobutyl ether (10 parts) were used instead of dipropylene glycol methyl ether acetate (21 parts). The emulsion composition had a nonvolatile content of 55.1%, a pH of 8.0, a viscosity of 400 mPa·s, a number average molecular weight of 43,000, and a molecular weight distribution of 3.2. The polymer obtained in the first step had a Tg of 18° C., the polymer obtained in the second step had a Tg of 3° C., and the total Tg of these polymers of the first and second steps was 10° C.
EXAMPLE 33
[0266] Emulsion composition 33 for vibration damping materials was prepared in the same manner as in Example 22, except that diisononyl phthalate (10 parts) and dipropylene glycol monopropyl ether (10 parts) were used instead of dipropylene glycol methyl ether acetate (21 parts). The emulsion composition had a nonvolatile content of 55.1%, a pH of 8.0, a viscosity of 400 mPa·s, a number average molecular weight of 46,000, and a molecular weight distribution of 3.1. The polymer obtained in the first, step had a Tg of 18° C., the polymer obtained in the second step had a Tg of 3° C., and the total Tg of these polymers of the first and second steps was 10° C.
COMPARATIVE EXAMPLE 21
[0267] Comparative emulsion composition 21 for vibration damping materials was prepared in the same manner as in Example 22, except that dimethyl fumarate (21 parts) was used instead of dipropylene glycol methyl ether acetate (21 parts). The emulsion composition had a nonvolatile content of 55.3%, a pH of 8.1, a viscosity of 680 mPa·s, a number average molecular weight of 45,000, and a molecular weight distribution of 3.1. The polymer obtained in the first step had a Tg of 18° C., the polymer obtained in the second step had a Tg of 3° C., and the total Tg of these polymers of the first and second steps was 10° C.
EXAMPLE 34
[0268] Emulsion composition 34 for vibration damping materials was prepared in the same manner as in Example 22, except that diisononyl adipate (21 parts) was used instead of dipropylene glycol methyl ether acetate (21 parts). The emulsion composition had a nonvolatile content of 55.4%, a pH of 8.1, a viscosity of 770 mPa·s, a number average molecular weight of 43,000, and a molecular weight distribution of 3.2. The polymer obtained in the first step had a Tg of 18° C., the polymer obtained in the second step had a Tg of 3° C., and the total Tg of these polymers of the first and second steps was 10° C.
EXAMPLE 35
[0269] Emulsion composition 35 for vibration damping materials was prepared in the same manner as in Example 22, except that the monomer emulsion of the first step was composed of methyl methacrylate (190 parts), 2-ethylhexyl acrylate (100 parts), styrene (200 parts), acrylic acid (10 parts), t-dodecyl mercaptan (1.0 part), a previously adjusted 20% aqueous solution of LATEMUL 118B (trade name, produced by Kao Corp.) (75 parts) and deionized water (100 parts), that the monomer emulsion of the second step was composed of methyl methacrylate (150 parts), 2-ethylhexyl acrylate (85 parts), styrene (155 parts), butyl acrylate (100 parts), acrylic acid (10 parts), t-dodecyl mercaptan (1.0 part), a previously adjusted 20% aqueous solution of LATEMUL 118B (trade name, produced by Kao Corp.) (75 parts) and deionized water (100 parts), and that diisononyl phthalate (130 parts) was used instead of dipropylene glycol methyl ether acetate (21 parts). The emulsion composition had a nonvolatile content of 57.6%, a pH of 7.9, a viscosity of 1420 mPa·s, a number average molecular weight of 44,000, and a molecular weight distribution of 3.2. The polymer obtained in the first step had a Tg of 48° C., the polymer obtained in the second step had a Tg of 18° C., and the total Tg of these polymers of the first and second steps was 32° C.
COMPARATIVE EXAMPLE 22
[0270] Comparative emulsion composition 22 for vibration damping materials was prepared in the same manner as in Example 35, except that diisononyl phthalate was not used. The emulsion composition had a nonvolatile content of 54.7%, a pH of 8.1, a viscosity of 390 mPa·s, a number average molecular weight of 44,000, and a molecular weight distribution of 3.2. The polymer obtained in the first step had a Tg of 48° C., the polymer obtained in the second step had a Tg of 18° C., and the total Tg of these polymers of the first and second steps was 32° C.
[0271] The details of the commercial products used in the above examples and comparative examples are shown below. The isothiazolinone-based compounds have no influence on the vibration damping property and peel strength of the emulsion compositions for vibration damping materials.
<Isothiazolinone-Based Compound>
[0000]
*FINECIDE HS-10: produced by Tokyo Fine Chemical CO., LTD, active component: 5%, 2-methyl-4-isothiazolin-3-one (MIT)
*ROCIMA 553: produced by Dow Chemical Co., active component: 12%, 2-octyl-4-isothiazolin-3-one (OIT) and 2-methyl-4-isothiazolin-3-one (MIT)
*PROXEL GXL: produced by Lonza, active component: 20%, 1,2-benzisothiazolin-3-one (BIT)
*PROXEL NBZ: produced by Lonza, isothiazolinone active component: 5%, 1,2-benzisothiazolin-3-one (BIT) and zinc pyrithione (ZPT)
*Topside 1000: produced by Permachem Asia, Ltd., active component: 5%, 5-chloro-2-methyl-4-isothiazolin-3-one (O-MIT) and 2-methyl-4-isothiazolin-3-one (MIT)
<Emulsifier>
[0000]
*HITENOL 18E: produced by Dai-ichi Kogyo Seiyaku Co., Ltd., ammonium polyoxyethylene alkyl ether sulfate (anionic emulsifier)
*LATEMUL 118B: produced by Kao Corp., sodium polyoxyethylene alkyl ether sulfate (anionic emulsifier)
*LATEMUL WX: produced by Kao Corp., ammonium polyoxyethylene polycyclic phenyl ether sulfate (anionic emulsifier)
*Newcol 707SF: produced by Nippon Nyukazai Co., Ltd., sodium polyoxyethylene oleyl ether sulfate (anionic emulsifier)
*EMAL O: produced by Kao Corp., sodium lauryl sulfate (anionic emulsifier)
*EMULGEN 1118S: produced by Kao Corp., polyoxyethylene alkyl ether (nonionic emulsifier)
* HITENOL NF-08: produced by Dai-ichi Kogyo Seiyaku Co., Ltd., ammonium polyoxyethylene styryl phenyl ether sulfate (anionic emulsifier)
[0284] The vibration damping modifiers used in the above examples and comparative examples are shown in Table 1. The classes (A-1) and (A-2) in Table 1 correspond to the classes (A-1) and (A-2) of vibration damping modifiers specified herein. The vibration damping modifiers that belong to neither (A-1) nor (A-2) are categorized into other classes.
[0000]
TABLE 1
Class of
vibration
Boiling point
Solubility
damping agent
Compound
(° C.)
(g/water 100 g)
(A-1)
Propylene glycol diacetate
190
8
Dipropylene glycol monopropyl ether
212
19
Dipropylene glycol monobutyl ether
229
5
Dipropylene glycol methyl ether acetate
213
19
Other class
Diethylene glycol monoethyl ether
202
∞
Ethylene glycol monobutyl ether acetate
188
1
Ethylene glycol mono-n-butyl ether
171
100
(A-2)
Diisodecyl phthalate
420
—
Diisononyl phthalate
402
—
Dioctyl phthalate
384
—
Dioctyl adipate
335
—
Diisononyl adipate
406
—
Other class
Dimethyl fumarate
192
—
<Preparation of Thick-Film Coating Composition for Heat-Drying (Vibration Damping Coating Composition)>
[0285] The emulsion compositions for vibration damping materials obtained in Examples 1 to 18 and Comparative Examples 1 to 9 and 14 to 17 were individually mixed with the materials shown below to prepare thick-film coating compositions for heat-drying (vibration damping coating compositions).
Emulsion composition for vibration damping materials: 359 parts Calcium carbonate (NN #200 *1 ): 620 parts Carbon black: 1 part Starch: 46.8 parts Dispersant (AQUARICK DL-40S *2 ): 6 parts Thickener (ACRYSET WR-650 *3 ): 4 parts Defoaming agent (NOPCO 8034L *4 ): 1 part Foaming agent (F-30 *5 ): 6 parts *1: Filler produced by NITTO FUNKA KOGYO K. K. *2: Polycarboxylic acid-based dispersant (active component: 44%) produced by Nippon Shokubai Co., Ltd. *3: Alkali-soluble acrylic thickener (active component: 30%) produced by Nippon Shokubai Co., Ltd. *4: Defoaming agent (mainly made of hydrophobic silicone+mineral oil) produced by SAN NOPCO Ltd. *5: Forming agent produced by Matsumoto Yushi-Seiyaku Co., Ltd.
[0299] Vibration damping property, coating viscosity, and coating thixotropy of the thick-film coating compositions for heat-drying were measured or calculated by the following methods. The results are shown in Tables 2 to 4.
<Vibration Damping Property Test>
[0300] A thick-film coating composition for heat-drying was applied onto a cold rolled steel plate (SPCC, 15 mm in width×250 mm in length×1.5 mm in thickness) to a thickness of 3 mm, and dried at 150° C. for 30 minutes. Thus, a vibration damping coating with a surface density of 4.0 Kg/m 2 was formed on the cold rolled steel plate. vibration damping property of the coating was determined as follows: loss coefficients at particular temperatures (20° C., 40° C., and 60° C.) were determined by a resonance method (3 dB method) using a cantilever method (loss coefficient measurement system produced by ONO SOKKI CO., LTD.). The vibration damping property were evaluated based on the total loss coefficient (the sum of loss coefficients at 20° C., 40° C., and 60° C.). A larger total loss coefficient corresponds to better vibration damping property.
<Coating Viscosity>
[0301] A thick-film coating composition for heat-drying was adjusted to 23° C., and measured for viscosity using a BH-type viscometer (produced by Tokimec Inc.) under the conditions of 2 min −1 (=2 rpm) and 20 min −1 (=20 rpm).
<Coating Thixotropy>
[0302] The thixotropy was calculated by the following formula.
[0000] Thixotropy=viscosity under the condition of 2 min −1 /viscosity under the condition of 20 min −1
[0000]
TABLE 2
Comparative
Comparative
Comparative
Comparative
Comparative
Comparative
Comparative
Comparative
Comparative
Example 1
Example 2
Example 3
Example 4
Example 5
Example 6
Example 7
Example 8
Example 9
Weight average
48,000
51,000
40,000
38,000
71,000
240,000
82,000
240,000
240,000
molecular weight
Tg (° C.)
9.5
10.2
3.4
10.2
9.5
9.5
9.5
9.5
9.5
Particle size (nm)
222
203
169
248
103
95
105
111
110
Nonvolatile content
54.9
55.0
54.6
55
54.0
54.6
56.5
55.1
55.0
(%)
pH
8.2
8.1
8.0
8.0
8.3
7.8
8.3
8.0
7.7
Viscosity
410
500
290
240
320
350
1200
400
350
(mPa · s)
Loss coefficient
0.024
0.039
0.074
0.063
0.020
0.018
0.015
0.018
0.019
(20° C.)
Loss coefficient
0.131
0.160
0.170
0.167
0.098
0.075
0.082
0.065
0.065
(40° C.)
Loss coefficient
0.060
0.068
0.080
0.058
0.043
0.031
0.039
0.035
0.032
(60° C.)
Total loss
0.215
0.267
0.324
0.288
0.161
0.124
0.136
0.118
0.116
coefficient
Coating viscosity
360
500
380
520
950
920
1020
1000
980
(Pa · s)(2 min −1 )
Coating viscosity
60
120
70
105
250
240
300
270
260
(Pa · s)(20 min −1 )
Coating thixotropy
6.0
4.2
5.4
5.0
3.8
3.8
3.4
3.7
3.8
[0000]
TABLE 3
Example 1
Example 2
Example 3
Example 4
Example 5
Example 6
Weight average molecular weight
50,000
42,000
51,000
40,000
50,000
39,000
Tg (° C.)
9.5
3.4
9.5
3.4
9.5
3.4
Particle size (nm)
235
211
231
171
222
170
Nonvolatile content (%)
54.8
54.5
55.4
54.9
54.6
54.6
pH
8.2
8.1
8.2
8.0
8.1
8.0
Viscosity (mPa · s)
410
500
410
290
360
280
Loss coefficient (20° C.)
0.042
0.084
0.036
0.096
0.031
0.081
Loss coefficient (40° C.)
0.155
0.198
0.135
0.202
0.134
0.194
Loss coefficient (60° C.)
0.067
0.092
0.061
0.084
0.062
0.089
Total loss coefficient
0.264
0.374
0.232
0.382
0.227
0.364
Coating viscosity (Pa · s)(2 min −1 )
310
370
350
350
290
370
Coating viscosity (Pa · s)(20 min −1 )
50
60
60
55
50
60
Coating thixotropy
6.2
6.2
5.8
6.4
5.8
6.2
Comparative
Example 7
Example 8
Example 9
Example 10
Example 11
Example 14
Weight average molecular weight
39,000
40,000
40,000
43,000
40,000
42,000
Tg (° C.)
3.4
3.4
3.4
3.4
3.4
3.4
Particle size (nm)
169
171
173
168
170
169
Nonvolatile content (%)
54.3
54.5
54.5
54.6
54.5
54.5
pH
8.0
8.0
8.0
8.0
8.0
8.0
Viscosity (mPa · s)
280
280
280
230
290
280
Loss coefficient (20° C.)
0.080
0.084
0.080
0.094
0.076
0.075
Loss coefficient (40° C.)
0.189
0.198
0.174
0.192
0.180
0.171
Loss coefficient (60° C.)
0.086
0.092
0.082
0.086
0.083
0.080
Total loss coefficient
0.355
0.374
0.336
0.372
0.339
0.326
Coating viscosity (Pa · s)(2 min −1 )
370
370
340
350
380
360
Coating viscosity (Pa · s)(20 min −1 )
60
60
60
55
65
55
Coating thixotropy
6.2
6.2
5.7
6.4
5.8
6.5
[0000]
TABLE 4
Comparative
Comparative
Example 15
Example 16
Example 12
Example 13
Example 14
Weight average molecular weight
41,000
41,000
48,000
40,000
41,000
Tg (° C.)
3.4
3.4
9.5
3.4
3.4
Particle size (nm)
169
171
224
171
173
Nonvolatile content (%)
54.4
54.4
55.4
55.1
55.1
pH
8.1
8.0
8.1
8.0
8.0
Viscosity (mPa · s)
290
290
430
290
290
Loss coefficient (20° C.)
0.076
0.077
0.036
0.082
0.084
Loss coefficient (40° C.)
0.173
0.170
0.135
0.175
0.177
Loss coefficient (60° C.)
0.079
0.079
0.061
0.081
0.081
Total loss coefficient
0.328
0.326
0.232
0.338
0.342
Coating viscosity (Pa · s)(2 min −1 )
380
360
350
370
370
Coating viscosity (Pa · s)(20 min −1 )
57
60
60
60
60
Coating thixotropy
6.7
6.0
5.8
6.2
6.2
Comparative
Example 15
Example 16
Example 17
Example 17
Example 18
Weight average molecular weight
41,000
42,000
42,000
42,000
41,000
Tg (° C.)
3.4
3.4
3.4
3.4
3.4
Particle size (nm)
168
172
171
170
175
Nonvolatile content (%)
55.1
55.0
55.1
55.1
57.6
pH
8.0
8.0
8.0
8.1
8.0
Viscosity (mPa · s)
2760
290
590
640
560
Loss coefficient (20° C.)
0.080
0.096
0.075
0.083
0.088
Loss coefficient (40° C.)
0.172
0.202
0.171
0.173
0.184
Loss coefficient (60° C.)
0.081
0.084
0.080
0.081
0.086
Total loss coefficient
0.333
0.382
0.326
0.337
0.358
Coating viscosity (Pa · s)(2 min −1 )
2140
340
540
510
840
Coating viscosity (Pa · s)(20 min −1 )
680
55
89
82
97
Coating thixotropy
3.1
6.2
6.1
6.2
8.7
[0303] Vibration damping coating compositions were prepared in the same manner as described above using the vibration damping emulsion compositions prepared in Examples 1 to 3 and 19 to 35 and Comparative Examples 1 to 4, 10 to 13, and 18 to 22, and evaluated for vibration damping property and measured for peel strength of coatings as described below. The results are shown in Tables 5 to 7. The average particle sizes, nonvolatile contents, pH values, and viscosities of the vibration damping emulsion compositions are also shown in Tables 5 to 7.
<Vibration Damping Property Test>
[0304] A vibration damping coating composition prepared above was applied onto a cold rolled steel plate (SPCC, 15 mm in width×250 mm in length×1.5 mm in thickness) to a thickness of 3 mm, and dried at 150° C. for 30 minutes. Thus, a vibration damping coating with a surface density of 4.0 Kg/m 2 was formed on the cold rolled steel plate. The coating was determined for vibration damping property as follows: loss coefficients at particular temperatures (20° C., 40° C., and 60° C.) were determined by a resonance method (3 dB method) using a cantilever method (loss coefficient measurement system produced by ONO SOKKI CO., LTD.). A larger the total loss coefficient corresponds to better vibration damping property.
<Coating Peel Strength>
[0305] The peel strength was measured using a Building Research Institute type adhesion tester in the manner described below.
[0306] The substrate used was a 20 cm×20 cm×3 mm cold rolled steel plate (SPCC). A vibration damping coating composition prepared above was applied to a thickness of 3 mm, dried in a hot air drier at 130° C. for 30 minutes, and then cooled to room temperature. As shown in FIG. 1 , an attachment 3 with an adhesion area of 4.0 cm×4.0 cm was attached to the dried vibration damping coating composition 2 on the substrate 1 with an epoxy resin adhesive 4 (CEMEDINE 1500, produced by CEMEDINE CO., LTD.). The adhesive was aged at 25° C. for 4 days to cure, and a notch 5 extending to the substrate was made by a utility knife along the circumference of the attachment 3 . Then, the attachment 3 was pulled using a Building Research Institute-type adhesion tester (LPT-1500, produced by YAMAMOTO KOJUKI CO., LTD.) in the direction 6 that was perpendicular to the surface of the substrate 1 with the coating of the vibration damping coating composition 2 formed thereon to measure the load (breaking load) required to peel the coating of the vibration damping coating composition 2 from the substrate 1 . The test was performed at 25° C., and the loading rate of the Building Research Institute-type adhesion tester was about 100 kPa/sec. The peel strength was calculated by the following formula from the measured breaking load and the adhesion area between the attachment 3 and the vibration damping coating composition 2 (=the area of the coating of the vibration damping coating composition 2 peeled off from the substrate 1 ).
[0000] Peel strength (kPa)=(breaking load (N)/adhesion area (cm 2 ))×10
[0000]
TABLE 5
Compar-
Compar-
Compar-
Compar-
Compar-
Compar-
Compar-
Compar-
ative
ative
ative
ative
ative
ative
ative
ative
Example
Example
Example
Example
Example
Example
Example
Example
1
2
3
4
10
11
12
13
Particle size (nm)
222
203
169
248
103
95
105
135
Nonvolatile content (%)
54.9
55.0
54.6
55.0
54.7
54.6
54.5
54.9
pH
8.2
8.1
8.0
8.0
7.8
7.8
8.3
8.0
Viscosity (mPa · s)
410
500
290
240
150
350
350
440
Vibration damping
20° C.
0.024
0.039
0.074
0.063
0.033
0.018
0.035
0.028
property (loss
40° C.
0.131
0.160
0.170
0.167
0.101
0.075
0.109
0.142
coefficient)
60° C.
0.060
0.068
0.080
0.058
0.035
0.031
0.037
0.065
Total
0.215
0.267
0.324
0.288
0.169
0.124
0.181
0.235
Coating peel strength (kPa)
745
725
1014
569
186
137
177
216
[0000]
TABLE 6
Exam-
Exam-
Exam-
Exam-
Exam-
Exam-
Exam-
Exam-
Exam-
Exam-
Exam-
ple 1
ple 2
ple 3
ple 19
ple 20
ple 21
ple 22
ple 23
ple 24
ple 25
ple 26
Particle size (nm)
235
211
231
232
101
98
128
134
123
129
126
Nonvolatile content (%)
54.8
54.5
55.4
55.1
54.5
54.6
54.9
54.7
54.8
54.9
54.8
pH
8.2
8.1
8.2
8.2
7.8
7.8
8.0
8.0
8.0
8.0
8.0
Viscosity (mPa · s)
410
500
410
410
340
350
430
430
420
400
440
Vibration damping
20° C.
0.042
0.084
0.036
0.054
0.023
0.020
0.046
0.044
0.045
0.052
0.034
property (loss
40° C.
0.155
0.198
0.135
0.161
0.096
0.092
0.164
0.160
0.163
0.166
0.153
coefficient)
60° C.
0.067
0.092
0.061
0.069
0.037
0.035
0.070
0.069
0.071
0.068
0.068
Total
0.264
0.374
0.232
0.284
0.156
0.147
0.280
0.273
0.279
0.286
0.255
Coating peel strength (kPa)
874
1138
818
941
276
238
332
291
328
342
258
[0000]
TABLE 7
Comparative
Comparative
Comparative
Example 18
Example 19
Example 20
Example 27
Example 28
Example 29
Example 30
Particle size (nm)
131
132
127
97
135
128
130
Nonvolatile content (%)
54.3
54.7
54.6
55.4
55.4
55.4
55.4
pH
8.0
8.1
8.0
8.2
8.0
8.0
8.0
Viscosity (mPa · s)
390
420
400
410
400
400
400
Vibration
20° C.
0.03
0.032
0.032
0.030
0.044
0.038
0.043
damping property
40° C.
0.148
0.148
0.143
0.085
0.155
0.148
0.152
(loss coefficient)
60° C.
0.066
0.068
0.065
0.032
0.065
0.063
0.066
Total
0.244
0.248
0.240
0.147
0.264
0.249
0.261
Coating peel strength (kPa)
223
237
228
266
294
245
302
Comparative
Comparative
Example 31
Example 32
Example 33
Example 21
Example 34
Example 35
Example 22
Particle size (nm)
128
132
134
130
129
154
151
Nonvolatile content (%)
55.4
55.1
55.1
55.3
55.4
57.6
54.7
pH
8.0
8.0
8.0
8.1
8.1
7.9
8.1
Viscosity (mPa · s)
1700
400
400
680
770
1420
390
Vibration
20° C.
0.039
0.042
0.055
0.031
0.041
0.051
0.009
damping property
40° C.
0.149
0.160
0.168
0.144
0.151
0.163
0.014
(loss coefficient)
60° C.
0.067
0.066
0.073
0.062
0.067
0.071
0.161
Total
0.255
0.268
0.296
0.237
0.259
0.285
0.184
Coating peel strength (kPa)
314
289
370
219
292
321
244
REFERENCE SIGNS LIST
[0000]
1 : Substrate
2 : Vibration damping coating composition
3 : Attachment
4 : Epoxy resin adhesive
5 : Notch made by a utility knife
6 : Direction of pulling attachment by Building Research Institute-type adhesion tester
|
The present invention aims to provide a composition for vibration damping materials which provides excellent vibration damping property. The present invention relates to an emulsion composition for vibration damping materials including: a vibration damping modifier including a compound that has 7 or more carbon atoms, a boiling point of 190° C. or higher, and at least two ether groups or at least two ester groups in the molecule; and a polymer emulsion.
| 2
|
INCORPORATION BY REFERENCE
[0001] The disclosure of the following priority application is herein incorporated by reference:
[0002] Japanese Patent Application No. 10-58120, filed Mar. 10, 1998
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The present invention relates to an electronic camera having an electronic zoom function whereby a portion of an image obtained by capturing an image of a subject is displayed in an enlargement and an optical viewfinder.
[0005] 2. Description of the Related Art
[0006] There are single or fixed focus type electronic still cameras in the prior art that have a function of enlarging the central portion of an image created at an image-capturing element through image processing to obtain an image that appears as if it were photographed with a telephoto lens. Hereafter, this function is referred to as “electronic zoom.”
[0007] It is to be noted that the enlarged image obtained through the electronic zoom may be displayed on, for instance, a liquid crystal display provided at the camera body of the electronic still camera.
[0008] In addition, some electronic still cameras that are provided with a zoom lens to perform optical zooming (hereafter referred to as “optical zoom”) are also capable of achieving electronic zoom.
[0009] With such an electronic still camera, even when the zoom-in achieved through the optical zoom has reached its limit, for instance, an image that appears as if it were photographed at a focal length that is longer than the actual focal length can be created by implementing a zoom-in through the electronic zoom.
[0010] [0010]FIGS. 5A and 5B illustrate the relationship between the zooming and the focal length achieved through the optical zoom and the electronic zoom. In the figures, the “actual focal length” indicates the focal length determined through the optical zoom, whereas the “synthesized focal length” represents the focal length determined by combining the optical zoom and the electronic zoom.
[0011] Normally, an electronic still camera capable of optical zoom is provided with an optical zoom viewfinder at which the range of the subject within the viewfinder screen can be varied by moving the viewfinder lens.
[0012] However, since the range of the subject is changed in conformance to the actual focal length at the optical zoom viewfinder, the range of the subject within the viewfinder screen cannot be changed if the zoom-in achieved through the optical zoom has reached its limit, as illustrated in FIG. 5A.
[0013] In addition, as illustrated in FIG. 5B, if a zoom-in is implemented through the electronic zoom while a zoom-in through the optical zoom is in progress, it is difficult to move the viewfinder lens in conformance to the electronic zoom and, as a result, it is not possible to match the range of the subject within the viewfinder screen with the range of the subject displayed on a liquid crystal display or the like.
[0014] Thus, there is a concern that when the photographer performs photographing while monitoring the optical viewfinder, he may not realize that the electronic zoom is set and he may press the release button thinking erroneously that the image of the subject as seen in the viewfinder will be recorded.
[0015] In other-words, there is a-problem in that, in such a case, since the range of the subject, whose image is photographed while the electronic zoom is set, does not match the range of the subject within the viewfinder screen, an image that the photographer does not expect is recorded.
[0016] It is to be noted that electronic still cameras having an optical viewfinder (including an optical viewfinder without a zooming function) among the single focus type electronic still cameras described earlier, too, have a similar problem.
SUMMARY OF THE INVENTION
[0017] An object of the present invention is to provide an electronic camera capable of reducing photographing errors occurring as a result of the range of the subject in the viewfinder screen not matching the photographing range, and in particular, photographing errors resulting from the range of the subject in the viewfinder screen not matching the range of the subject displayed by a means for display.
[0018] In order to attain the above object, an electronic camera according to the present invention comprises: an image-capturing unit that creates an image by capturing an image of a subject; an enlarged image generating unit that creates an enlarged image by enlarging a portion of the image created by the image-capturing unit; an optical viewfinder that enables verification of a subject range corresponding to a range of the image created by the image-capturing unit; and a warning output unit that issues a warning when the enlarged image generating unit is in operation.
[0019] Another electronic camera comprises: an image-capturing unit that creates an image by capturing an image of a subject; an enlarged image generating unit that creates an enlarged image by enlarging a portion of the image created by the image-capturing unit; an optical viewfinder that enables verification of a subject range corresponding to a range of the image created by the image-capturing unit; a display unit that displays the image created by the image-capturing unit or the enlarged image created by the enlarged image generating unit; a decision-making unit that makes a decision as to whether or not the subject range within a viewfinder screen, which can be verified in the optical viewfinder, and a range of the subject displayed at the display unit match; and a warning output unit that issues a warning when the decision-making unit has decided that the subject range within the viewfinder screen and the range of the subject displayed at the display unit do not match.
[0020] In this case, preferably, the decision-making unit decides that the subject range within the viewfinder screen and the range of the subject displayed at the display unit do not match when the enlarged image created by the enlarged image generating unit is displayed on the display unit.
[0021] Also, preferably, the electronic camera further comprises a magnification power setting unit that accepts an external operation related to setting of a photographing magnification power at the image-capturing unit or setting of a magnification power to be used when the enlarged image generating unit creates an enlarged image, and the decision-making unit decides that the subject range in the viewfinder screen and the range of the subject displayed at the display unit do not match when a magnification power setting for creating an enlarged image is received via the magnification power setting unit.
[0022] In each of electronic cameras described above, preferably, the warning output unit issues a warning so that a photographer can be made aware the warning while verifying the subject range through the optical viewfinder. Also, preferably, the warning output unit implements display of the warning near the optical viewfinder.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] [0023]FIG. 1 is a functional block diagram of an electronic still camera;
[0024] [0024]FIG. 2 shows an external view of the electronic still camera;
[0025] [0025]FIG. 3 is an operational flowchart of an embodiment;
[0026] [0026]FIGS. 4A and 4B present examples of indices for indicating the focal length states;
[0027] [0027]FIGS. 5A and 5B indicate the relationship between zooming and focal length; and
[0028] [0028]FIG. 6 shows an example of a liquid crystal display within the optical viewfinder.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0029] The following is a detailed explanation of an embodiment of the present invention in reference to the drawings.
[0030] [0030]FIG. 1 is a functional block diagram of an electronic still camera adopting the present invention.
[0031] [0031]FIG. 2 is an external view of the electronic still camera adopting the present invention.
[0032] In FIG. 1, a control unit 11 within an electronic still camera 10 is connected to an image-capturing unit 13 , an image processing unit 14 , a liquid crystal display 15 , a memory interface 16 , an external operation input unit 17 , a warning lamp 18 and a viewfinder unit 19 via a control bus 12 .
[0033] In this embodiment, the external operation input unit 17 reads the “ON/OFF” state of a release button 20 and the setting status of a zoom switch 21 , both shown in FIG. 2 and reports the readings to the control unit 11 . It is to be noted that the focal length corresponding to the setting status of the zoom switch 21 is reported to the image-capturing unit 13 , the viewfinder unit 19 and the like via the control unit 11 .
[0034] The image-capturing unit 13 , which is provided with a photographic lens and an image-capturing element (not shown), captures the image of a subject to create an image by driving the photographic lens in correspondence to the focal length indicated by the control unit 11 .
[0035] The viewfinder unit 19 , which is provided with a viewfinder lens (not shown), captures the image of the subject to create an image at the viewfinder screen by driving the viewfinder lens in correspondence to the focal length indicated by the control unit 11 .
[0036] It is to be noted that the image created at the image-capturing unit 13 is provided to the image processing unit 14 to undergo the image processing that is to be detailed later, and is also displayed on the liquid crystal display 15 or is recorded in a recording medium such as a memory device via the memory interface 16 if the release button 20 is turned “ON”. In addition, the image created at the viewfinder unit 19 is provided to the photographer via a viewfinder window 22 illustrated in FIG. 2.
[0037] [0037]FIG. 3 is a flowchart of the operation achieved in the embodiment.
[0038] The following is an explanation of the operation achieved in the embodiment given in reference to FIGS. 1 ˜ 3 .
[0039] When the main power is turned on, the control unit 11 issues instructions to the image-capturing unit 13 to create an image by capturing the image of the subject, and issues instructions to the image processing unit 14 and the liquid crystal display 15 to perform monitor display of the subject.
[0040] In response to these instructions, the image-capturing unit 13 starts to capture the image of the subject (FIG. 3, S 1 ) and the image processing unit 14 performs image processing on the image created at the image-capturing unit 13 such as A/D conversion and gamma correction before providing the image to the liquid crystal display 15 . In other words, the image created at the image-capturing unit 13 is displayed on the monitor (FIG. 3, S 2 ).
[0041] It is to be noted that while such processing is in progress, the corresponding image is provided at the viewfinder screen and to the photographer via the viewfinder window 22 , as explained earlier.
[0042] The control unit 11 constantly watches or monitors the state of the release button 20 and the setting status of the zoom switch 21 reported by the external operation input unit 17 as explained earlier, to make a decision as to whether or not the zoom switch 21 has been operated (FIG. 3, S 3 ).
[0043] In addition, if it has been ascertained that the zoom switch 21 has been operated through such decision making, the control unit 11 makes a decision as to whether or not the electronic zoom is set (FIG. 3, S 4 ).
[0044] It is to be noted that while various methods may be conceived for the photographer to set the electronic zoom, the electronic zoom is assumed to be set when the “T” side (telephoto side) of the zoom switch 21 has been pressed down for 2 seconds or more after the zoom-in through the optical zoom achieved by the image-capturing unit 13 has reached its limit, in this embodiment.
[0045] When it is ascertained at the control unit 11 that the electronic zoom is set, it decides that the range of the subject whose image is displayed on the monitor and the range of the subject in the viewfinder screen do not match (FIG. 3, S 5 ), and the warning lamp 18 is turned on (FIG. 3, S 6 )
[0046] In addition, the control unit 11 reports the setting status of the zoom switch 21 reported by the external operation input unit 17 to the image processing unit 14 . Also, it issues instructions to the image processing unit 14 and the liquid crystal display 15 to perform monitor display of an enlarged or magnified image through the electronic zoom.
[0047] In response to these instructions, the image processing unit 14 enlarges the image created at the image-capturing unit 13 in correspondence to the setting status of the zoom switch 21 and provides the enlarged image to the liquid crystal display 15 . Thus, through this processing, the electronic zoom is implemented and the enlarged image is displayed on the monitor (FIG. 3, S 7 ).
[0048] Now, if the electronic zoom is not set in a state in which the zoom switch 21 has been operated (FIG. 3, S 4 NO), the control unit 11 ascertains that the optical zoom is set, and implements the optical zoom through the image-capturing unit 13 (FIG. 3, S 8 ) and repeats the processing in S 2 and the subsequent steps in FIG. 3.
[0049] In addition, based upon the state of the release button 20 and the setting status of the zoom switch 21 reported by the external operation input unit 17 , the control unit 11 makes a decision as to whether or not the release button 20 has been turn on (FIG. 3, S 9 ), and if it is ascertained that the release button 20 has been turn on, it issues instructions to the image processing unit 14 and the memory interface 16 to record the image. In response to these instructions, the image that is displayed on the monitor undergoes compression processing at the image processing unit 14 to be provided to the memory interface 16 where it is recorded in a recording medium such as a memory device (FIG. 3, S 10 ).
[0050] As explained above, in this embodiment, when the electronic zoom is set via the zoom switch 21 , an enlarged image is displayed on the liquid crystal display 15 and the warning lamp 18 provided near the viewfinder window 22 becomes lit.
[0051] With this, the photographer is notified that the electronic zoom is in progress and that the range of the subject within the viewfinder screen and the range of the subject displayed on the liquid crystal display 15 do not match, with a high degree of reliability.
[0052] Consequently, even when the photographer is operating the zoom switch 21 while monitoring the viewfinder window 22 , he will be aware of the fact that the electronic zoom is in progress if the warning lamp 18 becomes lit so that he can verify the range of the subject by checking the image that is displayed on the liquid crystal display 15 .
[0053] It is to be noted that while the electronic zoom is set when the zoom-in through the optical zoom has reached its limit in the embodiment, a separate operating switch for switching between the optical zoom and the electronic zoom may be provided (or an icon corresponding to a selector switch may be added in the operating screen in the case of an electronic still camera capable of displaying an operating screen on the liquid crystal display), to make it possible to set the electronic zoom even while the optical zoom is in progress, as illustrated in FIG. 5B.
[0054] However, with an electronic still camera in which the electronic zoom is set in this manner, it is necessary to warn-that the range of the subject in the viewfinder screen does not match the range of the subject whose image is on monitor display even when the optical zoom is in progress after the electronic zoom has been implemented.
[0055] In addition, while the warning lamp 18 is provided in the vicinity of the viewfinder window 22 to issue a warning that the range of the subject within the viewfinder screen does not match the range of the subject whose image is on monitor display in this embodiment, if the present invention is adopted in an electronic still camera provided with a liquid crystal focusing screen within the viewfinder unit, for instance, a warning may be displayed on the focusing screen instead.
[0056] Now, while image processing is performed by the image processing unit 14 on an image created at the image-capturing unit 13 , an index that indicates the focal length state, as illustrated in FIGS. 4A and 4B, for instance, may be superimposed on the image.
[0057] To be more specific, while the optical zoom is in progress, the shaded area is increased or reduced in response to the operation of the zoom switch 21 by the photographer, as illustrated in FIG. 4A, whereas when the electronic zoom is in progress after the optical zoom has reached its limit, an image with the shaded area blinking is superimposed.
[0058] It is to be noted that a warning that the range of the subject in the viewfinder screen does not match the range of the subject whose image is on monitor display may be issued by blinking a portion of, or the entirety of the index indicating the state of the focal length.
[0059] In addition, in the case of an electronic still camera in which the electronic zoom is set when the zoom-in through the optical zoom has reached its limit, as in the embodiment, the photographer may be notified that the electronic zoom is in progress instead of being issued with a warning, since, when the electronic zoom is in progress, the range of the subject within the viewfinder screen and the range of the subject whose image is on monitor display never match.
[0060] Furthermore, while the decision-making as to whether or not the range of the subject whose image is on monitor display and the range of the subject in the viewfinder screen match is implemented by making a decision as to whether or not the electronic zoom has been set via the zoom switch 21 in this embodiment, this decision making may be implemented by making a decision as to whether or not an enlarged image is on display.
[0061] For instance, the image processing unit 14 may decide that the range of the subject whose image is on monitor display and the range of the subject in the viewfinder screen do not match and issue a warning, when the control unit 11 issues instructions to create an enlarged image to the image processing unit. Moreover, an image that is equivalent to a warning display (e.g., a message such as “Electronic zoom in progress!!”) may be superimposed on the enlarged image.
[0062] While the explanation is given above in reference to the embodiment by using an electronic still camera as an example, the present invention is not restricted to be adopted in an electronic still camera. For instance, the contents of the present invention may be adopted in a video camera handling motion pictures. In other words, the present invention may be adopted in all types of electronic cameras provided with both an optical viewfinder and an electronic zoom function.
[0063] While the explanation is given above in reference to the embodiment on the warning issued through the warning lamp 18 or through display on the liquid crystal focusing screen, i.e., on an example in which the warning is visually recognized, it may be recognized by sound, such as with a buzzer.
[0064] In reference to the embodiment, the explanation is given above on an example in which the warning is issued in regard to whether or not the electronic zoom is set or in regard to the subject range of image on monitor display and the subject range that can be seen via the optical viewfinder not matching. When such a warning is issued, display may be implemented to make it possible to ascertain the degree of enlargement or magnification achieved through the electronic zoom, as well. For instance, display that enables verification of the range over which enlargement processing is being performed through the electronic zoom may be provided on the liquid crystal display within the optical viewfinder. FIG. 6 shows an example of such a liquid crystal display within the optical viewfinder. A frame 24 , 25 or 26 that indicates the subject range in which the electronic zoom is being performed may be superimposed on liquid crystal display or the like within a subject range 23 seen through the viewfinder window 22 . When the frame 25 is displayed, for instance, the subject range corresponding to the frame 25 is enlarged through the electronic zoom. In addition, when the frame 26 among the frames 24 , 25 and 26 is displayed, the power of magnification or the factor of enlargement achieved by the electronic zoom is at its maximum.
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an electronic camera includes: an image-capturing unit that creates an image by capturing an image of a subject; an enlarged image generating unit that creates an enlarged image by enlarging a portion of the image created by the image-capturing unit; an optical viewfinder that enables verification of a subject range corresponding to a range of the image created by the image-capturing unit; and a warning output unit that issues a warning when the enlarged image generating unit is in operation.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is directed to a concealing trim cap assembly for a wall or ceiling panel system, and more particularly to a trim cap assembly for a security ceiling for prison cells and the like.
2. Description of the Prior Art
United States patent application Ser. No. 295,824, filed on Jan. 11, 1989, (Gailey), now U.S. Pat. No. 4,997,570 entitled "Security Panel System" discloses a security panel system having a minimum number of structural components that can be readily constructed into security panels, such as the walls and ceilings of a prison cell or other detention facility. The security panel system disclosed therein, however, appears to have exposed screw or bolt heads where the trim member is fastened to the channel member, and the trim member appears to include no provision for concealing the screw or bolt heads. Even where tamper resistant screws or bolts are used in assembling the security panels into a wall or ceiling, the exposed bolt or screw heads provide an unnecessary opportunity for an inmate or detainee to try to disassemble the ceiling or wall in an attempt to escape.
It is therefore a principal object of the present invention to provide a secure trim assembly for wall or ceiling panel which covers exposed screw or bolt heads and other vulnerable points in the wall or ceiling security panel system.
SUMMARY OF THE INVENTION
The foregoing and other objects have been attained and the disadvantages of prior devices overcome by providing a concealing trim assembly for a wall or ceiling panel system, comprising a trim member fastenable to a channel member of a ceiling or wall panel support, the trim member having a base portion and first and second means for slidably retaining a trim cap; means for fastening the trim member to the channel member; and a trim cap for concealing the means for fastening the trim member to the channel member. The trim cap has first and second edges matable with the first and second means for slidably retaining a trim cap, and at least one clip means for biasing the first and second edges of the trim cap with respect to the first and second means for retaining a concealment trim cap.
Preferably, the first means on the trim member includes a first channel extending longitudinally on a first side of the trim member, while the second means on the trim member includes a second channel extending longitudinally along a second and opposite side of the trim member. In the preferred embodiment disclosed herein, the first channel is offset with respect to the second channel, and the trim member has a base portion having a generally L-shaped cross-section.
Advantageously, the first channel extends along the first edge of the trim member, and is generally C-shaped in cross-section. The second channel is formed by a recess included in the second edge of the trim member which cooperates with a longitudinal edge of the channel member to form the second channel when the trim member is fastened to the channel member. The first channel may also be a recess formed between first and second arms extending longitudinally along and substantially parallel to the base portion of the trim member.
The invention also provides a concealing trim assembly for a wall or ceiling panel system, comprising a trim member including a generally L-shaped base portion having a first leg substantially perpendicular to a second leg. The trim member also has a first channel defined by a recess formed between first and second fingers extending parallel to the base portion, and a second channel formed by a depression in an opposite side of the base, which is preferably offset with respect to the first channel. The assembly also includes a trim cap having first and second edges, the first edge offset with respect to the second edge, for slidable retention in the first and second channels of the trim member. The assembly further includes a clip means for locking the first and second edges of the trim cap against the first finger and the side forming the depression in the trim member, and means for fastening the clip means and the trim member to the channel member.
As a further feature of the invention, the means for fastening the clip and the trim member is a single screw which fastens the clip and the trim member to the channel member. The invention also features a clip having a bottom portion including an aperture for a screw and a tongue extending at an angle from the bottom portion.
The invention further provides a concealing trim assembly wherein the clip has a flange having an aperture to receive means for fastening the clip to the trim member and a generally U-shaped tongue which extends at an acute angle from adjacent the trim member to adjacent the first channel.
Other features, aspects and advantages of the invention may be understood by reviewing the following detailed description of the preferred embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a bottom perspective view of a prior ceiling structure for which the trim assembly of the present invention is particularly adapted
FIG. 2 is a bottom perspective view of a preferred embodiment of the trim assembly of the present invention shown mounted on the ceiling structure of FIG. 1.
FIG. 3 a cross-sectional view of the trim assembly taken along line 3--3 of FIG. 2.
FIG. 3A a cross-sectional view of the trim cap for use in the trim assembly of FIG. 2.
FIG. 4 is a perspective view of a clip for use in the trim assembly invention shown in FIG. 2.
FIG. 5 is a cross-sectional view of the clip of FIG. 4 taken along line 5--5 of FIG. 4.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, there is shown a security wall or ceiling panel system as disclosed in U.S. patent application Ser. No. 295,827, filed on Jan. 11, 1989, (Gailey), the entire disclosure of which is incorporated herein by reference and made a part hereof. The security panel system 10 is illustrated as a ceiling being constructed above the walls 11 of a room structure such a detention cell. The security panel system 10 includes generally flat pan members 18 having ribs 20 and 22 which can interlock by snapping two adjacent pan members 18 together so that rib 20 slidably inserts into rib 22. The security panel system 10 includes channel members 28 which may be combined to form carrier members which allow joinder of adjacent rows of pan members 18. The security panel system lo also includes trim members 44 which capture the ends of pan members 18. Such a trim member 44 is shown in FIG. 1 as having an L-shaped cross-section to cover the edge of pan member 18, that is, prevent access to its ends and limit its capability to be disassembled.
The trim assembly of the present invention provides an improvement over trim member 44 shown in FIG. 1. As shown in FIG. 2, the improved trim assembly, generally designated by the reference numeral 100, includes three principal parts: a trim member 110, a trim cap 200 and at least one clip means 300.
As shown in FIGS. 2 and 3, the trim member 110 has a base portion 112 having a generally L-shaped cross section formed by first and second arms 114, 116 which meet to form an approximately right angle 118. The arms 114, 116 are sized to overlap a corner of channel member 28 and the edge of pan member 18 to cover the exposed edges of pan member 18 and channel member 28 with a rigid structure which resists bending and tampering as required in security and prison applications.
Trim member 110 also includes first 120 and second 122 means for slidably retaining a trim cap 200. Preferably, first means 120 is positioned on a first side 124 of the trim member 110 and includes a first channel 126 (see FIG. 3) extending longitudinally along the first side 124 of the trim member 110. As shown most clearly in FIG. 2, the first means 120 is generally C-shaped in cross-section, and includes spine 128 extending upward from arm 116 and first 130 and second 132 fingers substantially parallelly spaced to form first channel 126, which is, in effect, a recess or space between the first 130 and second 132 fingers. As shown in FIG. 3, the first and second fingers 130, 132 extend longitudinally along, and are substantially parallel to, arm 116 of the trim member 110.
As mentioned above, trim member 110 also includes second means 122 for slidably retaining a trim cap 200, as shown in FIG. 3. The second means 122 includes a second channel 134 extending longitudinally along a second side 136 of the trim member 110. The second channel 134 may have a generally C-shaped cross-section similar to the first channel 126, but preferably the second channel 134 is formed as a recess defined by third finger 138 on trim member 110 which cooperates with the adjacent longitudinal edge of pan member 18 or channel member 28 where the trim member 110 overlaps and is fastened to the channel member 28. As shown in FIGS. 2 and 3, second means 122 is formed by second spine 142 extending upward from second arm 116 and third finger 138 extending outward at a substantially right angle from second spine 142. As also shown in FIGS. 2 and 3, the first channel 126 faces the same direction as the second channel 134, but they are preferably offset with respect to one another. That is, the first channel 126, as shown in FIG. 3, is positioned higher with respect to pan member 18 than the second channel 134, so that the trim assembly 100 provides no exposed edges facilitating unauthorized prying or removal, and so that the clip 300 can bias the trim cap 200 against the trim member 110, as will be described below.
The trim member 110 also includes means for fastening the trim member to the channel member 28 such as an aperture (not shown) for receiving a screw 146, bolt, pop rivet or other mechanical fastening means known to those of ordinary skill in the art. Preferably, the screw 146 used in fastening the trim members 110 to the channel members 28 should not respond to commonly available flat blade or Philips head screwdrivers. In this way, should tampering occur, the screw 146 would resist unauthorized loosening or removal.
The first 126 and second 134 channels of the trim member 110 slidably engage the trim cap 200, as shown in FIGS. 2 and 4. The trim cap 200 conceals means for fastening the trim member 110 to the channel member 28, and is adapted to mate with first and second channels 126, 134 on trim member 110. Accordingly, the trim cap 200 should preferably have a top 202, a central longitudinally extending portion and bounded by first 204 and second 206 elbows. The first elbow 204, which engages the first channel 126 on the trim member 110, extends downwardly and outwardly from top 202 at a substantially right angle 208 and forms first edge 210 which may slide into first channel 126 to be slidably retained therein.
Similarly, a second elbow 206 downwardly but inwardly extends from the other side of trim cap 200, also at a substantially right angle 212 to form second edge 214 which may slide into and engage second channel 134. Both the trim member 110 and trim cap 200 can be fabricated from steel stainless steel, aluminum or an aluminum alloy using a conventional continuous casting method or other conventional method of construction.
In addition, the trim assembly 100 preferably includes at least one clip 300 or spring means for biasing the first 210 and second 214 edges of the trim cap 200 against the underside of first 132 and third 138 fingers of trim member 110 to retain the trim cap 200 in place and avoid tampering or unauthorized removal. The clip 300, preferably made of spring steel, has a flange 302 having a centrally disposed aperture 304 through which screw 146 or other fastening means may affix the clip 300 on the trim member 110. The clip 300 has a U-shaped slot 306 dividing flange 302 from tongue 308. Tongue 308 curves upward at a preferably acute angle, as shown in FIG. 5, to provide a biasing force to lock the trim cap 200 against trim member 110.
The trim assembly 100 components may be put together as shown in FIGS. 2 and 3. After pan members 18 are snapped together, and the outermost pan member 18 is inserted into channel member 28 to form a ceiling structure as illustrated in FIG. 1, the trim components of the present invention may be installed. First, trim member 110 is positioned so that arms 114, 116 abut the exposed edges of channel member 28 and adjacent pan member 18. Once in place, trim member 110 should cover such exposed edges. While holding trim member 110 in position, clip 300 is aligned so that its aperture 304 is concentric with the aperture (not shown) on trim member 110, and then screw 146 is inserted through aperture 304 and the aperture in the trim member 110 and driven into place. Each additional aperture (not shown) on trim member 110 is similarly provided with a clip 300 and screw 146. Next, trim cap 200 is slid into place over clip 300 by engaging first and second longitudinally extending channels 126, 134 and sliding the trim cap 200 into place. The trim assembly 100 is now in place, thereby covering over the channel members 28 and the screws 146 or other fastener, to prevent tampering or unauthorized removal. The installed trim assembly 100 has an attractive appearance with clean lines.
It should be understood that a preferred embodiment of a trim assembly has been described, and that many alterations, modifications, and changes in the invention may occur to persons of ordinary skill. For example, the trim assembly may be used in other paneling and ceiling environments. Indeed the trim assembly 100 is so functional and attractive that it may be used without substantial modification in homes and offices. In addition, adjustments may be made to the overall geometry of the trim assembly 100, such as changing the degree of offset of the first and second channels 126,134. It is therefore intended that the scope of the invention be governed solely by the following claims, including all equivalents.
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The invention provides a concealing trim assembly for a wall or ceiling panel system, comprising a trim member fastenable to a channel member of a ceiling or wall panel support, the trim member having a base portion and first and second means for slidably retaining a trim cap; means for fastening the trim member to the channel member; and a trim cap for concealing the means for fastening the trim member to the channel member. The trim cap has first and second edges matable with the first and second means for slidably retaining a trim cap, and at least one clip means for biasing the first and second edges of the trim cap with respect to the first and second means for retaining a concealment trim cap.
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FIELD OF INVENTION
The present invention relates generally to asphalt roofing shingles and their manufacture, and more particularly to a method of applying microorganism resistant granules to a continuously moving strip of asphalt coated material which is suitable for use as roofing shingles.
BACKGROUND OF THE INVENTION
A common method of manufacturing asphalt roofing shingles involves producing a continuous strip of granule covered asphaltic shingle strip material which is subsequently cut into individual roofing shingles. To produce the asphaltic strip material, either an organic felt, a glass fiber mat, or other suitable substrate is coated with hot, liquid asphalt, or a liquid asphalt and filler mixture. This may be accomplished by passing the substrate material through a coater containing the liquid asphalt, or the asphalt may be sprayed or otherwise applied to the substrate. The hot, tacky asphaltic strip is subsequently passed beneath one or more granule applicators or hoppers which apply the protective and/or aesthetically pleasing surface granules to the asphaltic strip material.
The manufacture of shingles from such an asphalt coated strip generally involves dispensing at least two different types of granules. "Headlap" granules, which are relatively low in cost and primarily serve the functional purpose of protecting the underlying asphalt material, are applied to a shingle at regions which will ultimately be covered by adjacent shingles when installed upon a roof. Colored granules or other "prime" granules are relatively expensive and are applied to the shingle at regions which will ultimately be visible when the shingles are installed upon a roof. Prime granules are disposed upon the asphalt strip for both the functional purpose of protecting the underlying asphalt strip and for the purpose of providing an aesthetically pleasing roof. In a typical shingle manufacturing process, the continuous asphalt coated strip may be sufficiently wide to allow for each predetermined length of the strip to be cut into several roofing shingles of such predetermined length. A traditional size for a roofing shingle is three feet by one foot. For example, some plants utilize an asphaltic strip which is sufficiently wide to allow three, one foot wide shingles of a predetermined length to be cut from each such length of asphaltic strip. However, other plants utilize an asphaltic strip which is sufficiently wide to allow four, five, or six, one foot wide shingles to be cut from each length. In the manufacturing process, the asphaltic strip is conceptually divided into an equal number of prime lanes, and headlap lanes. Prime lanes receive an application of prime granules while headlap lanes receive an application of headlap granules. In a three shingle wide configuration, the asphalt coated strip therefore is divided lengthwise into six lanes, three headlap lanes and three prime lanes. When a desired length of the asphalt coated strip is cut into three shingles, each shingle will be comprised of a length of headlap lane and the adjacent length of prime lane.
One problem commonly facing homeowners and others having asphalt shingled roofs, among other types of roofs, has been the growth of algae and fungus on the exposed surfaces of the roof. On a roof covered with asphalt shingles, this problem manifests itself as severe discoloration of the exposed shingle surfaces. Although this algae and fungus growth is especially prevalent in the Gulf Coast area of the United States and other warm and humid climates, it has also been found to occur in the northern regions of the United States. The discoloration generally becomes visibly apparent during the second or third year after the roofing shingles have been applied, beginning as dark spots which develop into dark streaks which eventually cover a majority of the roof. For aesthetic and sun reflective purposes, granules disposed upon the exposed or prime portions of roofing shingles are often white or light-colored and such fungus or algae or other microorganism growth on a light-colored or white shingle is particularly noticeable and unsightly.
To combat the problems associated with the growth of fungus, algae, and other microorganisms upon the exposed surfaces of roofing shingles, it is generally known to include, upon the exposed surfaces of the shingles, granules composed of or containing copper and/or other metals such as zinc, or particles of metallic zinc or copper. When wetted by rain or otherwise, such granules release copper and zinc compounds respectively which act as algicides and/or fungicides to inhibit the growth of algae and/or fungus. Such copper, zinc, or other metallic compound containing granules are very expensive, even when compared to ordinary prime or colored granules. They also may not be the same color as the prime granules being used. Therefore for aesthetic and economic reasons, the exposed surfaces of such algae and fungus resistant shingles contain primarily ordinary colored "prime" granules and a relatively small percentage of the expensive copper or zinc containing granules interspersed among the ordinary prime granules.
To minimize costs and to maximize algae and fungus fighting effectiveness, it is generally desirable to have a predetermined percentage of the anti-microorganism copper or zinc containing granules disposed upon the prime surface of each shingle. Such granules have heretofore been mixed with the prime granules to this predetermined percentage by weight or volume and applied with the ordinary prime granules to the prime lanes of the strip of asphalt covered material. However, because of normal variations in the manufacturing process, the weight of prime granules applied to each length of the various prime lanes of the asphalt strip can vary. This variance necessarily causes a deviation from the desired predetermined percentage of copper or zinc containing granules being disposed upon the prime areas of the asphalt strip. This results in some shingles having more copper, zinc, or other such microorganism resistant granules than is necessary while others may have an insufficient amount of such granules as is necessary to effectively fight fungus and/or algae.
In addition, the manufacture of roofing shingles necessarily involves dispensing more granules onto the asphalt coated strip than are necessary to coat the strip. This excess ensures that all areas of the strip are coated to provide a superior shingle, and prevents the hot, tacky asphalt coated strip from contacting and sticking to the rollers of a manufacturing production line. After the initial application of granules, the continuous strip of asphalt and granule coated material is passed around an apparatus for removing these excess or "backfall" granules. This apparatus is commonly a large diameter drum referred to as a slate drum. Backfall granules are collected in a backfall hopper and are reapplied to the asphalt coated strip. In the process of removing the excess prime and headlap granules, it is possible to keep the backfall headlap granules from commingling with the backfall prime granules. This is desirable because such granules can then be re-applied through the backfall hopper to the appropriate lanes of the strip of asphaltic material. It would be undesirable to apply backfall headlap granules to the prime lanes of the asphaltic coated strip. However, the process of preventing the backfall headlap granules from commingling with the backfall prime granules necessarily causes some backfall prime granules to become commingled with the backfall headlap granules. This results in some of the backfall prime granules being applied to the headlap lanes of the asphaltic strip through the backfall hopper. Such application of the relatively expensive backfall prime granules to the headlap regions of the asphaltic strip is referred to as the "downgrading to headlap" of the prime granules. This also causes some of the very expensive anti-microorganism granules which were mixed with and applied simultaneously with the ordinary prime granules to be "downgraded to headlap" where their algicidal or fungicidal properties are not needed and are not helpful.
SUMMARY OF THE INVENTION
The present invention is therefore directed to a method of manufacturing a microorganism resistant roofing shingle comprising the steps of supplying a continuous strip of asphalt coated material having at least one prime lane; applying anti-microorganism granules to the at least one prime lane of the continuous strip of asphalt coated material; and applying at least a second type of granule to the at least one prime lane of the continuous strip of asphalt coated material. By applying the anti-microorganism granules to the tacky asphalt-coated strip prior to applying the prime granules, nearly 100 percent of the anti-microorganism granules will be adhered to the prime areas of the shingle, and there will be virtually no waste of the expensive anti-microorganism granules. The continuous strip of asphalt coated material preferably also includes at least one headlap lane, and the process preferably further comprises the step of applying headlap granules to this headlap lane.
In a preferred embodiment, the anti-microorganism granules are copper containing granules while the second type of granule applied to the prime lanes is an ordinary colored or other type of prime granule.
The anti-microorganism granules may be dispensed from a roll-type hopper such as a fluted roll hopper including means for controlling the quantity of granules dispensed therefrom. In a preferred embodiment, such means for controlling the quantity of granules dispensed from a fluted roll hopper may include gate means disposed at the output area of such a hopper. As another means to control the output from such a feeder, the speed at which the fluted roll rotates may be varied, manually or by means of computer control, in relation to the speed of the asphaltic strip moving past the hopper.
In another preferred embodiment, the anti-microorganism granules are dispensed from a vibratory feeder including means for controlling the quantity of granules dispensed therefrom. The means for controlling the quantity of granules dispensed from such a vibratory hopper may be a weigh scale or loss-in-weight feeder to control the feed or input stream of granules into the vibratory feeder. In another preferred embodiment, the vibratory feeder is overfed or "choke" fed with anti-microorganism granules and the rate at which they are dispensed from the feeder is controlled by varying the vibratory action of the feeder. The vibratory feeder may also contain a gate at its output region or orifice to control the output of the feeder. The gate opening is preferably preset while the vibratory action of the feeder is preferably variable and automatically changes depending upon the speed at which the strip of asphaltic material moves beneath the feeder.
The present invention therefore allows for the accurate application, in terms of quantity and location, of anti-microorganism granules upon the prime lanes of the moving strip of asphalt coated strip material, such that the anti-microorganism granules will stick to the prime lanes and not become downgraded to headlap granules due to backfall operations. Precise amounts of anti-microorganism granules are applied to each shingle to render their use more cost-effective.
The present invention also relates to a microorganism resistant shingle manufactured according to process disclosed herein.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view in elevation of an apparatus employing the method of the present invention;
FIG. 2 is a schematic plan view of a portion of the asphaltic strip material having been coated with granules, and showing a roofing shingle, made by the method of the present invention, as a part thereof.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown in FIG. 1, a substrate or base sheet 10 is passed, using means known in the art, through coater 12 containing liquid asphalt, or a mixture of liquid asphalt and filler material as is known in the art. The coater maintains the asphalt compound at an elevated temperature to create a continuous strip of hot, tacky, asphalt coated material or asphaltic strip 14. Asphalt mixture may alternatively be sprayed onto one or both sides of base sheet 10. Substrate or base sheet 10 is preferably made from a glass fiber mat although organic felt or other suitable materials as are known in the art may be utilized.
Asphaltic strip 14 is shown in more detail in FIG. 2 as containing six distinct regions or lanes including three headlap lanes h1, h2, and h3, and three prime lanes p1, p2, and p3. A roofing shingle 40 is shown in ghost and may be cut from asphaltic strip 14 as shown. In this manner, three roofing shingles of any length desired may be cut from each such length of asphaltic strip 14. Each shingle would contain one headlap lane h1, h2, or h3, and one respective adjacent prime lane p1, p2, or p3. Accordingly, shingle 40 includes a headlap region 42 and a prime region 44. The headlap region 42 of shingle 40 is that portion which is covered by adjacent shingles when shingle 40 is ultimately installed upon a roof. The prime region 44 of shingle 40 is that portion which remains exposed when shingle 40 is ultimately installed upon a roof. It is upon the prime region 44 therefore that the growth of fungus, algae, or other such microorganisms may produce an unsightly appearance which is to be avoided. Shingle 40 is preferably cut from asphaltic strip 14 to be three feet long by one foot wide. Shingle 40 also preferably includes two cut-out regions 46 which act to form three tabs 48. Those skilled in the art will recognize that asphaltic strip 14 may be a wide variety of widths to allow different numbers of shingles to be cut therefrom. For example, some roofing shingle manufacturing plants utilize an asphaltic strip 14 which is sufficiently wide to allow four, one foot wide shingles to be cut therefrom. This wider asphaltic strip would include an additional headlap region, and an additional prime region. Those skilled in the art will also recognize that different size roofing shingles, in terms of length and/or width, may be cut from asphaltic strip 14.
Asphaltic strip 14 is next caused to pass, using means known in the art, beneath first granule applying means, such as a hopper or feeder 16. The hopper or feeder 16 deposits a predetermined amount of anti-microorganism granules 18 onto prime lanes p1, p2, and p3, of asphaltic strip 14. The hopper or feeder 16 may be a fluted roll hopper having a gated output orifice as is well known in the art, or any other hopper or feeder as is known in the art. In the preferred embodiment, however, a vibratory feeder is used as first hopper 16 to dispense the anti-microorganism granules 18. A vibratory feeder deposits a more uniform "curtain" of granules 18 having well defined edges over the desired prime lanes p1, p2, p3 of asphaltic strip 14 to uniformly distribute the microorganism granules 18 upon the prime lanes p1,p2,p3 without causing said microorganism resistant granules 18 to be inadvertently applied to the headlap lanes h1,h2,h3. Anti-microorganism granules are typically applied at a range of eight to twelve percent (8%-12%) of the total weight of granules applied to the prime lanes, and a vibratory feeder is thought to provide a more uniform dispensing of this relatively low amount of granules 18. First hopper or feeder 16 preferably has a first output orifice designed to apply granules to prime lanes p1, p2, and a second output orifice designed to apply granules to prime lane p3.
First hopper 16 receives a supply of anti-microorganism granules from a source using any of the numerous means as are known in the art. In using a vibratory feeder as the granule applying means 16, the feeder may be overfed or "choke" fed, wherein the output therefrom is controlled by means of a gate controlled opening at its output 17, and/or by controlling the frequency and amplitude of the vibration of the feeder 16. The gate opening at the output 17 is preferably preset at the desired opening or height while the frequency and amplitude of the vibration of the feeder 16 may vary depending upon the rate at which asphaltic strip 14 is moving beneath the feeder. Alternatively, a weigh scale or a loss-in-weight scale may be used to supply the anti-microorganism granules into first hopper 16 at a predetermined rate to thus control the output of anti-microorganism granules 18 from first hopper 16. In such an arrangement, the input supply of anti-microorganism granules may depend upon, among other things, the speed at which asphaltic strip 14 moves beneath first hopper 16. First hopper 16 may be adapted with any other suitable means known in the art to control the output of granules 18 dispensed therefrom. For example, when first hopper 16 is of the gated output fluted roll type, the speed at which the fluted roll rotates, and consequently the output from the hopper 16, may be manipulated to vary depending upon, among other things, the speed at which asphaltic strip 14 moves beneath first hopper 16.
Anti-microorganism granules 18 are known in the art and are preferably designed to inhibit the growth of algae, fungus, and/or other microorganisms. Anti-microorganism granules may be similar in appearance and composition to ordinary roofing granules as are known in the art or may be another particulate substance such as, for example, small pieces of metallic copper or zinc. Thus, the term granule, as used herein, would include any suitable particulate or particle-like material. The anti-microorganism granules may be made entirely from copper or contain copper or copper compounds. Anti-microorganism roofing granules are available commercially from the Minnesota Mining and Manufacturing Company, St. Paul, Minn., also known as 3M. The quantity of such granules deposited upon the prime lanes p1, p2, and p3 varies depending upon the exact composition of granules utilized. Any such quantities for the various granules are known in the art. It is thought preferable to deposit an amount of algicidal or fungicidal or other such granules at an average of 8% to 12% by weight of the total granules applied to the prime lanes p1, p2, p3 of asphaltic strip 14. For example, if a total of thirty pounds (30 lbs.) of granules stick or adhere to each 100 square feet of prime lane, ideally, 10% or three pounds (3 lbs.) of these granules would be anti-microorganism granules. However, this rate may vary and the invention is not meant to be limited to any particular algicidal or fungicidal granule, or any particular rate of application of such anti-microorganism granules.
Subsequent to anti-microorganism granules 18 being deposited onto prime lanes p1, p2, p3 of asphaltic strip 14, strip 14 passes beneath second granule applicator means such as hopper or blender 22 which preferably dispenses ordinary prime granules 24 onto prime lanes p1, p2, p3 using means known in the art. Numerous types of prime granules are well known in the art and may include, for example, colored granules. Second hopper or blender 22 is preferably a fluted roll type hopper although any variety of hopper known in the art may be utilized to apply the prime granules 24. Second hopper 22 is adapted with any suitable means for controlling the quantity of granules 24 dispensed therefrom, such as an output gate 23. Output of granules 24 is preferably designed to vary, using means known in the art, depending upon the speed at which asphaltic strip 14 moves beneath blender 22. Blender 22 receives a supply of prime granules from a source by any of the numerous means as are well known in the art. Blender 22 typically dispenses several different shades of prime granules 24 at predetermined intervals of prime lanes p1, p2, p3, to provide a more aesthetically pleasing and textured appearance to an installed roof.
The application of headlap granules to the headlap lanes h1, h2, h3 of asphaltic strip 14 preferably occurs after the application of prime granules 24, although it may occur before. Application of the headlap granules, which are lower in cost and less aesthetically pleasing, preferably occurs when asphaltic strip 14 passes beneath third granule applicator means such as hopper or backfall hopper 30 which deposits headlap granules onto the headlap lanes h1, h2, h3 of asphaltic strip 14. Backfall hopper 30 is preferably a fluted roll hopper adapted with any suitable means for controlling the quantity of granules dispensed therefrom, such as an output gate. In addition to receiving backfall headlap granules and backfall prime granules, third hopper 30 preferably receives additional headlap granules from a source by any of the numerous means as are well known in the art. The roll speed and/or the gate opening of backfall hopper 30 may be varied, using means known in the art, depending upon the speed at which asphaltic strip 14 moves beneath backfall hopper 30 to control the output of granules 29.
Slate drum 28 is designed to cause any excess non-adhered granules, both prime and headlap, to be removed from asphaltic strip 14 and to be deposited into backfall hopper 30 for re-application to asphaltic strip 14. By continuously depositing an excess of granules onto asphaltic strip 14, strip 14 is more likely to be completely covered with granules. Due to the fact that prime granules are more expensive than headlap granules, and due to the fact that it is undesirable to have any backfall headlap granules deposited onto the prime lanes p1, p2, p3 of asphaltic strip 14, backfall hopper is preferably designed to keep backfall headlap granules separate from backfall prime granules. In this manner, backfall headlap granules may be re-applied to the headlap lanes h1, h2, h3 of asphaltic strip 14, and backfall prime granules may be reapplied to the prime lanes p1, p2, p3 of asphaltic strip 14. To prevent any backfall headlap granules from being re-applied to the prime lanes p1, p2, p3, some of the backfall prime granules from the areas adjacent to the headlap lanes h1, h2, h3, must be diverted into the backfall headlap supply and are therefore "downgraded" to headlap granules. This causes a waste of some of the relatively expensive prime granules. Those skilled in the art will recognize however that if the very expensive fungicidal, algicidal or other such anti-microorganism granules 18 are applied before the application of the ordinary prime granules 24, substantially all of the anti-microorganism granules 18 will remain adhered to tacky surface of the prime lanes p1, p2, p3 and will not be dislodged by slate drum 28. Those skilled in the art will also recognize that the prime granules which are downgraded to headlap will contain very few or none of the very expensive anti-microorganism granules.
Although the invention has been described in terms of initially applying anti-microorganism granules, secondly applying prime granules, and lastly applying headlap granules, those skilled in the art will recognize that the invention resides in applying a predetermined amount of the anti-microorganism granules 18 to the prime lanes p1, p2, p3, separate from and prior to the application of the ordinary prime granules 24 to the prime lanes p1, p2, p3. Therefore, the application of the headlap granules to the headlap lanes h1, h2, h3 of asphaltic strip 14 may occur before the application of the anti-microorganism granules to the prime lanes p1, p2, p3, or after, or the headlap granules may be applied between the application of the anti-microorganism granules and the prime granules. Additionally, small amounts of other granules may be applied to the prime lanes prior to the application of the anti-microorganism granules provided that the prime lanes are substantially uncovered to allow most of the anti-microorganism granules to stick to the prime lanes.
While the foregoing description has set forth the preferred embodiment of the invention in particular detail, it must be understood that numerous modifications, substitutions and changes can be undertaken without departing from the true spirit and scope of the present invention as defined by the ensuing claims.
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A method of manufacturing a microorganism resistant asphaltic roofing shingle includes supplying a tacky asphaltic strip material having a prime lane, and applying prime granules onto the prime lane to substantially cover the prime lane so that approximately all of the prime granules adhere to the asphaltic strip material. An excessive amount of backfall granules are applied onto the prime lane on top of the prime granules. Prior to applying the prime granules onto the prime lane of the asphaltic strip material, anti-microorganism granules are applied onto the prime lane so that nearly 100 percent of the anti-microorganism granules adhere to the asphaltic strip material.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application claims priority to International Patent Application number PCT/EP2013/076114, filed on Dec. 10, 2013 which claims priority to German Patent Application number 10 2012 112 184.2 filed on Dec. 12, 2012 and is hereby incorporated by reference in its entirety.
FIELD
The disclosure relates to a method and a device for the reverse current protection of a number of strings of a photovoltaic generator being connected in parallel to a common DC link.
BACKGROUND
Reverse currents are defined as currents flowing in the opposite direction to the currents generated by the photovoltaic generator in normal operation.
Where a number of strings of a photovoltaic generator are connected in parallel to a common DC link, a reverse current may arise e.g. if an individual string is in shadow, and thus the intermediate circuit voltage delivered by the other, unshadowed strings of the DC link causes a reverse current to flow through the shadowed string.
The constituent photovoltaic modules in the strings of a photovoltaic generator will not be damaged by small reverse currents. However, where a plurality of strings are connected in parallel, the risk will arise that an individual string which is in shadow or which, for other reasons, delivers a significantly lower output voltage than the strings connected in parallel, will receive currents from all the remaining strings in the form of reverse currents. The string concerned will rapidly be overloaded as a result.
If a string with an incorrect polarity is connected on a common bus connection with a number of other strings, it will short-circuit the other strings connected on the bus connection. The resulting short-circuit current, i.e. the sum of the currents generated by the other strings, will not flow back through the string connected with an incorrect polarity, but will therefore flow counter to the forward direction of a correctly connected string. In any case, the high short-circuit current in all the other strings will constitute a potential source of damage to the string connected with an incorrect polarity. The overloading of the affected string may also cause further damage—specifically, the outbreak of fire may occur as a result of the overheating of components in the affected string.
From EP 2 284 973 A1, a photovoltaic installation with a plurality of strings is known, each of which is comprised of a number of photovoltaic modules connected exclusively in series. The strings are connected to one another in parallel on bus lines. A transformer feeds electrical energy from the bus lines into a grid system. By the regulation of the transformer, it is possible to adjust the voltage released between the bus lines. Each string is provided with a current sensor which, as a minimum requirement, detects whether a reverse current is flowing to the string, and indicates said reverse current to the control system. The control system reduces the voltage between the bus lines, thereby interrupting the reverse current. Accordingly, the individual strings are not provided with a reverse current-blocking diode. The current sensors are preferably arranged in a number of decentralized terminal units. A number of strings in the field are connected in parallel to the terminal units by means of a pair of connecting cables, and these connecting cables are then routed to a central unit which incorporates the transformer. The central unit is provided with terminals for the connection of the central terminal units to the bus lines.
From EP 2 282 388 A1, a device is known for the in-feed of electrical energy from a plurality of strings of photovoltaic modules into a grid system. The device is provided with a connection for each string, which incorporates means for overcurrent protection and for the selective tripping of the string. Each string is customarily comprised, not only of a series circuit of photovoltaic modules, but of a regular arrangement of multiple sub-strings, which are combined to form a parallel circuit. Means for overcurrent protection and for the selective tripping of individual strings are each provided with a power circuit-breaker, with a motor-driven opening and closing system, connected in series to a current sensor between the relevant string and a bus line. The bus line is connected to an inverter.
From DE 101 20 595 A1, a solar energy system comprising a standard solar cell chain and a sub-standard solar cell chain is known. The DC voltage delivered by the sub-standard solar cell chain is raised to the level of the DC output voltage from the standard solar cell chain by means of a booster unit. The DC voltage from the standard solar cell chain and the raised DC voltage are fed to an inverter, which generates an AC voltage which is then delivered to an electric power supply system. A reverse current-blocking diode is arranged respectively between the standard solar cell chain and the booster unit on one side, and the inverter on the other side. The booster unit may be configured as a voltage-raising circuit, i.e. as a boost converter.
From DE 10 2009 032 288 A1, a photovoltaic installation is known. The photovoltaic installation is comprised of photovoltaic modules, which are connected to form a number of module strings, and are protected against reverse currents. The module strings are connected to dedicated DC/DC converters, and the outputs from the DC/DC converters are fed to the input of a common inverter. The DC/DC converters are arranged in at least one generator terminal box, which is physically separated from the inverter. One or two module strings may be connected to each DC/DC converter. Where two module strings are connected per DC/DC converter, string protection facilities may be omitted. Where only one module string is connected per DC/DC converter, string diodes may also be omitted, as the galvanic isolation function delivered by the DC/DC converters inhibits any reverse current. As no further control function is available on the galvanically-isolating DC/DC converters, the current can be prevented by the DC/DC converters. Any additional DC isolating point may be omitted accordingly. Moreover, the individual module strings may be disconnected, without disconnecting the entire photovoltaic installation.
From US 2007/0107767 A1, a DC generating system is known, comprised of a number of strings of energy-generating cells connected in parallel to bus lines. The current flowing through each string is measured by a current sensor. Each string is also provided with a switching module, for the connection of the relevant string to the bus lines, the disconnection or short-circuiting thereof by means of a dynamic load.
SUMMARY
The disclosure includes a method and a device for reverse current protection of a number of strings in a photovoltaic generator, which are connected in parallel to a common DC link, the execution of which is associated with only minimal hardware expenditure.
The disclosure relates to a method for reverse current protection of a number of strings of a photovoltaic generator being connected to a common DC link in parallel in small groups respectively via a corresponding DC/DC converter, whereby the current flowing through each of the DC/DC converters is detected, and a reverse current flowing through one of the DC/DC converters is inhibited by the control of the DC/DC converter. It is understood that not every small reverse current will necessarily be inhibited by one of the DC/DC converters, but that a threshold value can be set for a reverse current to be inhibited by each of the DC/DC converters. The unnecessary tripping of the control function on the DC/DC converter for the inhibition of the reverse current can be avoided accordingly.
The disclosure furthermore relates to a device for reverse current protection of a number of strings of a photovoltaic generator, which are connected to a common DC link in parallel in small groups respectively via a corresponding DC/DC converter. In one embodiment each DC/DC converter is associated with a current sensor detecting the current flowing via the DC/DC converter, whereby a central control system is configured to inhibit the flow of a reverse current through one of the DC/DC converters by the control of the DC/DC converter. The device according to the disclosure may be configured as part of an energy-generating installation.
By the method or the device according to the disclosure, it is possible to achieve a fail-safe operation of a higher-order energy-generating installation. This means that any individual fault will not induce or maintain an unsafe, or potentially fire-inducing condition in the energy-generating installation. This performance can be achieved with no additional components, by means of an appropriate control system.
In this context, a string is understood as a series circuit of a number, in general a plurality of photovoltaic modules. In principle, a string may comprise a number of sub-strings connected in parallel. However, this is often not the case.
In this context, a reverse current through a DC/DC converter is understood as a current whereby electrical energy from the DC link flows in the strings which are connected via the DC/DC converter to the DC link. I.e. a reverse current through a DC/DC converter flows in the opposite direction to the current which should be flowing from the strings to the DC link. A reverse current of this type through a DC/DC converter is indicative of a fault which is associated with a critical current, specifically a reverse current, through one of the connected strings. This will apply, even where the reverse current through the DC/DC converter is only small and, accordingly, the associated reverse current through one of the connected strings is not critical. In the present disclosure, only the currents flowing through the DC/DC converters are monitored for reverse currents. Overload protection in all the connected strings can nevertheless be achieved.
In this context, a small group is understood as a sufficiently small number of strings such that neither a reduction in the output voltage of one of the strings associated with shadowing, or other reasons, nor the connection of one of the strings with an incorrect polarity, shall cause the current from the remaining strings in the small group flowing through one string to result in damage to the string. This will be ensured if the small group comprises two strings, or even a single string. In one embodiment the group will be comprised of two strings, in the interests of maximum security, but also as a means of halving the number of DC/DC converters, in comparison to an arrangement with only one string per DC/DC converter.
According to the disclosure, a reverse current flowing through one of the DC/DC converters, which might result in the overloading of a connected string, is inhibited by the appropriate control of the DC/DC converter. In principle, this is achieved in an arrangement whereby the DC/DC converter in which the reverse current occurs is controlled in order to effect the interruption of the reverse current. A control facility of this type will be available e.g. where the DC/DC converters are configured as buck converters. In many instances, however, this is not the case.
In one embodiment any reverse current flowing through one of the DC/DC converters should be inhibited by the control of the remaining DC/DC converters, thereby interrupting the flow of current from the string connected thereby to the common DC link. This will be possible e.g. even where the DC/DC converters are configured as boost converters.
Where the DC/DC converters are configured as boost converters, which can be used for the independent MPP tracking of connected strings, any reverse current flowing through one of the DC/DC converters can be inhibited by the closure of the boost converter switches of the remaining DC/DC converters. This closure of the boost converter switches short-circuits the remaining DC/DC converters. The boost converter diodes of the remaining DC/DC converters will prevent the short-circuiting of the DC link as well by the boost converter switches.
Prior to the closure of the boost converter switches of the remaining DC/DC converters, an attempt may be made to inhibit the reverse current flowing through one of the DC/DC converters by the opening of the boost converter switches in the remaining DC/DC converters. The boost function of the latter will be tripped accordingly, and the voltage on the common DC link, which generates the reverse current, will be reduced.
In this form of embodiment of the disclosure, provided that the boost converter diodes are in serviceable condition, these will also protect the individual DC/DC converters against the occurrence of reverse currents. This means that a reverse current from the DC link flowing through one of the DC/DC converters can only occur if the associated boost converter diode is defective, and is no longer executing its blocking function. Only the boost converter diodes can prevent the application of currents generated by the strings in other sub-groups to strings, which are connected with an incorrect polarity.
If only one of the two strings in a sub-group is connected with an incorrect polarity, the current sensor of the associated DC/DC converter will register no current, or an unusually low current, through the DC/DC converter. If both strings in the relevant sub-group are connected with an incorrect polarity, or the sub-group incorporates only one string which is connected with an incorrect polarity, the current sensor will register a limited reverse current. As this case already subsumes the occurrence of two faults, it is not relevant to the appraisal of fail-safety, but is considered here for the purposes of the further description of the disclosure. Conversely, a defective boost converter diode, in combination with a reverse current from the remaining strings, connected via the remaining DC/DC converters, will result in an increased reverse current, which will flow if the boost converter switch is open, but will be short-circuited if the boost converter switch is closed. In this way, it will be possible to distinguish these cases by the analysis of the occurrence of the reverse current, specifically by reference to the magnitude thereof and/or its dependence upon the circuit state of the associated boost converter switch. Accordingly, a fault signal can conceivably be generated which corresponds to the analysis result. As a minimum, the fault signal can indicate an initial state, which is associated with a defective boost converter diode, and a second state, which corresponds to the connection of one or more strings with an incorrect polarity.
The above description assumes that the current sensors of the DC/DC converter, configured as a boost converter, are arranged at the string-side input end of the DC/DC converter, i.e. ahead of the relevant boost converter switch.
If, according to the disclosure, a reverse current has been inhibited by the closure of the boost converter switches of the remaining DC/DC converters, configured in the form of boost converters, the boost converter switch of the DC/DC converter via which the reverse current has occurred will be permanently open. In this case, the strings of the DC link which are connected to the latter via this DC/DC converter will at least be fed with sufficient electrical energy to permit the emergency operation of a connected inverter or the control function thereof, which can also be supplied from the DC link.
If, in a device according to the disclosure, one or more strings, via an inverter configured as a boost converter, are connected with an incorrect polarity on the DC link, which simultaneously features a defective boost converter diode, the closure of the boost converter switches of the remaining DC/DC converters will also result in the interruption of the reverse current, provided that the latter originates from the strings connected to the remaining DC/DC converters. In this case, however, which is likewise not relevant to the appraisal of fail-safety due to the occurrence of multiple independent faults, after the opening of the boost converter switch of the DC/DC converter in which the reverse current occurs, there will be no charging of the DC link by the connected strings, at least not with the desired polarity. In this specific configuration, the closure of the boost converter switch of the boost converter which incorporates the defective boost converter diode will be advantageous.
The current sensors of the device according to the disclosure, which are allocated to the individual DC/DC converters, are necessary for the execution of separate MPP tracking with the individual DC/DC converters, anyway. The boost converters are the DC/DC converters which are used to execute separate MPP tracking of this type on individual strings in “multi-string inverters”. The disclosure exploits only the boost converter switches and the boost converter diodes of such boost converters. Additional switches or diodes are not necessary. In other words, in a multi-string inverter which is provided with a number of boost converters connected in parallel for separate MPP tracking, the disclosure can be effected mainly by software modifications, provided that the current sensors of the individual DC/DC converters are also suitable for the detection of reverse currents.
Advantageous further developments of the disclosure are indicated in the patent claims, the description and the drawings. The advantages of characteristics and of combinations of multiple characteristics specified in the description are provided by way of example only, and may be achieved alternatively or cumulatively, without the advantages necessarily proceeding from forms of embodiment according to the disclosure. With no resulting amendment to the subject matter of the attached patent claims, the following remarks will apply to the content disclosed in the original application documents and the patent: further characteristics—specifically the relative arrangement and mutual interaction of multiple components—may be observed from the drawings. The combination of characteristics of different forms of embodiment of the disclosure, or of characteristics of different patent claims is also possible, notwithstanding the selected objects of reference in the patent claims, and is proposed accordingly. This also applies to characteristics which are represented in separate drawings, or are specified in the description thereof. These characteristics may also be combined with characteristics of different patent claims. Likewise, characteristics described in the patent claims may not be relevant to further forms of embodiment of the disclosure.
In respect of number, the characteristics specified in the patent claims and in the description are assumed to be present in the exact number specified, or in a greater number than that specified, with no requirement for the explicit use of the adverbial phrase “at least”. For example, where reference is made to one element, it is to be understood that exactly one element, two elements or more elements are present. These characteristics may be supplemented by further characteristics, or may be the only constituent characteristics of the product concerned.
The reference numbers included in the patent claims do not constitute any restriction of the scope of the subject matter protected by the patent claims. Their sole purpose is to facilitate the understanding of the patent claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The disclosure is further clarified and described hereinafter, with reference to the preferred forms of embodiment represented in the figures.
FIG. 1 shows a block diagram of a device according to the disclosure, which is connected between individual strings of a photovoltaic generator and an intermediate input circuit of an inverter.
FIG. 2 shows a block diagram of a specific form of embodiment of the device according to the disclosure, also connected between strings of a photovoltaic generator and the intermediate input circuit of an inverter, in which two different potential faults are illustrated.
FIG. 3 shows a flow diagram for one form of embodiment of the method according to the disclosure.
DETAILED DESCRIPTION
The present disclosure concerns the protection of strings, or of energy-generating installations and structures such as buildings which are associated with energy-generating installations or in which the latter are installed, against overloads of this type. It is desirable that a degree of protection should be provided whereby, in case of the occurrence of any given individual fault, these installations will be securely protected.
The present disclosure is specifically intended for application in a photovoltaic installation in which the DC link is configured as an intermediate input circuit of an inverter, which feeds energy generated by the photovoltaic generator into a public AC grid system.
FIG. 1 shows a device 1 , which is connected between the individual strings 2 of a photovoltaic generator 3 and a DC link 4 of an inverter 5 . The strings 2 are each comprised of a plurality of photovoltaic modules or photovoltaic cells connected in series, which are not illustrated in detail here. For each string 2 , the device 1 is provided with a pair of terminals 6 , 7 . In each case, two terminals 6 and the associated two terminals 7 in the device 1 are assembled such that the strings 2 connected thereto form a parallel circuit directly at the input of the device 1 . These strings 2 connected in parallel are then each connected via a DC/DC converter 8 to bus lines 9 and 10 . The bus lines 9 and 10 are routed via terminals 11 and 12 in the device 1 to the DC link 4 , which is symbolized here by an intermediate circuit capacitor 13 . The inverter 5 feeds electrical energy from the DC link 4 into an AC grid system 14 .
In order to maximize the available electrical energy in the DC link 4 , the DC/DC converters 8 are configured for the individual MPP tracking of the strings 2 connected thereto. This means that the DC/DC converters 8 are configured to adjust the working point, i.e. the operating voltage, of the strings 2 connected thereto, in relation to the voltage of the DC link 4 , such that the electric power generated by the strings 2 is maximized. In addition to the output voltage of the strings 2 , the current flowing in the relevant DC/DC converter 8 must also be measured, in order to determine the current power output. Current is measured by means of a current sensor 15 .
The current sensor 15 is also used to detect the occurrence of reverse currents, flowing opposite to the normal current flow direction of the strings 2 in the DC link 4 . Reverse currents of this type may jeopardize the integrity of the strings 2 , specifically where these currents originate from many other strings 2 , which then flow through the individual strings concerned. Where a reverse current of this type flows through one of the DC/DC converters 8 , a control device 16 receiving the currents, in particular the reverse currents, measured by the current sensors 15 as input signals 23 , controls the DC/DC converter 8 such that the reverse current is inhibited. The precise action to be undertaken for this depends on the type of the DC/DC converter 8 .
If the DC/DC converters 8 are configured e.g. as buck converters, the buck converter switches of the remaining DC/DC converters, in which no reverse current is present, may be opened, in order to isolate the strings 2 connected thereto from the DC link 4 . The DC link 4 will then be charged only by the strings 2 to which the reverse current was previously flowing. In each case, the control system 16 for the inhibition of the reverse current will only control the DC/DC converters 8 provided for individual MPP tracking, and will not control any additional isolating switches or similar. Likewise, no additional diodes are provided for the inhibition of a reverse current. It is assumed that, in each pair of strings 2 connected to a DC/DC converter 8 , a reverse current can flow from one to the other, as this reverse current is limited to the current generated by the first of these strings 2 . Even the connection of a string 2 with an incorrect polarity, such that it short-circuits a string connected in parallel, will result at most in the flow of a short-circuit current from one string 2 through the two strings 2 connected to a DC/DC converter 8 . Such a current value can be accommodated by the strings 2 permanently, with no resulting damage or overheating. If, in a form of embodiment not represented, three strings 2 are connected to a DC/DC converter 8 , polarity reversal in an individual string 2 ′ will, at most, correspond to the current loading of this string with double the short-circuit current, generated by the two other strings. Even this loading can be accommodated by many strings permanently and without damage. In many cases, the configuration with three strings is therefore advantageous, on the grounds of the reduced number of DC/DC converters for a given number of strings. Conversely, in the case of load-sensitive modules, the configuration with only two strings 2 per DC/DC converter 8 is desired.
FIG. 1 represents a total of three DC/DC converters 8 , each with two strings 2 connected. In principle, however, fewer DC/DC converters 8 , and consequently fewer strings 2 may also be present. Specifically, the number of DC/DC converters 8 and the number of strings 2 connected thereto may be higher. Specifically, three strings 2 may also be connected to each DC/DC converter 8 .
FIG. 2 represents a device 1 with only two DC/DC converters 8 which, in this instance, is specifically configured as a boost converter 18 . Here again, the number of DC/DC converters 8 may be greater. Each DC/DC converter 8 is again provided with two terminals 7 and two terminals 6 for each respective string 2 . Again, the terminals 7 might be combined in one terminal 7 , if the associated string 2 is already connected in parallel outside the device 1 . Otherwise, the basic design of the device 1 corresponds to that represented in FIG. 1 .
However, by the configuration of the DC/DC converters 8 as boost converters 18 , the boost converter diodes thereof 19 basically act as blocking devices for reverse currents from the DC link 4 to the strings 2 connected to the relevant DC/DC converter 8 . In principle, therefore, such reverse currents can only occur if a boost converter diode 19 is defective. In the upper DC/DC converter 8 shown in FIG. 2 , this is represented by a short-circuit path 20 , indicated by a dashed line, which is shown parallel to the boost converter diode 19 . As a result of the defect in this boost converter diode 19 , the boost converter 18 also becomes entirely functionless, and if the voltage in the DC link 4 is higher than the corresponding string voltage, a reverse current will flow in the connected strings 2 . If this reverse current is detected by the current sensor 15 , the control system, which is not represented here, will close the boost converter switches 21 on all the remaining DC/DC converters 8 , in order to short-circuit the strings 2 connected thereto. Consequently, these will no longer charge the intermediate circuit capacitor 13 , and the reverse current will be inhibited after the voltage of the intermediate circuit capacitor 13 has been reduced to a sufficient degree by discharging associated with the reverse current. If the control system simultaneously opens the boost converter switch 21 of the DC/DC converter 8 on which the reverse current 15 has occurred, the strings 2 connected thereto will at least be able to maintain a background charge on the intermediate circuit capacitor 13 of the DC link 4 . This background charge will be sufficient for the minimum supply of monitoring and signaling systems of the device 1 , which are not represented in greater detail here, or of the inverter 5 , in order to permit the more detailed analysis of the reverse current fault arising, the clearance and/or the upward referral thereof.
In principle, a reverse current through one of the current sensors 15 may also occur if both of the strings 2 connected to the corresponding DC/DC converter 8 are connected with an incorrect polarity which, again, will not be a case considered in the exclusive appraisal of fail-safety. This reverse current will flow via the associated boost converter switch 21 which, in general, will only exercise a forward blocking function. This reverse current cannot be inhibited by the control system, by the opening of the boost converter switches 21 on the remaining DC/DC converters 8 , although it may be detected by the control system. As such, a reverse current flowing through a DC/DC converter 8 of two strings 2 connected thereto with an incorrect polarity will not be critical, as it will not exceed the current which will flow upon the short-circuiting of the strings connected to one of the remaining DC/DC converters by means of the boost converter switch thereof.
On the lower DC/DC converter 8 represented in FIG. 2 , it is shown that not both, but only one string 2 ′ is connected with an incorrect polarity. In general, this will not generate a reverse current detected by the associated current sensor 15 , but will result in a current flowing in the circuit formed by both the strings 2 and 2 ′ connected to the DC/DC converter 8 . The connection of only two strings 2 and 2 ′ restricts this current to a harmless level. In the case of this fault, the current sensor 15 will detect that no current is flowing through the DC/DC converter 8 , even though, under the conditions considered, a current should be flowing.
FIG. 3 shows a potential form of embodiment of the method according to the disclosure, represented by a flow diagram. In a first act 100 , the currents flowing through each of the DC/DC converters are detected. At 110 , these currents are then checked for the occurrence of a reverse current. If no reverse current is detected (− at 110 ), the method branches back to 100 , and the detection of all currents is repeated subsequently. If the flow of a reverse current is detected through a DC/DC converter (+ at 110 ), the affected DC/DC converter is tripped at 120 . Where the DC/DC converter is configured as a boost converter, the boost converter switch will also open. At 130 , this tripping is also applied to the remaining DC/DC converters. Thereafter, at 140 , the current flowing in the affected DC/DC converter is detected once more and, at 150 , it is confirmed whether the reverse current has already been inhibited by the measures implemented. If this is the case, the method branches back to 140 , and the current flowing through the affected DC/DC converter is checked on a regular basis, as it is possible for the reverse current to recur.
If the reverse current cannot be inhibited by the tripping of all the DC/DC converters, the unaffected DC/DC converters will be short-circuited at 160 , i.e. controlled in such a way that they will feed no further current to the common intermediate circuit.
In a potential alternative, the method branches directly from act 120 to act 160 . In this case, upon the occurrence of a reverse current, a state will be directly achieved in which only the affected string can still feed current to the intermediate circuit. This will reliably terminate the reverse current situation. Conversely, in acts 130 , 140 and 150 , an intermediate state is achieved, in which all the strings will potentially feed current to the intermediate circuit, and in which all strings will be at the same service voltage, as all the DC/DC converters have been tripped. In many cases, this will be sufficient to terminate the reverse current situation.
Finally, it should once more be emphasized that, in the device 1 , the flow of current from the strings 2 to the DC link 4 involves no electrical or electronic components, as these are not required anyway for the individual MPP tracking of the strings 2 connected to a given DC/DC converter 8 .
Many variations and modifications may be made to the preferred embodiments of the disclosure without departing substantially from the spirit and principles of the disclosure. All such modifications and variations are intended to be included herein within the scope of the present disclosure, as defined by the following claims.
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In order to protect reverse currents, several strings of a photovoltaic generator, which are connected in small groups respectively via a DC/DC-converter, parallel to a common DC voltage intermediate circuit, the current which flows over each of the DC/DC-converter is detected and if a reverse current is detected flowing through one of the DC/DC converters, the converter is stopped by controlling the DC/DC-converter.
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BACKGROUND OF THE PRESENT INVENTION
[0001] 1. Field of Invention
[0002] The present invention relates to a process of preparation of L-Arginine ketoglutarate 1:1 and 2:1, and more particularly to a process of preparation of L-Arginine ketoglutarate 1:1 and 2:1 which employs solid L-Arginine as raw materials directly to react with a-Ketoglutaric acid such that mass production of a high yield and low cost end product is realized.
[0003] 2. Description of Related Arts
[0004] L-arginine α-ketoglutarate 1:1 and 2:1 are widely used as sports nutrition ingredients. However, conventional method of preparation of L-arginine α-ketoglutarate 1:1 and 2:1 are complicated, time consuming and costly which are not suitable for industrialization. In particular, the conventional method makes use of L-arginine solution and large amount of organic solvents for the reactions, and obtains the final products of L-arginine α-ketoglutarate 1:1 and 2:1 through crystallization. The high level of complexity, the large amount of organic solvents required, the high production cost and the high production time required have make it difficult for mass production of L-arginine α-ketoglutarate 1:1 and 2:1 and industrialization.
SUMMARY OF THE PRESENT INVENTION
[0005] The invention is advantageous in that it provides a method of preparation of L-arginine α-ketoglutarate 1:1 which is cost effective and suitable for mass production.
[0006] Another advantage of the invention is to provide a method of preparation of L-arginine α-ketoglutarate 1:1 which does not require the use of a large amount of solvents throughout the process.
[0007] Another advantage of the invention is to provide a method of preparation of L-arginine α-ketoglutarate 1:1 through which a shorten period of production time is required to obtain a higher yield of final products.
[0008] Another advantage of the invention is to provide a method of preparation of L-arginine α-ketoglutarate 2:1 which is cost effective and suitable for mass production.
[0009] Another advantage of the invention is to provide a method of preparation of L-arginine α-ketoglutarate 2:1 which does not require the use of a large amount of solvents throughout the process.
[0010] Another advantage of the invention is to provide a method of preparation of L-arginine α-ketoglutarate 2:1 through which a shortened period of production time is required to obtain a higher yield of final products.
[0011] Additional advantages and features of the invention will become apparent from the description which follows, and may be realized by means of the instrumentalities and combinations particular point out in the appended claims.
[0012] According to the present invention, the foregoing and other objects and advantages are attained by a method of preparation of L-arginine α-ketoglutarate 1:1 through a reactor comprising the steps of:
[0013] (i) reacting methyl dichloroacetate and acrylic acid methyl ester with sodium methoxide to obtain dimethyl 2,2-dichloroglutarate;
[0014] (ii) reacting dimethyl 2,2-dichloroglutarate hydroxide solution to obtain a crude a-ketoglutaratic acid aqueous solution;
[0015] (iii) purifying the crude α-ketoglutaratic acid aqueous solution to obtain a purified α-ketoglutaratic acid aqueous solution, and providing the purified a-ketoglutaratic acid aqueous solution in the reactor;
[0016] (iv) adjusting a concentration of the purified α-ketoglutaratic acid aqueous solution by adding water into the reactor;
[0017] (v) adding a quantity of solid L-arginine to the purified α-ketoglutaratic acid aqueous solution, wherein the quantity of the solid L-arginine is equals to one equivalent mole of the purified α-ketoglutaratic acid aqueous solution;
[0018] (v′) stirring a mixture of solid L-arginine and the purified α-ketoglutaratic acid aqueous solution through the reactor;
[0019] (v″) setting a controlled temperature of the reactor such that the solid L-arginine dissolves and reacts with the purified α-ketoglutaratic acid aqueous solution in the reactor at the controlled temperature for a controlled period of time;
[0020] (vi) obtaining a resulting L-arginine α-ketoglutarate 1:1 solution from step (v″), wherein a pH of the resulting L-arginine α-ketoglutarate 1:1 solution is approximately 3˜4; and
[0021] (vii) obtaining a final product of L-arginine α-ketoglutarate 1:1 from step (vi) through spay drying, wherein a yield of the final product is approximately 94%.
[0022] In accordance with another aspect of the invention, the present invention provides a method of preparation of L-arginine α-ketoglutarate 2:1 through a reactor comprising the steps of:
[0023] (i) reacting methyl dichloroacetate and acrylic acid methyl ester with sodium methoxide to obtain dimethyl 2,2-dichloroglutarate;
[0024] (ii) reacting dimethyl 2,2-dichloroglutarate hydroxide solution to obtain a crude a-ketoglutaratic acid aqueous solution;
[0025] (iii) purifying the crude α-ketoglutaratic acid aqueous solution to obtain a purified α-ketoglutaratic acid aqueous solution, and providing the purified a-ketoglutaratic acid aqueous solution in the reactor;
[0026] (iv) adjusting a concentration of the purified α-ketoglutaratic acid aqueous solution by adding water into the reactor;
[0027] (v) adding a quantity of solid L-arginine to the purified α-ketoglutaratic acid aqueous solution, wherein the quantity of the solid L-arginine is equals to two equivalent mole of the purified α-ketoglutaratic acid aqueous solution;
[0028] (v′) stirring a mixture of solid L-arginine and the purified α-ketoglutaratic acid aqueous solution through the reactor;
[0029] (v″) setting a controlled temperature of the reactor such that the solid L-arginine dissolves and reacts with the purified α-ketoglutaratic acid aqueous solution in the reactor at the controlled temperature for a controlled period of time;
[0030] (vi) obtaining a resulting L-arginine α-ketoglutarate 2:1 solution from step (v″), wherein a pH of the resulting L-arginine α-ketoglutarate 2:1 solution is approximately 6.5˜7; and
[0031] (vii) obtaining a final product of L-arginine α-ketoglutarate 2:1 from step (vi) through spay drying, wherein a yield of the final product is approximately 97%.
[0032] Still further objects and advantages will become apparent from a consideration of the ensuing description and drawings.
[0033] These and other objectives, features, and advantages of the present invention will become apparent from the following detailed description, the accompanying drawings, and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] FIG. 1 is a schematic illustration of a method of preparation of L-arginine a-ketoglutarate 1:1 and 2:1 according to a preferred embodiment of the present invention.
[0035] FIG. 2 is a block diagram of a method of preparation of L-arginine a-ketoglutarate 1:1 according to the above preferred embodiment of the present invention.
[0036] FIG. 3 is a block diagram of a method of preparation of L-arginine a-ketoglutarate 2:1 according to the above preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0037] Referring to FIGS. 1 to 3 of the drawings, a method of preparation of L-arginine α-ketoglutarate 1:1 and 2:1 according to a preferred embodiment of the present invention comprises the steps of:
[0038] (i) reacting methyl dichloroacetate and acrylic acid methyl ester with sodium methoxide to obtain dimethyl 2,2-dichloroglutarate;
[0039] (ii) reacting dimethyl 2,2-dichloroglutarate with a hydroxide solution to obtain a crude α-ketoglutaratic acid aqueous solution;
[0040] (iii) purifying the crude α-ketoglutaratic acid aqueous solution to obtain a purified α-ketoglutaratic acid aqueous solution;
[0041] (iv) adjusting a concentration of the purified α-ketoglutaratic acid aqueous solution by adding water;
[0042] (v) adding a quantity of solid L-arginine to the purified α-ketoglutaratic acid aqueous solution, wherein the quantity of the solid L-arginine is equals to one equivalent mole of the purified α-ketoglutaratic acid aqueous solution for producing L-arginine a-ketoglutarate 1:1, wherein the quantity of the solid L-arginine is equals to two equivalent moles of the purified α-ketoglutaratic acid aqueous solution for producing L-arginine a-ketoglutarate 2:1;
[0043] (vi) obtaining a resulting L-arginine α-ketoglutarate 1:1 solution or 2:1 solution from step (v), wherein a pH of the resulting L-arginine α-ketoglutarate 1:1 solution is approximately 3˜4, wherein a pH of the resulting L-arginine α-ketoglutarate 2:1 solution is approximately 6.5˜7; and
[0044] (vii) obtaining a final product of L-arginine α-ketoglutarate 1:1 or 2:1 from step (vi) through spray drying, wherein a yield of the final product of L-arginine a-ketoglutarate 1:1 is approximately 94%, wherein a yield of the final product of L-arginine a-ketoglutarate 2:1 is approximately 97%.
[0045] In particular, referring to FIGS. 1 and 2 of the drawings, a method of preparation of L-arginine α-ketoglutarate 1:1 according to a preferred embodiment of the present invention comprises the steps of:
[0046] (i) reacting methyl dichloroacetate and acrylic acid methyl ester with sodium methoxide to obtain Dimethyl 2,2-dichloroglutarate;
[0047] (ii) reacting dimethyl 2,2-dichloroglutarate with a hydroxide solution to obtain a crude α-ketoglutaratic acid aqueous solution;
[0048] (iii) purifying the crude α-ketoglutaratic acid aqueous solution to obtain a purified α-ketoglutaratic acid aqueous solution;
[0049] (iv) adjusting a concentration of the purified α-ketoglutaratic acid aqueous solution by adding water;
[0050] (v) adding a quantity of solid L-arginine to the purified α-ketoglutaratic acid aqueous solution, wherein the quantity of the solid L-arginine is equals to one equivalent mole of the purified α-ketoglutaratic acid aqueous solution;
[0051] (vi) obtaining a resulting L-arginine α-ketoglutarate 1:1 solution from step (v), wherein a pH of the resulting L-arginine α-ketoglutarate 1:1 solution is approximately 3˜4; and
[0052] (vii) obtaining a final product of L-arginine α-ketoglutarate 1:1 from step (vi) through spray drying, wherein a yield of the final product is approximately 94%.
[0053] In particular, referring to FIGS. 1 and 3 of the drawings, a method of preparation of L-arginine α-ketoglutarate 2:1 according to a preferred embodiment of the present invention comprises the steps of:
[0054] (i) reacting methyl dichloroacetate and acrylic acid methyl ester with sodium methoxide to obtain Dimethyl 2,2-dichloroglutarate;
[0055] (ii) reacting dimethyl 2,2-dichloroglutarate with a hydroxide solution to obtain a crude α-ketoglutaratic acid aqueous solution;
[0056] (iii) purifying the crude α-ketoglutaratic acid aqueous solution to obtain a purified α-ketoglutaratic acid aqueous solution;
[0057] (iv) adjusting a concentration of the purified α-ketoglutaratic acid aqueous solution by adding water;
[0058] (v) adding a quantity of solid L-arginine to the purified α-ketoglutaratic acid aqueous solution, wherein the quantity of the solid L-arginine is equals to two equivalent mole of the purified α-ketoglutaratic acid aqueous solution;
[0059] (vi) obtaining a resulting L-arginine α-ketoglutarate 2:1 solution from step (v), wherein a pH of the resulting L-arginine α-ketoglutarate 2:1 solution is approximately 6.5˜7; and
[0060] (vii) obtaining a final product of L-arginine α-ketoglutarate 2:1 from step (vi) through spray drying, wherein a yield of the final product is approximately 97%.
[0061] Referring to FIGS. 1 to 3 of the drawings, preferably, the preparation of dimethyl 2,2-dichloroglutarate is further described as follows:
[0062] In a 3000 liter reactor, methyl dichloroacetate and acrylic acid methyl ester are added. The stirring is controlled to start and a first controlled temperature is adjusted to 0-60° C. Then, sodium methoxide is added slowly to form a first reaction mixture. After the sodium methoxide is added, the first reaction mixture is stirred at the first controlled temperature for 1-4 hours. Subsequently, 100-300 liter of water is added to wash the first reaction mixture. The first reaction mixture is washed with water twice. The organic phase is then separated and distillation under reduced pressure is set to obtain dimethyl 2,2-dichloroglutarate.
[0063] In other words, the step (i) is carried out through the following steps:
[0064] (i.1) adding methyl dichloroacetate and acrylic acid methyl ester in a reactor;
[0065] (i.2) start stirring and setting a first controlled temperature of 0-60° C. through the reactor;
[0066] (i.3) adding sodium methoxide slowly to form a first reaction mixture;
[0067] (i.4) allowing reaction for 1-4 hours in the reactor at the first controlled temperature with stirring;
[0068] (i.5) washing the first reaction mixture after step (i.4) twice, wherein, preferably, 100-300 liter of water is added for each washing; and
[0069] (i.6) separating organic phase from the first reaction mixture in step (i.5), and setting for distillation under reduced pressure through the reactor to obtain dimethyl 2,2-dichloroglutarate.
[0070] It is worth mentioning that no organic solvent is used in the preparation of dimethyl 2,2-dichloroglutarate, as illustrated in the above process.
[0071] Preferably, the preparation of α-ketoglutaratic acid is further described as follows:
[0072] Dimethyl 2,2-dichloroglutarate 3 obtained from the above method is mixed with a hydroxide solution at a second controlled temperature for 0.5-8 hours to form a second mixture. Inorganic salt is added to the second mixture and is stirred for 0.5-5 hours to form a large amount precipitate. The second mixture is then filtered to obtain a-ketoglutarate salt, which is stirred with water and inorganic acid to pH>4.5. The inorganic salt is then removed through filtration to obtain a crude α-ketoglutaratic acid aqueous solution.
[0073] In other words, the step (ii) is carried out through the following steps:
[0074] (ii.1) mixing the dimethyl 2,2-dichloroglutarate obtained from step (i) with a hydroxide solution at a second controlled temperature for 0.5-8 hours to form a second mixture;
[0075] (ii.2) adding inorganic salt to the second mixture and stirring for 0.5-5 hours for precipitation of α-ketoglutarate salt;
[0076] (ii.3) filtering the α-ketoglutarate salt out; adding water and inorganic acid to the α-ketoglutarate salt while stirring and adjusting a pH to pH>4.5; and
[0077] (ii.4) removing the inorganic salt through filtration to obtain the crude a-ketoglutaratic acid aqueous solution.
[0078] Preferably, the purification of α-ketoglutaratic acid is further described as follows:
[0079] The crude α-ketoglutaratic acid aqueous solution obtained from the above process is passed through cation exchange resin, anion exchange resin, and cation exchange resin to remove impurities. Then, the aqueous solution obtained is concentrated to 25-55% by weight, which is to be used as the starting material for preparation of L-arginine α-ketoglutarate 1:1 and 2:1.
[0080] In other words, the step (iii) is carried out through the following steps:
[0081] (iii.1) passing the crude α-ketoglutaratic acid aqueous solution through cation exchange resin, anion exchange resin, and cation exchange resin to remove impurities to obtain a purified α-ketoglutaratic acid aqueous solution; and
[0082] (iii.2) adjusting a concentration of the purified α-ketoglutaratic acid aqueous solution to 25-55% by weight.
[0083] The overall yield for steps (i) to (iii) from the above process is 75%. In step (iii.1), both cation and anion exchange resins are used to remove impurities effectively.
[0084] Preferably, referring to FIG. 2 of the drawings, the preparation of L-arginine a-ketoglutarate 1:1 is further described as follows:
[0085] In a reactor, the purified and concentrated α-ketoglutaratic acid solution is added followed by water to adjust to a certain concentration. One equivalent mole of solid L-arginine is added while the reaction mixture is being stirred. The temperature is controlled to dissolve all solid and form pH 3-4 L-arginine α-ketoglutarate 1:1 solution. The final product is obtained directly via spray drying with a yield of 94%.
[0086] In other words, the preparation of L-arginine α-ketoglutarate 1:1 from a-ketoglutaratic acid solution is carried out through the following steps:
[0087] (iv) setting a concentration of the purified α-ketoglutaratic acid aqueous solution by adding water;
[0088] (v) adding a quantity of solid L-arginine to the purified α-ketoglutaratic acid aqueous solution, wherein the quantity of the solid L-arginine is equals to one equivalent mole of the purified α-ketoglutaratic acid aqueous solution;
[0089] (vi) obtaining a resulting L-arginine α-ketoglutarate 1:1 solution from step (v), wherein a pH of the resulting L-arginine α-ketoglutarate 1:1 solution is approximately 3˜4; and
[0090] (vii) obtaining a final product of L-arginine α-ketoglutarate 1:1 from step (vi) through spay drying, wherein a yield of the final product is approximately 94%.
[0091] Preferably, referring to FIG. 3 of the drawings, the preparation of L-arginine a-ketoglutarate 2:1 is further described as follows:
[0092] In a reactor, the purified and concentrated α-ketoglutaratic acid solution is added followed by water to adjust to a certain concentration. Two equivalent mole of solid L-arginine is added while the reaction mixture is being stirred. The temperature is controlled to dissolve all solid and form pH 6.5-7 L-arginine α-ketoglutarate 2:1 solution. The final product is obtained directly via spray drying with a yield of 97%.
[0093] In other words, the preparation of L-arginine α-ketoglutarate 2:1 from a-ketoglutaratic acid solution is carried out through the following steps:
[0094] (iv) setting a concentration of the purified α-ketoglutaratic acid aqueous solution by adding water;
[0095] (v) adding a quantity of solid L-arginine to the purified α-ketoglutaratic acid aqueous solution, wherein the quantity of the solid L-arginine is equals to two equivalent mole of the purified α-ketoglutaratic acid aqueous solution;
[0096] (vi) obtaining a resulting L-arginine α-ketoglutarate 2:1 solution from step (v), wherein a pH of the resulting L-arginine α-ketoglutarate 2:1 solution is approximately 6.5˜7; and
[0097] (vii) obtaining a final product of L-arginine α-ketoglutarate 2:1 from step (vi) through spay drying, wherein a yield of the final product is approximately 97%.
[0098] It is worth mentioning that solid L-arginine is added directly to the α-ketoglutaratic acid solution to eliminate the need to prepare L-arginine solution. The product solution is spray dried directly to obtain the final product in dry product powder. Compared to the conventional processes, the method of preparation of the present invention eliminates the use of a large amount of organic solvents and reduces the production time and cost.
[0099] One skilled in the art will understand that the embodiment of the present invention as shown in the drawings and described above is exemplary only and not intended to be limiting.
[0100] It will thus be seen that the objects of the present invention have been fully and effectively accomplished. It embodiments have been shown and described for the purposes of illustrating the functional and structural principles of the present invention and is subject to change without departure from such principles. Therefore, this invention includes all modifications encompassed within the spirit and scope of the following claims.
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A process for preparation of α-ketoglutaric acid, L-arginine α-ketoglutarate 1:1 and 2:1, comprising the steps of: providing a α-ketoglutaratic acid aqueous solution at an adjusted concentration; adding one equivalent mole of solid L-arginine to the α-ketoglutaratic acid aqueous solution; stirring and allowing reaction under a controlled temperature; (e) obtaining a resulting L-arginine α-ketoglutarate 1:1 solution with a pH of approximately 3˜4 or L-arginine α-ketoglutarate 2:1 solution with a pH of approximately 6.5˜7; and obtaining a final product of L-arginine α-ketoglutarate 1:1 or 2:1 through spay drying. The yield of the final product is approximately 94% for L-arginine α-ketoglutarate 1:1 and 97% for L-arginine α-ketoglutarate 2:1 through the process. Large amount of solvents is eliminated and reaction time is shortened but the yield is increased, hence realizing mass production through reactor in a cost and time effective manner.
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FIELD OF THE INVENTION
The objective of the present invention relates to improved process for the manufacture of a d-threo-ritalinic acid hydrochloride and l-threo-ritalinic acid hydrochloride in an optically pure form by the resolution of dl-threo-ritalinic acid using a chiral carboxylic acid.
BACKGROUND OF INVENTION
Methylphenidate available in the market to treat Attention Deficient Hyperactivity Disorder (ADHD) is dl-threo mixture. It is a controlled substance. Methylphenidate contains two chiral carbon atoms and so exists in four enantiomeric forms. Of all the forms, the studies of its threo-diastereomer revealed that d-threo isomer has been found to be more active and also showed significant metabolic difference than l-threo enantiomer.
To date, there have been several methods disclosed in the literature for preparing d-threo enantiomer of methylphenidate. For example, the process reported first by Patrick et. al. [ The Journal of Pharmacology and Experimental Therapeutics, 241, 152-158 (1987)], describes the use of expensive resolving agent, 1,1′-binaphthyl-2,2′-diyl hydrogen phosphate in the resolution of dl-threo-methylphenidate. More efficient resolutions, using a O,O-Diaroyltartaric acid or menthoxy-acetic acid or dibenzoyl-D-tartaric acid are disclosed in WO9727176, GB97/00643, U.S. Pat. No. 6,100,401, U.S. Pat. No. 6,121,453, U.S. Pat. No. 6,162,919 and U.S. Pat. No. 6,242,464. Resolution of threo-methylphenidate may also be achieved by enzymatic hydrolysis methods proposed by Prashad (1998) [U.S. Pat. No. 7,247,730] and in WO98/25902.
U.S. Pat. No. 2,957,880 discloses the resolution of erythro-phenylpiperidyl acetamide using tartaric acid. This, however, must be followed by amide hydrolysis and equilibration at the benzylic centre, to give the threo isomer of the ritalinic acid.
In addition, U.S.2002/0019535 describes the manufacture of threo-ritalinic acid by resolution of threo-ritalinic acid hydrochloride using chiral base (S)-(−)-1-phenethylamine affording the product in 77% ee.
It would be desirable to find
1) a satisfactory substrate for resolution that did not involve handling of the active drug and 2) a more practical and efficient process to produce compound with high optical purity. Ritalinic acid in threo form might be a target. threo-Ritalinic acid contains a carboxylic group and a tertiary amino function in the moiety, due to which either chiral carboxylic acid or chiral organic base can be used for resolution. The d-threo-enantiomer of ritalinic acid thus obtained can be converted to d-threo-methylphenidate hydrochloride by reaction with methanol and hydrochloric acid.
The present invention provides an improved process for preparing d- and l-threo isomers of ritalinic acid of formula I & II,
and its salt by resolution of dl-threo-ritalinic acid of the formula III using chiral carboxylic acid of the formula IV as the resolving agent.
The method of the present invention is quite preferable and economical for the preparation of d-threo-ritalinic acid as an industrial procedure and gives d-threo-ritalinic acid hydrochloride with high optical purity.
More particularly, the process involves the resolution of di-threo-ritalinic acid with (+)-dibenzoyl-D-tartaric acid to yield the desired tartrate salt of d-threo-isomer of ritalinic acid in the first step and the breaking of salt in the second step to obtain the hydrochloride form of the d-threo-isomer with high optical purity, while the l-threo-isomer and the dibenzoyltartaric acid are recovered from the mother liquors as shown below:
OBJECTIVES OF THE INVENTION
The main objective of the present invention is to provide an improved process for the resolution of dl-threo-ritalinic acid
Another objective of the present invention is to provide an improved process for the preparation of d-threo-ritalinic acid hydrochloride and l-threo-ritalinic acid hydrochloride by resolving the dl-threo-ritalinic acid using chiral carboxylic acid as the resolving agent.
Another objective of the present invention is to provide an improved process for the preparation of d-threo-ritalinic acid hydrochloride by resolving the dl-threo-ritalinic acid involving the use of stoichiometric quantity of the resolving agent.
Still another objective of the present invention is to provide an improved process for the preparation of d-threo-ritalinic acid hydrochloride by resolving the dl-threo-ritalinic acid with reduced process steps for isolating d-threo-ritalinic acid in high optical purity of >99%.
Yet another objective of the present invention is to provide an improved process for the preparation of d-threo-ritalinic acid hydrochloride by resolving the dl-threo-ritalinic acid involving the recovery of derivative of tartaric acid from the mother liquors with highest yield.
As a result, the present invention provides a simple but efficient, economical, less time consuming and less tedious method for producing d-threo-ritalinic acid hydrochloride.
DETAILED DESCRIPTION OF THE INVENTION
Accordingly, the present invention provides an improved process for the preparation of d-threo-ritalinic acid hydrochloride and l-threo-ritalinic acid hydrochloride by resolution of dl-threo-ritalinic acid using chiral carboxylic acid which comprises of
(i) dissolving dl-threo-ritalinic acid in a solvent, water mixture (60:40) and adding a solution of an ester of tartaric acid in a solvent to the dissolved dl-threo-ritalinic acid solution at a temperature in the range from −10° C. to 100° C. for a period ranging from 5 min to 5 h. (ii) heating the mass to reflux for a period ranging from 15 min to 24 h and filtering it through the hyflo bed and cooling the filtrate to a temperature in the range of −10° C. to 40° C. to obtain a slurry containing solid mass of d-threo-ritalinic acid-tartaric acid ester salt. (iii) maintaining the resulting slurry for a period ranging from 30 min to 24 h and filtering to obtain d-threo-ritalinic acid-tartaric acid ester salt. (iv) adding to the mother liquor, concentrated or dilute hydrochloric acid, solvent and concentrating the mother liquor under vacuum by maintaining temperature 40° C. to 100° C. (v) adding organic solvent to the concentrated mother liquor. (vi) cooling the mass to a temperature in the range of −15° C. to 40° C. and filtering to get l-threo-ritalinic acid hydrochloride and the mother liquor containing the resolving agent. (vii) adding organic solvent and water along with organic or inorganic acids to the d-threo-ritalinic acid-tartaric acid ester salt obtained in step (iii) and removing the water present in the acid using the known methods. (viii) adding an organic solvent to the concentrated mass obtained in step (vii) under stirring at a temperature range of −10° C. to 25° C. and filtering, to get the d-threo-ritalinic acid hydrochloride and the mother liquor containing the resolving agent. (ix) concentrating the mother liquors obtained in step (vi) and (viii) basifying and acidifying by conventional methods and filtering the resolving agent.
The dl-threo-ritalinic acid used in step (i) may be prepared through multi-step process in which 2-chloropyridine and benzyl cyanide initially are coupled to form α-pyrid-2-yl-phenylacetonitrile. The resulting α-pyridyl-2-ylphenylacetonitrile then is hydrated in the presence of acid to yield α-pyrid-2-ylphenylacetamide which in turn is catalytically hydrogenated to yield α-piperid-2-ylphenylacetamide and then is hydrolysed and epimerized to dl-threo-ritalinic acid. The solvent used in the step (i) along with water may be selected from organic solvents. The solvent used to dissolve ester of tartaric acid may be selected from organic solvents. Conventional esters of tartaric acid used, may include dibenzoyltartaric acid and ditoluoyltartaric acid, the preferred one being (+)-dibenzoyltartaric acid of 0.2 to 1.6 eq to that of ritalinic acid, preferably, 1.06 eq in a solvent, preferably methanol adding at a temperature ranging preferably below 50° C., for a period preferably ranging from 5 min to 5 h. Heating the mass in step (ii) at reflux temperature preferably in 1 h to 2 h and filtering the mass through hyflo bed. The filtrate is cooled to a temperature preferably 20° C. to 25° C.
The resulting mass of step (iii) is maintained under stirring preferably for 13 h before filtering the d-threo-ritalinic acid-tartaric acid ester salt.
The mother liquor of step (iii) is concentrated under vacuum at a temperature preferably 70° C. to 80° C. after the addition of concentrated or dilute hydrochloric acid along with solvent preferably toluene. The solvent used in step (v) may be selected from water, aliphatic ketones or alcohols, the preferred one being acetone.
The mass obtained is cooled in step (vi) to a temperature in the range −15° C. to 40° C., preferably 10° C. before filtering the l-threo-ritalinic acid hydrochloride.
In step (vii), the solvents like aliphatic ketones or aromatic ketones or alcohols or aromatic/aliphatic hydrocarbons preferably toluene are added to d-threo-ritalinic acid-tartaric acid ester salt along with organic or inorganic acids, preferably hydrochloric acid and heated to evaporate the solvent.
In step (viii), solvents like aliphatic ketones or aromatic ketone or alcohols preferably acetone is added under stirring for preferably 15 min to 30 min at a temperature range of −10° C. to 25° C. preferably 5° C. to 10° C. while filtering the d-threo-ritalinic acid salt. The mother liquors of steps (vi) and (viii) are concentrated together, diluted with water and basified. The ester of tartaric acid formed was filtered after acidification.
The details of the invention are given in the examples given below which are provided solely to illustrate the invention and therefore should not be construed to limit the scope of the invention.
Example 1
di-threo-Ritalinic acid
100
g
(+)-Dibenzoyl-D-tartaric acid
182
g
Methanol
2.3
L
Water
1.8
L
Acetone
175
mL
HCl
65
mL
Toluene
450
mL
di-threo-Ritalinic acid (100 g, 0.456 mole) was dissolved in methanol-water mixture (1.8 L and 1.6 L) at room temperature and stirred for 15 min.
(+)-Dibenzoyl-D-tartaric acid (182 g, 0.483 moles) was dissolved in 300 mL of methanol and was added at a temperature below 50° C. in 30 min. The resulting mass was heated to reflux temperature 78° C. to 85° C. and maintained for 1 h to 2 h. The mass was filtered through hyflo bed and washed with 200 mL of water-methanol mixture (1:1). The filtrate was cooled to 20° C. to 25° C. and maintained for 13 h. The precipitated material out was filtered and washed with 200 mL of chilled water-methanol mixture (1:1) to obtain 132 g d-threo-ritalinic acid-dibenzoyl tartaric acid salt.
The mother liquor obtained was treated with 35 mL of conc. hydrochloric acid, 225 mL of toluene and concentrated under vacuum by maintaining a temperature of 70° C. to 80° C. On addition of 100 mL of acetone to the residue and on cooling to 10° C. followed by filtration 45 g of 1-threo-ritalinic acid hydrochloride was isolated.
Purity by HPLC
99.78%
Chiral purity
99.05%
Yield
90%
mp
236° C.-240° C.
[α] D
−88.5° (c = 2% in methanol)
To 132 g of d-threo-ritalinic acid-dibenzoyl tartaric acid salt, toluene 225 mL, 100 mL water and 30 mL of 35% hydrochloric acid were added and concentrated under vacuum by maintaining temperature of 60° C. to 65° C. On addition of 75 mL of acetone to the residue and on cooling to 5° C. to 10° C. followed by filtration, 46 g of d-threo-ritalinic acid hydrochloride was obtained.
Purity by HPLC
99.92%
Chiral purity
99.95%
Yield
92%
mp
238° C.-240° C.
[α] D
+89.08° (c = 2% in methanol)
Respective mother liquors obtained from the d-threo-ritalinic acid hydrochloride and the l-threo-ritalinic acid hydrochloride were concentrated, basified and acidified to recover (+)-dibenzoyl-D-tartaric acid in 90% yield showing optical rotation of −113° and melting point 88° C.-93° C.
Spectroscopic Interpretation
The structure of the product, d-threo-ritalinic acid hydrochloride was confirmed with the help of the following spectroscopic data.
a) IR (cm −1 ) (KBr)
O—H str. of bonded COOH group at 3150-2710, H -H str. at 2567, 2509, C═O str. of COOH group at 1709, benzenoid bands at 1585, 1456, C—N str. at 1396, C—O str. at 1182, C—H out of plane bending of mono-substituted benzene ring at 729,704.
b) 1 H NMR (DMSO-d 6 , 300 MHz) (δ H )
1.24-1.66 (6H, m, —NH—C H 2 —C H 2 —C H 2 of piperidyl ring), 2.96 (1H, s, Ha of
3.29 (1H, d, Hb of
[where Ha and Hb are diastereotopic protons], 3.73 (1H, s, —CH—C H —NH—), 4.08 (1H, d, Ph-C H —COOH), 7.27-7.43 (5H, m, aromatic protons), 8.67 (1H, bs, N H proton), 9.73 (1H, bs, COO H proton).
c) 13 C NMR (DMSO-d 6 , 300 MHz) (δ c )
21.29 (—NH—CH 2 —CH 2 — C H 2 ), 21.44 (—NH—CH— C H 2 ), 25.50 (—NH—CH 2 — C H 2 ), 44.56 (—NH— C H 2 —), 53.21 (Ph-CH— C H—NH), 56.69 (Ph- C H—COOH), 127.85-134.89 (aromatic protons), 172.38 (CH— C OOH).
d) Mass Spectrum (EI)
[M] +. at m/z 220 (<1), [M +. -CO 2 ] at m/z 175 (2), [M + -C 5 H 9 N] at m/z 136 (2),
at m/z 84 (100), tropylium cation at m/z 91 (11), [m/z 84-(CH 2 N)] at m/z 56 (21).
ADVANTAGES OF THE INVENTION
1. The process uses resolving agent which is easily available
2. The resolving agent used can be recovered almost quantitatively.
3. Resolution process is simple as it requires lesser number of steps and the d-threo-ritalinic acid is obtained in >99% optical purity in >90% of theoretical yield (first crop).
4. The process is very economical and useful for commercial production as the variable cost is very low.
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The invention disclosed in this application relates to an improved process for the manufacture of d-threo-ritalinic acid hydrochloride and l-threo-ritalinic acid hydrochloride in an optically pure form by the resolution of dl-threo-ritalinic acid using a chiral carboxylic acid The d-threo-ritalinic acid hydrochloride prepared by the process of the present invention on esterification gives d-threo-methylphenidate, a very well known CNS stimulant.
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This is a continuation of my previous application Ser. No. 747,834, filed June 24, 1985, and now U.S. Pat. No. 4,648,638, issued Mar. 10, 1987.
BACKGROUND OF THE INVENTION
This invention relates to power locks for sliding doors and the like, and more particularly, to a power operated lock assembly utilizing a reciprocal bolt for movement into and out of the path of movement of the door.
Sliding doors are very popular for all types of homes. In the modern home, it is not uncommon to find two or more sliding doors, especially in living areas of the home, such as opening onto a porch, patio, balcony or carport. A sliding door provides many advantages including ease of operation, large glazing areas for admission of light into the home and a wide passage for ease of entry and exit through the doorway.
The only shortcoming of sliding doors that has kept the door from being even more popular than it is, is the matter of security when locked. In the past, the sliding door has been subject to criticism from security officers for the lack of security locking means. In an attempt to fill the gap, various make-shift arrangements have been provided by homeowners, such as a wooden stick laying in the track of the door to jam the door against movement toward the open position. However, such an arrangement is very inconvenient and generally unsightly. The stick is prone to be misplaced while the door is open and provides a particular hazard for small children who will play with the stick. When the stick is removed, the door is left open and subject to unauthorized entry. Sliding door manufacturers do provide a lock at the forward jamb of the door, but the lock is very fragile and can be easily broken by insertion of a crow bar or other prying tool. The lock is also usually positioned by the manufacturer very close to the jamb so that operation of the lock is difficult without hitting the knuckles against the sharp edges of the door jamb.
Also, although power operated doors and windows have been in use for several years, insofar as I am aware, there has not been a power operated lock suitable for a sliding door. Locks adapted for automobile doors and other types of swinging doors are simply not adaptable to a sliding door arrangement where special problems of positioning of the components, strength required and ease of operation are present. For this reason, new locks in the field have been limited to purely mechanical locks of the type requiring direct engagement with the components of the lock in order to operate it. The mechanical locks are not adapted for remote control and thus do not provide convenience for the homeowner. Two typical prior lock arrangements are shown in the patents to Buck et al U.S. Pat. No. 3,768,847 (a simple sliding bolt utilized with a manually operated mechanical release button required to be pushed to unlock the door) and the Stevens U.S. Pat. No. 4,248,461 (a manually operated pivoting lever having a plurality of notches for engagement with a plate).
Another manually operable bolt lock (similar to the Buck patent '847) is shown in U.S. Pat. No. 3,082,617 to Kerman. A key-actuated closure lock has a bolt which enters a recess in the closure sash to prevent movement of the sash. This lock cannot be actuated from outside the closure.
U.S. Pat. No. 3,950,018 to Pickering discloses a very complicated locking device for railway freight car or other freight vehicle doors. The lock, which is built into the freight car door, is provided with a movable bolt which enters a recess in the doorway to prevent opening of the door. The lock may be opened by the use of compressed gas, by a solenoid or by the use of a key used in conjunction with the compressed gas. This massive lock, which is built into the heavy freight car door, cannot be used with a door such as a sliding glass door.
U.S. Pat. No. 4,141,610 to Ando discloses a showcase lock wherein the armature of a solenoid extends into a recess in the glass showcase door to lock this door whenever it is in the closed position. Unless the solenoids are continuously energized, the doors will be locked at all times when the doors are closed. This would be totally unsuitable for use, for example, with a sliding glass door opening onto a patio or deck.
U.S. Pat. No. 2,765,648 to Hatcher discloses an electro-magnetic vehicle door lock actuated by two solenoids. One of the solenoids is energized to unlock the door and the other is energized to lock the door. The structure of this lock is unsuitable for a sliding glass door and the use of two solenoids requires an unduly complicated control circuit.
Thus, the need is present for an effective power operated lock for a sliding closure, such as a sliding door for a home.
With this in mind, it is an object of this invention to provide a power operated lock for a sliding door which overcomes the problems present in known locks.
It is another object of this invention to provide a power operated lock for a sliding door which can be operated for opening from either the inside or outside and which can also be manually operated.
It is a still further object of this invention to provide a power lock which is simple in construction and inexpensive to manufacture, yet has exceptional strength so that the door cannot be pried open.
It is still another object of the present invention to provide a power door lock assembly with power operation and including cooperative parts that are easy to engage to provide the locking and unlocking functions.
Still another object of this invention is to provide a power operated lock that is easy to set and includes visual indicating means allowing the user to determine at a glance whether the lock is set in a locked condition.
Additional objects, advantages and other novel features of the invention will be set forth in part in the description that follows and in part will become apparent to those skilled in the art upon examination of the following, or may be learned with practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
SUMMARY OF THE INVENTION
To achieve the foregoing and other objects, and in accordance with the purposes of the present invention as described herein, a lock assembly is provided having a reciprocal bolt mounted in a stationary housing adjacent the sliding closure, such as a sliding door. The bolt is positioned for movement into and out of the path of the door. A member slidably mounted in the housing is provided with a cam surface in engagement with the bolt; the cam surface being such that when the member is in a first position, the bolt is retracted from the path of the door and when the member is in a second position, the bolt extends into the path of the door. Means are provided for locking the member in the second position to retain the bolt in the path of the door when it is desired that the door be locked.
In the preferred embodiment, the slide member takes the form of a plate mounted on a support bracket in the housing. Bent-up wings guide the plate and include support apertures for the bolt. A camming aperture on the sliding plate provides the cam surface engaging an operator pin on the bolt. A spring biased armature on the power solenoid engaging a locking aperture on the plate forms the locking means. A manually operable plunger aligned with the armature allows release, and thus unlocking action by pushing of the armature from the locking aperture.
A pivotal reset lever engages an upstanding tab on the plate to allow locking of the lock assembly. The end of the bolt includes a roller to engage the frame of the door if the lock assembly is set prior to closing the door. Once the full closed position is reached, the bolt snaps into the locked position in the path of movement, such as behind the rear edge of the frame.
Still other objects of the present invention will become readily apparent to those skilled in this art from the following description wherein there is shown and described the preferred embodiment of this invention, simply by way of illustration of one of the best modes contemplated for carrying out the invention. As it will be realized, the invention is capable of other different embodiments, and its several details are capable of modifications in various, obvious aspects all without departing from the invention. Accordingly, the drawings and descriptions will be regarded as illustrative in nature and not as restrictive.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings incorporated in and forming a part of the specification, illustrate several aspects of the present invention, and together with the description serve to explain the principles of the invention. In the drawings:
FIG. 1 is a perspective view showing the lock assembly of this invention mounted adjacent to a sliding glass door;
FIG. 2 is an end view of the lock assembly showing the manner in which the bolt extends into the path of the door;
FIG. 3 is a slightly enlarged side view with the side of the lock assembly cut away to show the relationship of the various parts;
FIG. 4 is a plan view of the lock assembly with the top of the housing cut away to show the positioning of the cam plate and bolt when in an unlocked conditon;
FIG. 4A is a view of FIG. 4 showing the positioning of the cam plate and the bolt when the bolt extends into the path of the door for locking; and
FIG. 5 is a cross sectional view taken on line 5--5 of FIG. 3 showing a spring loaded plunger used to push the solenoid armature downward to manually unlock the lock.
Reference will now be made in detail to the present preferred embodiment of the invention, an example of which is illustrated in the accompanying drawings.
DETAILED DESCRIPTION OF THE INVENTION
Referring now in detail to the drawings, there is shown a lock assembly 10 mounted adjacent to a sliding glass door 11 which is movable on a track 12 between open and closed positions. The lock 10 is provided with a housing 14 which supports a bolt 15 for movement along a path into and out of the path of the door 11. It will readily be apparent that, when the bolt 15 extends into the path of the door 11, and more particularly, behind the frame when the door is fully closed, the door 11 cannot be opened.
The lock 10 rests on a floor 13 adjacent to the door 11 and is securely attached to the floor by heavy screws 18. With the lock so mounted, the sturdiness of the bolt 15 makes it impossible to pry the door 11 open.
A bracket 16 (best shown in FIG. 3) secured to the housing 14 supports a cam plate or member 17. Wings 19 of the bracket 16 extend upward past the cam plate 17 and are provided with angled extensions 20, the angled extensions 20 extending outwardly over the plate 17, in such a manner that the plate 17 is free to slide back and forth between the bottom edges of the angled extensions 20 and the upper surface of the bracket 16 as shown in FIGS. 3 and 4, wings 29 of the bracket 16 have aligned apertures for receipt of the bolt 15.
The plate 17 is provided with a camming aperture 21 having a 45° edge surface 22 which serves as a cam. A pin 25 secured to the bolt 15 extends through the aperture 21. Preferably, the camming aperture forms a substantially right triangle with the camming surface forming the hypotenuse. The pin 25 is free to move within the triangular aperture 21 to allow partial movement of the bolt 15 toward said second position upon engagement with the closure door 11 in the open position. A spring 26 connected between the housing 14 and the pin 25 serves to pull the pin 25 into engagement with the cam surface 22. When the plate 17 is moved into the position shown in FIG. 4, the cam surface 22 moves the pin 25 against the action of the spring 26 to retract the bolt 15 from the path of the door 11 to allow the door to be opened and the lock to be reset. When the plate 17 is moved to the position shown in FIG. 4A, the pin 25 rides down the cam surface 22 under the action of the spring 26, and moves the end of the bolt 15 into the path of the door 11 to prevent opening of the door.
A tension spring 30 connected between the plate 17 and the bracket 16 urges the plate 17 into the position shown in FIG. 4 to retract the bolt 15 and thereby free the door 11. In order to retain the plate 17 in the position shown in FIG. 4A to prevent the door 11 from being opened, the plate 17 is provided with a locking aperture 31 positioned to be in alignment with the armature 32 of a solenoid 33 mounted on the bracket 16. Thus, when the plate 17 is moved to the position shown in FIG. 4A, the spring-biased armature 32 of the solenoid 33 enters the locking aperture 31 in the plate 17 to prevent movement of this plate, and thereby retain the bolt 15 in the path of the door 11.
To energize the solenoid 33 and withdraw the armature 32 from the aperture 31, the homeowner presses a pushbutton switch 40 mounted on a wall near the door 11 or a key-operated switch 41 mounted outside the door 11. A standard electrical circuit (not shown) provides current through the leads 33a, 33b and thus draws the armature 32 downwardly, releasing the plate 17. This allows the tension spring 30 to move the plate 17 into the position shown in FIG. 4 to thereby unlock the door.
A reset level 42 pivotally mounted on the housing 14 is provided with a finger 43 which engages a tab 44 on the plate 17 to move this plate into the position shown in FIG. 4A when the lever 42 is depressed. In this condition, the bolt 15 extends into the path of the door 11 so that the door 11 cannot be opened. It will be readily apparent that, when the solenoid 33 is energized to allow the tension spring 30 to move the plate 17 to the position shown in FIG. 3, the tab 44 moves the finger 43 to raise the lever 42.
While the lever 42 serves to reset the lock to the locked condition, it also serves as a visual indicator of the status of the lock. The homeowner can determine, at a glance and from a distance, whether the lock is in a locked status. If the lever 42 is in a raised position, the door 11 is unlocked. If the lever 42 is in the lowered position, as shown in FIGS. 1 and 2, the door 11 is locked.
The bolt 15 is provided with a roller 45 which extends beyond the end of the bolt. The use of the roller 45 enables the homeowner to set the lock to the locked condition when the door 11 is in an open or partially open position. With the door 11 open or partially opened, the homeowner depresses the lever 42 to set the lock to the locked condition. This moves the plate 17 into the position shown in FIG. 4A and allows the spring 26 to move the bolt 15 toward the door until the roller 45 engages the surface of the door. The homeowner may then exit the door and pull it closed behind him. As the door 11 is moved toward the closed position, the roller 45 rolls across the surface of the frame of the door 11 until the door is fully closed. At that time, the spring 26 snaps the bolt 15 into the position shown in FIGS. 1 and 2, thereby locking the door.
While the lock assembly can be unlocked by operation of either of the switches 40 or 41 to energize the solenoid 33, it is also possible to unlock the lock manually. This is done by depressing a spring-loaded plunger 50 mounted on the housing above the armature 32 of the solenoid 33. The plunger 50 is provided with a pin 51 for pushing the armature 32 downward and out of the locking aperture 31, thereby allowing the spring 30 to move the plate 17. The edge of the aperture 31 kicks the pin 51 as the plate 17 is released and the plunger 50 is retracted. The plate 17 is now in the position shown in FIG. 4 to retract the bolt 15 from the path of the door 11 and allow opening movement.
In operation, the homeowner first depresses the lever 42 to move the plate 17 into the reset position shown in FIG. 4A. This moves the bolt 15 into the path of the door 11. When it is desired to open the door 11, the homeowner actuates either of the switches 40 or 41, or depresses the plunger 50. This removes the armature 32 from the locking aperture 31 in the plate 17 and allows the spring 30 to move the plate 17 to the position shown in FIG. 4. This retracts the bolt 15 from the path of the door 11 so that the door may now be opened.
From the above description, it can be seen that numerous improved results and advantages can be obtained with this new lock assembly 10. The structure is simple and of low cost, as well as being easy to operate. It will be readily apparent that this lock assembly 10 can be manually locked and unlocked by simply touching the foot on the plunger 50 and lever 42, respectively, without bending or stooping. Unlocking is however normally power controlled through either of the switches 40, 41.
The sliding plate 17 has an edge surface 22 within aperture 21 and the spring 26 that cams the bolt 15 to the correct position. The aperture 21 is triangular to allow partial movement of the bolt 15 toward the locked position upon release. The roller 45 on the bolt 15 engages the frame until snapping into position (see FIG. 1) in the fully closed position.
The locking aperture 31 in the plate 17 overlies the spring biased armature 32 providing the highly desired secure locking action needed. The bolt 15 and the plate 17 both are securely positioned by the wings of bracket 16.
The entire assembly 10 including housing 14 is strong and rugged to give maximum security to the sliding closure. The lock assembly is positioned at the side of the door opening so as not to restrict in any way passage through the door. The housing of the assembly 10 can be of aluminum so as to blend well with the aluminum finish of the door 11 and the profile of the lock assembly 10 easily allows the curtains at the door to pass over and around the same without difficulty. When the curtain is pulled, the lock assembly 10 is in fact barely visible.
The foregoing description of the preferred embodiment of the invention is presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Obvious modifications and variations are possible in light of the above teachings. For example, in addition to operating the outside switch 41 by a key, cipher device or remote control, a switch may be directly interconnected with an automatic garage door opener. Similarly, both switches 40, 41 may also disarm a burglar alarm simultaneously to avoid the possibility of sounding the alarm by mistake. While the preferred embodiment has been shown with respect to a sliding door, it is clear that other closures, such as windows, sliding showcase doors or the like can be equally well served by the concepts of my invention.
With the above in mind, it is clear the present embodiment was chosen and described simply to provide the best illustration of the principles of the invention and its practical application in order to enable one of ordinary skill in the art to utilize the concepts of the invention in various embodiments and with various modifications as are suited to the particular use contemplated. Also, such modifications and variations are deemed to be within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally and equitably entitled.
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A lock assembly for a sliding closure has a bolt movable into and out of the path of the closure by a movable plate. A cam surface on the plate retracts the bolt from the path of the closure. A first spring moves the bolt into the path of the closure as the plate is moved by a pivoting reset lever engaging a tab on the plate. The plate is urged in the opposite direction by a second spring. A locking aperture on the plate and a solenoid with an armature engaging the aperture are provided for locking the plate in position at the limit of its travel to hold the bolt in the path of the closure. The solenoid is operated by either an inside or outside switch to release the plate and disengage the bolt. Alternatively, a plunger on the housing can be pushed to manually disengage the armature.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a polyurethane polymeric material and a method of making the same, and particularly to a multifunctional environmentally protective polyurethane composite material and a method of making the same.
[0003] 2. Description of the Prior Art(s)
[0004] Recently, due to public awareness about ecological and environmental issues, the use of environmentally friendly materials that are recyclable, light-weighted, and easily processed is an inevitable trend. Polymer composites can produce synergistic effects, and also may retain the respective properties of each component.
[0005] Thermoplastic polyurethane (TPU) has the advantages of conventional engineering plastics, and also has excellent properties, such as high impact resistance, high flexing resistance, high elongation, high tear-resistance strength, high weather resistance and so on. In addition, owing to the non-toxic nature of thermoplastic polyurethane, thermoplastic polyurethane has been widely used as an environmentally friendly material and therefore has wide application. For example, thermoplastic polyurethane can be applied to elastic fibers, artificial leather resins, adhesives, pipes, and other protective materials. Furthermore, in order to improve the properties of thermoplastic polyurethane and the economic benefits, additives of thermoplastic polyurethane are currently used in the industry. Additives can not only reduce the amount of thermoplastic polyurethane and production costs, but also increase the physical and chemical properties of thermoplastic polyurethane.
[0006] Conventional additives of thermoplastic polyurethane include: the inorganic material used to increase the strength of thermoplastic polyurethane; the antioxidants, stabilizers, and flame resistant agents used to improve the stability and fire resistance of thermoplastic polyurethane; the organic antistatic agents used to enhance the antistatic effect of thermoplastic polyurethane; the ultraviolet protective agents used to increase the ultraviolet resistance of thermoplastic polyurethane; and the lubricants used to improve the processability and flowability of thermoplastic polyurethane.
[0007] The conventional additives mentioned above may enhance the chemical and physical properties of thermoplastic polyurethane, such as the strength, the stability, the fire resistance, the antistatic effect, the ultraviolet resistance and the processing flowability, but the type and origin of the conventional additives are not entirely beneficial to the environment, some of which may even cause additional burdens or harm to the environment.
[0008] To overcome the shortcomings, the present invention provides a multifunctional, environmentally protective polyurethane composite material and a method of making the same to mitigate or obviate the aforementioned problems.
SUMMARY OF THE INVENTION
[0009] The main objective of the present invention is to add an environmentally protective additive into thermoplastic polyurethane, so as to achieve the purpose of increasing the physical and chemical properties of the thermoplastic polyurethane as well as environmental protection.
[0010] To achieve the aforementioned objective, the present invention provides a multifunctional environmentally protective polyurethane composite material comprising a thermoplastic polyurethane; an environmentally protective additive including a substance selected from the group consisting of: recycled polymer, plant fiber, mineral and metal powder; and a thickening dispersant including a substance selected from the group consisting of: natural rubber and synthetic rubber.
[0011] In accordance with the present invention, the environmentally protective additive is not limited to recycled materials, but further comprises an environmentally friendly additive. The environmentally protective additive would not produce additional waste or can even suppress increase of waste.
[0012] In accordance with the present invention, the recycled polymer is selected from the group consisting of: polyethylene (PE), polyvinyl chloride (PVC), polypropylene (PP), polystyrene (PS), polyethylene terephthalate (PET), nylon, fluoride plastic, polyimide (PI), polycarbonate (PC), acrylonitrile butadiene styrene (ABS) and tire. As a result that the origin of the recycled polymer is a waste material, using the recycled polymer as the environmentally protective additive will reduce the existing amount of waste and further suppress the increase of waste.
[0013] In accordance with the present invention, the plant fiber is derived from the group consisting of: cork, bamboo charcoal, wood powder, grain shells, bagasse, coffee grounds, tea leaves, waste paper and mixtures thereof. As the plant fiber is originated from the nature and can be biologically decomposed, using the plant fiber as the environmentally protective additive will not produce additional waste but further suppress the increase of waste.
[0014] In accordance with the present invention, the mineral is selected from the group consisting of: zeolite, clay, diatomaceous earth, graphite and limestone. As the mineral is originated from the nature, using the mineral as the environmentally protective additive will not produce additional waste but further suppress the increase of waste.
[0015] Preferably, the hardness of the thermoplastic polyurethane is between 6 D and 80 D, wherein the hardness between 6 D and 80 D can be converted into between 20 A and 100 A.
[0016] Preferably, the melt index of the thermoplastic polyurethane is between 1 gram per 10 minutes and 50 grams per 10 minutes.
[0017] Preferably, the synthetic rubber of the thickening dispersant is selected from the group consisting of: polyisoprene rubber (IR), polybutadiene rubber (BR), acrylonitrile butadiene rubber (NBR), styrene-butadiene-styrene block copolymer (SBS), styrene-butadiene rubber (SBR), styrene-ethylene-butylene-styrene block copolymer (SEBS), styrene-isoprene-styrene block copolymer (SIS) and a chemically modified product thereof.
[0018] In accordance with the present invention, the chemically modified product of rubber is designated to a product produced by connecting a rubber and a polymer via a chemical method. For example, the chemically modified product of rubber is, but not limited to, maleic anhydride (MA) grafted styrene-ethylene-butylene-styrene block copolymer.
[0019] In accordance with the present invention, the thermoplastic polyurethane is made from a polyol, a diisocyanate and a chain extender.
[0020] Preferably, the polyol is selected from the group consisting of: polyester, polyether and polycaprolactone.
[0021] Preferably, the average molecular weight (Mw) of the polyol is between 500 and 5000.
[0022] Preferably, the diisocyanate is selected from the group consisting of: toluene-2,4-diisocyanate, toluene-2,6-diisocyanate, 4,4′-diphenylmethane diisocyanate, 2,4′-diphenylmethane diisocyanate, polymeric diphenylmethane diisocyanate and hexamethylene diisocyanate.
[0023] Preferably, the chain extender is selected from the group consisting of: ethylene glycol, 1,4-butanediol and 1,6-hexanediol.
[0024] In accordance with the present invention, the concentration of the thickening dispersant is 0.1 to 80 weight percent (wt %) based on the weight of the multifunctional environmentally protective polyurethane composite material.
[0025] In accordance with the present invention, the concentration of the environmentally protective additive is 0.1 to 80 weight percent (wt %) based on the weight of the multifunctional environmentally protective polyurethane composite material.
[0026] In addition, the present invention provides a method for making the multifunctional environmentally protective polyurethane composite material comprising the steps of blending the thermoplastic polyurethane, the environmentally protective additive and the thickening dispersant to obtain a mixture; and molding the mixture to obtain the multifunctional environmentally protective polyurethane composite material.
[0027] Preferably, in the step of blending the thermoplastic polyurethane, the environmentally protective additive and the thickening dispersant to obtain a mixture, the environmentally protective additive and the thickening dispersant are blended under an operation temperature ranging from 25° C. to 70° C., a screw speed ranging from 50 revolutions per minute to 200 revolutions per minute and a blending time ranging from 0.5 hour to 1 hour to obtain an intermediate. Then the intermediate is blended with the thermoplastic polyurethane under an operation temperature ranging from 50° C. to 60° C., a screw speed ranging from 50 revolutions per minute to 200 revolutions per minute and a blending time ranging from 0.5 hour to 1 hour to obtain the mixture.
[0028] Preferably, in the step of molding the mixture to obtain the multifunctional environmentally protective polyurethane composite material, the mixture is melted and extruded under a melting temperature ranging from 130° C. to 220° C. and a screw speed ranging from 50 revolutions per minute to 120 revolutions per minute to obtain the multifunctional environmentally protective polyurethane composite material.
[0029] Based on the present invention, by the thickening dispersant, the environmentally protective additive is uniformly added into the thermoplastic polyurethane to form the multifunctional environmentally protective polyurethane composite material. The environmentally protective additive can reduce the existing amount of waste or further suppress increase of waste. In addition, the multifunctional environmentally protective polyurethane composite material is light-weighted, slip-resistant, abrasion-resistant, highly processable and low-cost with the use of the thickening dispersant and the environmentally protective additive.
[0030] Other objectives, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] FIG. 1 is a flow diagram of a method of making the multifunctional environmentally protective polyurethane composite material in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0032] For a better understanding about the technical features of the present invention and its effect, and for implements in accordance with the disclosures of the specification, embodiments, details and figures are further shown as follows.
[0033] In each embodiment in accordance with the present invention, properties of the multifunctional environmentally protective polyurethane composite material of each embodiment are evaluated based on thermoplastic polyurethane of each embodiment.
[0034] In accordance with the present invention, the analysis method of material properties is as follows.
[0035] Light weight was represented by specific gravity. A material with lower specific gravity had a lighter weight.
[0036] Flowability was represented by melt index. A material with larger melt index had a better flowability.
[0037] Slip resistance was represented by coefficient of friction (COF) measured by ASTM F2913-11. A material with larger COF had a better slip resistance.
[0038] Formability was represented by manufacturing cycle time. A material with shorter manufacturing cycle time had a better formability.
[0039] Abrasion resistance was represented by volume loss measured by DIN-53516. A material with less volume loss had a better abrasion resistance.
Embodiment 1
[0040] In the present embodiment, a multifunctional environmentally protective polyurethane composite material in accordance with the present invention comprises a thermoplastic polyurethane, an environmentally protective additive and a thickening dispersant.
[0041] With reference to FIG. 1 , a method of making the multifunctional environmentally protective polyurethane composite material of the present embodiment comprises steps as follows.
[0042] The environmentally protective additive and the thickening dispersant were blended by an agitator-type blender under an operation temperature of 25° C., a screw speed of 150 revolutions per minute (r.p.m.), and a blending time of 1 hour; an intermediate was obtained.
[0043] The intermediate was blended with the thermoplastic polyurethane by the agitator-type blender under an operation temperature of 60° C., a screw speed of 150 r.p.m. and a blending time of 1 hour; a mixture was obtained.
[0044] The mixture was melted and extruded by an extrusion moulding machine under a melting temperature of 180° C. and a screw speed of 70 r.p.m.; the multifunctional environmentally protective polyurethane composite material was obtained.
[0045] In the present embodiment, the thermoplastic polyurethane was TPU-785 manufactured by Sunko Ink. Co., Ltd. The hardness and the melt index of the thermoplastic polyurethane were 85 A and 14.318 grams per 10 minutes (g/10 mins), respectively. The environmentally protective additive was cork. The thickening dispersant was polybutadiene rubber manufactured by TSRC Corp. The product ID of the polybutadiene rubber was TAIPOL BR0150L. The weight ratio between the thermoplastic polyurethane, the environmentally protective additive and the thickening dispersant was 40:30:30.
[0046] With reference to Table 1, in the present embodiment, the specific gravity of the multifunctional environmentally protective polyurethane composite material and the specific gravity of the thermoplastic polyurethane was respectively 1.803 and 1.196. Accordingly, by the use of cork, the multifunctional environmentally protective polyurethane composite material of the present embodiment had a lower specific gravity than the thermoplastic polyurethane. That is, the multifunctional environmentally protective polyurethane composite material of the present embodiment was light-weighted.
[0000]
TABLE 1
Analysis result of material property of Embodiment 1
Specific gravity
Multifunctional environmentally protective
1.083
polyurethane composite material
Thermoplastic polyurethane
1.196
Embodiment 2
[0047] The present embodiment was similar to Embodiment 1. The difference between the present embodiment and Embodiment 1 was that the mixture was melted and extruded by the extrusion moulding machine under a melting temperature of 200° C. and a screw speed of 90 r.p.m. to obtain the multifunctional environmentally protective polyurethane composite material.
[0048] In addition, in the present embodiment, the thermoplastic polyurethane was TPU-195 manufactured by Sunko Ink. Co., Ltd. The hardness and the melt index of the thermoplastic polyurethane were 95 A and 7.164 g/10 mins, respectively. The environmentally protective additive was recycled tire powder. The thickening dispersant was polybutadiene rubber manufactured by TSRC Corp. The product ID of the polybutadiene rubber was TAIPOL BR0150H. The weight ratio between the thermoplastic polyurethane, the environmentally protective additive and the thickening dispersant was 60:20:20.
[0049] With reference to Table 2, in the present embodiment, the melt index of the multifunctional environmentally protective polyurethane composite material and the melt index of the thermoplastic polyurethane were respectively 8.753 g/10 mins and 7.164 g/10 mins. Accordingly, by use of recycled tire powder, the multifunctional environmentally protective polyurethane composite material of the present embodiment had a higher melt index than the thermoplastic polyurethane. That is, the multifunctional environmentally protective polyurethane composite material of the present embodiment had a better flowability and was easily processed.
[0000]
TABLE 2
Analysis result of material properties of Embodiment 2
Melt index
Multifunctional environmentally protective
8.753 g/10 min
polyurethane composite material
Thermoplastic polyurethane
7.164 g/10 min
Embodiment 3
[0050] The present embodiment was similar to Embodiment 1. The difference between the present embodiment and Embodiment 1 was that the mixture was melted and extruded by the extrusion moulding machine under a melting temperature of 200° C. and a screw speed of 90 r.p.m. to obtain the multifunctional environmentally protective polyurethane composite material.
[0051] In addition, in the present embodiment, the thermoplastic polyurethane was TPU-975 manufactured by Sunko Ink. Co., Ltd. The hardness of the thermoplastic polyurethane was 75 A. The thickening dispersant was acrylonitrile butadiene rubber manufactured by TSRC Corp. The product ID of the acrylonitrile butadiene rubber was TAIPOL NBR8052. The weight ratio between the thermoplastic polyurethane and the thickening dispersant was 50:50.
[0052] With reference to Table 3, in the present embodiment, the COF of the multifunctional environmentally protective polyurethane composite material was larger than that of the thermoplastic polyurethane. Also, the manufacturing cycle time of the multifunctional environmentally protective polyurethane composite material was shorter than that of the thermoplastic polyurethane. Accordingly, by use of the thickening dispersant, the multifunctional environmentally protective polyurethane composite material of the present embodiment had a better slip resistance and a better formability than the thermoplastic polyurethane.
[0000]
TABLE 3
Analysis result of material properties of Embodiment 3
manufacturing
COF
cycle time
Multifunctional environmentally
0.43
22 seconds
protective polyurethane
composite material
Thermoplastic polyurethane
0.32
36 seconds
Embodiment 4
[0053] The present embodiment was similar to Embodiment 1. The difference between the present embodiment and Embodiment 1 was that the mixture was melted and extruded by the extrusion moulding machine under a melting temperature of 215° C. and a screw speed of 90 r.p.m. to obtain the multifunctional environmentally protective polyurethane composite material.
[0054] In addition, in the present embodiment, the thermoplastic polyurethane was TPU-764 manufactured by Sunko Ink. Co., Ltd. The hardness and the melt index of the thermoplastic polyurethane were 64 D and 5.482 g/10 mins, respectively. The environmentally protective additive was graphite powder. The thickening dispersant was polybutadiene rubber manufactured by TSRC Corp. The product ID of the polybutadiene rubber was TAIPOL BR015H. The weight ratio between the thermoplastic polyurethane, the environmentally protective additive and the thickening dispersant was 90:5:5.
[0055] With reference to Table 4, in the present embodiment, the volume loss of the multifunctional environmentally protective polyurethane composite material was less than that of the thermoplastic polyurethane. Accordingly, by the use of the graphite powder, the multifunctional environmentally protective polyurethane composite material of the present embodiment had a better abrasion resistance than the thermoplastic polyurethane.
[0000]
TABLE 4
Analysis result of material properties of Embodiment 4
Volume loss
Multifunctional environmentally
51.96 meter cube (mm 3 )
protective polyurethane
composite material
Thermoplastic polyurethane
63.31 meter cube(mm 3 )
Embodiment 5
[0056] The present embodiment was similar to Embodiment 1. The difference between the present embodiment and Embodiment 1 was that the mixture was melted and extruded by the extrusion moulding machine under a melting temperature of 180° C. and a screw speed of 60 r.p.m. to obtain the multifunctional environmentally protective polyurethane composite material.
[0057] In addition, in the present embodiment, the environmentally protective additive was cork and recycled tire powder. The thickening dispersant was acrylonitrile butadiene rubber manufactured by TSRC Corp. The product ID of the acrylonitrile butadiene rubber was TAIPOL NBR8052. The weight ratio between the thermoplastic polyurethane, the environmentally protective additive and the thickening dispersant was 66:17:17. The weight ratio between the cork and the recycled tire powder was 5:5.
[0058] With reference to Table 5, in the present embodiment, the specific gravity of the multifunctional environmentally protective polyurethane composite material was smaller than that of the thermoplastic polyurethane. The melt index and the COF of the multifunctional environmentally protective polyurethane composite material were both larger than those of the thermoplastic polyurethane. The manufacturing cycle time of the multifunctional environmentally protective polyurethane composite material was shorter than that of the thermoplastic polyurethane. Accordingly, by the use of the cork and the recycled tire powder, the multifunctional environmentally protective polyurethane composite material of the present embodiment had a lighter weight, a better flowability, a better abrasion resistance and a better formability than the thermoplastic polyurethane.
[0000]
TABLE 5
Analysis result of material properties of Embodiment 5
Specific
Melt
Manufacturing
gravity
index
COF
cycle time
Multifunctional
1.152
16.294 g/10 mins
0.48
22 seconds
environmentally
protective
polyurethane
composite
material
Thermoplastic
1.196
14.138 g/10 mins
0.25
28 seconds
polyurethane
Embodiment 6
[0059] The present embodiment was similar to Embodiment 1. The difference between the present embodiment and Embodiment 1 was that the mixture was melted and extruded by the extrusion moulding machine under a melting temperature of 215° C. and a screw speed of 90 r.p.m. to obtain the multifunctional environmentally protective polyurethane composite material.
[0060] In addition, in the present embodiment, the thermoplastic polyurethane was TPU-764 manufactured by Sunko Ink. Co., Ltd. The hardness and the melt index of the thermoplastic polyurethane were respectively 64 D and 5.482 grams per 10 minutes (g/10 mins). The environmentally protective additive was cork, recycled tire powder and graphite powder. The weight ratio between the thermoplastic polyurethane, the environmentally protective additive and the thickening dispersant was 68:28:4. The weight ratio between the cork, the recycled tire powder and the graphite powder was 20:10:5.
[0061] With reference to Table 6, in the present embodiment, the specific gravity of the multifunctional environmentally protective polyurethane composite material was smaller than that of the thermoplastic polyurethane. The melt index of the multifunctional environmentally protective polyurethane composite material was larger than that of the thermoplastic polyurethane. The volume loss of the multifunctional environmentally protective polyurethane composite material was less than that of the thermoplastic polyurethane. Accordingly, by the use of the cork, the recycled tire powder and the graphite powder, the multifunctional environmentally protective polyurethane composite material of the present embodiment had a lighter weight, a better flowability and a better abrasion resistance than the thermoplastic polyurethane.
[0000]
TABLE 6
Analysis result of material properties of Embodiment 6
Specific
Melt
Volume
gravity
index
loss
Multifunctional
1.163
6.328 g/10 mins
58.73 mm 3
environmentally
protective
polyurethane
composite
material
Thermoplastic
1.214
5.482 g/10 mins
62.31 mm 3
polyurethane
Embodiment 7
[0062] The present embodiment was similar to Embodiment 1. The difference between the present embodiment and Embodiment 1 was that the mixture was melted and extruded by the extrusion moulding machine under a melting temperature of 200° C. and a screw speed of 90 r.p.m. to obtain the multifunctional environmentally protective polyurethane composite material.
[0063] In addition, in the present embodiment, the thermoplastic polyurethane was TPU-195 manufactured by Sunko Ink. Co., Ltd. The hardness and the melt index of the thermoplastic polyurethane were respectively 95 A and 7.164 grams per 10 minutes (g/10 mins). The environmentally protective additive was cork and recycled tire powder. The thickening dispersant was polybutadiene rubber manufactured by TSRC Corp. The product ID of the polybutadiene rubber was TAIPOL BR0150H. The weight ratio between the thermoplastic polyurethane, the environmentally protective additive and the thickening dispersant was 40:20:40. The weight ratio between the cork and the recycled tire powder was 20:10.
[0064] With reference to Table 7, in the present embodiment, the specific gravity of the multifunctional environmentally protective polyurethane composite material was smaller than that of the thermoplastic polyurethane. The melt index and the COF of the multifunctional environmentally protective polyurethane composite material were both larger than those of the thermoplastic polyurethane. The manufacturing cycle time of the multifunctional environmentally protective polyurethane composite material was shorter than that of the thermoplastic polyurethane. Accordingly, by the use of the cork and the recycled tire powder, the multifunctional environmentally protective polyurethane composite material of the present embodiment had a lighter weight, a better flowability, a better abrasion resistance and a better formability than the thermoplastic polyurethane.
[0000]
TABLE 7
Analysis result of material properties of Embodiment 7
Specific
Melt
Manufacturing
gravity
index
COF
cycle time
Multifunctional
1.088
8.577 g/10 mins
0.56
15 seconds
environmentally
protective
polyurethane
composite
material
Thermoplastic
1.198
7.164 g/10 mins
0.48
18 seconds
polyurethane
Embodiment 8
[0065] The present embodiment was similar to Embodiment 1. The difference between the present embodiment and Embodiment 1 was that the mixture was melted and extruded by the extrusion moulding machine under a melting temperature of 170° C. and a screw speed of 90 r.p.m. to obtain the multifunctional environmentally protective polyurethane composite material.
[0066] In addition, in the present embodiment, the environmentally protective additive was cork, recycled tire powder, recycled polyethylene and diatomaceous. The weight ratio between the thermoplastic polyurethane, the environmentally protective additive and the thickening dispersant was 55:36:9. The weight ratio between the cork, the recycled tire powder, the recycled polyethylene and the diatomaceous was 30:15:10:5.
[0067] With reference to Table 8, in the present embodiment, the specific gravity of the multifunctional environmentally protective polyurethane composite material was smaller than that of the thermoplastic polyurethane. The melt index of the multifunctional environmentally protective polyurethane composite material was larger than that of the thermoplastic polyurethane. The volume loss of the multifunctional environmentally protective polyurethane composite material was less than that of the thermoplastic polyurethane. Accordingly, by the use of the cork, the recycled tire powder, the recycled polyethylene and the diatomaceous, the multifunctional environmentally protective polyurethane composite material of the present embodiment had a lighter weight, a better flowability and a better abrasion resistance than the thermoplastic polyurethane.
[0000]
TABLE 8
Analysis result of material properties of Embodiment 8
Specific
Melt
Volume
gravity
index
loss
Multifunctional
1.182
16.815 g/10 mins
92.63 mm 3
environmentally
protective
polyurethane
composite
material
Thermoplastic
1.196
14.318 g/10 mins
108.42 mm 3
polyurethane
Embodiment 9
[0068] The present embodiment was similar to Embodiment 1. The difference between the present embodiment and Embodiment 1 was that the mixture was melted and extruded by the extrusion moulding machine under a melting temperature of 190° C. and a screw speed of 90 r.p.m. to obtain the multifunctional environmentally protective polyurethane composite material.
[0069] In addition, in the present embodiment, the thermoplastic polyurethane was TPU-970 manufactured by Sunko Ink. Co., Ltd. The hardness and the melt index of the thermoplastic polyurethane were respectively 70 A and 5.024 grams per 10 minutes (g/10 mins). The environmentally protective additive was cork, recycled tire powder and recycled polyethylene terephthalate. The thickening dispersant was polybutadiene rubber manufactured by TSRC Corp. The product ID of the polybutadiene rubber was TAIPOL BR0150L. The weight ratio between the thermoplastic polyurethane, the environmentally protective additive and the thickening dispersant was 50:35:15. The weight ratio between the cork, the recycled tire powder and the recycled polyethylene terephthalate was 20:20:30.
[0000]
TABLE 9
Analysis result of material properties of Embodiment 9
Specific
Melt
Manufacturing
gravity
index
COF
cycle time
Multifunctional
1.18
8.982 g/10 mins
0.38
30 seconds
environmentally
protective
poryurethane
composite
material
Thermoplastic
1.24
5.024 g/10 mins
0.31
38 seconds
poryurethane
[0070] With reference to Table 9, in the present embodiment, the specific gravity of the multifunctional environmentally protective polyurethane composite material was smaller than that of the thermoplastic polyurethane. The melt index and the COF of the multifunctional environmentally protective polyurethane composite material were larger than those of the thermoplastic polyurethane. The manufacturing cycle time of the multifunctional environmentally protective polyurethane composite material was shorter than that of the thermoplastic polyurethane. Accordingly, by the use of the cork, the recycled tire powder and the recycled polyethylene terephthalate, the multifunctional environmentally protective polyurethane composite material of the present embodiment had a lighter weight, a better flowability, a better abrasion resistance and a better formability than the thermoplastic polyurethane.
Embodiment 10
[0071] The present embodiment was similar to Embodiment 1. The difference between the present embodiment and Embodiment 1 was that the mixture was melted and extruded by the extrusion moulding machine under a melting temperature of 190° C. and a screw speed of 90 r.p.m. to obtain the multifunctional environmentally protective polyurethane composite material.
[0072] In addition, in the present embodiment, the thermoplastic polyurethane was TPU-970 manufactured by Sunko Ink. Co., Ltd. The hardness and the melt index of the thermoplastic polyurethane were respectively 70 A and 5.024 g/10 mins. The environmentally protective additive was recycled tire powder, wood powder and clay. The thickening dispersant was polybutadiene rubber manufactured by TSRC Corp. The product ID of the polybutadiene rubber was TAIPOL BR0150H. The weight ratio between the thermoplastic polyurethane, the environmentally protective additive and the thickening dispersant was 67:30:3. The weight ratio between the recycled tire powder, the wood powder and the clay was 30:10:5.
[0073] With reference to Table 10, in the present embodiment, the specific gravity of the multifunctional environmentally protective polyurethane composite material was smaller than that of the thermoplastic polyurethane. The melt index of the multifunctional environmentally protective polyurethane composite material was larger than that of the thermoplastic polyurethane. The volume loss of the multifunctional environmentally protective polyurethane composite material was less than that of the thermoplastic polyurethane. Accordingly, by the use of the cork, the recycled tire powder and the graphite powder, the multifunctional environmentally protective polyurethane composite material of the present embodiment had a lighter weight, a better flowability and a better abrasion resistance than the thermoplastic polyurethane.
[0000]
TABLE 10
Analysis result of material properties of Embodiment 10
Specific
Melt
Volume
gravity
index
loss
Multifunctional
1.15
6.38 g/10 mins
102.43 mm 3
environmentally
protective
polyurethane
composite
material
Thermoplastic
1.24
5.024 g/10 mins
110.88 mm 3
polyurethane
[0074] Comparison 1
[0075] In the present comparison, a thermoplastic polyurethane was blended with cork by an agitator-type blender under an operation temperature of 25° C., a screw speed of 150 revolutions per minute (r.p.m.) and a blending time of 1 hour; then a mixture was obtained. The thermoplastic polyurethane was TPU-785 manufactured by Sunko Ink. Co., Ltd. The hardness and the melt index of the thermoplastic polyurethane were 85 A and 14.318 g/10 mins, respectively. The weight ratio between the thermoplastic polyurethane and the cork was 70:30.
[0076] The mixture was melted and extruded by an extrusion moulding machine under a melting temperature of 180° C. and a screw speed of 70 r.p.m. to obtain an environmentally protective polyurethane composite material. However, after extrusion moulding, the mixture was broken immediately and could not be formed into the environmentally protective polyurethane composite material.
[0077] Comparison 2
[0078] In the present comparison, a thermoplastic polyurethane was blended with recycled tire powder by an agitator-type blender under an operation temperature of 25° C., a screw speed of 150 revolutions per minute (r.p.m.) and a blending time of 1 hour; then a mixture was obtained. The thermoplastic polyurethane was TPU-195 manufactured by Sunko Ink. Co., Ltd. The hardness and the melt index of the thermoplastic polyurethane were 95 A and 7.164 g/10 mins, respectively. The weight ratio between the thermoplastic polyurethane and the recycled tire powder was 80:20.
[0079] The mixture was melted and extruded by an extrusion moulding machine under a melting temperature of 200° C. and a screw speed of 90 r.p.m. to obtain an environmentally protective polyurethane composite material.
[0080] However, the specific gravity and the particle size of the recycled tire powder were 1.432 and 0.1 millimeter (mm). The specific gravity and the particle size of the thermoplastic polyurethane were 1.198 and 2 millimeters. Therefore, the recycled tire powder was heavier and smaller than the thermoplastic polyurethane.
[0081] Since the recycled tire powder was heavier and smaller than the thermoplastic polyurethane, the composition distribution of the mixture was not uniform, such that the recycled tire powder was extruded first and resulted in the screw slippage. As such, the environmentally protective polyurethane composite material could not be obtained.
[0082] To sum up, by the thickening dispersant, the environmentally protective additive was uniformly added into the thermoplastic polyurethane to obtain the multifunctional environmentally protective polyurethane composite material of the present invention. Using the environmentally protective additive would not produce additional waste and would even suppress an increase of waste. In addition, as proved in Embodiments 1, 2 and 4 to 10, with the use of the thickening dispersant and the environmentally protective additive, the multifunctional environmentally protective polyurethane composite material of the present invention had advantages of light weight, good flowability, good slip resistance, good abrasion resistance and good formability. Moreover, the cost of the environmentally protective additive taken from natural products or recycled materials was low; thus, the multifunctional environmentally protective polyurethane composite material of the present invention was cost effective.
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A multifunctional environmentally protective polyurethane composite material comprises a thermoplastic polyurethane; an environmentally protective additive including recycled polymer, plant fiber, mineral, or metal powder; and a thickening dispersant including natural rubber or synthetic rubber. By the thickening dispersant, the environmentally protective additive is uniformly added into the thermoplastic polyurethane to form the multifunctional environmentally protective polyurethane composite material. The environmentally protective additive can reduce the existing amount of waste or suppress increase of waste. With the use of the thickening dispersant and the environmentally protective additive, the multifunctional environmentally protective polyurethane composite material has advantages of light weight, good flowability, slip resistance, abrasion resistance, formability and low cost.
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CROSS-REFERENCE TO RELATED APPLICATION
This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/047,511 filed May 23, 1997.
BACKGROUND OF THE INVENTION
The present invention is concerned with separation of small particles. More particularly, the invention is concerned with separation of small particles by use of a fluctuating potential acting on particles having a characteristic coefficient of friction.
Separation of small particles, especially colloidal particles, and in particular macromolecular biological particles in liquids, presents a technical challenge. Mechanical filtration is inadequate or ineffective and, if it is possible, is extremely slow. Mechanical filters are also likely to cause physical damage to proteins and other small particles (of the order of one to one thousand micrometers in major dimensions). The term "major dimension" is taken to mean the diameter of the smallest sphere that would contain the particles.
It is known that nonequilibrium fluctuations in time acting on a particle in an anisotropic periodic potential U(x) can cause transport of the particle in a medium. Thermal noise can complicate the situation and is sometimes necessary to get any flow at all. The study of such systems has been motivated in part by recent advances in the experimental study of motor proteins, i.e., proteins that convert the energy of ATP hydrolysis into motion along a biopolymer. These tiny engines may work by using the nonequilibrium fluctuations, brought about by the ATP turnover, to make a Brownian step in one direction more likely than in the opposite direction. This biasing of Brownian motion is an operating principle that is fundamentally different from that of macroscopic engines. Furthermore, nanotechnological devices have been constructed where the same principles are employed to drive microscopic particles.
In this application we cause a potential to fluctuate in such a way that the direction of the biasing depends on the coefficient of friction of the particle and thus we have a method for the separation of such particles. The setup is summarized by the following Langevin equation: ##EQU1## where β is the coefficient of viscous friction, ξ(t) is the function representing zero-average normalized white noise, and D controls the amplitude of this noise. The fluctuation-dissipation theorem D=kT/β relates the coefficient of friction and the amplitude of thermal noise. The functions f(t) and g(t) describe the "nonthermal" additive and multiplicative noise, respectively. When g(t) does not vary in time and f(t)=0 no transport can occur. Transport occurring with f(t)=0 and constant g(t) means that thermal fluctuations are converted into work and implies a violation of the second law of thermodynamics. A great many investigations have focused on additive fluctuations or oscillations. In our method we focus on multiplicative noise, i.e., a g(t) that varies in time while f(t)=0, which means that the periodic potential changes shape but no net macroscopic force every occurs. The study of multiplicative noise has already led to the construction of a device to drive and possibly separate small particles or macromolecules. Multiplicative noise is also more likely to be the operating principle for motor proteins. The binding of ATP, the subsequent hydrolysis, and the release of ADP do not cause a macroscopic force along a biopolymer, but simply change the distribution of charges in the motor protein and thus the energy profile that the motor protein "feels" on the periodic biopolymer. The fluctuations of this profile can account for the observed speeds and stopping forces of real motors.
The models for which fluctuation-induced flow has been studied have generally been as simple as possible. A piecewise-linear potential with two pieces per period and a two-state additive or multiplicative Markovian fluctuation allows for analytic evaluation and it can, furthermore, be understood how and why flux occurs and how and why it changes when parameter values are changed. But when only slight complications are added the behavior of the system can become surprisingly rich and flux can actually change its direction more than once when a certain parameter is varied. In the prior art a two-piece piecewise-linear potential has been examined, and this examination showed how in the fast noise limit of an added fluctuation the direction of the induced flow depends on a characteristic of the noise. In a similar system with a three-state fluctuating force the many flux reversals were explained as noise characteristics were varied. Other prior art investigated a three-piece piecewise-linear potential. When transition rates between such a potential and a flat potential are changed, a reversal of flow occurs. While the prior art methods have observed a variety of interesting characteristics of particle flux, there has been no demonstration of the ability to efficiently separate different particles sizes.
It is therefore an object of the invention to provide an improved method and system for separating small particles.
It is another object of the invention to provide a novel method and system for applying a fluctuating potential to separate smaller colloidal particles from larger colloidal particles.
It is a further object of the invention to provide a method and system for applying a motor force to a molecule that is attached to a biopolymer.
These and other objects of the invention will become apparent by reference to the description of the invention.
SUMMARY OF THE INVENTION
Small particles, of the order of 0.1 to 1000 micrometers in major dimensions, are separated in a film of liquid by applying an anisotropic periodic electric field that fluctuates or oscillates in time to bias the Brownian motion of the particles. The different viscosities of the particles in the liquid causes motion of the particles to respond differently to a varying electric field so that the particles tend to accumulate in different regions in the liquid according to their size. In one embodiment of the invention a single container is used to effect the separation. In another embodiment, two or more containers are used to cascade the separation process.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic drawing of an apparatus for separating small particles according to the present invention.
FIG. 2 is a schematic drawing of a cascaded apparatus for separating particles.
FIG. 3 is a plot of the potential as a function of position along the horizontal X axis with the potential shown along the vertical axis.
FIG. 4 is a plot of the flux of particles as a function of logγ (a variable which controls the speed of the fluctuation).
FIG. 5 is a plot of the effective voltage variation at low-frequency for the system of FIG. 3.
FIG. 6 is a plot of the effective voltage variation at high frequency for the system of FIG. 3.
FIG. 7 illustrates how at high γ for high values of E the short slope acts as a fluctuating barrier.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a schematic drawing of an apparatus for separating small particles according to the present invention, and FIG. 2 is a schematic drawing of a cascaded apparatus for separating particles. In FIGS. 1 and 2, a container 20 contains a liquid 22 and a plurality of particles 24. The particles 24 are typically biological particles, in particular, although not necessarily, proteins, and the liquid 22 is typically water The particles 24 are preferably of a size that subjects them to Brownian motion in the liquid 22; in particular, macromolecules or proteins. A set of electrodes 26 is connected to a power supply 28 to apply an anisotropic periodic electric potential to the liquid 22 and the particles 24 that fluctuates or oscillates in time. We have found that imposing such a potential with the set of electrodes 26 causes differently sized particles 24 to move in opposite direction. This can be characterized as an applied bias to the Brownian motion, with particles 24 affected differently by the applied bias according to their size and the consequent amount of viscous friction in the liquid 22. Appropriate selection of the variable γ, that characterizes the speed of the oscillation/fluctuation in time, causes the smaller ones of the particles 24 to be concentrated in one area of the container 20 and the larger ones to be concentrated in a different area. The electrodes 26 are preferably spaced as close together as possible to take maximum advantage of the Brownian motion. A first tube 28 can be connected to a first pump 30 to extract the fraction of particles 24 that is larger than some arbitrary major dimension L 1 and pump the extracted fraction of the particles 24 into a container 40. The second tube 34 can be connected to a second pump 36 to extract the fraction of the particles 24 that is smaller than some major dimension L 2 (L 2 >L 1 ). Similar tubes 37 and 38 may be used for further particle extraction. It is thus possible to sort out geometrically identical particles from any suspension to any desired accuracy. The values for L 1 and L 2 can be set by taking the right value of the parameter γ. The separation process allows for the making of monodispersed colloidal suspensions, i.e., suspensions of particles which are substantially uniform in size. Such monodispersed colloids have many applications in modern technology, such as in the formation of colloidal crystals.
A two-piece piecewise-linear potential is considered here, but the imposed fluctuation is multiplicative and three-state. We consider a specific case for which analytic solution is possible and where flux reversals can be intuitively understood. FIG. 3 is a schematic diagram of the potential as a function of position. In FIG. 3 V + (x) is a two-piece piecewise-linear potential with an energy difference E between minimum and maximum. V 0 (x) is a flat potential and by multiplying V + (x) by -1, which is equivalent to turning it upside down, we obtain V - (x). The arrows in FIG. 3 indicate how the transitions occur. The transition rates are such that equal amounts of time are spent in V + (x) and V - (x), leaving three parameters, γ, μ and λ, to vary. The value of γ varies all of transition rates and thus the speed of the fluctuations. The parameter μ governs the separation of time scales for the V + ←→V 0 fluctuation relative to the V 0 ←→V - fluctuation; μ times as many transitions are made into V + as into V - but the dwelling time in V + is μ times as small as the one in V - so the fractions of time in V + and V - end up to be the same. Obviously, for μ=1 the system is effectively isotropic and no flux can occur. With λ we can regulate the time spent in V 0 relative to V + and V - . As λ→βthe fluctuation becomes dichotomous between V + and V - and as λ→0 all time is spent in V 0 . A commonly used variable is the "flatness". When we identify the V + state with g=1, the V - state with g=-1, and the V 0 state with g=0, the flatness is defined as φ=(g 4 )/(g 2 ) 2 and as such is a good measure for how close to zero the value of g stays on the average. For our case the flatness can be derived to be φ=1+1/(2λ).
To make the resulting formulas as concise as possible we absorb the coefficient of friction of the Brownian particle β into the time scale, take energy units of kT and take L as the unit of distance. The Fokker-Planck equations for the probability distribution in the stationary state are the following: ##EQU2## where i=1 represents the system on the interval (0,α) and i=2 represents the system on the interval (α,1). P + (x), P 0 (x), and P - (x) are the joint probability densities for the particle to be at x and the potential to be in the V + , V 0 , or V - configuration, respectively. The terms F i - , F i 0 , F i - are the respective Fokker-Planck operators: F i - =∂ x .sbsb.x P i + -f i + ∂ x p i + [correct these] and likewise for F i 0 and F i - , where f i + , f i 0 , and f i - represent the forces -∂ X V i + , -∂ X V i 0 , and -∂ X V i - . Because of the piecewise linearity these forces are independent of x. In the matrix the terms μ, λ, and γ parameterize the flow of probability from one potential to another. (f i + -∂ x )P i + is the flow J i + along the x axis in the +state; likewise we have J i 0 =(f i 0 -∂ x )P i 0 and J i 0 =(f i - -∂ x )P i - . The net flow at any point x is J=J i + +J i 0 +J i - and in the stationary state this quantity must be the same at any point x. The above matrix equation can be viewed as a way of saying ∂ X J=0 in terms of forces, transition rates, and probability densities. There are boundary conditions at x=α and x=0 (which must coincide with x=1), where the probability densities P i + , P i 0 and P i - and the flows J i + , J i 0 and J i must be identical for i=1 and i=2.
The problem reduces to two sets of three coupled ordinary differential equations that are connected at the boundaries x=α and x=0. The two linear systems are sixth order and have constant coefficients. Because of the symmetry of the system the zero eigenvalue turns out to be degenerate, so the solution is the sum of a constant, a linear term, and four exponentials. The coefficients are determined by the connections at x=α and x=0. Because J=J i + +J i 0 +J i - is valid at both x=α and x=0 there is one redundancy, and this leaves room for the normalization of the total probability over one period. A conventional computer algebra system like MATHEMATICA (a trademark of Wolfram Research, Inc.) can solve the system and determine the induced flow within seconds.
FIG. 4 shows the induced flow J as a function of logγ for three different values of λ with μ=1000. There are two extrema and a flux reversal. Maximum and minimum flow have about the same absolute value. Next we will explain flux reversals in terms that are more intuitive and more directly comprehensible than the large body of algebra solved by the MATHEMATICA program.
We define -3<logγ<0 as the low-frequency domain. In this domain the sojourns into the minus state are too rare to be of significance, but the flipping between V - and V 0 is sufficiently frequent to bring about a pumping effect. An important notion is the adiabatic adjustment time. The adiabatic adjustment time on each of the two slopes is the characteristic time for a probability distribution to adjust to the shape of the potential V(x) on that slope and we take this time to be equal to the characteristic time for diffusion over the width of that slope if it were a flat potential. The adiabatic adjustment time on the slope (0,α) thus equals α 2 /2 and the adiabatic adjustment time on the short slope (α,1) equals (1-α) 2 /2. In the context of a two-state model there is no significant flux occurring when the dwelling time in each state is much shorter than the time for adiabatic adjustment on each of the slopes. In this case the probability distribution is simply the distribution on the average potential. Maximal flux occurs when the dwelling times are in between the adiabatic adjustment times on the long and the short slope. As shown in FIG. 5, at maximal flux in the low frequency domain we can think of the system as being adiabatic at all times and with a short slope that flips between 0 and E/α and a stationary long slope with the average height of λE/(λ+1) (see FIG. 5).
Note that in the V + state the slopes have opposite signs and that this is not the case in V 0 . For the purpose of a rough approximation we can assume that no flux occurs in the V + state and that the negative flux happens because of the sliding down in the V 0 state. For the values we took (E≈10 and α≈10/11) the time (1-α) 2 /2 to diffuse over the flat part of the V 0 state is negligible in comparison to the time (α 2 /E that it takes to slide down the long slope. Taking α 2 to be one and multiplying by the fraction of time spent in the 0 state we derive J low fr =αE/((2λ+1)(λ+1)), or in terms of the flatness J low fr =((φ-1)E/(φ(2φ-1)).
In the high-frequency domain, 0<logγ<3, μ is such that (μγ) -1 is shorter than any adiabatic-adjustment time scale of the system. This means that we think of the system as flipping between the weighted average of the V + and V 0 state, V avg =(λV + +V 0 )/(λ+1), and the V - state as in FIG. 6.
The 1/(λ+1) appears in front of the rate of the transition to the - state because, when in the V avg state, 1/(λ+1) is the fraction of time spent in the 0 state from where the transition to the V - state is possible. As in the previous case, we obtain flux when the dwelling times are between the adiabatic adjustment times of the long slope and the short slope. The long slope has a flat average. For high enough E we can think of the short slope as a barrier that fluctuates between being absorbing and reflecting as in FIG. 7.
For all λ the dwelling time in V avg is longer and therefore we expect positive flux. We obtain this flux by subtracting the fraction of time spent in V - from the fraction spent in V avg and multiplying this difference with the exit rate from the unit interval. For a particle starting at the reflecting barrier it takes on the average half a unit of time to get to the absorbing barrier. This leads to the following estimate for the flux: J high fr =2/(2λ+1), or in terms of the flatness J high fr =2((φ+1)/φ.
Next we compare the approximations J low fr and J high fr with the exact evaluations as depicted in FIG. 4. For α=10/11 the adiabatic adjustment times of the two slopes are 2 orders of magnitude apart. Their geometric average occurs at α(1-α)/2 and on the logγ axis this corresponds to log[2/α(1-α)]=1.6. In the low-frequency domain the geometric average of the transition rates between V + and V 0 is μγ(λ) 1/2 and in the high frequency domain the geometric average of the transition rates between V avg and V - is γ/[γ/(γ+1)] 1/2 . In FIG. 4 the minima occur at μγ(λ) 1/2 ≈2/α(α-1) and the maxima at [λ/(λ+1)] 1/2 ≈2/(α(α-1)) within a factor of 4. The approximations predict that both extrema move left for increasing λ and this is indeed the case in FIG. 4. The estimates J low fr and J high fr are within a factor of 2 from the values of the actual extrema of the flux. The formula for J low fr predicts an extremum at λ=(2) 1/2 /2. In FIG. 4 we indeed observe that the maximal negative flux is smaller at λ=1/3 and λ=3 than at λ=1. The formula for J high fr predicts that the positive maximum becomes larger with decreasing λ. This prediction is borne out by the curves in FIG. 4.
Upon redimensionalizing the variables possible applications and the current invention come to mind. To unscale the flipping rates they have to be multiplied with kT/βL 2 , where L is the length of a period of the potential and β represents the coefficient of viscous friction of the diffusing particle. The value of β is specific for each molecule and depends on shape and size. For a given flipping rate, different macromolecules thus find themselves at different locations along the logγ axis in FIG. 3. It is always possible to impose a flipping rate on the system such that a molecule with friction β 2 moves in a direction opposite to the one of a molecule with friction β 1 . Devices for the separation of macromolecules usually operate based on the fact that molecules with a larger β move slower in a certain direction when a force is applied in that direction. The device proposed here is actually able to let molecules with different β's move in opposite directions. Thus a device of short length would already be able to separate very efficiently.
In nanotechnology it is now possible to construct grids with a period of about 5 μm. The creation of a field as in FIG. 3 on such a scale is thus feasible. In dilute solutions proteins like hemoglobin have friction coefficients of about 10-10s -1 . This translates into a diffusion coefficient of about 50 μm 2 /s. So keeping the system in the flat state for a tenth of a second is enough to allow diffusion over about half a period. In terms of our setup this means that the negative minimum occurs when the flipping rate between V + and V 0 is about 20 Hz and maximum flow occurs when the flipping rate between V - and V 0 is about 20 Hz. After redimensionalization the formulas for J low fr and J high fr become ##EQU3## When we take E=10 (this is in principle under experimental control with the electrical field strength) we find speeds of about 10 μm/s.
Polystyrene and latex spheres with submicrometer radii are commercially available. The coefficient of friction of such beads is easily evaluated with the Stokes' formula β=6 πηr, where η is the coefficient of viscosity. A bead with a radius of 0.5 μm thus has a coefficient of friction that is about 100 times as much as that of a hemoglobin molecule. This means that the extrema of the flux are about 0.1 μm/s at characteristic flipping rates of about 0.2 Hz and that separation of particles with radii different by a factor of 2 should be accomplishable in under an hour.
Latex and polystyrene beads have a higher dielectric permittivity at optical frequencies than water. This implies that they "like to get out of the dark and into the light." Periodic light intensity patterns can be easily created with laser beams. When narrow laser lines are oscillated over the film very rapidly (faster than any characteristic timescale of the system) a colloidal particle at position x will feel the average intensity at position x. By taking the right velocity pattern during the oscillation any potential profile can in principle be realized. So the three-state fluctuating potential of FIG. 3 that can separate the particles can also be created using such optical forces instead of electric forces.
The preceding description should be taken as illustrative and not as limiting. The invention is defined by the following claims.
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Small particles, of macromolecular size or the like, are separated in a liquid by size by applying electric fields of predetermined distributions in time and space to enhance the Brownian motion of the particles so as to favor motion of particles of a particular size. When the particles are separated by size they can be removed from the region in which they have accumulated and they can be collected by size.
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BACKGROUND OF THE INVENTION
When congestion or rubbernecking occurs on major highways, vehicles stand still and idle their engines. As the congestion builds up, the wait time increases. The congestion wastes fuel and aggravates the driver's nerves.
Often it is the drivers own curiosity that helps to fuel the delay which is known as rubbernecking. As the name implies, rubbernecking refers to the action of passing drivers or motorists who divert their attention from the roadway in front of them to the unusual situation that is existing within eyeshot of the driver. This unusual situation can be a car accident, a hit pedestrian, road construction, road repair, a patrol car that pulled over a motorist, or some other disturbance. Because the driver is drawn to the disturbance, the driver must slow the car down to get a better view, and this leads to what is known as “rubbernecking.”
It is a desire of this invention to address several issues regarding rubbernecking; 1) find a way to decrease the wait time, 2) decrease waste of fuel, and 3) attempt to remove the need to rubberneck.
Here are some fuel expenditure conditions in the US, as illustrated in FIG. 9 . Almost 140 billion gals of fuel is used in the US. During a traffic jams, the study estimates, that in 75 of the largest metropolitan areas, almost 6 billion gals are wasted in traffic jams. Not to mention the time that is wasted waiting in a traffic jam.
A desirable feature of this invention would be to deter the need to perform rubbernecking. In addition, another feature of this invention would be to control the traffic flow while in a congested state to decrease the congestion.
BRIEF SUMMARY OF THE INVENTION
This invention relates to the idea of replacing the view of the accident with a second view that lacks detail. Ideally, this second view should be applied uniformly across a region of the country to substitute the disturbance with this commonly known second view. It is important to point out that this invention would decrease rubbernecking gradually since the need for rubbernecking should secede after a period of time because the reward of rubbernecking will not provide a visual of the unusual situation, instead the second view will be shown. Once this second view is accepted by all drivers in this region of the country, the drivers will tend to disregard the need to rubberneck.
The second view is a quickly erected shield that blocks the view of the disturbance from the passing drivers. This shield could have standardized appearance, but the net result will be that the driver would not be able to see disturbance. Features such as color, width and height of the shield or shields can be resolved to provide for better uniformity of the second view. As the uniformity improves, there will be a lesser chance for the driver or motorist to slow down.
One way of erecting the second view is by filling balloons with helium which in turn lifts shields to block the disturbance. The bottom end of the shield will have a counter weight to hold the base of the shield against the ground. In case of stiff cross winds, the ends of the shield can further be help in place by additional wires quickly connected to local support.
Another aspect of this invention is to control the flow of congested traffic in real time. Wirelessly controlled mobile flat units can be placed on the shoulder of the road and then moved onto the roadway remotely controlled by a master unit. As these flat units are moved onto the roadway, the congested traffic can run over these flat units without damaging them. Once these units are in position, a signal is given to raise or extend a reflective, illuminated post which also has an LCD (Liquid Crystal Display) display. This spacing of these marked posts defines and establishes a new dynamically adjusted roadway. As the traffic follows these roadways, the congestion becomes reduced until it is eliminated.
After the congestion is eliminated, the marked posts are slowly moved by the processor unit until the new sets of lanes superimpose the original set of lanes in the roadway. Then, the posts are lower or retracted and the units moved to the shoulder of the road for future reuse.
Another aspect of this invention is that the marked posts are positioned with the guidance of a master processor that has the details of the roadway in memory. The memory can be in the master processor or located on a web server. If the master processor knows; 1) which roadway is blocked, 2) the location of the accident, and 3) the positioning of the mobile flat units, the master processor issues instructions to the mobile units to optimize and reduce the flow of the congested traffic.
Once the shields are in place and the reward of rubbernecking is reduced, the traffic will become less affected by the rubbernecking event and the waste of fuel waiting in long traffic lines can be decreased. In addition, because of the active control of congested traffic, the ability to control and reduce congestion offers another approach to improving fuel usage in the US.
Another preferred embodiment of the preferred invention includes an apparatus that blocks the view of a vehicular accident by a passing motorist comprising: at least one shield, such that the shield is located between the vehicular accident and the passing motorist, whereby the shield is juxtaposed to a concrete barrier, whereby the shield is juxtaposed to the vehicular accident, whereby the shield is an inflatable structure defining a thin rectangular structure, whereby the shield is plastic.
Another preferred embodiment of the preferred invention includes an apparatus comprising: a plurality of mobile flat units, a master processor that controls a movement of the mobile flat units, a highway having more than one lane and a new set of lanes defined by a final position of the mobile flat units, further comprising: a communication channel established between the master processor and each of the flat units, whereby the communication channel can be wired or wireless between the mobile flat units and the master processor, further comprising: a motor to move the mobile flat units: a local processor coupled to the motor and a wireless block to control the motor based on a command received from the master processor, further comprising: a plurality of rubber tracks coupled to the motor and a road, whereby a post in the plurality of mobile flat units is extended at the final position, further comprising: the post in the plurality of mobile flat units can be retracted during the movement, further comprising: at least one LCD (Liquid Crystal Display) or LED (Light Emitting Diode) that can display instructions.
Another preferred embodiment of the preferred invention includes a method of creating a new set of lanes comprising the steps of: placing a plurality of mobile flat units in an initial position, controlling a movement of the mobile flat units over a roadway by using a master processor, moving the mobile flat units to a final position and creating the new set of lanes defined by the final position of the mobile flat units, further comprising: communicating information either wired or wirelessly between the master processor and each of the mobile flat units, whereby the initial position is located in a shoulder of the highway. The method further comprising: extending a post in the mobile flat units when they are in the final position, further comprising: moving the mobile flat units slowly so that the new set of lanes superimpose the original set of lanes in the roadway, retracting the post in the mobile flat units and moving the mobile flat units off the active portion of the highway, further comprising: providing motorists with instructions printed on a display screen located on the post.
BRIEF DESCRIPTION OF THE DRAWINGS
Please note that the drawings shown in this specification may not be drawn to scale and the relative dimensions of various elements in the diagrams are depicted schematically and not to scale.
FIG. 1 shows a typical major throughput highway.
FIG. 2 illustrates a traffic accident located in the shoulder of the road and the rubbernecking that starts to form.
FIG. 3 depicts a top view of the highway shown in FIG. 1 .
FIG. 4 a shows the inventive technique being applied to FIG. 2 to conceal the traffic accident from rubberneckers.
FIG. 4 b shows the inventive technique being applied to FIG. 2 a second way to conceal the traffic accident from rubberneckers.
FIG. 5 depicts the top view of the highway shown in FIG. 4 a illustrating the decrease in rubbernecking of this inventive technique.
FIG. 6 illustrates a traffic accident located directly in one of the lanes of the roadway and the rubbernecking that starts to form.
FIG. 7 shows the inventive technique being applied to FIG. 6 to conceal the traffic accident from rubberneckers.
FIG. 8 depicts the top view of the highway shown in FIG. 7 illustrating the decrease in rubbernecking of this inventive technique.
FIG. 9 shows a table illustrating the fuel usage in the US.
FIG. 10 shows the inventive technique being applied to FIG. 2 to control congestion building up in the roadway (note that the view is the southbound view of FIG. 2 ).
FIG. 11 a depicts the front view of a mobile flat unit that has the marked post extended.
FIG. 11 b shows the side view of a mobile flat unit that has the marked post extended.
FIG. 11 b illustrates the top view of a mobile flat unit that has the marked post extended.
FIG. 11 c depicts the top view of a mobile flat unit that has the marked post extended.
FIG. 11 d depicts the top view of a mobile flat unit that has the post retracted into the recessed cavity.
FIG. 12 a illustrates the front view of a portion of a mobile flat unit illustrating the traction belt used to move the unit onto the roadway.
FIG. 12 b shows the side view of a portion of a mobile flat unit and some of the electronics inside the unit.
FIG. 13 depicts a tire of a vehicle rolling over the mobile flat unit.
FIG. 14 a illustrates the top view of the southbound lanes of FIG. 10 with the mobile flat units positioned in the shoulder of the roadway.
FIG. 14 b shows the top view of the southbound lanes of FIG. 10 with the mobile flat units being positioned.
FIG. 14 c illustrates the top view of the southbound lanes of FIG. 10 with the mobile flat units in position and posts extracted to control traffic flow dynamically.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates a view of a typical highway or interstate 1 - 1 . The highway is bounded by 1 - 2 and 1 - 29 which defines the paved region of the highway. This highway 1 - 1 stretches from North to South as shown by the arrow. The highway has four paved lanes 1 - 16 , 1 - 18 , 1 - 23 and 1 - 28 heading North and has four paved lanes 1 - 3 , 1 - 5 , 1 - 9 and 1 - 14 heading South. The North and South directions are separated by the concrete barrier 1 - 15 . Each of the two outer lanes of the North and South directions serve as shoulders. The inner shoulders of the North and South directions are 1 - 16 and 1 - 14 , respectively. The outer shoulders the North and South directions are 1 - 28 and 1 - 3 , respectively. The active portion of the highway comprises lanes 1 - 18 and 1 - 23 traveling North and the lanes 1 - 5 and 1 - 9 traveling South.
The various lanes are separated by barriers, markings, depressions, or lines for demarcation purposes. For instance, the lanes that are traveling South 1 - 3 , 1 - 5 , 1 - 9 and 1 - 14 are bordered by markings 1 - 2 , 1 - 4 , 1 - 8 , 1 - 13 , and 1 - 15 , respectively and the lanes traveling North 1 - 16 , 1 - 18 , 1 - 23 and 1 - 28 are bordered by markings 1 - 15 , 1 - 17 , 1 - 22 , 1 - 27 and 1 - 29 , respectively. The markings 1 - 4 , 1 - 13 , 1 - 17 and 1 - 27 may have rumble strips formed in them to make the characteristic sound once the tires rolls over them. The barrier 1 - 15 separates the North from the South lanes as mentioned earlier. The dotted lines 1 - 8 and 1 - 22 separate the two active portions in each direction into two lanes.
The northbound traffic has moving vehicles 1 - 19 and 1 - 20 traveling at velocity 1 - 21 . While vehicles 1 - 25 and 1 - 26 are traveling at velocity 1 - 24 . In the southbound lanes vehicle 1 - 6 is traveling at velocity 1 - 7 while vehicles 1 - 10 and 1 - 11 are traveling at velocity 1 - 12 . Although it is not necessary for both vehicles in the same lane to travel at the same velocity at all times. Also note that a vehicle can be any moving vehicle such as a motorcycle, car, truck, van, scooter, tractor trailer, 18 wheeler or tandem rig.
The shoulders 1 - 3 , 1 - 14 , 1 - 16 and 1 - 28 are used to decelerate any vehicles traveling on the active portion of the highway for emergency care (typically when the car starts to fail in operation, a fender bender or minor collision) or unavoidable stoppage (police request) or for any other need to stop a vehicle.
FIG. 2 illustrates a view of a typical highway or interstate 2 - 1 after an accident 2 - 3 in the outer shoulder 1 - 3 between two vehicles 2 - 4 and 2 - 5 . Rubbernecking lines 2 - 6 and 2 - 7 start to build up in the Southbound lanes before the accident as those who are passing the accident want to slow down to get a better view. As these vehicles slow down, the following vehicles start forming rubbernecking lines 2 - 6 and 2 - 7 since the traffic before them has slowed down. The vehicles assume a bumper to bumper configuration. Likewise, in the northbound direction, rubbernecking lines 2 - 12 and 2 - 13 starts to form. All of these vehicles desire a view of the disturbance or accident so they slow down. The dotted region 2 - 2 is used and indicated in FIG. 3 .
Depending on the time of day, (for example, weekdays 8 AM or 5 PM) the rubbernecking traffic can build up quickly. FIG. 3 illustrates the bird's eye view 3 - 1 of FIG. 2 from above. Note that dotted region 2 - 2 . The accident is at 2 - 3 . The rubbernecking lines are illustrated in regions as 3 - 2 and 3 - 3 for the southbound and northbound lanes, respectively. The length of these rubbernecking lines could extend for several miles. Most cars in the rubbernecking lines are standing still or moving very slowing and are wasting fuel whether the fuel is gasoline, diesel, chemical reactions, or electric charge. In addition, besides the waste of fuel, each motorist is stretched to the edge of their patience of just waiting in the rubberneck or congested line. After the vehicles pass the accident, the traffic starts to move again as illustrated in regions 3 - 4 and 3 - 5 where the spacing between vehicles increases again.
FIG. 4 a illustrates the inventive technique of using shields to block the details of the accident 2 - 3 which is behind the shields 4 - 4 a through 4 - 4 n . The shields are connected to the balloons by wires 4 - 3 a through 4 - 3 n and are lifted by helium balloons 4 - 3 a through 4 - 3 n . Another possibility is for a shield that can be constructed so that it can hold helium eliminating the need for the wires and balloons. Ideally, the traffic would be flowing in the northern directions at velocities 4 - 6 and 4 - 7 and in the southern directions at velocities 4 - 4 and 4 - 5 . These velocities should be larger than the velocities given for FIG. 2 without the shields in place.
A bird's eye view of FIG. 4 a is given in FIG. 5 . Due to the shields 4 - 4 a through 4 - 4 n and the lack of information to rubberneckers, the motorists will not slow sown to view just a shield, although they may slow slightly to drive with caution. The “rubbernecking” lines indicated in the regions 5 - 3 and 5 - 4 have been improved in that not all cars are bumper to bumper and the traffic flow improves.
FIG. 4 b illustrates a second inventive technique of using shields to block the details of the accident 2 - 3 . The shields 4 - 4 a through 4 - 4 n are now placed juxtaposed to the barrier 1 - 15 . The shields are connected to the balloons by wires 4 - 3 a through 4 - 3 n and are lifted by helium balloons 4 - 3 a through 4 - 3 n.
Another possibility instead of balloons is to use light rigid shield extensions that fit over the barrier 1 - 15 to block the view of the northbound traffic. Although this solves half of the rubbernecking problem (only the northbound lane), the ability to position these shields could be performed very quickly.
FIG. 6 shows a portion 6 - 2 of a road 6 - 1 . An accident 6 - 3 between two vehicles 6 - 4 and 6 - 5 occurred in the outer southbound lane 1 - 5 . The traffic flow 6 - 8 of the vehicles 6 - 6 is stopped. While the flow 6 - 9 of the traffic 6 - 7 is reduced due to rubbernecking and the traffic of the vehicles 6 - 6 trying to enter the inner lane. In the northbound lanes, the traffic flow 6 - 10 of the vehicles 6 - 12 and the traffic flow 6 - 11 of the vehicles 6 - 13 are reduced due to rubbernecking.
FIG. 7 shows the inventive technique of using shields to block the details of the accident 6 - 3 which is behind the shields 7 - 4 a through 7 - 4 n and shields 7 - 5 a through 7 - 5 n . The shields are connected to the balloons by wires and are juxtaposed to the accident. New traffic patterns are established. The traffic flow 7 - 8 comprising vehicles 7 - 3 and 7 - 6 occur in the shoulder of the southbound lane. While the traffic flow 7 - 9 is formed by the vehicles 7 - 7 . The northbound traffic flows of 7 - 10 and 7 - 11 due to the vehicles is reduced.
A bird's eye view 8 - 1 of FIG. 7 is given in FIG. 8 . Due to the shields and the lack of information to rubberneckers, the vehicles begin forming new lanes before the accident in region 8 - 3 . And due to the shields, the northbound lanes do not suffer a backup in region 8 - 4 .
FIG. 9 provides a table illustrating the fuel usage in the US being almost 140 billion gals a year. Due to the traffic jams caused by rubbernecking and roadway congestion, almost 6 billion gals of fuel is wasted in the largest 75 metropolitan areas. According to the analysis of the 75 largest metropolitan areas by the Texas Transportation Institute in 2002, the average rush-hour driver wastes about 62 hours in traffic annually. The length of the average traffic jam has been increasing over the years. The Urban Mobility Report, from the Texas Transportation Institute, has indicated in 1982, traffic lasted for 4.5 hours a day in the 75 cities studied, however, in 2000, the traffic congestion time increased to seven hours a day.
FIG. 10 illustrates the use of extended mobile flat units 10 - 2 a to 10 - 2 n and 10 - 3 a to 10 - 3 n after being placed in position to control traffic congestion 10 - 1 . Note that this is the same scenario as shown in FIG. 2 but the view is from the southbound direction instead of the northbound direction. The flat units can be used in conjunction with the shields or each can be used alone to reduce traffic congestion. The traffic flows 10 - 4 and 10 - 5 in the southbound direction are controlled dynamically with the use of the mobile flat units.
FIG. 11 a shows an insert 11 - 2 presenting the front view of an extended mobile flat unit 10 - 2 . The extended post 11 - 4 can have LED's (Light Emitting Diodes) 11 - 5 and reflective paint (not shown). The top of the post 11 - 3 has a display panel. The display panel can be an illuminated LCD or LED panel that can be used to display instructions 11 - 8 . Some examples of instructions can include; 10 MPH, STOP, 5 MPH or any other instruction that can be directed to the motorists in the vehicles. The section 11 - 7 will be described later with regards to height, contents, durability, mobility, etc.
FIG. 11 b depicts an insert 11 - 10 presenting the side view 11 - 9 of an extended mobile flat unit 10 - 2 . The extended post 11 - 4 is viewed from the side.
FIG. 11 c illustrates an insert 11 - 12 presenting the top view 11 - 11 of an extended mobile flat unit 10 - 2 . The extended post 11 - 13 is viewed from the top and a cavity 11 - 14 is embedded in the unit 10 - 2 .
FIG. 11 d shows an insert 11 - 16 presenting the top view 11 - 15 of a retracted mobile flat unit 10 - 2 . Note that the post 11 - 17 is rotated into the recessed cavity 11 - 14 and prevents tires from damaging the retracted post when the tire rolls over the mobile unit 10 - 2 . A dotted rectangle 11 - 18 illustrates one of the rubber tracks that are located beneath the unit 10 - 2 .
FIG. 12 a depicts the front view 12 - 1 of a mobile flat unit 10 - 2 . The rubber track 11 - 18 mentioned earlier is wrapped around two cylindrical shafts 12 - 3 and 12 - 4 . As the shaft 12 - 4 rotates counterclockwise, the unit moves in the direction 12 - 7 . The arrow 12 - 5 presents the side view shown next.
FIG. 12 b illustrates the side view 12 - 5 of a mobile flat unit 10 - 2 . The rubber track 11 - 18 mentioned earlier as well as additional rubber tracks 12 - 2 and 12 - 8 are presented. The rubber tracks are shown in contact with the road 12 - 9 . A local processor 12 - 11 receives/transmits instructions from/to the wireless block 12 - 12 . The motor 12 - 10 controls the movement of the cylindrical shafts (not shown) which move the rubber tracks and thereby move the unit in/out of the page. Although not shown, the unit also contains all the components required to form the system. For example, batteries, memory, clocks that may be required but not shown.
FIG. 13 shows the off-angle view 13 - 1 of a vehicle's tire 13 - 2 rolling over the unit 10 - 2 that is on the road 12 - 9 . The height of the unit is minimized and the edges are tapered to allow easy entry and exit of the tire over the unit. The unit must be built to withstand the forces of the various masses that the tires of the vehicles transfer to them.
FIG. 14 a depicts a top view 14 - 1 of a master processor 14 - 2 controlling the mobile flat units 10 - 2 a to 10 - 2 n and 10 - 3 a to 10 - 3 n . The flat units can be positioned in the shoulder of the roadway. The control to move the units is performed wirelessly by the communications paths 14 - 3 , 14 - 4 , 4 - 5 and 14 - 6 . As an alternative, the mobile flat units can communicate using wired connections (not shown). This control moves the units in the direction of the arrows 14 - 7 into lane 1 - 5 . To simplify the drawings, the traffic of vehicles traveling over these lanes is not shown, but it is understood that the mobile flat units can be rolled over by the tires of vehicles without damaging the units. The master processor 14 - 2 contains all the components necessary to control the flat units, such as, wireless systems, computation systems, memory storage systems, and contact with a roadway database that described the features of the roadway. In the remaining figures of moving the mobile flat units into place, the master controller is not shown.
FIG. 14 b depicts a top view 14 - 8 of the mobile flat units 10 - 2 a to 10 - 2 n and 10 - 3 a to 10 - 3 n moved closer into final position. The units are still moving in the direction 14 - 9 and are now located in the two lanes of the southbound lanes 1 - 9 and 1 - 5 .
FIG. 14 c shows a top view 14 - 10 of the mobile flat units 10 - 2 a to 10 - 2 n and 10 - 3 a to 10 - 3 n moved when they are in final position. At this point, a command from the master controller is given to extend the post as illustrated in the inset 14 - 11 . The vehicles 14 - 13 now use the new lanes defined by the extended posts.
Once the traffic congestion is controlled, the mobile units are slowly moved under the master control in the opposite direction with active traffic flowing in the lanes. The movement occurs until the mobile flat units 10 - 2 a to 10 - 2 n are overlaying the center line 1 - 8 and the mobile flat units 10 - 3 a to 10 - 3 n are overlaying the edge line 1 - 4 . At this point, the posts are retracted and the vehicles follow the lines in painted lines in the road. Meanwhile, the mobile flat units are moved into the shoulder 1 - 3 for pickup and removal.
Finally, it is understood that the above description are only illustrative of the principles of the current invention. It is understood that the various embodiments of the invention, although different, are not mutually exclusive. In accordance with these principles, those skilled in the art may devise numerous modifications without departing from the spirit and scope of the invention. For example, in place of helium balloons used to lift the shield, hydrogen can be used. Rigid rods connected to a base can be used to hold the shield in place. The mobile base units can also communicate directly with the passing vehicles to provide instructions directly to the vehicle processor located in the vehicle. Both, the rubbernecking and congestion control can be used together or individually.
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One estimate indicates that rubbernecking and congestion consumes about 4% of this country's fuel. Two approaches are presented to help solve this problem. The first uses shields to block the view of a car accident. Rubbernecking is reduced since the visibility of the car accident is reduced. A second approach uses mobile flat units that can be remotely controlled to enter a roadway that is carrying active traffic. The traffic runs over these units that are being moved until the master processor indicates that the mobile flat units are in position. A post is extended from the flat unit that issues commands to the motorists so the master processor can begin to control and reduce congestion. Both approaches can be used to help decrease fuel waste in the US.
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BACKGROUND AND SUMMARY OF THE INVENTION
This invention pertains to ventilating systems for buildings specifically adapted to house livestock. The system includes vents adapted to direct the airflow in a direction adapted to create a turbulence designed to avoid direct drafts on the livestock.
In years past, most livestock was raised in open pastures, feed lots and the like. Livestock under those conditions were subjected to a full range of temperatures from the heat of summer to the bitter cold of winter in the northern parts of the United States. Frequently at those extremes of temperatures, the animals were subject to added stress because of the weather. Precipitation in the form of rain or snow added to that stress. The result was sometimes illness; or at the very least, a reduction in the efficiency of the conversion of feed into meat.
More recently meat-type animals have been raised in enclosesd buildings. Especially female animals during late gestation and just after birth of their young have been confined in pens in fully enclosed buildings. Both the female and the young are susceptible to disease at these times, and are best protected from either cold or hot drafts within the building.
By my invention, I provide a ventilating system that avoids direct draft onto the animals in the building, at the same time providing fresh air and avoiding chilling or overheating the livestock. Besides avoiding draft, my invention provides fresh and cool air to the area of the building at which the manure handling equipment is normally located. It is accepted that animals tend to go to cooler air to drop manure, and thus by my system, I provide for more convenience in manure handling because the animals will tend to congregrate near the fresh air.
It might also be noted that in my new system, all of the air in the buildings is drawn to certain exhaust fans and that by the introduction of fresh air in a turbulent condition in which the air is not allowed to become stale, I provide an improved ventilation system.
My system also provides much better clearing up of carbon monoxide, ammonia gas and moisture. Previous systems accomplished this only by drawing large amounts of air through the building. These amounts were acceptable when the air was reasonably warm. However in winter climates in northern states, the amount of air required to eliminate staleness was excessive so that it became too cold. By causing the turbulence, I pick up the carbon monoxide, ammonia gas, etc. without the need for pulling in the excess air that was required by former systems.
FIGURES
FIG. 1 is a detailed sectional view of the duct and ventilator of my system as it would normally be used,
FIG. 2 is a diagrammatic view of a center installation of my system which may be desired in certain applications,
FIG. 3 is a top plan view of the ventilator used in my system,
FIG. 4 is an elevational view of a part of the ventilator and
FIG. 5 is a sectional view from line 5--5 of FIG. 4.
DESCRIPTION
Briefly my invention comprises a ventilating system especially useful in buildings designed for the raising of livestock. The system avoids the problem of the direct draft of cold outside air onto the livestock in the building.
More specifically and referring to the drawings, my system is designed for multiple use. The particular design for buildings where the livestock is principally penned in the center of the buliding and having walkways down the outside, is shown in FIG. 1. In this type building manure handling systems normally are placed along the outer walls. Where the aisle for the livestock handlers is down the center, usually in buildings greater than 32 feet wide, I use the system shown in FIG. 2. In such buildings, manure handling systems are usually placed along the center aisles so that fresh cool air should be available there. The systems are essentially similar except for the process of creating turbulence in the in-coming air.
Referring to FIG. 1, I provide a duct system 10 having an outside opening 11 under the eaves 12 of the building adjacent its outer wall 13. I prefer to form the duct simply, by placing a board or similar barrier forming a cap 14 above the ceiling joints 15 so that the duct is simply the space between the joists 15, above the ceiling 16 and below the cap 14. Near the eave, it may be desirable, to provide walls 17 attached to the roof rafters 18 and extending to a soffit board 19 to enclose the duct more completely. For best results, these ducts are not isolated but extend along the full length of the side of the building.
The duct between the joists in the embodiment of FIG. 1 should be relatively short. A barrier board 20 should define the end of the duct and direct any incoming airflow through a deflector 22. Preferably, this barrier is formed as a part of the deflector. That deflector may be built as a separate piece as shown in FIGS. 4-6.
The deflector, as shown in FIGS. 4-6, includes an intake portion 35 extending normally upward and terminating in a flange 26 extending around the entire deflector. In some installations (best shown in FIG. 2 and described later) the deflector is open at the top 27. In the type of installation shown in FIG. 1, one wall of the upper section or intake portion 25 may be formed with an opening 28. In FIG. 1, this opening is open to the duct so that fresh air coming from the opening 11 will be conducted into the deflector. The intake section in either installation extends through the ceiling 16 and between the joists 15 and is fastened to the ceiling by fasteners such as nails extending through the flange 26.
Below the flange 26, the deflector includes an air directing portion 31. This director 31 includes principally a scoop-shaped extension adapted to change the direction of flow of the air approximately 90 degrees from a vertical to a nearly horizontal direction. In the system of FIG. 1, this air director 31 is placed to direct the air towards the outer wall 13. Because the deflector is placed close to the wall, the air stream thus directed as it impinges on the wall creates a turbulence which breaks up the draft so that there will not be a draft directed at the animals in the building, but at the same time providing relatively cool air in the region of the manure handling system.
The air directing portion 31 of the deflector may preferably be lined with a layer of insulating material 32. This allows cold air to be drawn through the deflector without chilling the exterior of the directing part. If that surface is chilled, condensation frequently forms and then drips into the building. Such dripping is undesirable, especially if it falls onto the livestock in the building.
A door 33 pivotted at the top is used to close the outlet of the air directing portion of the deflector. This door in the closed position is held slightly off the vertical to be certain of closure. Not more than ten degrees deviation from the vertical is necessary, and no particular angle is required so long as closure is accomplished when ventilation is not required.
In warmer temperatures, the exhaust fans which commonly draw the air from the buildings are run at higher speeds, thus drawing more air into the building. This increased flow will cause the door 33 to open somewhat wider and the air to leave the deflector in a more nearly horizontal flow. Thus, as the draft becomes stronger, the turbulence also becomes greater, with the result that direct draft is avoided as desired.
In the alternate system illustrated in FIG. 2, the upper part 25 of the deflector is left open at the top 27 and it does not have an opening 28 formed in it. No ducting from the eaves is required here, but air is admitted to the attic of the building through one or more cupolas 32. It will be evident that the system of getting air to the deflector are substantially interchangeable, although I prefer to use the ducted air where the deflectors are directed against an outer wall.
The deflectors are arranged in pairs in the system of FIG. 2 with the air from one of the pairs being directed toward the air coming from the other. Thus, the air streams impinge on each other creating the desired turbulence to avoid the undesired draft.
In both systems, air is blown out of the building by the usual ventilating fans (not shown) which discharge through vents 35 on the outer wall of the building. This action by exhausting stale air from the building serves to draw fresh air into the building either through the ducts of the system of FIG. 1 or through the cupolas 32 of FIG. 2.
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A ventilating system for a livestock confinement barn in which the outside air is directed against a wall or against other streams of air to destroy direct drafts of air which might chill the enclosed livestock. NAME: Allen W. Meendering TITLE: Livestock Building Ventilator
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to pyrrolidonyl oxazoline compounds, and more particularly, to polymerizable pyrrolidonyl 4,5-unsubstituted oxazoline monomers, homopolymers thereof having advantageous complexation and solubilization properties, and copolymers with other monomers.
2. Description of the Prior Art
Polyvinylpyrrolidone (PVP) is a well known synthetic polymer having properties which are suitable for many pharmaceutical, cosmetic, clinical and industrial uses. An important property of PVP is an ability to form complexes with a variety of compounds, such as iodine, phenolic materials, dyes etc.
Other useful properties of PVP include water solubility, adhesion to many substrates, suspending and emulsifying capabilities, relative inertness, ability to form clear brittle films from various solvents, and its non-toxicity.
However, PVP is not without its deficiencies. Some of these include a high glass transition temperature, Tg, of 175° C. and a high melt viscosity, which preclude its use in thermoplastic forming operations; an amorphous structure; non-biodegradability, which prevents complete elimination from the body after intravenous administration; and steric crowding between the pyrrolidone lactam ring and the hydrocarbon backbone of the polymer which limits its complexation with other molecules when dipole-dipole interactions are involved.
Accordingly, it is an object of the present invention to provide new and improved pyrrolidone-containing polymers.
The literature has disclosed two pyrrolidonyl 4,4'-dimethyl substituted oxazoline compounds for use as an intermediates in the synthesis of medicinal drugs [Zoretic, P.A. J. Org. Chem. 45, No. 5, 810-814 (1980) and Zoretic, P.A. J. Org. Chem. 42, No. 19, 3201-3203 (1977)]. However, the presence of the dimethyl substituent group in the oxazoline ring is known to preclude its polymerization into polymeric materials [Levy, A. J. Poly. Sci Part 1-A 6, 57-62 (1968)].
Accordingly, it is another object of this invention to provide polymerizable monomers of pyrrolidonyl oxazolines, and homopolymer and copolymers thereof.
A particular object herein is to provide a polymerizable pyrrolidonyl 4,5-unsubstituted oxazoline monomer and a homopolymer thereof having a lactam ring which is spaced away from the hydrocarbon backbone of the polymer, thus avoiding the steric crowding deficiency of PVP.
Still another object of the invention is to provide pyrrolidonyl oxazoline polymers having two amide moieties per repeat unit to enhance its complexation properties.
Among the other objects herein is to provide advantageous processes for the homopolymerization and copolymerization of the monomer compounds of the invention.
SUMMARY OF THE INVENTION
What is provided herein are:
A. Polymerizable Monomers
Pyrrolidonyl 4,5-unsubstituted oxazolines having the formula: ##STR1## where m is 0 to 4 and R is hydrogen or lower alkyl; preferably m is 0 and R is methyl; e.g. 2-(1-methyl-2-pyrrolidon-4-yl)-2-oxazoline; or ##STR2## where m is 0-4; e.g. 1-](2-oxazolin-2-yl)methyl]-2-pyrrolidone, where m=1.
B. Homopolymers of A
Pyrrolidonyl 4,5-unsubstituted oxazolines are polymerized to form homopolymers having the formula: ##STR3## where n is an integer having a value of from 10 to 50,000; or ##STR4## where n is as defined above.
C. Copolymers of A with Comonomers
Comonomers are copolymerized with pyrrolidonyl 4,5-unsubstituted oxazoline monomers to provide useful copolymers.
D. Properties
The polymers of the invention have
(1) excellent hydrotropic properties thus increasing the water solubility of many drugs and other organic compounds previously considered as water insoluble;
(2) effective complexation properties with iodine, phenolic and carboxylic acid compounds; and
(3) water solubility.
DETAILED DESCRIPTION OF THE INVENTION
In accordance with the present invention, there is provided herein polymerizable pyrrolidonyl 4,5-unsubstituted oxazoline monomers, homopolymers and copolymers.
1. Polymerizable Monomers
The monomer compounds of the present invention are readily synthesized by a commercially feasible and economic process. In general, the process comprises condensing pyrrolidone carboxylic acids (I) and (II) with ethanolamine (III) to form the corresponding hydroxyamide intermediates (IV) and (V), respectively, which in turn are cyclodehydrated to form the desired oxazoline monomers (VI) and (VII), respectively. ##STR5##
In the case of 2-(1-methyl-2-pyrrolidon-4-yl)-2-oxazoline the starting material (I) (R=CH 3 , m=0) is provided by reaction between itaconic acid and methyl amine and elimination of water.
The above reactions can be conveniently carried out in a one-pot synthesis. The condensation reaction is carried out at a temperature of about 70°-150° C. under atmospheric pressure or pressures up to about 500 psig for a period of about 10-20 hours. Cyclodehydration is effected at a pot temperature of about 230°-260° C. (vapor temperature of about 110°-170° C.) under reduced pressure.
Although these reactions can be effected in the absence of a solvent, it is recommended that an inert liquid, such as xylene, toluene or other inert liquid be employed. These solvents form an azeotrope with water which is utilized to remove the by-product in order to increase the overall yield of the reaction.
In a similar manner, pyroglutamic acid, i.e. 5-oxo-2-pyrrolidinecarboxylic acid, where R=H and m=0 in the above formula (I), can be condensed with ethanolamine and cyclodehydrated to form the corresponding monomer 2-(2-pyrrolidon-5-yl)-2-oxazoline.
1-[(2-oxazolin-2-yl)methyl]-2-pyrrolidone, for example, can be obtained by condensation of pyrrolidone and chloroacetic acid to form 2-pyrrolidone acetic acid, where m=1 in the above formula (II), or, alternatively, by condensing butyrolactone with glycine, and the starting carboxylic acid condensed with ethanolamine and cyclodehydrated to form
1-[(2-oxazolin-2-yl)methyl]-2-pyrrolidone.
2. Homopolymers
A. Preparation
The pyrrolidonyl 4,5-unsubstituted oxazoline monomer (VI) can be homopolymerized to form polymer (VIII), as shown below: ##STR6##
The polymerization reaction is carried out cationically with an initiator such as an alkyl halide, a boron-fluorine compound, a antimony-fluorine compound, an oxazoline salt of a strong acid, a strong acid or an ester of a strong acid. Typical polymerization initiators include dimethyl sulfate and methyl p-toluenesulfonate. In general, the polymerizations of the present invention are carried out in solutions of (VI) and the initiator at a temperature between about 60° C. and 170° C.
The following polymerization can be carried out in a similar manner. ##STR7##
B. Structure
The polymers of the invention are characterized by a pendant pyrrolidonyl group which is spaced away from the backbone of the polymer, and two amide groups per repeat unit. One amide group comes from the oxazoline ring; its nitrogen atom is included in the polymer backbone, while its carbonyl group is located outside the backbone and is available for hydrogen bonding with other compounds or ions. The second amide group is present in the pyrrolidonyl ring, and it is sterically unhindered and is available for dipole-dipole interactions and hydrogen bonding.
C. Properties
The polymers of this invention have a number average molecular weight ranging between about 1,600 and about 8,500,000, preferably about 10,000 and 100,000 depending upon the catalyst, and reaction temperature and time.
The polymeric products of this invention form complexes with a wide variety of components including phenolics and other compounds having an acidic hydrogen, such as benzoic acid and salicylic acid. Insoluble compounds are rendered water soluble through the formation of complexes with the present polymers, and toxic compounds, in the complexed form, become less irritating.
Having thus generally described the invention, reference is now had to the accompanying examples which set forth preferred embodiments but which are not to be construed as limiting to the scope of the invention as more broadly defined above and in the appended claims.
EXAMPLE 1
Preparation of 2-(1-Methyl-2-Pyrrolidon-4-yl-) -2-Oxazoline Monomer (MPO)
A. Starting Material
A 5-liter, 4-necked flask equipped with stirrer, cooling (ice water) bath, addition funnel, thermometer, and dry ice condenser was charged with 1310 g. (10.1 mol) of itaconic acid, and 1500 ml. of xylene. Then 800 g. of a 40% aqueous methylamine solution was added dropwise with stirring over a one-hour period while keeping the temperature between 22° and 28° C. The reaction mixture was then stirred for 12 hours at room temperature. The reaction flask was then fitted with a Deal-Stark receiver, reflux condenser and electric heating mantle, and a total of 661 g. of water (660 g. expected) was removed azeotropically over a period of 13 hours. During this period, the reflux temperature rises to 135° C. from 104° C. The reaction product was subjected to GC analysis which indicated that 1-methyl-5-oxo-3-pyrrolidinecarboxylic acid was the major product.
B. Condensation
The flask then was cooled to 115° C. and 763 g. (12.5 mol) of ethanolamine was added gradually over about 1.5 hrs. with stirring. Upon completion of the addition, the solution was left overnight. 260 ml. of an expected 360 ml. water was removed azeotropically over a 12-hour period. 360 ml. of water is the total expected for complete conversion to the oxazoline.
C. Cyclodehydration
The xylene was distilled off at atmospheric pressure and the temperature of the pot was allowed to rise to 155° C. Part of this crude material (685 g.) was vacuum distilled (230°-260° C., 0.1 mm Hg) to yield 241 g. of MPO (liquid; 91% purity).
EXAMPLE 2
Polymerization of MPO
Preparation of Poly[2-(1-Methyl-2-Pyrrolidon-4-yl)-2-Oxazoline] (PMPO)
A charge of 20 ml. of MPO and 0.044 g. of methyl-p-toluenesulfonate was prepared under a nitrogen atmosphere. Then the reaction mixture was added to a tube which was sealed off under vacuum. The tube was then heated according to the following schedule:
______________________________________Temperature (°C.) Time (hr.)______________________________________ 60 16 70 24 80 30.5 90 41.5100 8110 15120 8130 17140 8150 15.5160 24170 8______________________________________
The solid polymer obtained had a relative viscosity in water (1% solution, 25° C.) of 1.63. The absolute molecular weight of the material, as determined by vapor phase osmometry, was 12,100 and Tg was 150° C.
EXAMPLE 3
Copolymerization of MPO
Copolymers with 2-Ethyl-2-Oxazoline
A one-liter flask equipped with a condenser and a nitrogen purge was charged with 100 g. of MPO (purity greater than 99%, as determined by GC), 100 g. of 2-ethyl-2-oxazoline, 400 g. of N-methylpyrrolidone solvent, and methyl p-toluenesulfonate initiator (500:1 molar ratio of MPO to initiator). The reaction mixture then was heated at 100° C. for 20 hours and then at 130° C. for 6.5 hours. At this point, no further change in the infrared spectrum of the mixture was noted. The copolymer product was isolated by precipitation with diethyl ether. The polymer has a relative viscosity in water of 1.38 (1% aqueous solution at 25° C.).
The copolymer exhibited solubility properties in organic solvents (ethanol, acetonitrile, methylene chloride, chloroform, ethyl acetate, 2-butanone and acetone) between those shown by its component homopolymers. Accordingly, a homopolymer of 2-ethyl-2-oxazoline (PEOX 50-Dow) (relative viscosity in water of 1.38) was soluble, while PMPO was insoluble, in these solvents. A 50:50 mixture of the two homopolymers also was insoluble in the listed solvents. The copolymer on the other hand, was soluble in ethanol, acetonitrile, methylene chloride and chloroform and insoluble in ethyl acetate, 2-butanone and acetone.
EXAMPLE 4
Complexation of PMPO with Organic Compounds
1. Phenol
The extent of complexation of phenol by PMPO was measured as a percent change of phenol absorbance, A, at 277 nm. The tests solutions were prepared from 25 ml. of 0.5% aqueous phenol in 25 ml. of water saturated heptane with and without 2.5 g. of polymer. The absorbance in the case of the sample containing polymer was corrected by subtracting the absorbance of a mixture containing 25 ml. water, 25 ml. water-saturated heptane and 2.5 g. polymer.
The test solutions were agitated until undissolved polymer was no longer visible (1 hour). The phases were allowed to separate overnight. The polymer has a negligible solubility in the heptane layer. 1 ml. of the heptane layer then was diluted with 10 ml. of water--saturated heptane and its absorbance at the phenol band of 277.5 nm was measured. The % decrease in phenol absorbance upon addition of polymer is calculated.
The results are summarized below.
______________________________________ Corrected Test AbsorbanceTest No. Solution A % Decrease in A______________________________________1 phenol/ 0.965 -- heptane2 phenol/ 0.507 47.5 heptane/ PMPO3 phenol/ 0.530 44.0 heptane/ PVP-30______________________________________
These test results shown that the polymer of the invention exhibits a high degree of complexation with phenol and is somewhat higher than PVP itself.
2. Benzoic Acid
The above phenol experiment was repeated using 0.2% benzoic acid and absorbance was measured at 274 nm. The % decrease in absorbance of benzoic acid in the presence of PMPO (relative viscosity 1.54) was 58%. A control PVP C30 polymer also was 58%.
3. Salicylic Acid
The above phenol experiment was repeated using 0.2% salicyclic acid and absorbance was measured at 312 nm. The % decrease with PMPO (relative viscosity 1.54) was 86% whereas PVP C30 was only 83%.
4. Iodine
10 g. of PMPO polymer, 1.3333 g. of iodine and 0.8725 g. of potassium iodide were added to 87.7942 g. of water and stirred overnight. The weight ratio of total iodine to polymer was 0.2, and the weight ratio of molecular iodine to iodide was 2:1. The weight percentage of the polymer-iodine complex was 12% (neglecting potassium). The solution was filtered and 20.83 g. of solution was weighed out and diluted to 25 g. total with distilled water. One ml of sample solution was added to a 2 oz. bottle and 25 ml. of water-saturated heptane was added. The tests were performed in duplicate. The bottles were shaken vigorously for two minutes and the phases allowed to separate. The absorbance of the heptane phase at 515 nm (I 2 ) versus a water-saturated heptane blank (1 cm. cell) was determined on a Perkin-Elmer 559A UV/VIS spectrophotometer. The absorbance measurements were performed in duplicate. The results are shown below.
______________________________________SOLUTION ABSORBANCE______________________________________1 0.252 Average 0.251 Absorbance2 0.242 = 0.248 0.246______________________________________
The same experiment was performed in the absence of PMPO. Upon filtration, insoluble iodine could be seen in the filter; this was not the case when polymer was present. Thus, PMPO in this instance acts to solubilize iodine. The absorbance of the heptane phase was 0.745; the presence of PMPO reduces the amount of I 2 which can be extracted showing complexation.
EXAMPLE 5
Solubilization of Furosemide by PMPO
Furosemide is a drug which is substantially insoluble in water at room temperature (0.06%). A 0.5% solution of the drug in 40% aqueous solution of PMPO (relative viscosity of 1.23) was observed to be clear at room temperature indicating solubilization of the insoluble compound by the polymer of the invention.
While the invention has been described with particular reference to certain embodiments thereof, it will be understood that changes and modifications may be made which are with the skill of the art. Accordingly, it is intended to be bound by the following claims only, in which:
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What is described herein are polymerizable pyrrolidonyl 4,5-unsubstituted oxazoline monomers, homopolymers thereof, and copolymers with other monomers. A preferred polymerizable monomer compound is 2-(1-methyl-2-pyrrolidon-4-yl)-2-oxazoline. The polymers herein have excellent hydrotropic properties thus increasing the water solubility of organic compounds previously considered as water insoluble, and exhibit complexation with water soluble cosolutes.
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[0001] The present application claims priority from Japanese applications JP2006-182951 filed on Jul. 3, 2006, the content of which is hereby incorporated by reference into this application.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a liquid crystal display device, and more particularly to a technique which is effectively applicable to a direct backlight used in a liquid crystal display device.
[0003] A TFT (Thin Film Transistor)-method liquid crystal display module has been popularly used as a display device of a liquid crystal television receiver set, a personal computer or the like.
[0004] The liquid crystal display module is constituted of a liquid crystal panel which arranges a drain driver and a gate driver on a periphery thereof and a backlight which radiates light to the liquid crystal panel.
[0005] The backlight is roughly classified into the side-light backlight and a direct backlight. Recently, along with remarkable spreading of liquid crystal television receiver sets, large sizing and the acquisition of large screen have been in progress with respect to a liquid crystal display module used in a liquid crystal television receiver set or the like. In such a large-sized and large-screen liquid crystal display module, the direct backlight which can acquire high brightness is adopted.
[0006] As a light source of the direct backlight, a cold cathode fluorescent lamp (CCFL) has been dominantly used. Although the CCFL exhibits a long life time, a tube diameter of the CCFL is small and hence, along with the progress of large-sizing of a screen, it becomes difficult to adopt the CCFL as the light source. Accordingly, recently, to sufficiently cope with the large-sized large-screen liquid crystal display module, there exists a demand for the application of a hot cathode fluorescent lamp (HCFL).
[0007] The HCFL possesses a large tube diameter compared to the CCFL and exhibits high brightness and hence, the HCFL can realize a backlight for a large screen with the number smaller than the number of the CCFL. However, since the number of the HCFL is small, there arises a drawback on brightness irregularities.
[0008] As means which can efficiently reduce the brightness irregularities when the number of fluorescent lamps is small, there has been proposed a technique which arranges the fluorescent lamps non-uniformly to achieve the brightness distribution in which the center of the screen exhibits high brightness and a peripheral portion of the screen exhibits the low brightness.
[0009] Further, as another means to overcome the brightness irregularities of fluorescent lamps, there has been known an example which uses a light curtain (see following patent document 1).
[Patent Document 1] JP-A-2005-117023
SUMMARY OF THE INVENTION
[0010] In an attempt to realize the distribution which exhibits high brightness at the center of the screen using the HCFL, due to the relationship between the brightness and the size, the use number of fluorescent lamps becomes smaller than the use number of the CCFL and hence, it is difficult to achieve the high brightness at the center of the screen by merely changing the arrangement position of the fluorescent lamps. Accordingly, the use of the light curtain with the fluorescent lamps is considered.
[0011] Most of the above-mentioned conventional light curtains have been studied on a premise that the CCFL is used as the fluorescent lamp. However, in the CCFL which exhibits low brightness efficiency, the use of the light curtain lowers the brightness and hence, the CCFL tends to object to the use of the light curtain and avoid the use of the light curtain per se. To the contrary, the HCFL can acquire the sufficiently high brightness and hence, the HCFL can acquire the sufficient brightness even when the light curtain is used.
[0012] However, the light curtain described in the above-mentioned example of the related art is a technique which makes the brightness uniform by controlling the distribution of transmissivity using a dot pattern having dots of different diameters. Such a dot pattern is, when the high brightness light source having a tube diameter which exceeds 10φ, for example, the HCFL is used, insufficient to make the brightness uniform. This is because that the dot pattern is usually formed by printing a reflective material and hence, density in printing is limited. When the tube diameter is large, a quantity of light which is radiated from one tube is large and hence, a quantity of light radiated directly above the tube is increased. However, in the dot pattern which has a limit in density, the dot pattern cannot sufficiently block light from the light source having the large tube diameter and hence, a portion above the tube becomes light thus giving rise to brightness irregularities. Accordingly, it is difficult to achieve the uniformity of brightness with the high brightness light source unless not only the light curtain but the arrangement position of the fluorescent lamp are taken into consideration.
[0013] Accordingly, it is an object of the present invention to provide a technique which can acquire both of high efficiency and thin and uniform thickness in a liquid crystal display device which includes a direct backlight which is formed of a high brightness light source such as an HCFL.
[0014] The above-mentioned and other objects and novel features of the present invention will become apparent from the description of this specification and attached drawings.
[0015] To briefly explain the summary of typical inventions among the inventions disclosed in this specification, they are as follows.
[0016] In a liquid crystal display device which includes a liquid crystal panel and a backlight unit which is arranged on a side of the liquid crystal panel opposite to a display screen of the liquid crystal panel, the backlight unit includes a housing, a plurality of light sources arranged in the inside of the housing, and a diffusion plate which is arranged between the plurality of light sources and the liquid crystal panel, the diffusion plate includes a plurality of light blocking regions at positions corresponding to the plurality of respective light sources, and the light blocking region at a center portion of the housing and the light blocking region at an edge portion of the housing exhibits transmissivities different from each other.
[0017] Further, in a liquid crystal display device which includes a liquid crystal panel and a backlight unit which is arranged on a side of the liquid crystal panel opposite to a display screen of the liquid crystal panel, the backlight unit includes a housing, a plurality of light sources arranged in the inside of the housing, a diffusion plate which is arranged between the plurality of light sources and the liquid crystal panel, and an intermediate plate which is formed between the plurality of light sources and the diffusion plate, the intermediate plate includes a plurality of light blocking regions at positions corresponding to the plurality of respective light sources, and the light blocking region at a center portion of the housing and the light blocking region at an edge portion of the housing exhibits transmissivities different from each other.
[0018] Further, the light source is a hot cathode fluorescent lamp (HCFL).
[0019] The light blocking regions are formed by crest-like prisms which are parallel to the longitudinal direction of the light sources.
[0020] Further, the plurality of light blocking regions are formed of a plurality of rectangular reflection patterns and the reflection pattern forming area is set narrower in the light blocking region at the housing edge portion than the light blocking region at the center portion of the housing.
[0021] According to the present invention, even when the light source of high brightness such as HCFL is used, it is possible to provide a liquid crystal display module having high brightness uniformity.
BRIEF DESCRIPTION OF THE DRAWING
[0022] FIG. 1 is a perspective view of a liquid crystal display module of the present invention;
[0023] FIG. 2 is a cross-sectional view of FIG. 1 ;
[0024] FIG. 3 is a view showing the distribution of light of respective constitutional elements of this embodiment;
[0025] FIG. 4 is a top plan view of a diffusion plate 3 ;
[0026] FIG. 5 is a view showing details of a light blocking region 7 (above fluorescent lamp on the center side);
[0027] FIG. 6 is a view showing details of a light blocking region 7 (above fluorescent lamp on an edge side);
[0028] FIG. 7 is a view showing details of a light blocking region 7 (above fluorescent lamp on the center side);
[0029] FIG. 8 is a view showing details of a light blocking region 7 (above fluorescent lamp on an edge side);
[0030] FIG. 9 is a view showing another example of the light blocking region 7 ;
[0031] FIG. 10 is a view showing details of a light blocking region 7 (above fluorescent lamp on the center side);
[0032] FIG. 11 is a view showing details of a light blocking region 7 (above fluorescent lamp on an edge side); and
[0033] FIG. 12 is a cross-sectional view of the embodiment which includes an intermediate plate 9 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0034] Hereinafter, embodiments of the present invention are explained in detail in conjunction with drawings.
[0035] Here, in all drawings for explaining the embodiments, parts having identical functions are given same symbols and their repeated explanation is omitted.
[0036] FIG. 1 is a perspective view showing the main constitution of a liquid crystal display module of the embodiment of the present invention, and FIG. 2 is a cross-sectional view of FIG. 1 .
[0037] In these drawings, numeral 1 indicates a liquid crystal panel, numeral 2 indicates an optical film such as a prism sheet or a diffusion sheet, numeral 3 indicates a diffusion plate, numeral 4 indicates a housing in which a light source 5 is mounted. A plurality of light sources 5 are mounted in the housing 4 , in this embodiment, an HCFL is used as the light source 5 . In case of a display of 32 inches, 4 to 6 pieces of tubes having diameter of 16 mm are mounted in the housing 4 . In this embodiment, an example in which 5 pieces of tubes are mounted in the housing 4 is described. Further, in the inside of the housing 4 , a reflection sheet 6 which reflects light from the light sources 5 is arranged. Light blocking regions 7 are formed on the diffusion plate 3 corresponding to mounting positions of the above-mentioned light sources 5 .
[0038] Here, the distribution of light of the respective constitutional elements of this embodiment is shown in FIG. 3 . This drawing shows only a half from the center to an end portion. The constitution of an opposite side not shown in the drawing also has the same constitution in symmetry.
[0039] FIG. 3(D) shows the light sources, wherein distances between respective fluorescent lamps and a distance between the fluorescent lamp and an edge of the housing are indicated as L 1 to L 3 . In this embodiment, these distances are set to a substantially equal pitch. To be more specific, L 1 =L 2 ≅L 3 (L 3 >L 2 /2). It is needless to say that there may be a case that the distances is set to satisfy a relationship of L 1 ≠L 2 ≠L 3 , and particularly, L 1 <L 2 , L 1 ≠L 2 ≠L 3 . For example, when the HCFL is used as the fluorescent lamp, the distances are set such that L 1 =65 mm, L 2 =67 mm, and L 3 =68 mm. To the contrary, when a CCFL is used as the fluorescent lamp, the distances are set such that L 1 =L 2 ≅L 3 =approximately 20 to 25 mm. The illumination distribution when the light radiated from these light sources arrives at the diffusion plate 3 is shown in FIG. 3(C) . Luminances above the center fluorescent lamp and above the fluorescent lamps adjacent to the center fluorescent lamp exhibit a shape which substantially conforms to a cross section of the tube. However, with respect to the illumination above the fluorescent lamp on the edge side, there is no fluorescent lamp close to the edge side and a space spreads and hence, the luminance is gradually lowered toward the edge side. The diffusion plate 3 is provided for overcoming such irregularities of luminance. FIG. 3(B) shows the transmissivity distribution of the diffusion plate 3 . Further, FIG. 3(A) shows the brightness distribution of the light which arrives at the liquid crystal panel 1 . The transmissivity distribution of the diffusion plate 3 is configured to possess the brightness distribution such that the brightness in the vicinity of the center is high as shown in FIG. 3(A) .
[0040] To be more specific, the transmissivity ( FIG. 3(B) ) of the diffusion plate 3 of this embodiment is configured to possess not only the distribution which reverses the contrast of the illuminance distribution shown in FIG. 3(C) but also possesses transmissivities which differ between the position above the center fluorescent lamp and the position above the fluorescent lamp on the edge side. Accordingly, widths and transmissivities of the plurality of light blocking regions 7 formed on the diffusion plate 3 are formed with adjustment at respective regions to realize the transmissivities shown in FIG. 3(B) .
[0041] The HCFL used in this embodiment exhibits the larger distance than the CCFL. Further, the HCFL radiates more light from one fluorescent lamp than the CCFL. Accordingly, the brightness is extremely increased right above the tube. Further, as described in this embodiment, from an optical point of view, the tube is arranged close to the center (according to the rough approximation, an optical system is folded by the reflection sheet 6 and hence, the tubes are optically uniformly arranged such that L 1 =L 2 , L 3 =L 1 /2). Accordingly, there exists a drawback that a periphery of the edge portion becomes dark. A technique which overcomes this drawback is explained hereinafter.
[0042] FIG. 4 is a top plan view of the diffusion plate 3 . As shown in the drawing, the light blocking region 7 is formed right above the fluorescent lamps corresponding to the number of the fluorescent lamps. The respective light blocking regions 7 can be realized by forming the diffusion plate 3 such that the transmissivities shown in FIG. 3(B) are acquired. For example, the light blocking region 7 at the center is formed to acquire the transmissivity of a portion (a) in FIG. 3(B) , and the light blocking region 7 on the edge side is formed to acquire the transmissivity of a portion (b) in FIG. 3(B) . Further, although distances are formed between the respective light blocking regions 7 in this drawing, the distances are not always necessary and the respective light blocking regions 7 may be continuously formed.
[0043] Hereinafter, examples of light blocking regions 7 for realizing the transmissivities shown in FIG. 3(B) are explained as embodiments 1 to 4.
Embodiment 1
[0044] As an embodiment 1, the detail of the light blocking regions 7 used in this embodiment is explained in conjunction with FIG. 5 and FIG. 6 . FIG. 5 is an enlarged view of the light blocking region 7 at a position SA 1 (above a center-side fluorescent lamp) shown in FIG. 4 , and FIG. 6 is an enlarged view of the light blocking region 7 at a position SA 2 (above an edge-side fluorescent lamp) shown in FIG. 4 . FIG. 5(A) and FIG. 6(A) are top plan views, and FIG. 5(B) and FIG. 6(B) are cross-sectional views. In the light blocking region 7 of this embodiment, the diffusion plate 3 is formed into a prism shape in which a plurality of crest shapes are continuously connected, wherein a size (width) of the crest differs between a center portion and a peripheral portion of the diffusion plate 3 . Further, lateral straight lines (ridges) of respective crests are set to an equal length.
[0045] In FIG. 5 , a large number of crests having the small width are formed, while in FIG. 6 , a large number of crests having the wide width are formed. Although the light blocking region 7 above the fluorescent lamp between the position SA 1 (above the center-side fluorescent lamp) and the position SA 2 (above the edge-side fluorescent lamp) is not shown, by forming the light blocking region into a prism having a crest shape of a size equal to the size of the prism at the position SA 1 or a size between the sizes of the prisms at the positions SA 1 , SA 2 , it is possible to ensure the continuity of the transmissivity.
[0046] Due to such a constitution, it is possible to change the transmissivity between the position SA 1 above the center-side fluorescent lamp and the position SA 2 above the edge-side fluorescent lamp.
[0047] As can be also understood from FIG. 6 , the shape of the light blocking region 7 on the position SA 2 side is formed in left-and-right asymmetry with respect to the light source 5 . Particularly, the light blocking region 7 is formed in the crest shape which widely extends to the edge side. Due to such a constitution, it is possible to realize the higher transmissivity at the edge side.
[0048] Further, with respect to the shapes of the respective crests, the ridges may be formed not only in a straight line but also in a line which changes a curvature thereof. For example, the ridges may be formed into a spherical lens shape or an aspherical lens shape.
Embodiment 2
[0049] Next, as an embodiment 2, another example of the light blocking region 7 is shown. FIG. 7 is an enlarged view of the light blocking region 7 at the position SA 1 (above a center-side fluorescent lamp) shown in FIG. 4 , and FIG. 8 is an enlarged view of the light blocking region 7 at the position SA 2 (above an edge-side fluorescent lamp) shown in FIG. 4 . In this embodiment, the light blocking region 7 is formed such that lengths of left and right ridges of each crest differ from each other. That is, the ridge on the center side is long and the ridge on the peripheral side is short.
[0050] Further, in this embodiment, in the same manner as the embodiment 1, a large number of crests having the small width are formed in FIG. 7 , while a large number of crests having the wide width are formed in FIG. 8 . Due to such a constitution, it is possible to change the transmissivity between the position SA 1 above the center-side fluorescent lamp and the position SA 2 above the edge-side fluorescent lamp.
[0051] As can be also understood from FIG. 8 , the shape of the light blocking region 7 on the position SA 2 side is, in the same manner as the embodiment 1, formed in left-and-right asymmetry with respect to the light source 5 , wherein the light blocking region 7 is formed in the crest shape which widely extends to the edge side. Due to such a constitution, it is possible to realize the higher transmissivity at the edge side.
Embodiment 3
[0052] Next, as the embodiment 3, another example of the light blocking region 7 is shown in FIG. 9 . In the above-mentioned embodiments 1, 2, the light blocking region 7 is formed of the prism having the crest shape only in cross section in the direction perpendicular to the fluorescent lamp. In this embodiment, the light blocking region 7 is formed of a prism having a crest shape in cross sections in two directions. That is, in the perpendicular direction as well as in the parallel direction with respect to the fluorescent lamp.
[0053] Also in this embodiment, by forming a large number of crests having a small width at the position SA 1 (above the center-side fluorescent lamp) and a large number of crests having a wide width at the position SA 2 (above the edge-side fluorescent lamp), it is possible to change the transmissivity between the position SA 1 above the center-side fluorescent lamp and the position SA 2 above the edge-side fluorescent lamp.
[0054] Further, the prism shape can be formed two-dimensionally and hence, the number of faces which reflect light is large whereby the further uniformity can be expected.
Embodiment 4
[0055] Next, as the embodiment 4, another example of the light blocking region 7 is explained in conjunction with FIG. 10 and FIG. 11 . In the above-mentioned embodiments 1 to 3, the example which forms the light blocking region 7 into the prism shape is explained. In this embodiment, the position distribution of transmissivity is controlled based on area gray scales of a reflection pattern 8 by forming the reflection pattern 8 made of aluminum or the like on the diffusion plate 3 by vapor deposition. Here, provided that a material of the reflection pattern 8 exhibits high reflectance, any material can be used. FIG. 10 is a view showing the light blocking region 7 at the position SA 1 (above a center-side fluorescent lamp), and FIG. 11 is a view showing the light blocking region 7 at the position SA 2 (above an edge-side fluorescent lamp). By forming a large number of reflection patterns 8 having a wide width at the position SA 1 (above the center-side fluorescent lamp) and a large number of the reflection pattern 8 having a narrow width at a position SA 2 (above the edge-side fluorescent lamp), it is possible to change the transmissivity between the position SA 1 above the center-side fluorescent lamp and the position SA 2 above the edge-side fluorescent lamp.
[0056] As can be also understood from FIG. 11 , the shape of the light blocking region 7 on the position SA 2 side is formed in left-and-right asymmetry with respect to the light source 5 . Particularly, the narrower reflection pattern 8 is formed at the edge side. Due to such a constitution, it is possible to realize the higher transmissivity at the edge side. Further, to enhance the transmissivity at the edge side, the reflection pattern 8 on a side closer to the edge than the light source 5 in FIG. 11 may not be formed.
[0057] In the embodiments explained heretofore, the examples which form the light blocking region 7 on the diffusion plate 3 arranged right below the optical sheet 2 are shown. Next, a constitutional example other than the above-mentioned example is explained as an embodiment 5.
Embodiment 5
[0058] The constitution of this embodiment is shown in FIG. 12 . In this embodiment, an intermediate plate 9 is newly arranged between a diffusion plate 3 and a light source 5 , and light blocking regions 7 are formed on the intermediate plate 9 . The intermediate plate 9 per se is formed of a material having a high transparency (an acrylic plate, a diffusion plate having a high total light transmissivity or the like) and, at the same time, the intermediate plate 9 is arranged in a spaced-apart manner from the diffusion plate 3 and the light source 5 . The relationship between a total light transmissivity T 1 of the diffusion plate 3 and a total light transmissivity T 2 of the intermediate plate 9 except for the light blocking regions 7 is set to T 2 >T 1 . To be more specific, the total light transmissivity T 1 is 50 to 60%, and the total light transmissivity T 2 is approximately 70%. This relationship is adopted for allowing light which is reflected on a reflection sheet 6 arranged in the inside of a housing 4 to be radiated to an intermediate space defined between the light sources from the intermediate plate 9 as much as possible. The constitutions shown in the above-mentioned embodiments 1 to 4 may be applicable to a shape of the light blocking regions 7 . Further, the closer the intermediate plate 9 is arranged to the light source 5 , the light blocking region 7 can be arranged closer to the light source 5 and hence, the brightness can be made uniform to some extent at a position close to the light source 5 and, at the same time, the brightness can be made further uniform between the intermediate plate 9 and the diffusion plate 3 . For example, when the HCFL having a diameter of 16 mm is used as the light sources 5 , by setting a distance between the fluorescent lamp and the intermediate plate 9 to approximately 3 mm, the transmissivity distribution of the respective light blocking regions 7 may be set uniform. In this embodiment, however, to spread the light which is already made uniform to some extent at the intermediate plate 9 between the intermediate plate 9 and the diffusion plate 3 (to enable the radiation of light to a remote place), it is necessary to ensure some distance. To be more specific, when the HCFL having a diameter of 16 mm is used as the light sources 5 , the distance of 10 mm or more becomes necessary.
[0059] In this embodiment, the light blocking regions 7 are arranged close to the light sources 5 and hence, a range that a viewer can directly observe the light sources 5 when the viewer observes in the oblique direction becomes narrow. Accordingly, this embodiment is advantageous for maintaining the brightness uniformity in any viewing angle.
[0060] Further, in this embodiment, in addition to the insertion of diffusion plate 3 between the light sources 5 and the liquid crystal panel, the intermediate plate 9 is inserted between the light sources 5 and the liquid crystal panel and, at the same time, the distance is ensured between the intermediate plate 9 and the diffusion plate 3 and hence, the light can be made uniform in two stages. Accordingly, a uniform light acquisition effect of this embodiment is large and hence, the reduction of thickness of the liquid crystal display module can be realized. To be more specific, in the embodiment which is explained in conjunction with FIG. 2 , it is necessary to set a distance from the bottom surface of the housing 4 to the diffusion plate 3 to 40 mm. However, in this embodiment, the distance from the bottom surface of the housing 4 to the diffusion plate 3 can be set to 30 mm.
[0061] Although the invention made by inventors of the present invention has been specifically explained in conjunction with the embodiments heretofore, it is needless to say that the present invention is not limited to the above-mentioned embodiments and various modifications are conceivable without departing from the gist of the present invention.
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A liquid crystal display device having a direct backlight which uses a high-bright light source achieves both of a high efficiency and thin uniformity. In a liquid crystal display device which includes a liquid crystal panel, and a backlight unit which is arranged on a side of the liquid crystal panel opposite to a display screen of the liquid crystal panel, the backlight unit includes a housing, a plurality of light sources arranged in the inside of the housing, and a diffusion plate which is arranged between the plurality of light sources and the liquid crystal panel, the diffusion plate includes a plurality of light blocking regions at positions corresponding to the plurality of respective light sources, and the light blocking region at a center portion of the housing and the light blocking region at an edge portion of the housing exhibits transmissivities different from each other.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a tool for installing rivets on and a method for connecting tool components, and more particularly, to a quick disconnect assembly for a tool head.
2. Description of the Related Art
Many manufacturing processes employ fasteners or rivets to permanently join one workpiece to another. One common rivet includes a rivet sleeve or body, and a rivet stem which extends through the sleeve with an enlarged head at the end opposite a rivet head on the sleeve.
Typically, to fasten two or more workpieces together, the rivet is placed through a hole in the workpieces such that the underside of the rivet head is flush against the workpiece while the tail of the sleeve and the head on the stem extend beyond the workpiece. While holding the rivet sleeve in place, the rivet stem is pulled axially further into a central bore in the sleeve such that the rivet stem head deforms and expands the tail of the rivet body on the backside of the workpieces. As the tension in the stem increases, the stem eventually breaks at a predefined location such that the stem head and the stem shank remain with the sleeve while the remainder of the stem shank is pulled free and discarded. The rivet is then permanently locked in place by the rivet head on the frontside surface of the workpieces and the expanded rivet body on their backside surface, thereby permanently fastening the workpieces together.
To perform the rivet setting operation described above, specially designed rivet setting tools have been developed that employ pneumatic or hydraulic pressure to actuate the device and set the rivet. While complex mechanically, these pneumatic and hydraulic tools are often preferred because they are stronger, faster, and more consistent than their human-powered counterparts.
One drawback of these devices, however, is that during operation a rivet can get jammed in the head of the rivet setting tool. When this occurs, the rivet setting tool is disabled and cannot operate further until the offending rivet is extracted from the tool head and the rivet setting tool is reset. Because traditional tool heads are attached to the rivet setting tool via screw threads, removal of the tool head requires the operator to use a wrench to loosen the tool head and then unscrew the tool head from the rivet setting tool. Further, a collet within the tool head must be separated from a drawbar, that reciprocates in the tool, before access can be had to the fastener gripping jaws and the obstructing fastener. Attaching a new tool head to the rivet setting tool is accomplished by the reverse operation but properly positioning and holding the jaws and other internal components while attaching the collet to the drawbar, is difficult and time consuming.
While the tool head replacement is being performed, the rivet setting tool is non-operational. If the tool is in an automated production line, this tool shut down creates a bottleneck in the entire production line, resulting in lost time and money. Consequently, the users of pneumatic- and hydraulic-powered rivet setting tools have long been in need of an apparatus and method for quickly rectifying these rivet jams.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide an apparatus and method for quickly and easily disconnecting a fastener installation tool head from a fastener installation tool body and replacing it with a functioning head, allowing a jammed head to be disassembled and unjammed away from the fastener installation site.
Another object of the present invention is to provide an apparatus and method for ensuring that when the fastener installation tool head is connected to the fastener tool installation body, the former is securely locked into its operational position and thereby prevented from either translational or rotational movement.
The present invention achieves these and other objects by providing a novel fastener installation tool head quick disconnect assembly. In a preferred arrangement, this tool head quick disconnect assembly consists of a sleeve assembly and an adapter housing assembly. The adapter housing assembly is rigidly attached to the fastener installation tool body via screw threads. The sleeve assembly is attached to the adapter housing assembly via a latching mechanism on the adapter housing assembly. When the tool operator desires to remove the sleeve assembly from the adapter housing assembly, the operator simply translates the latching mechanism rearwardly, rotates the sleeve assembly a small amount, and pulls the sleeve assembly forward, thereby quickly and easily disengaging the sleeve assembly from the adapter housing assembly. To re-engage the sleeve assembly with the adapter housing assembly, the operator simply reverses the procedure. Connecting the two assemblies includes connecting the rear of a sleeve to the front of an adaptor housing, and simultaneously connecting the rear of a collet in the sleeve to the forward end of a drawbar in the housing.
In a preferred arrangement, the sleeve assembly and the adapter housing assembly of the novel fastener tool head quick disconnect assembly employ two sets of engaging lugs, one of which cooperates with the latching mechanism, to ensure that when the sleeve assembly is connected to the adapter housing assembly, the sleeve mechanism is securely locked into its operational position and thereby prevented from either translational or rotational movement.
Moreover, in a preferred arrangement of the novel tool head quick disconnect assembly, the sleeve assembly contains both a groove/indent feature and opposing flush tapered surfaces for quickly and easily obtaining axial, lateral, and rotational alignment of its internal and external components and for ensuring that these components retain axial, lateral, and rotational alignment at all times during the operation of fastener installation tool. Similarly, the adapter housing assembly contains both a slot/set screw feature and opposing flush tapered surfaces for quickly and easily obtaining axial, lateral, and rotational alignment of its internal and external components and for ensuring that these components retain axial, lateral, and rotational alignment at all times during the operation of fastener installation tool.
The novel fastener tool head quick disconnect assembly greatly facilitates the removal and replacement of a rivet setting tool head. The significant changeover time-saving achieved by using the novel tool head quick disconnect assembly greatly reduces the down time of the fastener installation tool due to rivet jams. The production line is interrupted for far shorter time periods because of tool head changeovers, resulting in significantly increased line productivity and therefore substantial cost savings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a prior art apparatus.
FIG. 2 is a perspective view of a preferred embodiment of the fastener installation tool head quick disconnect assembly in accordance with the present invention.
FIG. 3 is a side elevation cross-sectional view of the fastener installation tool head quick disconnect assembly depicted in FIG. 2.
FIG. 4 is a perspective view of the fastener installation tool head quick disconnect assembly depicted in FIG. 2 with the sleeve assembly removed from the adapter housing assembly.
FIG. 4a is a rear elevation view of the sleeve assembly depicted in FIG. 4.
FIG. 4b is a front elevation view of the adapter housing assembly depicted in FIG. 4.
FIG. 5 is an exploded perspective view of the tool head depicted in FIG. 2, rotated such that the latching mechanism is illustrated.
FIG. 6 is an exploded perspective view of the tool head depicted in FIG. 2, rotated such that the groove/indent and slot/set screw features are illustrated.
The Prior Art
Referring first to FIG. 1, a known fastener installation tool 10 is comprised of two primary components: a tool body 12 and a tool head assembly 14. The assembly 14 includes a sleeve 16 slidably supporting jaws and a collet (not shown) for gripping a fastener stem. The collet is threaded to a drawbar (not shown) which is slidably mounted in the tool body. The sleeve is attached to the tool body 12 via a tool head mounting nut 20 or threaded directly to the tool body 12.
As discussed, during the operation of the tool 10, a rivet (not illustrated) may become undesirably lodged within the jaws within the sleeve 16, thereby obstructing it. In this event, it is typically necessary for the tool operator to remove the sleeve 16 from the tool body in order to remedy the problem. To remove the sleeve 16 from the tool body, a wrench is used to loosen the nut 22, thereby permitting the sleeve 16 to be unscrewed and removed from the tool body 12. However, before the offending rivet can be extracted from the jaws within the collet, the collet must be unthreaded from the drawbar. To reinstall the sleeve 16, the reverse procedure is performed, but as noted above this is a difficult task requiring too much down time for a production line.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 2, a novel fastener installation tool 30 in accordance with the present invention is illustrated. Analogous to the standard fastener installation tool 10, as illustrated in FIG. 1, the novel fastener installation tool 30 is comprised of two primary components: a tool body 32 and a tool head assembly 34. The body 32 of the novel tool 30 is essentially identical to the body 12 of the tool 10, of FIG. 1. The assembly 34 includes a sleeve assembly 36 which unlike the tool in FIG. 1, is attached to the adapter housing assembly 38 via a latching mechanism 42 on the adapter housing assembly 38.
Referring to FIGS. 3-6, the sleeve assembly 36 include a sleeve 44, a nosepiece 46, a collet 48, and a set of jaws 50. The cylindrically shaped sleeve 44 has a forward end to which the nosepiece 46 is threaded. As best illustrated in FIGS. 4 and 4a, located on the exterior surface of the rearward end of the sleeve 44 are three sleeve lugs 54, equally spaced around the perimeter of the sleeve 44, i.e., 120° apart. The rearward exterior surface of the sleeve 44 is tapered inwardly to form a sleeve taper 56 such that the exterior diameter of the rear of the sleeve 44 is at its smallest at the extreme rearward end.
The tubular nosepiece 46 has a central bore 58 running through its axis to accept a rivet stem.
The tubular collet 48 is located within the sleeve 44, immediately rearward of the nosepiece 46. The forward inner surface 60 of the collet 48 is tapered inwardly such that the smallest interior diameter of the collet 48 is at its extreme forward end. As best illustrated in FIGS. 3 and 6, the collet 48 has an axial groove 62 along its exterior surface. This groove 62 mates with rib indents 64 on the interior surface of the sleeve 44, thereby preventing relational rotation of the collet 48 and the sleeve 44 when the collet 48 is inserted into the sleeve 44. The collet 48 is prevented from sliding out of the sleeve 44 by a retaining ring 66.
As best illustrated in FIGS. 3, 4, 4a, and 4b, the rearwardmost interior surface of the collet 48 has three drawbar lug notches 68 to matingly receive three drawbar lugs 70. The notches 68 are equally spaced around the perimeter of the collet 48, i.e., 120° apart. As seen in FIG. 3, on the interior surface of the collet 48 and immediately forward of the notches 68 is channel 72, in which the drawbar lugs 70 are positioned once they have been translated through and cleared the notches 68.
A frustum-shaped set of jaws 50 is positioned within the collet 48 at its forward end. The exterior surface of each of the jaws 50 is tapered inwardly to form a jaws taper 74 such that the smallest exterior diameter of the jaws 50 is at its extreme forward end. The jaws taper 74 is of the identical slope as the collet taper 60 and therefore adapted such that the two opposing tapers fit flush against one another. This "self-centering" feature enables the jaws 50 to quickly and easily assume and retain axial alignment with the collet 48, regardless of their lateral position relative to one another. In addition, the forward end surface of the jaws 50 is tapered to be somewhat concave.
As best illustrated in FIGS. 4a, 5 and 6, the set of jaws 50 is comprised of three independent yet identical jaws, with each jaw comprising one-third or 120° of the entire frustum. As seen in FIG. 3, the jaws 50 contain a central bore 76 that is slightly smaller than the nosepiece central bore 58. Gripping grooves 78 are machined into the inner surface of the jaws central bore 76 in order for the jaws 50 to securely grasp a rivet stem.
A jaw follower 80 is contained entirely within the collet 48 and rests immediately rearward of the jaws 50. The forward end of the jaw follower 80 abuts the rearward surface of the jaws 50. The jaw follower 80 has a jaw bore 82 running through its central axis. The rearward end of the jaw follower 80 is in contact with a jaw spring 84 located within the collet 48. The spring 84 is fixed within the collet 48 by a retaining ring 86. The spring 84 applies axial pressure to the jaw follower 80, which in turn applies axial pressure to the jaws 50. Consequently, the spring 84 forces the jaws 50 to their forwardmost position in which each individual jaw is in intimate lateral contact with the other two jaws. In this forwardmost position, the jaw central bore 76 is at its smallest diameter. The jaw follower central bore 82 is larger than the jaw central bore 76, to allow a broken rivet stem to pass rearwardly through the jaw follower central bore 82.
As best illustrated in FIGS. 3-6, the other principal component of the present invention is the adapter housing assembly 38 including housing 88, a latching mechanism 42, a jaw follower tube 90, and a drawbar 92. The tubular adapter housing 88 receives the sleeve assembly 36 at its forward end of the housing 88 and is fixed to the tool body 32 at its rearward end. As seen in FIG. 3, the interior diameter of the housing 88 at its forward end is only slightly larger than the exterior diameter of the sleeve 44 at its rearward end.
The rearward exterior surface 94 of the housing 88 has threads 94 for attachment to the tool body 32. To remove the adapter housing assembly 38, and thereby the entire tool head quick disconnect assembly 34, from the tool body 32, the mounting nut 40 is loosened to permit the assembly 38 to be unscrewed and removed from the tool body 32. To reinstall the assembly 38, the reverse procedure is performed.
The forward interior surface of the housing 88 has three sleeve lug grooves or notches 96 to matingly receive the three sleeve lugs 54. One of the grooves 96a extends radially through the housing wall and thus is effectively a slot open to the forward edge of the housing. The grooves or notches 96 are equally spaced around the perimeter of the housing 88, i.e., 120° apart. As seen in FIG. 3, on the interior surface of the housing 88 and immediately rearward of the notches 96 is an annular sleeve lug channel 98, in which the lugs 54 are positioned once they have been translated through and cleared the notches 96.
An adapter housing annular taper 100 is located on the interior surface of the housing 88 just rearward of the sleeve lug channel 98. The taper 100 is of the identical slope as the sleeve taper 56 such that the two opposing tapers fit flush against one another. This "self-centering" feature enables the sleeve 44 to quickly and easily assume and retain axial alignment with the housing 88.
As best illustrated in FIGS. 3, 5, and 6, the latching mechanism 42 consists of a latch 102, a latch pin 104, and a latch spring 106. The latch body includes a radially inner portion which fits into an opening 107 in the housing that is open to the rear of groove 96a and opens radially inwardly to the channel 98. The opening also extends rearwardly beyond the channel and its circumferential dimension is greater than that of the groove 96a. The latch radial inner portion fits into the opening 107 but is circumferentially wider than the groove 96a so that forward movement of the latch is limited by the channel wall adjacent the groove 96a. The axial dimension of the latch is less than that of the opening 107 so that the latch can move rearwardly. The radially outer portion of the latch is circumferentially larger than that of the opening 107 so the latch radial inward movement is limited by the radially outer portion engaging the exterior of the housing.
The latch spring 106 is positioned within an axially extending socket 105 in the housing 88 that opens to the opening 107. The pin 109 is also in the socket in front of the spring 106 and extends into a hole in the latch. A shoulder on the pin engages the latch. The spring 106 applies axial pressure to the latch pin 104, which in turn applies axial pressure to the body 102. Consequently, in its resting state, the spring 106 forces the body 102 to its forwardmost position. In this resting position, the interior portion of the body 102 virtually entirely obstructs the upper portion of the sleeve lug channel 98, thereby preventing a sleeve lug 54 from resting within the upper portion of the channel 98 or passing through the uppermost sleeve lug notch 96a. When the latch 102 is translated to its maximum rearward position (either manually or otherwise), the spring 106 is compressed, and the channel 98 is entirely cleared of the obstructing latch, thereby permitting a lug 54 to fit entirely within the channel 98 or to pass through the uppermost notch 96a.
As seen in FIG. 3, the jaw follower tube 90 is composed of a forward jaw follower tube 108 and a rearward jaw follower tube 110. The forward end of the forward tube 108 abuts the jaw follower 80. A bore 112 through the tube 90 is approximately the same diameter as the jaw follower central bore 82, thereby allowing the tail of a rivet stem to pass rearwardly from the jaw follower central bore 82 through the tube 90.
The rearward tube 110 has a smaller outer diameter than the forward tube 108, but the diameter of the bore 112 running through the two components of the tube 90 is essentially identical. The forward portion of the rearward tube 110 is rigidly attached to the rearward portion of the forward tube 108. This rigid attachment can be accomplished by slightly enlarging the diameter of the bore 112 in the rearward portion of the forward tube 108 and then press fitting the forward portion of the rearward tube 110 into this enlarged portion of the bore 112.
A jaw follower tube spring 114 encircles the rearward tube 110 and abuts the rear of the forward tube 108. The rear of the spring 114 engages an inwardly extending annular flange 116a on a tubular drawbar piston 116. The spring 114 applies axial pressure to the forward tube 108, which in turn applies axial pressure to the jaw follower 80. Consequently, in its resting state, the spring 114 forces the tube 90 to its forwardmost position, in which the forward end of the forward tube 108 abuts the jaw follower 80.
As seen in FIG. 3, the tubular drawbar 92 is a critical link between the tool head 34 and the tool body 32. The drawbar 92 is rigidly attached to the drawbar piston 116 via drawbar threads 118. As best illustrated in FIGS. 3, 4, 4a, and 4b, located on the exterior surface of the forward end of the drawbar 92 are the three drawbar lugs 70, equally spaced around the perimeter of the drawbar 92, i.e., 120° apart. These three lugs 70 are matingly received by the corresponding three drawbar lug notches 68 on the rearward interior surface of the collet 48. Once the lugs 70 have been translated through and have cleared the notches 68, the lugs 70 are in the drawbar lug channel 72.
As best illustrated in FIGS. 3, 4b and 6, a single axial drawbar slot 120 is cut through the wall surface of the drawbar 92. The slot 120 runs from an area rearward of the lugs 70 and forward of the threads 118. The slot 120 to mates with a set screw 122 that runs through the side of the housing 88 and protrudes from its interior surface, thereby preventing relative rotation of the drawbar 92 and the housing 88 when the drawbar 92 is in the housing 88.
Assembly of the Components
Referring now to FIGS. 4-6 in conjunction with FIG. 3, the novel manner in which the components of present invention are assembled and the unique way in which its components cooperate with one another to achieve the desired objectives can be described. The draw piston 116 protrudes from the forward end of the tool body 32 being slidably mounted therein and urged rearwardly by the follower spring 114. The jaw follower tube 90 runs through the center of the piston 16 and the tool body 32, extending considerably forward of the piston 116.
The assembly operation is composed of four steps: (1) assembling the adapter housing assembly 38; (2) mounting the adapter housing assembly 38 onto the tool body 32; (3) assembling the sleeve assembly 36; and (4) mounting the sleeve assembly 36 onto the adapter housing assembly 38. To assemble the adapter housing assembly 38, the drawbar 92 is inserted into the rear of the adapter housing 88. The drawbar 92 is positioned within the housing 88 such that the set screw 122 protruding from the inner surface of the housing 88 falls within the axial drawbar slot 120 cut into the surface of the drawbar 92. As illustrated in FIG. 4b, when the set screw 122 is positioned within the drawbar slot 120, the drawbar 92 and the housing 88 are rotationally aligned such that the drawbar lugs 70 and sleeve lug notches 96 are coincident along the same radii.
The next step is to mount the adapter housing assembly 38 onto the tool body 32. Ensuring that the housing 88 and the drawbar 92 remain aligned as describe above, the adapter housing assembly 38 is inserted over the protruding jaw follower tube 90 until the drawbar 92 abuts the piston 116 and the housing 88 abuts the tool body 32. Next, by rotating the adapter housing assembly 38 clockwise, the drawbar threads 118 on the drawbar 92 engage the mating threads on the piston 116 while simultaneously the adapter housing threads 94 on the housing 88 engage the mating threads on the tool body 32. The adapter housing assembly 38 is rotated clockwise until the drawbar 92 is firmly tightened against the piston 116. Finally, the mounting nut 40 is rotated clockwise until it is firmly tightened against the tool body 32, at which time a wrench is used to securely tighten the nut 40. Note that the nut 40 prevents the housing 88 from rotating during operation of the fastener installation tool 30, while the set screw 122 in the drawbar slot 120 prevents the drawbar 92 from rotating during operation of the tool 30.
The third step is to assemble the sleeve assembly 36. The nosepiece 58 is selected and screwed onto the forward end of the sleeve 44. Next, the collet 48 containing jaws, a jaw follower, and a spring is inserted jaws-first into the rearward end of the sleeve 44. Note that the jaws 50, the jaw follower 80, and the jaw follower spring 84 are all held permanently in place within the collet 48 by the jaw spring retaining ring 86.
The collet 48 is positioned within the sleeve 44 such that the rib indents 64 protruding from the inner surface of the sleeve 44 slide within the axial collet groove 62 cut into the surface of the collet 48. As illustrated in FIG. 4a, when the rib indents 64 are positioned within the collet groove 62, the collet 48 and the sleeve 44 are rotationally aligned and fixed such that the drawbar notches 68 and the sleeve lugs 54 are coincident along the same radii. Note that the rib indents 64 in the collet groove 62 prevent the collet 48 from rotating relative to the sleeve 44 during operation of the fastener installation tool 30.
The final step is to engage the sleeve assembly 36 with the adapter housing assembly 38. Ensuring that the sleeve 44 and the collet 48 remain aligned as described above, the sleeve assembly 36 is inserted over the protruding jaw follower tube 90 until the collet 48 abuts the drawbar 92 and the sleeve 44 abuts the housing 88. Next, the sleeve assembly 36 is rotated until the three sleeve lugs 54 on the rearward exterior surface of the sleeve 44 align with the three sleeve lug notches 96 on the forward interior surface of the housing 88. Note that when the sleeve lugs 54 are aligned with the sleeve lug notches 96, the drawbar lugs 70 on the forward exterior surface of the drawbar 92 must necessarily be aligned with the drawbar lug notches 68 on the rearward interior surface of the collet 48. This precise alignment occurs because the drawbar 92 is rotationally aligned with the housing 88 via the set screw 122 and the drawbar slot 120, while the collet 48 is rotationally aligned with the sleeve 44 via the rib indents 64 and the collet groove 62.
As best illustrated in FIGS. 4, 4a and 4b, there are three possible rotational positions in which the sleeve assembly 36 can engage the adapter housing assembly 38, each engagement position 120° from the other two. Once the sleeve lugs 54 have been aligned with the sleeve lug notches 96, and, concomitantly, the drawbar lugs 70 been aligned with the drawbar lug notches 68, the sleeve assembly 36 is pushed rearwardly to positively engage the adapter housing assembly 38. During this operation, the three sleeve lugs 54 pass through the sleeve lug notches 96 and come to rest in the sleeve lug channel 98. Again, concomitantly, the three drawbar lugs 70 pass through the drawbar lug notches 68 and come to rest in the drawbar lug channel 72. A critical event occurs as this engaging operation takes place: The uppermost sleeve lug 54 comes into contact with the latch 102 as that lug begins to enter into the sleeve lug channel 98. As described earlier, in the resting position of the body 102, the interior portion of the body 102 virtually entirely obstructs the upper portion of the sleeve lug channel 98, thereby preventing a sleeve lug 54 from resting within the upper portion of the channel 98 or passing through the uppermost sleeve lug notch 96. When the latch 102 is translated to its maximum rearward position (either manually or otherwise), the latch spring 106 is compressed and the channel 98 is entirely cleared of the obstruction, thereby permitting a sleeve lug 54 to rest entirely within the upper portion of the channel 98 or pass through the uppermost sleeve lug notch 96. Therefore, by applying rearward axial force to the sleeve assembly 36 (or alternatively either manually or automatically translating the body 102 to its maximum rearward position), all three sleeve lugs 54 can come to rest in the sleeve lug channel 98, and, concomitantly, all three drawbar lugs 70 can come to rest in the drawbar lug channel 72.
Another important feature of the invention is relevant here. When the sleeve assembly 36 has been translated rearwardly to its maximum rearward position such that the sleeve lugs 54 rest within the sleeve lug channel 98, the sleeve taper 56 and the adapter housing taper 100 come in intimate contact with one another. As described previously, the adapter housing taper 100 is of the identical slope as the sleeve taper 56, and therefore adapted such that the two opposing tapers fit flush against one another. This "self-centering" feature enables the sleeve assembly 36 to quickly and easily assume and retain axial alignment with the adapter housing assembly 38.
The final step required to engage the sleeve assembly 36 with the adapter housing assembly 38 is to axially rotate the sleeve assembly 36 60° in either a clockwise or a counterclockwise direction. Upon this rotation, the sleeve lugs 54 rotate within the sleeve lug channel 98 and come to rest directly in between the sleeve lug notches 96. At this rotational position, the sleeve assembly 36 cannot be disengaged from the adapter housing assembly 38 because the sleeve lugs 54 are within the sleeve lug channel 98 and do not have any notches 96 through which to pass. Again, concomitantly, upon this rotation, the drawbar lugs 70 rotate within the drawbar lug channel 72 and come to rest directly in between the drawbar lug notches 68. At this rotational position, the collet 48 cannot be disengaged from the drawbar 92 because the drawbar lugs 70 are within the drawbar lug channel 72 and do not have any notches through which to pass.
An important feature of the present invention is that upon rotating the sleeve assembly 36 60°, as described above, the uppermost sleeve lug 54 clears the uppermost portion of the sleeve lug channel 98. When this occurs, the latch spring 106 returns the latch 102 to its resting position, in which the interior portion of the body 102 virtually entirely obstructs the upper portion of the channel 98, thereby preventing a sleeve lug 54 from resting within the upper portion of the sleeve lug channel 98 or passing through the uppermost sleeve lug notch 96. In essence then, the latching mechanism 42 serves to lock the sleeve assembly 36 into rotational position. That is, the sleeve assembly 36 cannot be disengaged from the adapter housing assembly 38 until the latch body 102 is translated to its maximum rearward position. Moreover, the latching mechanism 42 prevents the sleeve assembly 36 from rotating relative to the adapter housing assembly 38 during operation of the fastener installation tool 30.
To disengage the sleeve assembly 36 from the adapter housing assembly 38, all that is required is to translate the latch 102 to its maximum rearward position, thereby clearing the sleeve lug channel 98 and then to axially rotate the sleeve assembly 36 60° in either a clockwise or a counterclockwise direction. Upon this rotation, the sleeve lugs 54 rotate within the sleeve lug channel 98 and come to rest directly in line with the sleeve lug notches 96. At this rotational position, the sleeve assembly 36 can be disengaged from the adapter housing assembly 38 by forwardly translating the sleeve lugs 54 through the sleeve lug notches 96. Indeed, the latching mechanism 42 assists in ejecting the sleeve assembly 36 from the adapter housing assembly 38. Specifically, when the uppermost sleeve lug 54 is positioned within the uppermost portion of the sleeve lug channel 98, the latch 102 is in its maximum rearward position. Consequently, the latch spring 106 is depressed and applies forward axial pressure to the uppermost sleeve lug 54 via the latch pin 104 and the latch 102, thereby forcing the lug 54 out of the channel 98 and through the notch 96a.
Operation of the Tool
Referring again to FIG. 3, the operation of the novel fastener installation tool 30 can now be readily described. When a rivet (not illustrated) is to be installed using the novel fastener installation tool 30, the stem of the rivet is inserted into the nosepiece 46 of the sleeve assembly 36. Because the jaws 50 are initially at their resting state, the jaws central bore 76 is at its smallest diameter, which is slightly smaller than the nosepiece central bore 58. As the rivet stem pushes against the forward tapered surface of the jaws 50, they are pushed rearwardly, and therefore forced open slightly until the rivet stem is able to pass through the jaws 50. The rivet stem passes through the jaws 50 and stops when the rivet head rests firmly against the forward end surface of the nosepiece 46. Because the jaw follower 80 has also been pushed slightly rearwardly, the spring 84 has been compressed somewhat. As a result, the jaw spring 84 applies even greater axial pressure to the jaw follower 80, which in turn applies even greater axial pressure to the jaws 50. Consequently, the jaws 50 firmly grasp the rivet stem. Moreover, the gripping grooves 78 on the interior surfaces of the jaws 50 grasp corresponding grooves on the stem of the rivet to ensure a firm grasp of the rivet stem.
Next, pressurized fluid is applied to the draw piston 116 within the tool body 32 and pulls the piston 116 rearwardly. As described earlier, the drawbar 92 is fixed to the piston 116 via drawbar threads 118. In addition, the collet 48 is engaged with the drawbar 92 because the drawbar lugs 70 are locked into their operational position within the drawbar lug channel 72 in the collet 48. Consequently, as a result of the piston 116 being pulled rearwardly, the drawbar 92 and the collet 48 are also pulled rearwardly.
The rearward movement of the collet 48 forces the jaws 50, the jaw follower 80, and the jaw follower tube 90 to all move rearwardly in conjunction with the collet 48. As the jaws 50 move rearwardly, they grip the rivet stem more and more tightly.
Rearward movement of the jaw follower tube 90 necessarily compresses the jaw follower tube spring 114. As the spring 114 is compressed, it applies more and more forward axial pressure on the jaw follower tube 90, which in turn applies more and more forward axial pressure on the jaw follower 80, which in turn applies more and more forward axial pressure on the jaws 50. As a result, the opposing jaws taper 74 and collet taper 60 force the jaws 50 to constrict even more tightly around the rivet stem.
After the piston 116 has been engaged and begins to rearwardly translate the drawbar 92, the collet 48, and the jaws 50 which are firmly grasping the rivet stem, the rivet is set in the usual fashion. Upon increased load, the tool of the rivet stem eventually breaks off from the remainder of the stem in the rivet sleeve. Ideally, the rivet stem breaks cleanly at a specially formed breakneck groove located at the base of the rivet head. In this event, the broken rivet stem is free to be sucked through both the jaws central bore 76 and the jaw follower central bore 112. The free rivet stem can then be translated rearwardly through the jaw follower tube central bore 112 and expelled through the rear of the jaw follower tube 90 by the application of a vacuum to the tube 90.
As has been discussed previously, however, during the operation of the fastener installation tool 30, a rivet may become undesirably lodged within the sleeve assembly 36, thereby obstructing it. More specifically, the rivet stem may not break cleanly at the breakneck groove, it may wedge between the three independent jaws 50, or some other mishap may occur. If such an undesirable eventuality occurs, the rivet stem may become lodged within the sleeve assembly 36, thereby preventing further operation of the fastener installation tool 30.
The present invention greatly facilitates the correction of this problem. As described previously, the obstructed sleeve assembly 36 can be quickly and easily removed from the adapter housing assembly 38 and an obstruction-free sleeve assembly 36 can be quickly and easily reinstalled on the adapter housing assembly 38. The significant changeover time-saving achieved by using the novel tool head quick disconnect assembly 34 greatly reduces the down time of the fastener installation tool 30 due to rivet jams. The jammed head assembly can be taken as a unit to a convenient repair area to be disassembled and unjammed. Note that the jammed collet unit is retained in the sleeve to permit easy handling. In the end, the production line is interrupted for only a short time because of tool head changeovers, resulting in significantly increased line productivity and therefore substantial cost savings.
The foregoing description should be taken as illustrative and not as limiting. Additional advantages and modifications will be readily apparent to those skilled in the art. The invention in its broader aspects is, therefore, not limited to the specific details, preferred embodiment, or illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.
As one example of this, it should be noted that the feature of having the head assembly replaceable as a unit with the jaws and jaw follower captured in the collet, and the collet in turn captured in the sleeve is useful for reducing production line down time, without having the quick disconnect lugs and latching. That is, the invention provides a significant improvement even if the separate head assembly is joined by other means, since the assembly can be replaced as a unit and unjammed elsewhere.
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An apparatus and method for quickly and easily disengaging and re-engaging a fastener installation tool head from a fastener installation tool body. A novel fastener installation tool head quick disconnect assembly is provided, consisting in a preferred arrangement of a sleeve assembly and an adapter housing assembly. The adapter housing assembly is rigidly attached to the fastener installation tool body and the sleeve assembly is attached to the adapter housing assembly via a quick-disconnect latching mechanism on the adapter housing assembly. To remove the sleeve assembly from the adapter housing assembly the operator simply translates the latching mechanism rearwardly, rotates the sleeve assembly 60° to align an internal and an external set of lugs and grooves on the assemblies, and pulls the sleeve assembly forward disengage the sleeve assembly from the adapter housing assembly. To re-engage, the operator simply aligns the two components with one another, translates the sleeve assembly rearwardly into the adapter housing assembly, and rotates the sleeve assembly 60°, thereby quickly and easily locking the sleeve assembly into the adapter housing assembly.
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[0001] This application is entitled to the benefit of, and incorporates by reference essential subject matter disclosed in PCT Application No. PCT/EP2014/068517 filed on Sep. 1, 2014, which claims priority to Great Britain Application No. 1315459.6 filed Aug. 30, 2013.
BACKGROUND OF THE INVENTION
[0002] 1. Technical Field
[0003] The present invention relates to improved printing processes for applying barrier coatings for paper substrates, and to paper substrates made by such processes.
[0004] 2. Background Information
[0005] Packaging materials for sensitive substances such as food are often made from paperboard substrates which have a barrier coating to protect the contents from the packaging. The barrier coating can help prevent substances such as water or oils leaching from the food substance into the packaging material thereby spoiling the decorative surface of the material, or alternatively protect the food material itself from substances which may leach through the packaging and into the contents.
[0006] One particular problem that has been identified in the art is the leaching of mineral oil from paperboard substrates used as food containers. Thus, mineral oil is typically present in paperboard packaging materials due to the ink and other treatment agents present on the original paper source used to make the paperboard substrate. Typically, mineral oil will be present at levels of around 400 ppm in paperboard substrates, and is typically made up of around 25 weight percent mineral oil aromatic hydrocarbons (MOAH) and 75 percent mineral oil saturated hydrocarbons (MOSH). At these levels, mineral oil cannot generally be regarded as a “trace” contaminant and there is growing concern that leaching of mineral oils into food substances may pose a health risk.
[0007] At present, there is no statutory requirement for the amounts of MOAH and MOSH contamination in food. However, it is likely that the European authorities will soon regulate the amount of these contaminants that may be present. In the USA, some pure MOSH compounds are permitted in the FDA Regulations. However, given that many MOAH components (e.g. alkylated benzenes and phenanthrenes) are known carcinogens, it is inevitable that regulations governing the amounts of these components will soon be introduced. The Joint Expert Committee on Food Additives (JECFA) has recommended a maximum Acceptable Daily Intake (ADI) of medium and low viscosity mineral oils of 0.01 mg/kg. A proposed regulation in Germany will limit food contamination to less than 150 ppb by weight.
[0008] There are several proposed solutions to mitigate mineral oil contamination due to leaching. For example, in Switzerland the use of recycled fiber in food packaging is no longer allowed. Another solution is to treat the pulp to remove inks prior to forming paperboard, or even reformulating inks to avoid mineral oil being included.
[0009] Another possible solution is to minimize leaching by coating the paperboard with an impermeable barrier coating. To date, paper, polyethylene and propylene liners have been found not to work or not to work efficiently. Other proposals include the use of PET and aluminum foil liners. However, it has been suggested that the direct contact of food and aluminum may present other adverse health risks. Moreover, all of these methods suffer from higher costs.
[0010] Barrier coatings made from alcohol binders such as polyvinyl alcohol (PVOH) together with a plate-like filler such as kaolin have been disclosed in WO2013/017857. The examples show that boards coated with PVOH/kaolin mixtures at levels of about 5 g/m 2 show acceptable barrier properties. While the resultant barriers are promising, the printing methodologies used in the examples of WO2013/017857 are not amenable to large scale, high throughput production.
[0011] In view of the foregoing, there is a need for high throughput printing processes for applying barrier coatings on food grade packaging.
SUMMARY OF THE INVENTION
[0012] In a first aspect, the present invention is a process for forming a coated paper comprising: providing a paper substrate; gravure printing a coating composition on at least one surface of the paper substrate, wherein the coating composition comprises polyvinyl alcohol and an inorganic particulate, characterized in that the gravure cell volume is at least 50 cm 3 /m 2 .
[0013] Alternatively, the present invention is a process for forming a coated paper comprising: providing a paper substrate; gravure printing a coating composition on at least one surface of the paper substrate, wherein the coating composition comprises polyvinyl alcohol and an inorganic particulate, characterized in that the gravure cell depth is at least 60 μm.
[0014] In a second aspect, the present invention is a process for forming a coated paper comprising: providing a paper substrate; gravure printing a first composition comprising a polyvinyl alcohol on at least one surface of the paper substrate; gravure printing a second composition comprising an inorganic particulate on the polyvinyl alcohol layer; and gravure printing a third composition comprising a polyvinyl alcohol on the layer of inorganic particulate.
[0015] In such processes, the gravure cell volume is preferably at least 50 cm 3 /m 2 .
[0016] In such processes, the gravure cell depth is preferably at least 60 μm.
[0017] Preferably, the first and/or third compositions do not contain any inorganic particulate.
[0018] Preferably, the second composition comprises 0-20 wt % polyvinyl alcohol, at least 60 wt % inorganic particulate, and the remainder water.
[0019] A further aspect of the present invention relates to coated paper formed by such processes.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1A shows an embodiment of gravure cells that are approximately square.
[0021] FIG. 1B shows an embodiment of gravure cells that are approximately hexagonal.
[0022] FIG. 1C shows an embodiment of continuous cells (sometimes referred to as “Haschur cells”) separated by parallel walls.
[0023] FIG. 1D shows an alternative embodiment of continuous cell, in which the continuous cells are divided into rectangles by thin walls.
[0024] FIG. 1E shows a form of continuous gravure cell in which the walls are zig zag shaped so as to form a series of rhombuses.
DETAILED DESCRIPTION
[0025] By “printing” is meant applying a composition onto the surface of a preformed substrate. Thus, printing does not encompass methods involving actually forming the paperboard in combination with the coating via a co-extrusion process.
[0026] The printing process used in the present invention is a rotogravure (hereinafter “gravure”) method, i.e. methods where the substrate passes in between two rotating cylinders, one of which, the “gravure cylinder”, transfers ink from a reservoir to the substrate while the other, the “impression roll”, forces the substrate against the gravure cylinder to create a nip where the ink transfer takes place.
[0027] The compositions (i.e. the coating composition, and the first, second and third compositions mentioned above) used in the processes of the present invention typically comprise polyvinyl alcohol and/or an inorganic particulate.
The Inorganic Particulate
[0028] The inorganic particulate may, for example, be an alkaline earth metal carbonate or sulphate, such as calcium carbonate, magnesium carbonate, dolomite and gypsum; an aluminosilicate such as hydrous kandite clay including kaolin, halloysite clay, ball clay, anhydrous (calcined) kandite clay such as metakaolin, fully calcined kaolin and mica; or another material such as talc, perlite, diatomaceous earth, magnesium hydroxide and aluminum trihydrate; or combinations thereof.
[0029] Preferably, the inorganic particulate is a phyllosilicate. These silicates contain parallel sheets of silicate tetrahedra that often give rise to clean basal cleavage leading to formation of flakes or plate-like particles. Preferred phyllosilicates are selected from as kaolin, montmorillonite, and bentonite; and micas such as biotite and muscovite.
[0030] Advantageously, in one embodiment, the inorganic particulate is an aluminosilicate, for example, kaolin. In another embodiment, the inorganic particulate is a magnesium silicate.
[0031] Most preferably, the inorganic particulate is kaolin.
[0032] Preferably, the inorganic particulate has a high shape factor. Kaolin having a high shape factor is particularly preferred.
[0033] A product of high shape factor is considered to be more “platy” than a product of low shape factor. “Shape factor”, as used herein, is a measure of the ratio of particle diameter to particle thickness for a population of particles of varying size and shape as measured using the electrical conductivity methods, apparatuses, and equations described in U.S. Pat. No. 5,576,617, which is incorporated herein by reference. As the technique for determining shape factor is further described in the '617 patent, the electrical conductivity of a composition of an aqueous suspension of orientated particles under test is measured as the composition flows through a vessel. Measurements of the electrical conductivity are taken along one direction of the vessel and along another direction of the vessel transverse to the first direction. Using the difference between the two conductivity measurements, the shape factor of the particulate material under test is determined.
[0034] The shape factor of the inorganic particulate (e.g. kaolin) may suitably be equal to or greater than about 10. For example, the shape factor may be equal or greater than about 20, or equal or greater than about 30, or equal or greater than about 40, or equal or greater than about 50, or equal or greater than about 60 or about 70. The shape factor may be equal or greater than about 80, for example equal or greater than about 90 or about 100, for example up to about 110 or about 150.
[0035] For example, the shape factor may lie in one or more of the following ranges: 20 to 150; 20 to 110; 30 to 150; 30 to 110; 40 to 150; 40 to 110; 50 to 150; 50 to 110; 60 to 150; 60 to 110; 70 to 150; 70 to 110; 80 to 150; 80 to 119; 90 to 150; 90 to 110.
[0036] Unless otherwise stated, the mean (average) equivalent particle diameter (d 50 value) and other particle size properties referred to herein for the inorganic particulate are as measured in a well-known manner by sedimentation of the particulate material in a fully dispersed condition in an aqueous medium using a Sedigraph 5100 machine as supplied by Micromeritics Instruments Corporation, Norcross, Ga., USA (telephone: +1 770 662 3620; web-site: www.micromeritics.com), referred to herein as a “Micromeritics Sedigraph 5100 unit”. Such a machine provides measurements and a plot of the cumulative percentage by weight of particles having a size, referred to in the art as the ‘equivalent spherical diameter’ (esd), less than given esd values. The mean particle size d 50 is the value determined in this way of the particle esd at which there are 50% by weight of the particles which have an equivalent spherical diameter less than that d 50 value. The term d 50 is the particle size value less than which there are 90% by weight of the particles.
[0037] The inorganic particulate may have a mean equivalent particle diameter (d 50 ) less than or equal to about 10 microns (μm) (by Sedigraph), e.g. less than or equal to about 8 μm, or less than or equal to about 6 μm, or less than or equal to about 4 μm, or less than or equal to about 2 μm, or less than or equal to about 1.5 μm, particularly less than or equal to about 1 μm, e.g. less than or equal to about 0.5 μm, e.g. less than or equal to about 0.4 μm or, e.g., less than or equal to about 0.3 μm.
[0038] The value of d 50 may, for example, be in the range of about 0.2 μm to about 2 μm, for example about 0.3 to about 1.5 μm, for example about 0.3 to about 1 μm, or for example about 1 μm to about 2 μm. The inorganic particulate may have a d 50 of less than or equal to about 5 μm, particularly less than 3 μm, e.g., less than about 2 μm. The value of d 50 may, for example, be in the range of about 0.5 μm to about 3 μm, for example about 1 μm to about 3 μm or, for example, about 0.5 μm to 2 μm.
[0039] The range of fine content of inorganic particulate, i.e. the wt % less than 0.25 μm may lie in the range 5 wt % to 95 wt %, for example 40 wt % to 90 wt % or 5 wt % to 20 wt %. In an embodiment, the particulate (e.g. kaolin) has a shape factor equal to or greater than about 30 and a d 50 of less than about 2 μm. For example, the particulate (e.g. kaolin) may have a shape factor equal to or greater than about 60, or 70, or 90, and a d 50 of less than about 2 μm.
[0040] In another embodiment, the particulate (e.g. kaolin) has a shape factor between about 10 and about 20 and a d 50 of less than about 1 μm, for example, less than or equal to about 0.5 μm.
[0041] In another embodiment, the particulate (e.g. kaolin) has a shape factor between about 25 and about 50 and a d 50 of less than about 0.3 μm.
[0042] In another embodiment, the inorganic particulate is an aluminosilicate having a shape factor between about 20 and 40, and a d 50 of less than about 0.5 μm.
[0043] As noted above, the most preferred inorganic particulate is kaolin, which is a type clay comprising kaolinite. Kaolin clay used in this invention may be a processed material derived from a natural source, namely raw natural kaolin clay mineral. The processed kaolin clay may typically contain at least about 50% by weight kaolinite. For example, most commercially processed kaolin clays contain greater than about 75% by weight kaolinite and may contain greater than about 90%, in some cases greater than about 95% by weight of kaolinite.
[0044] Kaolin clay used in the present invention may be prepared from the raw natural kaolin clay mineral by one or more other processes which are well known to those skilled in the art, for example by known refining or beneficiation steps.
[0045] For example, the clay mineral may be bleached with a reductive bleaching agent, such as sodium hydrosulphite. If sodium hydrosulphite is used, the bleached clay mineral may optionally be dewatered, and optionally washed and again optionally dewatered, after the sodium hydrosulphite bleaching step.
[0046] The clay mineral may be treated to remove impurities, e.g. by flocculation, flotation, or magnetic separation techniques well known in the art. Alternatively the clay mineral used in the first aspect of the invention may be untreated in the form of a solid or as an aqueous suspension.
[0047] The process for preparing the particulate kaolin clay used in the present invention may also include one or more comminution steps, e.g., grinding or milling. Light comminution of a coarse kaolin is used to give suitable delamination thereof. The comminution may be carried out by use of beads or granules of a plastic (e.g. nylon), sand or ceramic grinding or milling aid. The coarse kaolin may be refined to remove impurities and improve physical properties using well known procedures. The kaolin clay may be treated by a known particle size classification procedure, e.g., screening and centrifuging (or both), to obtain particles having a desired d 50 value or particle size distribution.
[0048] When the inorganic particulate of the present invention is obtained from naturally occurring sources, it may be that some mineral impurities will contaminate the ground material. For example, naturally occurring kaolin can be present in association with other minerals. Thus, in some embodiments, the inorganic particulate includes an amount of impurities. In general, however, the inorganic particulate material used in the invention will contain less than about 5% by weight, preferably less than about 1% by weight, of other mineral impurities.
[0049] Commercially available kaolin that may be used in the invention are commercially available and are sold under various trade names.
The Polyvinyl Alcohol Binder
[0050] The binder component of the barrier coating serves not only as binder when applied to a paper product, but may also enhance the barrier properties of the barrier coating. In an advantageous embodiment of the first aspect, the water vapour transmission rate of a barrier coating composition according the present invention is improved (i.e., is reduced) compared to a barrier coating which does not comprise both an inorganic particulate and polyvinyl alcohol component as defined in accordance with the invention.
[0051] Polyvinyl alcohol may be obtained by conventional methods know in the art, such as, for example by partial or complete hydrolysis of polyvinyl acetate to remove acetate groups. Thus, a person of skill in the art will understand that polyvinyl alcohol obtained by hydrolysis of polyvinyl acetate may contain pendant acetate groups as well as pendant hydroxy groups.
[0052] Thus, in embodiments, the polyvinyl alcohol is derived from partially or fully hydrolyzed polyvinyl acetate.
[0053] The extent of hydrolysis may be such that at least about 50 mole % of the acetate groups are hydrolyzed, for example, at least about 60 mole % of the acetate groups are hydrolyzed, for example, at least about 70 mole % of the acetate groups are hydrolysed, for example, at least about 80 mole % of the acetate groups are hydrolyzed, for example, at least about 85 mole % of the acetate groups are hydrolyzed, for example, at least about 90 mole % of the acetate groups are hydrolysed, for example, at least about 95 mole % of the acetate groups are hydrolyzed or, for example, at least about 99 mole % of the acetate groups are hydrolyzed.
[0054] Preferred ranges of hydrolysis are from about 80 to about 99 mole %, more preferably from about 85 to about 99 mole %, even more preferably about 88 to about 98 mole %.
[0055] An alternative way of defining polyvinyl alcohols derived from partially or fully hydrolyzed polyvinyl acetate is by the residual acetyl content, that is the amount of the polymer still corresponding to acetyl groups.
[0056] The preferred residual acetyl content of the polyvinyl alcohol is from about 0.5 to about 15% w/w, more preferably from about 12.5 to about 0.5% w/w, even more preferably from about 11 to about 1% w/w.
[0057] The compositions used in the processes of the present invention, when they contain polyvinyl alcohol, preferably have a viscosity of about 200 to about 5000 mPa·s, more preferably from about 500 to about 4000 mPa·s, more preferably about 750 to about 3000 mPa·s, most preferably about 1000 to about 2500 mPa·s.
[0058] The viscosity of the compositions is typically measured using a Höppler falling-ball viscometer (DIN 53 015) or at 20° C. An alternative way of measuring the viscosity is using an Ubbelohde viscometer (capillary viscometer, DIN 51 562 and DIN 53 012), again at 20° C.
[0059] As the degree of hydrolysis increases, the viscosity of the polymer in water increases. Likewise, as the molecular weight of the polymer increases, the viscosity of aqueous solutions of the polymer increases. The molecular weight and degree of hydrolysis of the polyvinyl alcohol are therefore preferably adjusted to ensure that the above-mentioned viscosities are obtained.
[0060] In other words, as would be understood by the skilled person, the invention can utilize polyvinyl alcohol having a relatively high molecular weight and a relatively low degree of hydrolysis (i.e. relatively high residual acetyl content), or a similar viscosity solution can be achieved using a relatively low molecular weight polyvinyl alcohol having a relatively high degree of hydrolysis (i.e. a low residual acetyl content). The skilled person, intent on forming a composition having a particular viscosity, would have no difficulty adjusting the molecular weight and degree of hydrolysis of the polyvinyl alcohol to achieve the desired viscosity.
[0061] However, as higher molecular weight polyvinyl alcohols provide better barrier properties, it is preferred to use a polyvinyl alcohol having relatively high molecular weight and a relatively low degree of hydrolysis (i.e. relatively high residual acetyl content).
[0062] The preferred molecular weight of the polyvinyl alcohol will therefore depend on the degree of hydrolysis as well as the desired viscosity of the composition. However, by way of guidance, preferred molecular weights for polyvinyl alcohols having a degree of hydrolysis of about 88 mole % range from about 30,000 to about 160,000 g/mol, while preferred molecular weights for polyvinyl alcohols having a degree of hydrolysis of about 98 mole % range from about 25,000 to about 130,000 g/mol.
[0063] These molecular weights are mean average molecular weights (Mw) as determined by gel permeation chromatography combined with static light scattering on reacetylised specimens. Suitable methods for reacetylising are known in the art, and include pyridine/acetic anhydride mixture.
[0064] Typically, measuring the molecular weight of polyvinyl alcohol is laborious due to the reacetylisation and subsequent steps. Consequently, it is often easier to describe the molecular weight in terms of the viscosity of a freshly prepared 4% aqueous solution using DIN 53015 standard.
[0065] Thus, preferred viscosity according to the DIN 53015 of the polyvinyl alcohol is from about 3 to about 30 mPa·s, more preferably from about 4 to about 25 mPa·s, even more preferably from about 10 to about 23 mPa·s.
[0066] Typical examples of suitable polyvinyl alcohols include Mowiol polyvinyl alcohol available from Kuraray, for example Mowiol 4-88, Mowiol 5-88, Mowiol 8-88, Mowiol 18-88, Mowiol 6-98, Mowiol 10-98, and Mowiol 20-98.
Additional Components
[0067] The compositions used in the process of the present invention may contain one or more optional additional components, if desired. Such additional components, where present, are suitably selected from known additives for paper coating compositions. Some of these optional additives may provide more than one function in the coating composition. Examples of known classes of optional additives are as follows:
(a) one or more cross linkers; (b) one or more water retention aids; (c) one or more viscosity modifiers or thickeners; (d) one or more lubricity or calendering aids; (e) one or more dispersants; (f) one or more antifoamers or defoamers; (g) one or more optical brightening agents (OBA) or fluorescent whitening agents (FWA); (h) one or more dyes; (i) one or more biocides or spoilage control agents; (j) one or more levelling or evening aids; (k) one or more grease or oil resistance agents; (I) one or more surfactants; (m) one more binders other than the polyvinyl alcohol binder defined above, for example, a latex binder such as a styrene-butadiene rubber latex, an acrylic polymer latex, a polyvinyl acetate latex, or a styrene acrylic copolymer latex, which may be carboxylated; (n) one or more mineral fillers other than the inorganic particulate, for example an alkaline earth metal carbonate or sulphate, such as calcium carbonate, magnesium carbonate, dolomite, gypsum, a hydrous kandite clay such as kaolin, halloysite or ball clay, an anhydrous (calcined) kandite clay such as metakaolin or fully calcined kaolin, talc, mica, perlite or diatomaceous earth, or combinations thereof.
[0082] Any of the above additives and additive types may be used alone or in admixture with each other and with other additives, if desired. However, it is preferred that the composition does not contain a cross linker.
[0083] For all of the above additives, the percentages by weight (based on the dry weight of inorganic particulate (100%) present in the composition) can vary as understood by those skilled in the art. Where the additive is present in a minimum amount, the minimum amount may be about 0.01% by weight based on the dry weight of the inorganic particulate.
The Coating Compositions
[0084] In the first aspect, the composition used in the process according to the present invention comprises a mixture of the above defined inorganic particulate and polyvinyl alcohol, and optionally one or more further additive components, as discussed above. The composition may be in the form of an aqueous suspension of the above defined inorganic particulate and polyvinyl alcohol component, and optionally one or more further additive components, as discussed above.
[0085] In some embodiments, the coating composition used in the process consists of polyvinyl alcohol, inorganic particulate and water.
[0086] In an embodiment, the coating composition may comprise at least about 20% by weight inorganic particulate, based on the total weight of the solids in the barrier coating composition, for example, at least about 25% by weight inorganic particulate, for example at least about 30% by weight inorganic particulate, for example at least about 35% by weight inorganic particulate, for example at least about 40% by weight inorganic particulate, for example at least about 45% by weight inorganic particulate, for example at least about 50% by weight inorganic particulate, for example at least about 55% by weight inorganic particulate, for example at least about 60% by weight inorganic particulate, for example at least about 65% inorganic particulate, for example at least about 70% by weight inorganic particulate or, for example at least about 75% weight inorganic particulate. In another embodiment, the barrier coating composition comprises no more than about 50% by weight inorganic particulate. All these weight percentages are weight percent of the solids in the coating composition.
[0087] The inclusion of an inorganic particulate may advantageously provide additional benefits other than reduced liquid phase mineral oil transmission, such as, for example, making the system cheaper, improving water barrier properties (i.e., reducing moisture vapor transmission rates through coated paper products) and improving the applicability of the barrier coating composition to the paper substrate.
[0088] In an embodiment, the weight ratio of inorganic particulate to polyvinyl alcohol ranges from about 5:1 to about 1:10, for example, from about 5:1 to about 1:9, for example, from about 5:1 to about 1:7, for example, from about 5:1 to about 1:5, for example, from about 4:1 to about 1:4, for example, from about 3:1 to about 1:3, for example, from about 2:1 to about 1:2, for example, from about 1.5:1 to about 1:1.5, for example, from about 1.25:1 to about 1:1.25.
[0089] Particularly preferred weight ratios of inorganic particulate to polyvinyl alcohol include from about 4:1 to about 1:4, more preferably from about 3:1 to about 1:3, more preferably from about 2:1 to about 1:2, even more preferably from about 1.5:1 to about 1:1.5, most preferably from about 1.25:1 to about 1:1.25.
[0090] In another embodiment, the weight ratio of inorganic particulate to alcohol-based binder is about 1:1.
[0091] Thus, viewed in another way, the preferred amount of polyvinyl alcohol and inorganic particulate in the coating composition ranges from about 20 to about 80 wt % and from about 80 to about 20 wt % respectively, based on the total solids in the composition.
[0092] More preferably, the preferred amount of polyvinyl alcohol and inorganic particulate in the coating composition ranges from about 25 to about 75 wt % and from about 75 to about 25 wt % respectively; more preferably from about 30 to about 70 wt % and from about 70 to about 30 wt % respectively; even more preferably from about 40 to about 60 wt % and from about 60 to about 40 wt %/o respectively, based on the total solids in the composition.
[0093] Preferably, the polyvinyl alcohol and inorganic particulate are present in the coating composition at levels of about 50 wt % each, based on the total solids in the composition.
[0094] Typically, the coating composition comprises from 10 to 40% w/v solids, preferably from 15 to 35% w/v solids, more preferably from 18 to 30% w/v solids. The remainder of the composition is typically water.
[0095] The barrier coating composition may be prepared by mixing the polyvinyl alcohol binder, inorganic particulate, and the other optional additives (when present) in appropriate amounts into an aqueous liquid to prepare a suspension of said components. The coating composition may suitably be prepared by conventional mixing techniques, as will be known in the art. In embodiments in which the inorganic particulate is present an aqueous slurry of the inorganic particulate may be prepared using a suitable mixer, following which the slurry is blended with a solution of the polyvinyl alcohol binder. The resulting mixture may be screened prior to coating.
[0096] In a second aspect, the process of the invention uses two (or three) different types of coating compositions, referred to herein as the first composition, the second composition and the third composition.
[0097] The first composition is applied directly on the substrate and comprises a polyvinyl alcohol. Typically, the first composition does not contain any inorganic particulate.
[0098] The second composition is applied directly on the first composition and comprises inorganic particulate. Typically, the second composition does not contain any polyvinyl alcohol, although small amounts may be present to aid in the bonding of the particulate and to the adjacent layers. For example, the second composition may contain from 0 to 20 wt % polyvinyl alcohol, more preferably from 0 to 10 wt %, even more preferably from 0.1 to 8 wt %, most preferably from 1 to 5 wt %. When binder (e.g. polyvinyl alcohol) is present, the second composition generally contains a higher percentage (by weight) of inorganic particulate than polyvinyl alcohol (or binder polymers). In some embodiments, the second composition is free from binder polymer. In some embodiments, the second composition is free from wax.
[0099] Thus, the second binder composition preferably consists of water, inorganic particulate and from 0 to 20 wt % polyvinyl alcohol, more preferably from 0 to 10 wt %, even more preferably from 0.1 to 8 wt %, most preferably from 1 to 5 wt % polyvinyl alcohol.
[0100] The third composition is applied directly on the second composition and comprises polyvinyl alcohol. Typically, the third composition does not contain any inorganic particulate.
[0101] Considering each of these compositions in more detail, the first composition provides good adhesion to the substrate and inorganic particulate later. Typically, the first composition is a mixture of polyvinyl alcohol and water (preferably the first composition consists of polyvinyl alcohol and water) which contains from 15 to 50% w/v polyvinyl alcohol, preferably from 20 to 40% w/v polyvinyl alcohol, most preferably from 25 to 35% w/v polyvinyl alcohol.
[0102] Typically, the polyvinyl alcohol used in the first composition is selected to ensure excellent barrier properties. Preferably, the polyvinyl alcohol has a degree of hydrolysis ranging from 85 to 99 mole %, more preferably about 88 to about 98 mole %.
[0103] The second composition provides an inorganic barrier later which reduces the transmission rate of lipophilic materials. Typically, the second composition is a mixture of inorganic particulate, optionally polyvinyl alcohol and water (preferably the second composition consists of inorganic particulate, optionally polyvinyl alcohol and water) which contains at least 60 wt % inorganic particulate, preferably at least 70 wt % inorganic particulate, preferably up to 90 wt % inorganic particulate, more preferably from 75 to 90 wt % inorganic particulate, even more preferably from 80 to 90 wt % inorganic particulate. The amounts of the binder polymer (polyvinyl alcohol), if present, are as stated above.
[0104] The second composition can be applied on the first composition once it has dried. However, it is preferred to apply the second composition while the first composition has not fully dried. This ensures the first layer is flexible and the inorganic particulate is able to penetrate into it to improve adhesion between the polyvinyl alcohol and inorganic particulate layers, as well as improving flexibility in the overall production process (e.g. less time between prints to allow for complete drying).
[0105] The third composition provides good surface properties to the final substrate, as well as contributing towards the barrier properties. Typically, the third composition is a mixture of polyvinyl alcohol and water (preferably the third composition consists of polyvinyl alcohol and water) which contains from 10 to 35% w/v polyvinyl alcohol, preferably from 10 to 30% w/v polyvinyl alcohol, most preferably from 15 to 25% w/v polyvinyl alcohol.
[0106] Typically, the polyvinyl alcohol has a degree of hydrolysis ranging from 85 to 99 mole %, more preferably about 88 to about 98 mole %.
[0107] The first and third compositions can be the same. However, typically the first and third compositions are different. Preferably, the third composition has a lower polymer content and a lower viscosity than the first composition. This ensures that it has better printing properties and thus forms a more even surface finish to the substrate.
The Paper Substrate
[0108] The term “paper substrate”, as used in connection with the present invention, should be understood to mean all forms of paper, including board such as, for example, white-lined board and linerboard, cardboard, paperboard, coated board, and the like. There are numerous types of coated paper and board which may be made according to the present invention, including paper suitable for suitable for food packaging, perishable goods other than food, e.g., pharmaceutical products and compositions. The paper may be calendered or super calendered as appropriate. Paper suitable for light weight coating (LWC), medium weight coating (MWC) or machine finished pigmentization (MFP) may also be made according to the present methods.
[0109] Preferably, the paper product used in the process in the present invention is a board (i.e. paperboard), e.g. white-lined board, cardboard, paperboard or coated board.
[0110] The paper substrate may be formed on any material which is suitable for making a paper product therefrom. The paper substrate may be derived from any suitable source, such as wood, grasses (e.g., sugarcane, bamboo) or rags (e.g., textile waste, cotton, hemp or flax). The paper substrate may comprise pulp (i.e., a suspension of cellulose fibers in water), which may be prepared by any suitable chemical or mechanical treatment, or combination thereof.
[0111] Typically, the paper substrate comprises recycled pulp. The recycled pulp may contain MOH or MOSH or MOAH. The MOH, MOSH and MOAH may come from printing inks, which are retained in the paper substrate formed from the recycled pulp. In an embodiment, the recycled pulp is derived from recycled newsprint.
[0112] In another embodiment, the fibrous substrate comprises virgin pulp (i.e., pulp which is not derived from a recycled material). In a further embodiment, the fibrous substrate may comprise a mixture of recycled pulp and virgin pulp.
[0113] In an embodiment, the paper substrate has opposing first and second surfaces. The barrier coating composition may be coated on the first surface, the second surface, or both. In an advantageous embodiment, the first surface is a surface which faces the interior of the paper product when it is formed into a three-dimensional product and the opposing second surface faces the exterior of the paper product. Thus, in an embodiment in which the paper product is formed as food grade or pharmaceutical grade packaging, inside of which a foodstuff or pharmaceutical product or composition may be contained, the barrier coating reduces or prevents migration of mineral oil from the paper product to the foodstuff or pharmaceutical product or composition. The packaging may be in the form of a carton (e.g., milk and beverage cartons) or box (e.g., a cereal box) and the like.
[0114] The first and/or second surfaces may have other intermediary coatings or layers between each surface and the barrier coating.
[0115] Thus, in another advantageous embodiment in which the paper product is formable or formed into a three-dimensional product, which may be suitable as food grade or pharmaceutical grade packaging, at least a portion of a first interior facing surface of the paper substrate is coated with a barrier coating according to the present invention, and a second exterior facing surface of the paper substrate is coated or printed with an ink-based product. In this embodiment, the paper substrate may be derived from recycled pulp containing mineral oil and/or the ink-based product may comprise mineral oil.
[0116] Barrier coated paper products of the present invention include brown corrugated boxes, flexible packaging including retail and shopping bags, food and hygiene bags and sacks, milk and beverage cartons, boxes suitable for cereals and the like, self-adhesive labels, disposable cups and containers, envelopes, cigarette paper and bible paper.
Mineral Oil Transmission
[0117] By “mineral oil” is meant a group of refined mineral hydrocarbons, derived from a non-vegetable (i.e., mineral) source, particularly petroleum distillate, which may be divided into three classes: paraffinic oil, based on n-alkanes; naphthenic oil, based on cycloalkanes; and aromatic oils, based on aromatic hydrocarbons.
[0118] “Mineral oil hydrocarbons (MOH)” is an art-recognized term understood to refer to a mineral oil fraction comprising, without distinction, paraffinic, naphthenic and aromatic hydrocarbons.
[0119] “Mineral oil saturated hydrocarbons (MOSH)” is an art-recognized term used to refer to a mineral oil fraction comprising paraffinic and naphthenic hydrocarbons.
[0120] “Mineral oil aromatic hydrocarbons (MOAH)” is an art-recognized term used to refer to a mineral fraction comprising aromatic hydrocarbons.
[0121] MOH typically comprise 5-25% MOAH, with the balance MOSH.
[0122] Medium and low viscosity MOH comprise C 10 -C 25 hydrocarbons having a kinematic viscosity at 100° C. from 3-9 cSt, and molecular weights between 300-500. In an embodiment, the mineral oil comprises C 12 -C 25 hydrocarbons, for example C 12 -C 24 hydrocarbons, for example C 14 -C 22 hydrocarbons, for example C 16 -C 22 hydrocarbons, for example, C 18 -C 22 hydrocarbons.
[0123] The mineral oil may be derived from recycled pulp, from which the paper products of the present invention may be made. For example, the mineral oil may be derived from printing inks.
[0124] Liquid phase mineral oil transmission through the barrier coating is measured in accordance with the following procedure.
[0125] 1. coat the barrier on the reverse of a GD board;
[0126] 2. print an ink doped with 20 percent by weight diosopropylnaphthyl (DIPN) on the face of the board;
[0127] 3. make a sandwich of two of these boards with a layer of absorbent carbon in the middle, such that the barrier coatings are adjacent to the absorbent carbon;
[0128] 4. incubate at 50° C.;
[0129] 5. solvent extract DIPN from the absorbent carbon sandwich between the two boards;
[0130] 6. measure the peak area compared with known standards using gas chromatography.
[0131] Vapor phase mineral oil transmission may be determined by the following method. A barrier coated paper board product is prepared. The barrier coated samples are first cut in to circles of diameter 62.5 mm. The samples are left in a fume cupboard overnight prior to testing. Cotton wool pads of standard size are place in the bottom of a sealable beaker (a PAYNE cup). Approximately 10 ml of n-heptane are placed on to the cotton wool pad. This is then covered by the barrier coated samples and the edges are sealed. This is then weighed accurately to 4 decimal places and this is taken as time zero. The sealed beakers are left to stand in the fume cupboard and reweighed after 24 hours. As the volatile material escapes through the board, this results in a weight loss. Mineral oil vapor transmission rates (OVTR) are given as gsm per day.
The Coating Process
[0132] The total coat weight of the coating formed in the first and second aspect may be from about 1 to about 30 gsm. For example, from about 3 to about 20 gsm, for example, from about 4 to about 15 gsm, for example, from about 5 to about 15 gsm, for example, from about 5 to about 12 gsm, for example, from about 5 to about 10 gsm.
[0133] By “gsm” is meant grams per square meter (g/m 2 ).
[0134] The deposition of the coating compositions is by gravure printing. The applicant has found that if standard gravure printing rolls are used, the amount of coating composition which is deposited in insufficient to provide good barrier properties. In part, this may be due to the highly viscous nature of the coating compositions, which is not able to flow out of standard gravure cells during printing. After extensive efforts the applicant has found that specific types of gravure printing rolls need to be used to achieve commercially acceptable results. Thus, the gravure printing roll as used in the present invention typically has high cell volumes and large cell areas, which allow good deposition of the coating compositions onto the underlying substrate.
[0135] Thus, typically the cell volume is at least 50 cm 3 /m 2 , preferably at least 60 cm 3 /m 2 , for example from 60 to 200 cm 3 /m 2 , more preferably from 60 to 150 cm 3 /m 2 , even more preferably from 65 to 130 cm 3 /m 2 , even more preferably from 70 to 120 cm 3 /m 2 , with ranges such as from 75 to 120 cm 3 /m 2 being the most preferred.
[0136] These cell volumes are expressed as the volume of all cells per square meter of gravure roll, as is common in the art. As used herein, “cell volume” or “gravure cell volume” is therefore synonymous with total cell volume per unit area, unless it is clear from the context that individual cell volumes are being referred to.
[0137] As noted above, a further important criteria is the size of the opening of the cell, or cell width. The actual shape of gravure cells can vary, depending on the way in which the cells are formed (e.g. by a stylus, by laser etching etc.). Typical shapes for the individual gravure cells include rhombuses, squares, rectangles and hexagons (see FIG. 1 ). It is also possible to use continuous gravure cells, such that the gravure roll is effectively made up of a series of ridges, which may be parallel ( FIG. 1 c ) or zig-zag ( FIG. 1 e ) shaped so as to form rhombuses connected by channels.
[0138] The term “cell width” as used herein represents the shortest distance between the walls of a cell which passes through the center of the cell. Thus, the term “cell width” as used herein is different to the “cell opening” as usually reported for gravure cells comprising rhombus-shaped cells connected by a channel (this being typically the widest part of the cell”.
[0139] For discrete cells, the cell width is the smallest dimension across the center of the cell, which for rectangular cells would correspond to the length of the shorter sides of the rectangle. For continuous gravure cells formed from parallel ridges, the cell width corresponds to the distance be the ridges. For continuous gravure cells formed of zig-zag ridges forming rhombuses connected by channels, the cell width is the shortest distance between the ridges which passes through the center of the rhomboidal cells.
[0140] Typically, the cell width of the gravure cells used in the invention is at least 100 μm, preferably at least 150 μm, more preferably at least 200 μm, even more preferably at least 250 μm, for example from 100 to 800 μm, preferably from 200 to 700 μm, more preferably from 250 to 650 μm, even more preferably from 275 to 600 μm, most preferably from 300 to 600 μm.
[0141] The walls of the gravure cells are typically thin so as to ensure that the maximum amount of the surface of the gravure roll corresponds to cells capable of depositing the coating composition. Typically, the cell walls are at most 30 μm, preferably at most 25 μm, for example from 5 to 25 μm, preferably from 5 to 20 μm, more preferably from 5 to 15 μm.
[0142] Typically, the gravure cells are aligned so as to ensure that they have a high cell width. Thus, the angle of compression is typically around 45°. Preferred angles include from 25° to 65°, more preferably from 30° to 60°.
[0143] Typically, the gravure cells are deeper than conventional gravure printing rolls, to ensure that high cell volumes are obtained. Thus, typically the cell depth is at least 60 μm, preferably at least 70 μm, more preferably at least 80 μm.
[0144] In principle, there is no limit to the cell depth, providing the cell is strong enough to allow printing. However, as the cells are wide and the cell walls are thin, a balance needs to be struck to ensure that the cell walls are strong enough to withstand printing. This, typically, the gravure cells have a maximum depth of 300 μm, preferably 250 μm, more preferably 200 μm. Preferred ranges of cell depths therefore include 60 to 300 μm, more preferably from 70 to 250 μm, more preferably 70 to 200 μm, even more preferably 80 to 175 μm.
[0145] Typically, the printing cells used in the invention are formed by laser etching rather than using a stylus. However should a stylus be used, any stylus angle can in principle be used providing it produces a printing roll having the desired cell volume and cell width.
[0146] Typically, the cells in the gravure printing roll used in the invention are larger than conventional gravure printing cells. As a result, the printing rolls typically contain fewer cells. Thus, typically the printing rolls contain less than 30 cells (lines) per cm, preferably less than 25 cells (lines) per cm, even more preferably less than 20 cells (lines) per cm, typically from 5 to 20 cells (lines) per cm, preferably from 8 to 15 cells (lines) per cm.
[0147] The various dimensions of the cells (cell width, cell depth, wall thickness) can be measured by any suitable means including measurements taken from micrographs. However, commercially available devices can be used to take the measurements, such as Checkmaster II (Heimann GmbH) and Hommel Tester T1000 (Hommelwerke GmbH). All measurements are preferably made in accordance with DIN ISO 9001.
[0148] Typical gravure cells that can be used in the process of the present invention are shown in FIG. 1 .
[0149] FIG. 1 a shows gravure cells which are approximately square, with cell walls having a thickness of about 20 μm, the cell depth is approximately 150 μm, and the cell width is approximately 425 μm.
[0150] FIG. 1 b shows gravure cells which are approximately hexagonal, with cell walls having a thickness of about 20 μm, the cell depth is approximately 140 μm, and the cell width is approximately 350 μm. This configuration is sometimes referred to as a Wabe cell.
[0151] FIG. 1 c shows continuous cells separated by parallel walls. The walls are about 225 μm thick, the cells are about 375 μm wide and about 245 μm deep. These continuous cells are sometimes referred to as Haschur cells.
[0152] FIG. 1 d shows an alternative type of Haschur cell, in which the continuous cells are divided into rectangles by thin walls.
[0153] FIG. 1 e shows a form of continuous gravure cell in which the walls are zig zag shaped so as to form a series of rhombuses.
[0154] The larger cells used in the printing processes of the invention are capable of depositing high levels of the coating composition. Cells having a large depth are used to provide enough coating, but the cells also need to be the correct shape to facilitate deposition of the coating. Surprisingly, the applicant has found that using cells having the large cell widths and cell volumes as described herein, coating compositions having the typical viscosities disclosed herein can be deposited at levels sufficient to achieve commercially viable barrier coatings.
[0155] Thus, in preferred aspect, the invention relates to processes in which the coating composition is deposited at levels sufficient to form a coating having a basis weight of at least 5 gsm when dried.
[0156] More preferably, the coating composition is deposited at levels sufficient to form a coating having a basis weight of at least 6 gsm, more preferably at least 7 gsm, even more preferably at least 8 gsm, even more preferably at least 9 gsm and most preferably at least 10 gsm, when dried.
[0157] The applicant has found that when using inorganic particulate having a high shape factor (e.g. as defined above such as a shape factor equal to or greater than about 10), the transmission rates of thick coatings can be surprisingly high depending on the polymer used. In other words, inorganic particulates having a high shape factor can give lower barrier performance when deposited as a thick coating than when the same composition is deposited as a thin coating. Without wishing to be bound by theory, it is possible that the inorganic particulate particles in the thick coatings are not stacking in a planar fashion one on top of the other aligned in the plan of the coating, but rather some are oriented such that the plane of the plate is perpendicular to the plane of the coating (or at least rotated out of the plane of the coating to a significant extent). When aligned edge on in this way, the barrier properties are significantly reduced. This incorrect alignment is made possible by the thicker coating, allowing the plate-like particles room to rotate.
[0158] Thus, in embodiments where the particulate material has a high shape factor as set out above, it is preferred that the coating is deposited at levels of from 3 to 8 gsm (based on the dried weight of the coating), preferably from 3 to 7 gsm, even more preferably from 3 to 6 gsm. If necessary, multiple (thin) coatings can be applied to provide a (thick) coating having the desired barrier properties.
[0159] Based on the teaching provided herein, the skilled person would be able to devise a suitable gravure cylinder (i.e. cell volumes, cell widths, cell depth etc.) and optimized a coating composition (e.g. viscosity etc.) in order to achieve these levels of deposition without undue burden.
[0160] After deposition on the paper substrate, the coating may optionally be heated to aid in drying. For example, the coating may be heated to a temperature of from 20 to 80° C., preferably 30 to 80° C., more preferably 40 to 70° C.
[0161] The process of the first aspect present invention is capable of forming an effective barrier coating in one step (i.e. after printing one layer of the coating composition). However, pinholes can occur, which undermine the barrier properties. It is therefore preferred to use at least two printing steps, for example two, three or four. Preferably, two printing steps are used.
[0162] When applied in a series of coating layers according to the first aspect, the same or variable compositions can be used for each layer. For example, in one embodiment, a first layer of a barrier coating comprising only polyvinyl alcohol binder may be applied to the substrate followed by a top coat of a barrier coating composition comprising polyvinyl alcohol binder and an inorganic particulate.
[0163] In an alternative embodiment, two layers of a barrier coating comprising the polyvinyl alcohol binder and inorganic particulate may be applied one on top of the other. In such embodiments, the compositions in the first and second layers can be the same or different. For example, the first layer may contain a cheaper formulation and optionally coarser inorganic particulate in the coating composition.
[0164] When using multiple printing steps in the process of the first aspect, it is preferred that the final composition to be printed has a lower viscosity than the compositions applied in the preceding steps. Compositions having a lower viscosity tend to flow better from the gravure printing roll. Consequently, this ensures that the outermost layer is more even.
[0165] The second aspect of the invention is of course a multilayer printing process comprising at least three steps. As noted above, the third composition which corresponds to the outermost layer typically has a lower viscosity to ensure a more even coating is formed.
[0166] The first and third compositions are typically applied at levels similar to the first aspect, as set out above. Typically, the first composition is applied to form a thicker layer, as this is in contact with the underlying substrate. Generally, the second composition is applied as thinner layers, and optionally multiple thin layers of the second composition can be applied, to ensure better adhesion. Typically, the second composition is applied at levels to ensure a dried layer having 3 to 10 gsm, preferably 4 to 8 gsm, more preferably 5 to 7 gsm.
[0167] As noted above, the second composition can comprise small amounts of polyvinyl alcohol to act as a binder. In preferred embodiments, multiple layers of the second composition can be applied with layers of the first or third composition applied in between. For example, preferred sequences for the coating steps comprise: first composition; second composition; third composition; second composition; third composition, or alternatively first composition; second composition; first composition; second composition; third composition.
[0168] Typical examples of the process used in the second aspect include:
[0169] 25% w/v solution of 8-88 Mowiol PVOH; slurry of neat inorganic particulate (e.g. kaolin); 25% w/v solution of 8-88 Mowiol PVOH,
[0170] 25% w/v solution of 8-88 Mowiol PVOH; slurry of neat inorganic particulate (e.g. kaolin); 15% w/v solution of 10-98 Mowiol PVOH, and
[0171] 30-35% w/v solution of 5-88 Mowiol; slurry of neat inorganic particulate (e.g. kaolin); and 30-35% w/v solution of 5-88 Mowiol PVOH.
[0172] The barrier coating is typically on the internal surface of any three dimensional article formed from the paper substrate, such that it protects anything contained in the article from leaching of mineral oil or other contaminants in the paper substrate. After deposition of the barrier coating on the paper substrate, the opposing surface may be patterned by a separate printing surface prior to or after formation of the three dimensional article from the paper substrate.
[0173] An advantage of the printing processes of the present invention is that the barrier coating is rapidly formed on the paper substrate, without the need for any curing steps to cross link the coating or multiple passes through the print stations. Thus, in preferred embodiments, the decorative patterning may be applied to the opposing face of the paper substrate immediately after application of the barrier coating.
[0174] For example, a paperboard substrate could be coated using the process of the invention and then fed directly into a second printing process to decorate the opposing surface using e.g. a gravure or flexographic printing process. In this way, paperboard products such as cereal boxes can be formed in a single, in-line printing process, which have a barrier coating on the internal surface and the branding and nutritional information on the external surface.
[0175] The present invention is illustrated with reference to the following non-limiting examples.
EXAMPLES
Example 1
Reference
[0176] A 12% w/v solution of polyvinyl alcohol from Mowiol (grade 23-88-solution viscosity ˜2.1 Pa·s) was coated onto the reverse of MCM board using the gravure printing cylinders having the specifications as set out in the table below. The coating weight was approximately 4 gsm.
[0177] The first cylinder (Example 1b) was a conventional cylinder typically used to apply standard metal inks.
[0178] The second cylinder (Example 1c) was a Haschur cylinder having rectangular cells ( FIG. 1 d ), while the third cylinder (Example 1d) was a Wabe cylinder having hexagonal cells ( FIG. 1 b ).
[0179] After printing, the heptane vapor transmission rate was measured using the methodology described above. The results are shown in the table below:
[0000]
Cell
Volume
Cell Depth
Lines per
Number of
Weight loss
Example
(cm 3 /m 2 )
(μm)
cm
coats
(mg)
1a
—
—
—
—
6321
1b
35
56
40
2
5121
1c
75
75
30
1
2223
1d
67
75
30
1
785
[0180] The results show that increasing the cell volume and depth provides coatings with superior barrier properties. Thus, the conventional gravure roll (Example 1b) showed little improvement in the weight loss even after two coats. Despite having only one coat, the bespoke gravure rolls provided coatings having significantly improved barrier properties. The Wabe cylinder provided the best results, possibly due to the improved packing of the hexagonal cells.
Example 2
Reference
[0181] A12% w/v solution of Mowiol 28-99 polyvinyl alcohol (viscosity ˜5-7 Pa·s) was printed using gravure cylinders having the following characteristics:
[0000] Cylinder 1—cell volume 109 cm 3 /m 2
cell depth 140 μm 10 lines per cm
Cylinder 2—cell volume 99 cm 3 /m 2
20 lines per cm (hexagonal cells)
[0185] The mixture was found to be too viscous and failed to spread out after deposition on the substrate. The resultant coating consisted of a discontinuous array of dry droplets, each adhering firmly to the board but separated from the others.
Example 3
[0186] Mixtures of polyvinyl alcohol and inorganic particulate were gravure printed on a paper board substrate. The mixtures comprised either Mowiol 28-99 polyvinyl alcohol, or a 50:50 w/w mixture of Mowiol 28-99 polyvinyl alcohol with kaolin clay. The liquid phase mineral oil transmission rates were measured using the DIPN test set out above. The following results were obtained:
[0000]
DIPN
from
orange
peak
Example
Coating
(ppm)
3a
None
—
3b
PVOH
5
3c
PVOH/Kaolin A
1.5
3d
PVOH/Kaolin B
3
[0187] The results show that including the inorganic particulate reduces the transmission rate as compared to the polyvinyl alcohol alone. Kaolin A was found to give better barrier properties as compared to Kaolin B.
Example 4
[0188] Compositions formed from 50:50 w/w mixtures of Mowiol polyvinyl alcohol and kaolin inorganic particulate were gravure printed on board substrates. The OVTR of the printed substrates were then evaluated using the protocol set out above, and the results are shown in the table below:
[0000]
Total
solids
Coating
OVTR
Example
PVOH
Kaolin
(% w/v)
weight (gsm)
(g/m 2 · 24 hrs)
4a
5-88
Kaolin A
31.5
6
6.75
4b
5-88
Kaolin A
31.5
9
5.73
4c
8-88
Kaolin A
25.33
5
12.99
4d
8-88
Kaolin A
25.33
7
8.06
4e
8-88
Kaolin A
25.33
8
8.06
4f
8-88
Kaolin A
25.33
10
8.02
4g
8-88
Kaolin B
26
6
6.41
4h
18-88
Kaolin A
19
4
27.61
4i
18-88
Kaolin A
19
7
15.86
4j
18-88
Kaolin A
23
4
15.7
4k
18-88
Kaolin A
23
5
10.1
4l
18-88
Kaolin A
23
9
6.32
4m
18-88
Kaolin B
18.2
5
8.84
4n
18-88
Kaolin B
21.1
5
11.26
4o
10-98
Kaolin A
20
6
7.2
4p
10-98
Kaolin A
29
6
6.02
4q
10-98
Kaolin B
22.5
6
10.91
4r
10-98
Kaolin B
22.5
10
6.92
4s
10-98
Kaolin B
25.8
6
7.55
4t
20-98
Kaolin A
20
4
10.99
4u
20-98
Kaolin B
18
5
6.77
4v
20-98
Kaolin B
18
9
5.07
|
Improved processes for applying barrier coatings for paper substrates, and to paper substrates made by such processes are described herein. The processes of the present invention use modified gravure printing to apply coatings that include polyvinyl alcohol and inorganic particulate material. The barrier coatings help to prevent substances from leaching through to spoil the decorative surfaces of the paper substrates, and/or mitigate the effect of any substances that may leach from the paper substrate.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Patent Application No. 61/703,324 filed Sep. 20, 2012.
FIELD
[0002] The present invention relates generally to a disposal system for vacuumed dust and debris using sealable bags.
BACKGROUND
[0003] Bagless vacuum cleaners are increasingly popular for a variety of reasons which include the ability to visually inspect vacuumed contents, and the ability of the vacuum cleaner to maintain suction even when the dust and debris canister is full. Such vacuum cleaners however, can be messy when emptied. Dust and debris can become compacted in the vacuum cleaner. Agitating the vacuum cleaner vigorously over a waste bin in order to free the contents only makes matters worse by inducing fine particles of dust; some under 1 micron, to become airborne. Allergic sensitization, allergic reactions, exacerbation of asthma, and other health problems can be triggered by such airborne dust. It would be desirable to provide a disposal system that avoids spreading dust and debris.
SUMMARY
[0004] The present invention relates generally to a system for the collection and containment of vacuumed dust and debris, and more particularly to waste disposal bags for placement over a portion of a bagless vacuum cleaner, and into which the waste contents of the vacuum cleaner are emptied. In particular embodiments presented herein, when a bag opening encircles the portion of a vacuum cleaner, a tightening means for cinching the bag such that it stays connected to the vacuum cleaner can be transversely applied across or around the bag. The tightening means can be tape strip which partly or wholly encircles the bag, rubber banding partly or wholly encircling the bag, or any elastomeric or adhesive material partly or wholly encircling the bag. One embodiment described herein possesses a section of tape that is transversely applied across a bag that has been partially folded against itself once it is mounted to a waste container of a vacuum cleaner. The tape secures the fold and serves to restrict the bag opening encircling a waste containing portion of the bagless vacuum cleaner which is either connected to (in situ), or separated from the vacuum cleaner. Once waste has been transferred from the vacuum cleaner, the bag is separated therefrom, and the bag opening is sealed by pulling a portion of the opening having a section of pressure sensitive adhesive, over the bag opening.
[0005] In one aspect of the present invention, a bag opening 200 possesses both a projecting portion and a relatively less projecting portion. On the inner facing side of the projecting portion is at least one, and preferably two light-tack adhesive bands which are exposed by peel-way strips. Prior to applying the bag to a waste container of a vacuum cleaner, one of two adhesive bands on the projecting portion is exposed by removing a peel away strip. When pulling the bag opening over the waste container, one of the exposed light-tack adhesive bands is pressed against the body of the vacuum cleaner. To completely encircle the waste container, the bag is folded against itself as shown in FIG. 6 , and adhesive strap 270 c is placed across the fold line(s) 231 to cinch the bag opening about the waste container. When waste transfer is complete, (1) the previously applied light-tack adhesive band is separated from the bag, (2) the bag is detached from the waste container, (3) a second adhesive band on the projecting portion is exposed, and (4) the projecting portion is folded over and adhered to portions of the bag adjacent the non-projecting portion.
[0006] In another aspect of the present invention, a waste transfer and disposal bag has an opening that is flared somewhat like a funnel with an elasticized waist below the opening. The flared portion is grasped by a user in order to pull the elasticized waist over a portion of a vacuum cleaner. The elasticized waist receives, and fully encircles a portion of the vacuum cleaner; typically that portion which leads to the waste compartment, to prevent dust from escaping and becoming airborne. A bag sealing means includes an adhesive strip exposed by a peel-away backing on a portion of the flared opening which is pressed against another portion of the bag in order to seal the opening.
[0007] In yet another aspect of the present invention, an elasticized waist resides below the opening, producing a flared section comprised of projecting and non-projecting portions which are grasped by a user in order to pull the elasticized waist over a portion of a vacuum cleaner for emptying of vacuumed contents. When the waste transfer is complete, the bag is separated from the vacuum cleaner and a sealing means including an adhesive strip, preferably on a surface of the projecting portion, is folded over and adhered to portions of the bag adjacent the non-projecting portion.
[0008] The waste disposal bag of the present invention can include a handle or handles which comprise any portion of the bag extending above the bag opening.
[0009] It will be appreciated by those of ordinary skill in the art that elastic or inelastic bands, flat bands constructed of paper or other material having adhesive portions extending transversely over fold line(s) or gathers produced when bunching or reducing the bag opening to snuggly encircle a waste container can be employed without departing from the spirit and scope of the present invention. Those having ordinary skill in the art will appreciate that the body of the transfer and disposal bag can be any material such as plastic, paper, plastic and paper laminates, non-woven synthetics, biodegradable compositions, or any combination of the foregoing whether of single or multiple ply construction. Bags can be produced with or without gussets. Bag manufacture can employ among other processes, blow molding, heat sealing, sonic welding, folding, laminating and gluing together at seams, if any are present.
[0010] It will be appreciated by those of ordinary skill in the art that any elastic material such as flat or cylindrical bands, elastic thread with Lycra® or other suitable material whether natural or synthetic, can be used to produce the elasticized waist of the bag without departing from the spirit and scope of the present invention. Elastic stitching can be applied over circumferential elastic banding to attach the banding to the plastic bag, or elastic materials can be bonded directly to the bag through adhesive means which can include spray application of an elastomer over the elastic materials. The elastic elements can be bonded to the bag in various ways, such as the exemplary methods enumerated in U.S. Pat. No. 6,921,202 to Raterman, which is incorporated herein by reference in its entirety, or by elastic elements sandwiched between relatively non-elastic regions of the bag to constrict the bag opening. One method of attaching a rubber band circumferentially about a bag is to place the bag over a supportive frame that will maintain the bag in a flattened aspect and attach an elastic element to the outer surface of the bag using any suitable attachment means, whether by gluing, heat bonding or by stitching the elastic element to the bag. In any case, it is not intended that this disclosure limit the present invention to any one means of producing an elastic waist for fitting over and conforming to a portion of a vacuum cleaner.
[0011] The foregoing and other objects, features, and advantages of the invention will become more apparent from the following detailed description, which proceeds with reference to the accompanying figures wherein the scale depicted is approximate.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a plan view of one embodiment of a waste transfer and disposal bag according to the present invention in which the body of the bag has been flattened to show the upper projecting portion 210 with upper lip 212 a, and the lower portion 211 bordered by lip 212 b.
[0013] FIG. 2 is a plan view of the embodiment shown in ( FIG. 1 ) after filling with debris and separated from a waste container, in which lower lip 212 b is pulled up over lower adhesive band 270 b;
[0014] FIGS. 3 and 4 are sequential plan views of one sealing operation for the embodiment shown in ( FIG. 2 ) after filling with debris and separated from a waste container, in which a corner of the projecting portion 210 is pulled over exposed adhesive band 270 a;
[0015] FIG. 5 is a plan view of an embodiment of a waste transfer and disposal bag according to the present invention in which the body of the bag has been flattened to show the upper projecting portion 210 with adhesive bands 270 a, 270 b which are exposed via peel-away strips 272 , upper lip 212 a, and the lower portion 211 bordered by lip 212 b.
[0016] FIG. 6 depicts a preparatory step prior to attaching waste disposal bag 100 to a portion of a vacuum cleaner in which the lower adhesive band is exposed by peeling away strip 272 , and the bag is partially folded over itself to reduce opening 200 ;
[0017] FIG. 7 in a view taken from projecting side 210 , shows the embodiment of ( FIGS. 1-6 ) attached to a waste containing portion of a vacuum cleaner;
[0018] FIG. 8 in a view taken from lower side 211 , shows the embodiment of ( FIGS. 1-6 ) attached to a waste containing portion of a vacuum cleaner;
[0019] FIG. 9 is a view taken from projecting side 210 , of the waste and debris exiting the waste container of a vacuum cleaner into the bag;
[0020] FIG. 10 depicts the bag having been removed from the vacuum cleaner with peel away strip 272 being removed from top adhesive band 270 a in preparation for bag sealing;
[0021] FIGS. 11 and 12 are plan views of the embodiment shown in ( FIGS. 1-6 ) illustrating an alternative sealing operation, and showing respectively, flap 210 folded over top opening to seal the bag, and the reverse side of ( FIG. 11 ) showing corners c′ and d′ wrapped around the bag and brought together.
[0022] FIG. 13 is a plan view of a waste transfer and disposal bag according to the present invention in which the body of the bag has been flattened and stretched to show the position of an elasticized waist, indicated by the zig-zag lines;
[0023] FIG. 14 shows the bag of ( FIG. 13 ) in which the elasticized waist is relaxed, constricting the bag and forming gathers;
[0024] FIG. 15 a shows an exemplary method of forming an elasticized waist about the waste transfer and disposal bag according to the present invention;
[0025] FIG. 15 b shows another exemplary method of forming an elasticized waist about the waste transfer and disposal bag according to the present invention;
[0026] FIG. 15 c shows still another exemplary method of forming an elasticized waist about the waste transfer and disposal bag according to the present invention;
[0027] FIG. 15 d shows yet another exemplary method of forming an elasticized waist about the waste transfer and disposal bag according to the present invention;
[0028] FIG. 15 e shows yet another exemplary method of forming an elasticized waist with multiple rows of elastic material such as threading, banding or flocking, about the waste transfer and disposal bag that are printed on, stitched, glued, fused, sonically welded, laminated, or otherwise applied to the bag to produce a constricting effect when the bag opening is placed over a part of a vacuum cleaner;
[0029] FIG. 16 is a plan view of a waste transfer and disposal bag according to the present invention in which the body of the bag has been flattened and stretched to show the relative position of elasticized waist 220 , in which elastic element 240 is a flat elastic band circumferentially affixed to the bag;
[0030] FIG. 17 shows the bag of ( FIG. 16 ) in which the elasticized waist is relaxed, constricting the bag and forming gathers;
[0031] FIGS. 17 a and 17 b show a portion of the bag doubled against itself and stitched or heat sealed to form a channel for an elastic element;
[0032] FIG. 18 is a longitudinal view looking directly into opening 200 of a waste and disposal bag according to the present invention;
[0033] FIG. 19 is a cross-sectional view taken along lines 4 ′- 4 ′ of ( FIG. 18 ) showing bag opening 200 having a lower non-projecting portion transitioning to projecting portion 210 ;
[0034] FIG. 20 is a side view of a waste transfer and disposal bag according to the present invention showing a flaring portion above the elasticized waist 220 of the bag;
[0035] FIG. 21 is a side view of a filled waste transfer and disposal bag according to the present invention in which projecting portion 210 occludes the opening
[0036] FIG. 22 depicts opening 200 and waist 220 of the waste transfer and disposal bag according to the present invention encircling a portion of a vacuum cleaner;
[0037] FIG. 23 shows the bag of ( FIG. 22 ) with dust and debris transferred from the bagless vacuum cleaner;
[0038] FIG. 24 is a front view of the bag shown in ( FIGS. 22 and 23 ) with projecting portion 210 pulled over bag opening 200 and adhered to an opposite side of the bag;
[0039] FIG. 25 is a plan view of a flattened and stretched waste transfer and disposal bag with handles according to the present invention;
[0040] FIG. 26 shows bag of ( FIG. 25 ) in a relaxed state;
[0041] FIG. 27 shows bag of ( FIG. 25 ) in a relaxed state with the projecting portion 210 with adhesive strip 270 pulled over and sealing the opening;
[0042] FIG. 28 shows bag being grasped by the flared portion;
[0043] FIG. 29 shows bag being pulled over a detached waste canister from a bagless vacuum cleaner.
DETAILED DESCRIPTION OF THE INVENTION
Reference Listing
[0000]
100 bag
200 opening
210 projecting portion
211 lower portion
212 a upper lip
212 b lower lip
220 elasticized waist
230 gather
231 fold line
232 overlay
240 elastic element
250 gusset
270 adhesive
270 a upper adhesive band
270 b lower adhesive band
270 c cinching adhesive strap
271 release strip
272 peel-away strip
273 tab
280 handle
300 vacuum cleaner
400 debris
Definitions
[0066] In the following description, the term “bag” refers to a bag which is sized and shaped for placement over a waste containment portion, or waste container, of a bagless vacuum cleaner. Bagless vacuum cleaners typically possess a waste and debris canister with or without an access flap for emptying vacuumed waste. The bag of the present invention is sized and shaped to accept, encircle, and conform to at least a waste containing portion of a bagless vacuum cleaner which is either in-situ or separated from the vacuum cleaner. Unless otherwise explained, any technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The singular terms “a”, “an”, and “the” include plural referents unless the context clearly indicates otherwise. Similarly, the word “or” is intended to include “and” unless the context clearly indicates otherwise. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of this disclosure, suitable methods and materials are described below. The term “comprises” means “includes.” All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety for all purposes. In case of conflict, the present specification, including explanations of terms, will control. In addition, the materials, methods, and examples are illustrative only and not intended to be limiting.
[0067] Referring generally to FIGS. 1-29 , a transfer and disposal system for dust and debris which is particularly suited for bagless vacuum cleaners includes bag 100 with opening 200 having a projecting portion 210 terminating in upper lip 212 a, and a non-projecting portion terminating in a lower lip 212 b. Gathers 230 or fold lines 231 may be produced about the bag circumference whereby the opening diameter is reduced in order to encircle and conform to a portion of a bagless vacuum cleaner 300 .
[0068] Turning to FIGS. 1-12 a preferred embodiment includes a cinching means comprising an adhesive band that is affixed over fold lines of the bag once the bag diameter has been reduced. When the vacuum cleaner and bag are coupled, dust and debris contained in the vacuum cleaner are transferred to the bag. Once the bag and vacuum cleaner are separated, in part by un-cinching the bag, a sealing means is provided comprising at least one adhesive band 270 a which is preferably on the projecting portion 210 of the bag which is folded over the bag opening.
[0069] FIG. 1 is a plan view showing projecting portion 210 and lower portion with lip 212 b. Two adhesive bands; upper band 270 a, and lower band 270 b are covered with peel-away strips 272 . A third adhesive strap 270 c has an adhesive face toward release strip 271 which is similar to the peel-away strips 272 and permanently attached to the bag body. FIG. 2 is a plan view of the embodiment shown in ( FIG. 1 ) after filling with debris and separated from a waste container, in which lower lip 212 b is pulled up over lower adhesive band 270 b, thus forming a first seal of the bag opening. FIGS. 3 and 4 are sequential views of one sealing operation for the embodiment shown in ( FIG. 2 ) after it is filled with debris and separated from a waste container, and in which a corner c′ of the projecting portion 210 is pulled over to adhere exposed adhesive band 270 a to the bag body.
[0070] FIG. 5 is a plan view of an embodiment of a waste transfer and disposal bag according to the present invention in which the body of the bag has been flattened to show the upper projecting portion 210 with adhesive bands 270 a, 270 b which are exposed via peel-away strips 272 , upper lip 212 a, and the lower portion 211 bordered by lip 212 b. FIG. 6 depicts a step prior to attaching waste disposal bag 100 to a portion of a vacuum cleaner in which lower adhesive band 270 b is exposed by peeling away strip 272 , and the bag is then partially folded 231 over itself to reduce opening 200 .
[0071] FIGS. 7-9 shows an exemplary configuration for coupling the bag 100 to a vacuum cleaner. FIG. 7 shows the projecting portion 210 with adhesive strips facing the vacuum cleaner. Bottom strip 270 b can been exposed to adhere to the vacuum cleaner's surface. FIG. 8 shows the configuration from side opposite ( FIG. 7 ), and depicts a portion of the bag folded 231 over itself to shape and size the opening 200 to the particular vacuum cleaner. Adhesive strap 270 c is placed across fold line 231 to cinch the opening about the vacuum cleaner. FIG. 9 shows waste 400 transferred from the vacuum cleaner to the bag.
[0072] FIG. 10 shows adhesive strap 270 c having been detached from the bag in order to disconnect the bag from the vacuum cleaner. Peel-away strip 272 is removed to expose the top adhesive band 270 a in preparation for sealing.
[0073] FIGS. 11 and 12 in one sealing configuration, shows a first side of the bag in which (1) the top lip 212 a of the projecting portion pulled over to occlude the opening 200 , and on the opposite side, (2) corners c′ and d′ wrapped around the bag and brought together. Note that dotted lines in FIGS. 11 and 12 represent lower lip 212 b beneath projecting portion 210 .
[0074] Turning to FIGS. 13-29 , a transfer and disposal system for dust and debris includes bag 100 with opening 200 having a projecting portion 210 terminating in upper lip 212 a, and a non-projecting portion terminating in a lower lip 212 b. An elasticized waist 220 in a relaxed state forms gathers 230 about the bag circumference whereby the opening diameter is reduced, and in a stretched state allows the waist to encircle and conform to a portion of a bagless vacuum cleaner 300 . When the vacuum cleaner and bag are coupled, dust and debris contained in the vacuum cleaner are transferred to the bag. Once the bag and vacuum cleaner are separated, a sealing means is provided comprising an adhesive strip which is preferably on the projecting portion of the bag.
[0075] FIG. 13 depicts a waste transfer bag with an elasticized waist portion 220 . It should be understood that the FIG. 13 does not represent a normal state of the bag, but schematically shows the relative positions of the bag elements if the bag were to be stretched and flattened, such as between two panes of glass. Once the circumferential elasticized waist is applied, the bag assumes the relaxed state shown in FIG. 14 . The elasticized waist produces gathers in immediately adjacent sections, and a flaring above the waist. Regarding FIG. 14 , it should be noted that the grid pattern shown on projecting portion 210 is a visual device to help distinguish the projecting portion form the lower portion. Both portions are flared and together (1) serve as a guide to inserting a portion of a vacuum cleaner and (2) provides a user with easily gripped regions for positioning the waist 220 over a portion of a vacuum cleaner. Regarding the flared portion, the projecting and non-projecting portions transition from one to the other, and are therefore contiguous.
[0076] FIGS. 15 a - 15 d show various exemplary methods for producing an elasticized waist 220 . In FIG. 15 a, a flat elastic element 240 , is attached to the inside or outer surface of the bag by stitching which is indicated in the broken zig-zag pattern. FIG. 15 b shows a zig-zag pattern formed by a bonded elastic element(s) such as a cylindrical rubber strands arranged in a zig-zag pattern which can be heat bonded or otherwise adhered to the bag circumference by glue or spraying a coating of an elastomer over the strands. FIG. 15 c shows a flat elastic band shown in dotted line on the outer surface of the bag, yet beneath an strip overlay 232 bonded to the bag's surface which secures the elastic member to the bag. Likewise, FIG. 15 d shows a zig-zag pattern formed by an elastic strand shown in dotted line beneath an applied strip overlay. The overlay can be the same material as the bag body, such as polyethylene or cellophane which is glued or heat sealed over the elastic element. While it is preferable that the elastic elements completely encircle the bag to form a continuous waist, the elastic elements and bonding means can be applied in multiple non-connecting sections about the circumference of the bag.
[0077] FIG. 16 shows waste disposal bag 100 in a flattened aspect possessing a flat elastic member 240 which can be one or more elastic elements, such as rubber bands about the circumference of the bag producing an elasticized waist 220 . FIG. 17 shows the bag of ( FIG. 16 ) in a relaxed state producing a constricted waist. Regarding FIG. 17 , the grid pattern shown on projecting portion 210 is a visual device to help distinguish the projecting portion 210 from the lower portion. FIG. 17 a is cross-sectional views taken along lines 3 ′- 3 ′ of FIG. 16 , depicting a possible configuration for the elasticized waist in which a portion of the bag is doubled back and adhered to itself to form a channel resembling a casing for the elastic element. FIG. 17 b is another possible configuration showing the channel formed on the inside of the bag.
[0078] FIG. 18 is a view looking directly into the opening of a waste and disposal bag according to the present invention. FIG. 19 is a cross-sectional view taken along lines 4 ′- 4 ′ of ( FIG. 18 ), and best shows projecting portion 210 as it relates to bag opening 200 and elasticized waist 220 . The transition between upper and lower portions of the opening can be curved, or any transition profile between the respective portions of the opening possessing suitable tear resistance can be used.
[0079] FIG. 20 and FIG. 21 are side views showing respectively, a waste transfer and disposal bag 100 before and after filling. While the projecting portion has an adhesive region 270 which is preferably covered by a peel-away strip (not shown), it is intended that the adhesive region can be of any size up to entirely covering a side of the projecting portion, or positioned on another portion of the bag adjacent lower lip 212 b. After filling the bag, projecting portion 210 is folded over the opening. Although FIG. 21 shows a gap (at top) between the projecting and lower portions, this would not ordinarily be the case, because the projecting portion can adhere to any adjacent region of the bag and completely occlude the bag's opening.
[0080] FIG. 22 shows waste transfer and disposal bag 100 in which elasticized waist 220 has been pulled over an end of a waste filled bagless vacuum cleaner 300 . In some vacuum cleaners a movable flap covers the waste compartment, while in others the waste compartment can be completely separated from the vacuum cleaner. In any case, the elasticized waist fits snugly over the vacuum cleaner or a portion thereof during waste transfer to eliminate spillage and airborne dust. FIG. 23 shows the bag with transferred waste from the vacuum cleaner. FIG. 24 shows the bag when separated from the vacuum cleaner and sealed.
[0081] FIGS. 25-27 shows waste disposal bag 100 with handles 280 which can be any part of the bag projecting beyond the opening. FIG. 28 is a perspective view showing the constricted waist and the flaring of the bag opening. FIG. 29 shows the bag being pulled over a detached waste canister of a bagless vacuum in which the elasticized waist conforms to the shape of the canister. The bag is mounted over a portion of a vacuum cleaner by grasping the flared section on both sides of the bag in order to stretch the elasticized waist over the vacuum cleaner.
[0082] It should be understood that the drawings and detailed description herein are to be regarded in an illustrative rather than a restrictive manner, and are not intended to be limiting to the particular forms and examples disclosed. For example, modifications to the bag structure such as the minimum and maximum diameter of opening 200 in order to accommodate a particular make and model of vacuum cleaner as well as the type of closure element(s) used to cinch and therefore temporarily reduce the opening for snug fitting about a vacuum cleaner body, as well as the type of elastic elements used for the waist and the particular method of applying the elastic elements to the bag can be altered as required without departing from the scope of the invention. The bag itself can be rectangular when seen in a plan orientation, or any other shape for fitment about a vacuum cleaner that will suggest itself to a person of ordinary skill in the art. Accordingly, it is intended that the invention encompass any further modifications, sealing configurations consistent with the disclosed bag structure, changes, rearrangements, substitutions, alternatives, design choices, and embodiments as would be appreciated by those of ordinary skill in the art having benefit of this disclosure, and which fall within the spirit and scope of the following claims.
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A system for the collection and containment of vacuumed dust and debris, and more particularly to waste disposal bags for placement over a portion of a bagless vacuum cleaner, and into which the waste contents of the vacuum cleaner are emptied includes a bag body with a projecting portion and a relatively less projecting portion, an opening which is constricted about a portion of the bagless vacuum cleaner, and a light-tack adhesive strip facing the vacuum cleaner for temporarily affixing the bag thereto. The projecting portion serves as a flap that is folded over the opening to seal the bag once the bag is separated from the vacuum cleaner.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates, generally, to means for applying an anti-coagulant to intravenous devices, needles, and operating room surfaces. More particularly, it relates to an anti-coagulant-containing pad and to methods for using the pad.
2. Description of the Prior Art
Heparin-quaternary ammonium compounds have been used for many years as non-thrombogenic coatings for catheters. The advent of nonionic intravenous contrast media has increased interest in the use of this material due to the lack of any of the antithrombogenic activity demonstrated by ionic contrast media. Heparin acts as an anti-coagulant, increasing the time a catheter or stent can remain inserted in the body without danger of a blood clot occluding or causing other problems with the procedure. Excessive amounts of heparin hemolyse (break apart) red blood vessels. Many catheters are now pre-coated by catheter manufacturers using the concentrations mentioned below.
Heparin coatings have been applied to catheters made with polyethylene, polyurethane, Teflon®, nylon, vinyl, and to stainless steel and Teflon-coated guidewires.
Additional uses for heparin coatings include vascular stents, tubing for heart-lung bypass machines, indwelling catheters and drains, renal dialysis tubing, and cell saver tubing.
Pre-coating of catheters is usually achieved by dipping the device into a coating solution, evaporating the solvent, which may be isopropyl alcohol, or other suitable solvent, and packaging the device.
Dipping catheters and other devices creates a thick coating. Some of these coatings can be thick enough to occlude small-bore catheters. The FDA has recalled some small bore catheters for this reason. Moreover, the coatings become brittle with age and may flake off, thereby reducing the shelf-life of such devices.
Thus a need exists for an improved method for coating catheters, stents, and other medical devices with an anti-coagulant in a way that does not occlude small bore catheters. The improved method should also extend the shelf-life of a coated device.
Nuclear pharmacies load brachytherapy needles with radioactive seeds and send such needles to hospitals for implantation of the seeds into the prostate glands of prostate cancer patients. From time to time, not all of the seeds are implanted and the hospital returns the bloodied needle containing unused seeds to the nuclear pharmacy that supplied the needle and seeds for proper radioactive material disposal. This is problematic because mixed waste (biohazardous and nuclear) is being sent through the mail. Moreover, the nuclear pharmacy may not be licensed to handle such mixed waste materials. Most nuclear pharmacies are not so licensed. An improved means is therefore needed for cleaning blood from needles.
Drapes and sheets are used to absorb blood from surgical procedures. Blood is the most common contaminate of stainless steel trays, surgical room floors, surgical table pedestals, etc. The cleanup process after an operation is extremely important. Current methods for cleaning and decontamination include the use of biocides and hand-scrubbing of surfaces to remove blood splatter or clotted pools of blood. The cleaning and disinfecting must be thorough and completed before the operating room is used again. Current methods of scrubbing down the operating room and removing blood residue therefrom are time-consuming, labor-intensive, and subject to failure if the workers are insufficiently fastidious in their approach to the job.
An improved method is therefore needed to remove blood and other contaminates from operating rooms, stainless steel trays, and other surfaces.
U.S. Pat. No. 6,488,943 to Beerse et al. discloses antimicrobial wipes that provide improved immediate germ reduction. The disclosure does not address the treating of medical devices with anti-coagulants or the removal of blood from needles or other surfaces. Similarly, U.S. Pat. No. 6,489,284 to Suazon et al. discloses a dishwashing cleaning wipe including a single layer needle punched fabric wherein the fabric is impregnated with a cleaning composition. U.S. Pat. No. 6,429,183 discloses a cleaning wipe that includes a nonwoven fabric that is impregnated with an antibacterial composition.
In view of the prior art considered as a whole at the time the present invention was made, it was not obvious to those of ordinary skill in the pertinent art how the identified needs could be met.
SUMMARY OF THE INVENTION
The long-standing but heretofore unfulfilled need for means for repairing the H-BAC coating on a catheter, stent, or other intravenous device, for cleaning needles, and for decontaminating surfaces is now met by a new, useful, and nonobvious invention.
The novel method for enhancing or repairing an anti-coagulant coating on a medical device such as a catheter or stent includes the steps of providing a sterile, absorbent, soft, lint-free and at least slightly abrasive pad. An anti-coagulant in a solvent is applied to the pad and the pad is packaged in a sterile pouch to prevent evaporation of the solvent or deterioration of the anti-coagulant. The pouch is opened when a medical device that may or may not have an H-BAC coating is to be inserted into a mammalian body. The device, which may be a catheter, a stent, or the like, is wiped with the pad to apply the anti-coagulant thereto. If the medical device was previously coated with an anti-coagulant, the wiping of said device with the at least slightly abrasive pad removes cracked or loose anti-coagulant coating from the device and deposits another coating of the anti-coagulant onto the device. This repairs and rejuvenates the device and facilitates subsequent coatings as well.
In a second novel method, a needle is decontaminated. A sterile, absorbent, soft, lint-free and at least slightly abrasive pad is provided and an anti-coagulant in a solvent is applied to the pad. The pad is packaged in a sterile pouch to prevent evaporation of the solvent or deterioration of the anti-coagulant. The pouch is opened when a needle is to be decontaminated after having been inserted into a mammalian body. The needle is wiped with the pad to apply the anti-coagulant to the needle. The wiping process removes blood from the needle.
In a third novel method, surfaces that may come into contact with blood are decontaminated by providing a sterile, absorbent, soft, lint-free, and at least slightly abrasive pad. An anti-coagulant in a solvent is applied to the pad and the pad is packaged in a sterile pouch to prevent evaporation of the solvent or deterioration of the anti-coagulant. The pouch is opened when blood is to be removed from a surface. The surface is wiped with the pad to apply the anti-coagulant to the surface. The at least slightly abrasive pad removes cracked or loose anti-coagulant coating that may have been on the surface and deposits another coating of the anti-coagulant to the surface to facilitate future cleaning of the surface.
In all three novel methods, the preferred anti-coagulant is heparin-benzalkonium chloride. In a preferred formulation, the heparin-benzalkoniun chloride is formulated in a solution of 1.5% heparin-benzalkonium chloride (wt/vol) in a preselected solvent and the solution contains 850 USP heparin units/ml. The solvent is preferably isopropyl alcohol.
An important object of this invention is to provide methods for repairing medical devices that are pre-coated with an anti-coagulant and for re-coating said devices with an anti-coagulant just prior to their use.
Another important object is to provide a method for cleaning a needle after use.
Another important object is to provide a method for decontaminating surfaces such as surgical room floors, trays, and other items in an operating room in a way that is faster and more effective than conventional decontamination methods.
These and other important objects, advantages, and features of the invention will become clear as this description proceeds.
The invention accordingly comprises the features of construction, combination of elements, and arrangement of parts that will be exemplified in the description set forth hereinafter and the scope of the invention will be indicated in the claims.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A measured quantity of an anti-coagulant such as heparin-benzalkonium chloride (H-BAC) is put onto a wipe with a suitable solvent such as isopropyl alcohol and is packaged in a pouch.
In all embodiments, the wipe preferably takes the form of an absorbent, soft, substantially lint-free, and at least slightly abrasive material, preferably in the form of a pad.
The pad is formed of a material selected from a group of materials consisting of continuous filament, knitted nylon, continuous woven polyester, nonwoven polyester, hydroentangled polyester, and nonwoven polyester/cellulose. The material should be non-shedding as well. The pad may also take the form of a nonwoven fabric, a single layer needle punched fabric, or the like, i.e., it may be of any suitable absorbent material that may be impregnated with a compound as long as the material exhibits the desired qualities of abrasiveness, softness, absence of lint, and the like. The pad need not be thick and may be as thin as a sheet of paper. In a preferred embodiment, the pad is gauze-like.
In a first embodiment, an anti-coagulant is applied to the pad and the pad is packaged in a sterile pouch to prevent evaporation of the solvent or deterioration of the anti-coagulant. The pouch is opened at a time prior to the moment when a medical device that may or may not have an H-BAC coating is to be inserted into a mammalian body. The exterior surface of the device, which may be a catheter, a stent, or any other intravenous device, is wiped with the pad to apply the anti-coagulant thereto.
If the medical device was previously coated with an anti-coagulant, the wiping of the device with the at least slightly abrasive pad removes cracked or loose anti-coagulant coating from the device and deposits a new, rejuvenating coating of the anti-coagulant to the device. This repairs and rejuvenates the device and facilitates its future coating as well.
If the device was not previously coated with an anti-coagulant, the wiping of the device with the novel anti-coagulant pad ensures that the device will have a suitable coating of anti-coagulant thereon prior to its insertion into the body. The introduction of a foreign device, such as a catheter, into the bloodstream can induce substantial clot formation on the device surface. With an untreated catheter, almost the entire surface may be covered with clots in the first twenty four (24) hours after catheter placement. This clotting tendency is greatly reduced, or completely eliminated, by coating the catheter with heparin. This greatly increases the patient's safety and thus reduces complaints against the physician and the hospital.
The preferred formulation of the H-BAC disclosed herein is substantially similar to the formulation of said anti-coagulant as used by catheter manufacturers. However, since the anti-coagulant is applied in the novel way disclosed herein, the dipping process of the prior art and the associated problem of occluding a catheter lumen is avoided. Also avoided are excessive heparin concentrations which may cause hemolysis of red cells which contact the thickly coated device.
In the second novel method, a needle is cleaned by wiping the needle with the novel anti-coagulant-treated pad. Although any needle requiring decontamination may be cleaned by this novel method, it has particular utility in cleaning needles that are covered with blood or other biohazardous bodily fluids and which need to be sent through the mail to a manufacturer. Prior to this disclosure, decontamination of such needles was problematic.
For example, brachytherapy needles are loaded with radioactive seeds and sent to hospitals for implantation of the seeds into the prostate glands of prostate cancer patients by nuclear pharmacies. From time to time, not all of the seeds are implanted and the hospital returns the bloodied needle containing the remaining seeds to the nuclear pharmacy that supplied the needle and the seeds for proper disposal of nuclear waste. Most nuclear pharmacies are not licensed to handle bio-hazardous mixed waste. This disclosure teaches that the novel pad having the heparin-benzalkonium chloride solution is advantageously used at the hospital to remove the blood or other fluids from the needle so that the hospital does not return biologically hazardous mixed waste to the nuclear pharmacy. The novel H-BAC abrasive wipe combination quickly and easily breaks down and removes any clotted blood residue on the needle, thereby solving a long-existing problem in the medical service and nuclear pharmacy industries.
Although the novel pad may be used as preferred by the user, the preferred method of use includes the steps of wiping the needle or catheter by placing the needle on the pad, folding the pad over the needle, and withdrawing the needle while the pad remains folded over the needle. This procedure efficiently applies the anti-coagulant to the needle and simultaneously scrubs the needle.
In the third novel method, surfaces that may come into contact with blood are decontaminated by wiping said surfaces with the novel anti-coagulant-containing pad before the surfaces become bloodied to preclude the blood from clotting on such surfaces. This facilitates post-operative clean-up and decontamination of all pre-treated, bloodied surfaces. Advantageously, continued, repeated use of the H-BAC wipe during clean-up puts another layer of heparin on the cleaned surface and thereby facilitates the next cleaning of the surface. The amount of anti-coagulant used in the wipes may be adjusted so that it is sufficient to hemolyse the red blood cells, thereby preventing their ability to dry, stain, and clot.
Significantly, since the anti-coagulant prevents blood from coagulating, drying, and staining a treated surface, the clean-up after an operation is not only much easier, it is also much faster. The time saved reduces the time between operations and thus increases the profitability of the operating room.
The three exemplary uses for the novel pad disclosed herein are not exhaustive and other uses for the novel pads are included within the scope of this invention. The concentration of H-BAC may be varied for specific purposes. For example, there may be a first concentration for wiping catheters, a second concentration for cleaning needles, a third concentration for wiping operation room floors, a fourth concentration for wiping trays and other surfaces, and so on. The abrasiveness of the pad may also be varied, depending upon the task. The pad may also be manufactured to vary in its absorbability, its softness, and other characteristics as well.
It will thus be seen that the objects set forth above, and those made apparent from the foregoing description, are efficiently attained. Since certain changes may be made in the above construction without departing from the scope of the invention, it is intended that all matters contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.
It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention that, as a matter of language, might be said to fall therebetween.
Now that the invention has been described,
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A sterile, absorbent, lint-free, soft, and at least slightly abrasive pad is impregnated with an anti-coagulant. The pad is packaged in a sterile pouch and the pouch is opened to apply the anti-coagulant to an intravenous device such as a catheter or stent device, to clean blood from a used needle or to decontaminate an operating room surface. The anti-coagulant is preferably heparin-benzalkonium chloride formulated in a solution of 1.5% heparin-benzalkonium chloride by weight or volume, containing 850 USP heparin units per milliliter in a solvent such as isopropyl alcohol.
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BACKGROUND OF THE INVENTION
The present invention is directed to a composite papermaking fabric which is preferably used in the forming section but could also be used in the dryer section. The term composite fabric refers to a fabric comprising two woven structures one of which is the paper side fabric or upper fabric and the other of which is the machine side fabric or lower fabric. The paper side fabric includes a support surface which surface receives and supports the paper forming pulp during the paper forming operation. The lower or contact fabric separates the support fabric from the machine rollers during the paper forming operation and includes a roller contact or contact surface. Both fabrics must be stable and provide the required drainage. The support fabric must also provide an even support surface without unduly high knuckles or unduly deep knuckle depressions so as to not mark the paper during the paper forming operation.
The upper and lower fabrics are bound together with a binder yarn which in the instant case comprises fabric born or intrinsic warp yarns. The terms fabric born or intrinsic warp yarn indicates that the binder yarn while binding the upper and lower fabrics together also weaves in the machine direction with and is an integral part of the weave pattern of both the upper and lower fabrics. The term warp yam refers to yarns which weave in a single specified layer of the fabric and in the machine direction. The term weft yarn refers to yarns woven transverse of the warp yarns.
Composite papermaking fabrics are well known as are illustrated by the U.S. Pat. Nos. 5,152,326; 5,826,627; 6,202,705; and 6,240,973.
It is an object of the present invention to provide a composite papermaking fabric which provides uniform drainage, a smooth and even support surface and extended wear.
Another object of the invention is a papermaking fabric in which the support surface is formed in a one up, one down weave pattern.
Another object of the invention is a composite papermaking fabric in which fabric born or intrinsic warp yarns bind the upper and lower fabrics together and weave with weft yarns to form the lower fabric.
Another object of the invention is a composite papermaking fabric in which the weft yarn of the upper fabric at the binding points are supported against downward movement.
Another object of the invention is the provision of a composite papermaking fabric in which no pairing of weft yarns appear on either surface.
Another object of the invention is the provision of a composite papermaking fabric in which no pairing of warp and fabric born or intrinsic warp yarns appear on either surface.
SUMMARY OF THE INVENTION
The present invention is directed to a composite papermaking fabric having an upper fabric which includes a fiber support surface and is formed of warp yarns, fabric born or intrinsic warp yarns and weft yarns. The support surface is woven in a one up, one down weave pattern. The papermaking fabric also includes a lower fabric formed of fabric born or intrinsic warp yarns and weft yarns interwoven to provide a weft yarn dominated contact surface. Each fabric born warp or intrinsic yarn is controlled to weave over at least one of the upper fabric weft yarns during each repeat of the weave pattern forming binding points which act to bind the upper fabric with the lower fabric.
The preferred weave pattern requires that each fabric born or intrinsic warp yarn weave over two of the upper weft yarns to form two binding points which are spaced longitudinally of the weave pattern. The binding points form a broken twill line across the weave pattern and the width of the papermaking fabric.
To insure that the support surface is even and smooth, the upper warp yarns float beneath the upper weft yarns at each of the binding points forming a support beneath the upper weft yarns which acts to maintain knuckle height uniform across the support surface. The fabric born or intrinsic warp yarns weave with the weft yarns of the lower fabric in a broken twill pattern forming a plurality of even weft floats on the contact surface. There is a plurality of the weft yarn floats formed by each lower weft yarn per weave pattern repeat.
A composite papermaking fabric comprising an upper fabric formed with a support surface woven in a one up, one down weave pattern and a lower fabric formed with a weft dominated contact surface. The papermaking fabric comprises a plurality of warp yarns weaving with upper weft yarns in a selected first weave pattern and a plurality of fabric born or intrinsic warp yarns weaving with lower weft yarns in a selected second weave pattern forming the lower fabric and weaving with the upper weft yarns in the second selected weave pattern to cross over the upper weft yarns at selected locations forming binding knuckles. The fabric born or intrinsic warp yarns at the binding knuckles bind the upper fabric with the tower fabric. The binding knuckles cooperate with the knuckles of the warp yarns weaving in the first weave pattern to form the support surface in a one up, one down weave pattern.
The warp yarns weave beneath each of the upper weft yarn at the selected locations forming the binding knuckles providing support beneath the upper weft yarn and the binding knuckle which support assists in maintaining the binding knuckles parallel with the remainder of the knuckles of the support surface.
The weft yarn weaving with the fabric born or intrinsic warp yarns form the contact surface with two floats on the contact surface per pick throughout a weave pattern repeat.
DRAWINGS
FIG. 1 is a cutaway perspective view showing the support surface of the papermaking fabric through a portion of the weave pattern.
FIG. 2 is a cutaway perspective view showing the contact surface of the papermaking fabric through a portion of the weave pattern.
FIG. 3 is a side view showing the relationship of warp yarn 1 and fabric born or intrinsic warp yarn 2 with all of the weft yarns through the weave pattern.
FIG. 4 is similar to FIG. 3 showing the relationship of warp yarn 3 and fabric born or intrinsic warp yarn 4 with the weft yarns through the weave pattern.
FIG. 5 is similar to FIG. 3 showing the relationship of warp yarn 5 and fabric born or intrinsic warp yarn 6 with the weft yarns through the weave pattern.
FIG. 6 is similar to FIG. 3 showing the relationship of warp yarn 7 and fabric born or intrinsic warp yarn 8 with the weft yarns through the weave pattern.
FIG. 7 is similar to FIG. 3 showing the relationship of warp yarn 9 and fabric born or intrinsic warp yarn 10 with the weft yarns through the weave pattern.
FIG. 8 is similar to FIG. 3 showing the relationship of warp yarn 11 arid fabric born or intrinsic warp yarn 12 with the weft yarns through the weave pattern.
FIG. 9 is similar to FIG. 3 showing the relationship of warp yarn 13 and fabric born or intrinsic warp yarn 14 with the weft yarns through the weave pattern.
FIG. 10 is similar to FIG. 3 showing the relationship of warp yarn 15 and fabric born or intrinsic warp yarn 16 with the weft yarns through the weave pattern.
FIG. 11 is a diagram of the weave pattern of the support surface.
FIG. 12 is a diagram of the weave pattern of the contact surface.
DETAILED DESCRIPTION
Turning now to the drawings FIGS. 1 and 2 represent sectional perspective views of the composite papermaking in which the upper fabric A is formed with a paper pulp support surface C as shown in FIG. 1 and the lower contact fabric B which is formed with a lower roller contact surface D as shown in FIG. 2 . As shown in FIG. 1 and further illustrated in FIG. 11 , upper fabric A and more specifically, support surface C is woven in a one up, one down weave pattern allowing the support surface to present an even array of warp knuckles separated on each side by a weft knuckle. This is best illustrated in FIG. 11 where each X represents a warp yarn passing over a weft yarn on the support surface. Each passover forms a warp knuckle. Likewise, each weft yarn passing over a warp yarn on the support surface is represented by a blank square. These passovers form weft knuckles. Each X represents a binding point where the warp yarn passing over the weft yarn is an fabric born or intrinsic warp yarn.
The upper fabric A is woven utilizing eight warp yarns numbered 2 , 4 , 6 , 8 , 10 , 12 & 16 and with eight fabric born or intrinsic warp yarns numbered 1 , 3 , 5 , 7 , 9 , 11 , 13 & 15 per weave pattern repeat. The warp yarns and the fabric born warp yarns are arranged in pairs, i.e. fabric born warp yarn 1 and warp yarn 2 , fabric born warp yarn 3 and warp yarn 4 , etc. The weave pattern repeat also weaves with forty weft yarns numbered 1 – 40 . Weft yarns 2 , 3 , 5 , 7 , 8 , 10 , 11 , 12 , 13 , 15 , 17 , 18 , 20 , 22 , 23 , 25 , 27 , 28 , 30 , 32 , 33 , 36 , 37 , 38 & 40 weave with the warp yarns and the fabric born or intrinsic warp yarns to form the upper or support fabric A. Weft yarns 1 , 4 , 6 , 9 , 11 , 14 , 16 , 19 , 21 , 24 , 26 , 29 , 31 , 34 , 36 & 39 weave only with the fabric born or intrinsic warp yarn to form lower or contact fabric B.
Again turning to FIGS. 1 , 2 , 11 & 12 . In FIGS. 1 & 11 , the x represents the binding points or the positions in which a fabric born or intrinsic warp yarn passes over an upper weft yarn weaving with the support fabric A to bind the support fabric A with the contact fabric B forming the composite fabric. These binding points, which form binding knuckles 70 , are identified in FIGS. 1 and 3 – 10 .
FIGS. 3–10 are side views of each of the warp and fabric born or intrinsic warp yarns weaving with the weft yarns 1 – 40 through a complete repeat of the weave pattern. As is clearly shown, warp yarns 1 , 3 , 5 , 7 , 9 , 11 , 13 & 15 weave only with weft yarns 2 , 3 , 5 , 7 , 8 , 10 , 12 , 13 , 15 , 17 , 18 , 20 , 22 , 23 , 25 , 27 , 28 , 30 , 32 , 33 , 35 , 37 , 38 & 40 forming support fabric A. The weave pattern at selected points brings the upper warp yarns to float beneath five consecutive of the upper weft yarn picks, such as warp yarn 1 at the pick of weft yarns 15 , 17 , 18 , 20 & 22 in FIG. 3 and warp yarn 5 at the pick of weft yarns 5 , 7 , 8 , 10 and 12 in FIG. 5 . It is along these floats that the fabric born warp or intrinsic yarns are brought up to pass over two spaced picks, such as fabric born or intrinsic warp yarn 2 over picks 17 & 20 in FIG. 3 and fabric born warp yarn 6 over picks 7 and 10 in FIG. 5 , binding upper fabric A with lower fabric B. Throughout the remainder of the weave pattern, each of the fabric born or intrinsic warp yarns weaves with selected of the upper weft yarns securing support fabric A with contact fabric B at the binding points illustrated in FIG. 11 along each fabric born or intrinsic warp yarn. The binding points form a broken twill pattern over the support surface.
Again, as seen in FIGS. 1 & 3 – 10 at each binding point 70 , the associated upper warp yarn passes beneath the pick where the binding point is formed with the fabric born or intrinsic warp yarn. In the above referred to example , warp 1 passes beneath weft yarn or picks 17 & 20 at binding points 70 . Likewise in FIG. 5 warp yarn or pick 5 passes beneath weft yarns 7 & 10 at binding point 70 . By so controlling the upper warp yarns to be positioned beneath the binding points 70 they function to support the weft yarns and thereby the binding knuckles against vertical downward movement. This vertical support acts to help maintain the crest of the knuckles formed at binding points 70 elevated and on an even and substantially parallel plane with the remainder of the knuckles forming the support surface C. Also, by passing the upper warp yarns beneath the upper weft at the binding points no adjacent knuckles appear on the support surface at the binding points.
Turning now to FIGS. 2–10 & 12 contact fabric B will now be discussed. As seen in FIGS. 2 & 12 contact fabric B Is woven in a broken twill pattern with each fabric born or intrinsic warp yarn passing beneath four weft yarns at spaced locations on contact surface D. Each fabric born or intrinsic warp yarn either floats above the lower weft yarns and beneath the warp and weft yarns of the upper or support fabric A or passes over the two of the upper picks forming binding points 70 throughout the remainder of each weave pattern as earlier discussed.
Turning again to FIGS. 2 & 12 it can be seen that the weave pattern forming lower fabric B produces a weft dominated contact surface D with each weft weaving with the lower fabric warp yarns to form two floats per pick throughout the weave pattern each of which passes beneath three warp yarns. This weave pattern forms a weft yarn dominated running or contact surface D.
The yarns selected for forming the disclosed fabric may comprise yarns of the same diameter or of varying diameters if desired. For example, it may be desirable to weave the support fabric with weft yarns of less size than the weft yarns forming the contact fabric. The warp and the fabric born or intrinsic warp yarns preferably are of the same size. Variation in yarn size may be selected depending upon the performance requirements.
The materials chosen for the yarns can vary depending upon the performance needs of the formed papermaking fabric. Generally stability is of the utmost importance, it being desired that the drainage capability be maintained throughout the life of the papermaking fabric. Also, wearability is another vital factor due to cost. Accordingly, polyester yarns which exhibit excellent stability characteristics may be selected to form the support surface and as the fabric born or intrinsic warp yarns. The running or contact surface weft yarns may be polyamide yarns due to greater wearability characteristics. Also, the contact side weft yarns may be of a larger diameter than the support fabric weft yarns. Other synthetic materials and size combinations may be selected to form the warp, weft, and fabric born warp yarns of the invention dependent upon the required performance needs of the fabric.
While a preferred embodiment of the invention has been described using specific terms, such description is for illustrative purposes only, and it is to be understood that changes and variations may be made without departing from the spirit or scope of the following claims.
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A composite papermaking fabric comprising an upper support fabric and a lower contact fabric. The upper fabric is formed of warp yarns, fabric born warp yarns and weft yarns interwoven to provide the upper fabric with a support surface forming a one up, one down weave.
The lower fabric is formed of the fabric born warp yarns interwoven with weft yarns in a weave pattern which provides a weft yarn dominated contact surface. Each of the fabric born warp yarns also weaves over at least one of the upper fabric weft yarns during each repeat of the weave pattern forming binding points which bind the upper and lower fabrics together.
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BACKGROUND OF THE INVENTION
This invention relates to isotope separation, more particularly to isotope separation using collisionless magneto-plasma instabilities to slow down ions of a desired species from two counterstreaming, initially neutral beams by which one isotopic species of a given element may be separated from a mixture.
Heretofore other systems, principally gaseous diffusion and centrifuge techniques, have been used to separate isotopes. Such devices involve enormous capital and/or operating expenses, and can be economically justified only in very large scale plants. The reason for this lies in the fact that such techniques exploit the small (typically 1%) difference in the physical masses of the differing isotopes. No absolute separation is in general possible, only a preferential enrichment of one desired isotope. To obtain high concentrations of the latter, requires that the enriched output be recycled many times.
SUMMARY OF THE INVENTION
A continuously operating device which separates one isotopic species of a given element from a mixture. The given element is vaporized and formed into a neutral beam containing the isotopes desired to be separated. The plasma is accelerated through a laser beam which is formed by two separate lasers which operate in the continuous wave mode in which the beams are as nearly as possible in the same beam path. The two laser output beams excite and ionize the isotope of interest while leaving the remaining atoms unaffected. The ionized isotopes are then separated from the beam by an electrostatic deflection technique and the unaffected atoms continue on in their path and are directed to a recovery device.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic which illustrates the top view of a simplified isotope separator.
FIG. 2 is a schematic which illustrates a side view of the device shown in FIG. 1.
FIG. 3 is a schematic of an isotope separator which illustrates the relative parts.
DETAILED DESCRIPTION
Now referring to the drawing, there is shown in FIGS. 1 and 2 a simplified isotope separator. As shown, the system includes an incoming neutral beam 11 of atoms of a vaporized element containing isotopes desired to be separated from the mixture. The incoming neutral beam is accelerated through a CW laser output beam 12 which passes through channel 13. The laser beam formed by two separate continuous wave laser elements whose outputs are as nearly as possible in the same beam path. The beam 12 containing the two separate laser outputs is tuned to excite and ionize atoms of the isotope to be separated while leaving the atoms of the remaining isotopes unaffected during passage through the laser beam. After excitation and ionization of the atoms, there is a mixture of ions, electrons and neutrals. In order to separate the desired isotopes, the ions and electrons must be separated from the beam before recombination or any sequence of atomic processes resulting in ionization of a substantial number of undesired isotopes can take place.
The ions, electrons and neutral atoms are accelerated from the laser channel into an area in which the ions and electrons are electrostatically deflected from the beam by negative and positive plates, 14 and 15 respectively, which form a capacitor connected electrically to a voltage source 16. A magnetic field perpendicular to the electrostatic field is produced by permanent magnet poles 17 and 18. The unaffected atoms pass through the magnetic and electrostatic fields to a beam recovery device 19. During passage through the magneto-electric field the ions are attracted to the negatively charged plate and the electrons are attracted to the positively charged plate.
FIG. 3 illustrates a schematic of an isotope separator which makes use of two vapor beam sources 21, 22 and two pair of lasers 23, 24 such as described above for the device illustrated in FIG. 1, whose output beams propagate parallel with the capacitor collector plates 25 and transverse to the vapor beams. The vapor beams are directed toward each other at a slight angle relative to each other and perpendicular to respective laser beams with the beams intercepting each other at the center of the capacitor plates. A magnetic field is set up by a permanent magnet 26 with the magnetic field perpendicular to the length of the capacitor plates and across the beams. The area between the capacitor plates is enclosed by a vacuum chamber 27 into which the laser beams and vapor beams in each separate output path are injected. The laser beams operate in the CW mode, with as nearly as possible the same path. The drawing has been exaggerated in order to better illustrate the operation. The first vapor from beam source 21 passes through the combined laser output beam from laser pair 23 in which one laser output in the combined beam is strong enough to excite only those atoms of the isotope to be isolated and the other laser output in the beam ionizes only the excited atoms. Ionization is brought about since the laser that ionizes the atoms is of sufficiently short wavelength to excite transitions to the continuum from the excited state but not the ground state, and not resonant with any transition to an excited state of any isotope present and not excited. Since photo-excitation and photoionization times are both about 10 -8 sec., ionization takes place simultaneously with excitation and little energy is lost via reradiation resulting from spontaneous or stimulated emission. Excitation and ionization energies required are about 5 eV per atom; therefore wavelengths near the ultraviolet limit of the visible spectrum are used. The vapor beam from beam source 22 passes through the combined laser output beam from the laser pair 24 and is excited and ionized as set forth above for the vapor beam from beam source 21.
As seen in the drawing, the two plasma beams interpenetrate in the area bounded by the capacitor plates 25; therefore strong electrostatic instabilities are developed. The instabilities saturate at large amplitudes, and the resulting spectrum of high frequency oscillations effectively scatters the streaming charged particles. Therefore the ions of the isotopes to be separated are effectively stopped by the resulting "anomalous drag" and are electrostatically deflected from the beam stream at low velocity. The electrons are collected by the positively charged plate, the ions are collected by the negatively charged plate and the neutral isotopes continue on through the system to the beam collectors 28, 29.
The length, width, and separation distance between the capacitor plates as well as the laser intensities and other parameters have been set forth in the publication: "Isotope Separation Using Magneto-plasma Instabilities", by David L. Book, NRL Memorandum Report 2908, published by the Naval Research Laboratory, Washington, D.C. 20375 and incorporated herein as a part of this specification.
In use of an isotope separator such as shown in FIG. 3, the ions are collected within a few centimeters of the center of the system in which the length of the capacitor plate is less then 10 cm. The ions are braked to effectively zero velocity before collection, thereby eliminating problems of impurities or damage to the collectors.
Obviously many modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.
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A method of separating one isotopic species of a given element from a mixture. Collisionless plasma instabilities slow down the ions and oppositely charged electrodes separate the isotopes.
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BACKGROUND OF THE INVENTION
The present invention relates to a method for restoring a subterranean formation which may have become contaminated during an in situ leach operation and more particularly relates to a method of removing contaminants, i.e., ammonium ions, from a subterranean clay-containing formation after an in situ leach operation to restore the purity of any ground waters that may be present in the formation.
In a typical in situ leach operation, wells are completed into a mineral or metal value bearing (e.g., uranium) formation and a lixiviant is flowed between wells to dissolve the desired values into the lixiviant. The pregnant lixiviant is produced to the surface where it is treated to recover the desired values from the lixiviant. Unfortunately, many known, highly effective lixiviants not only leach the desired values from the formation but, also, they react with certain formations to give up chemical substances which remain in the formation after the lixiviants pass therethrough. Where the formation also contains ground waters and/or a water source which would otherwise be fit for human and/or animal consumption, these chemical substances will likely create a substantial contamination problem for this water. If this be the case, the formation must be treated after a leach operation to remove these contaminants to restore the purity of the water.
One method for improving the purity of a contaminated water source is to merely pump the water from the formation until the contaminant reaches an acceptably low level. Another, simple method is to pump uncontaminated water through the formation to flush out the contaminants. These methods work well where the contaminants are soluble and are not exchanged by some component of the formation from which it can only be released at a very slow rate. If the contaminants are exchanged by the formation, extremely large volumes of water must be used to adequately restore the formation.
In many known uranium and related value bearing formations, a substantial part of the formation matrix is comprised of calcium-based clays (e.g., smectite). This type formation presents a real formation water contamination problem when a known, highly effective lixiviant comprised of an aqueous solution of ammonium carbonate and/or bicarbonate is used to leach the desired values from the formation. Here, the ammonium ions from the lixiviant are exchanged into the smectite clays in the formation which make their removal by flushing with ground water a very slow and extended process.
One method for removing ammonium ions from a formation following a uranium leach operation is disclosed in U.S. Pat. No. 4,079,783, issued Mar. 21, 1978, and in copending U.S. application Ser. No. 824,686, filed Aug. 15, 1977, wherein a restoration fluid comprising an aqueous solution of a strong, soluble, alkaline compound is flowed through the formation to convert ammonium ions to an un-ionized form, i.e., ammonia (NH 3 ), which, in turn, can easily be flushed from the formation. However, while this approach achieves a good result, it requires a substantial amount of alkaline compound, e.g., lime or sodium hydroxide, and produces a large quantity of waste water containing calcium and ammonia which has to be properly disposed of at the surface.
Further, the ion exchange between the ammonium ions and the cations in the aqueous alkaline solution takes place according to the mass action law. Consequently, the rate of ammonium ion removal becomes slower and slower as more and more of the ammonium ions are removed. This makes the last or residual ammonium ions very difficult to remove. In order to meet certain governmental requirements (e.g., Texas requires no more than 3 parts per million level of ammonia in the formation water), it has been estimated that approximately 99.5 percent of the ammonium ions in a contaminated clay formation has to be exchanged by cations from the restoration fluid. This obviously requires a considerable amount of alkaline solution to be handled to restore the formation to the required specifications. Also, the ammonia content of the recovered restoration fluid requires this fluid to be treated to remove the ammonia before the fluid can be used to make up fresh restoration fluid for recycle or before it can otherwise be disposed of.
SUMMARY OF THE INVENTION
The present invention provides a method of removing a contaminant, i.e., ammonium ions (NH 4 + ) from a formation containing clay. Specifically, the formation is treated with a halogenated restoration fluid preferably comprised of chlorinated water and/or hypochlorite solution to quickly and completely restore the formation to an ecologically acceptable level. Further, the produced fluids in the present method (while they may contain ammonia) can readily be used to make up fresh restoration fluid for recycle without requiring an additional treating operation.
In leaching a formation containing clay with an ammonium carbonate and/or bicarbonate lixiviant, ammonium ions are exchanged into the clay and will slowly desorb into the ground waters in the formation, thereby contaminating same. In accordance with the present invention, after a leach operation has been completed, a halogenated restoration fluid preferably comprised of chlorinated water and/or a hypochlorite solution is flowed through the formation between wells previously used during the leach operation.
There are equilibria existing between ammonia (NH 3 ) and ammonium ions (NH 4 - ) in the formation water and between the ammonium ions in the clay and ammonium ions in the formation water. The chlorine in the restoration fluid forms hypochlorite which in turn reacts with the ammonia in the formation water and through a sequence of chemical reactions decomposes the ammonia into ecologically harmless water and nitrogen. This in situ decomposition of the ammonia breaks it from re-equilibration with the ammonium ions in the clay allowing more ammonium ions to desorb into the water to be converted to ammonia and so on. This process will continue as long as chlorine is added or until there is substantially no ammonia remaining in the formation water.
The fluids produced during the early part of the restoration cycle will contain substantial amounts of ammonia since this is formation water which has been pushed out of the formation as a slug by the initial injection of restoration fluid and has actually not been in substantial contact with the chlorine in the restoration fluid. In the present invention, however, even these early produced fluids can be used to make up fresh restoration fluid for recycle if it is desired. Chlorine and/or hypochlorite is added thereto and, as will be explained in more detail later, this chlorine will decompose the ammonia in the produced fluids during the makeup procedure.
In order to improve the efficiency of the present method, the pH of the chlorinated restoration fluid may be adjusted to within the range of 7 to 13 by adding a base, e.g., sodium or calcium hydroxide. At the higher pH, the ammonium ions in the formation are converted to ammonia at a faster rate and, accordingly, increases the contact rate between ammonia and chlorine from the restoration fluid.
In the present invention, the chlorinated restoration fluid is injected in a well previously used for the leach operation and fluids are produced from another well. The restoration fluid can be continuously injected until the ammonia concentration in the produced fluid drops below the desired level or the chlorinated restoration can be injected as a slug and followed by a substantially chlorine-free flushing fluid to complete the operation. Since chlorine is used in the disinfection of many municipal water supplies, the present invention presents no ecological problems even if some exclusion outside the contaminated formation occurs.
BRIEF DESCRIPTION OF THE DRAWING
The FIGURE is a graph showing experimental results of ammonium ion removal from a clay-bearing sand in accordance with the present invention by plotting ammonia concentration in the effluent against the number of bed volumes of restoration fluid passed through the sand.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In a typical in situ leach operation for recovering uranium and/or related values, wells are completed into a uranium or other value bearing formation and a lixiviant is flowed between the wells. The uranium and/or related values are dissolved into the lixiviant and are produced therewith to the surface where the pregnant lixiviant is treated to recover the desired values. For an example of such a leach operation, see U.S. Patent application Ser. No. 712,404, filed Aug. 6, 1976.
In many known formations where an in situ leach such as mentioned above is carried out, a substantial part of the formation matrix is comprised of calcium-based clays (e.g., smectite). When a desired, highly effective lixiviant, i.e., ammonium carbonate and/or bicarbonate, is used in the leach operation, ammonium ions (NH 4 + ) are exchanged into and strongly held by the clays and remain in the formation after the leach operation is completed. These ammonium ions slowly dissolve into any ground water that may be present in the formation and thereby pose a contamination threat to the water source.
Clays are complex compounds comprised of calcium, magnesium, aluminum, silicon, and oxygen. They are capable of exchanging calcium ions for other ions in much the same way as do commercial ion exchange resins used for softening water. This property of clays is illustrated by the equation:
Ca.sup.++ --clay+2M.sup.+ →M.sub.2.sup.+ --clay+Ca.sup.++(1)
where M + is another cation.
The ammonium ion (NH 4 + ) is strongly exchanged by clays so that NH 4 + is bound into the clay lattice:
Ca.sup.++ --clay+2NH.sub.4.sup.+ ⃡2NH.sub.4.sup.+ --clay+Ca.sup.++ (2)
The clay and aqueous solution constituting its environment are in equilibrium, i.e., reaction (2) is reversible. If NH 4 + in the solution, e.g., formation water, is decreased, NH 4 + will come off the clay and the calcium ion (Ca ++ ) will go back on. However, the clay-NH 4 + equilibrium is such that only a very small amount of NH 4 + in solution will maintain a large amount of NH 4 + on the clay, i.e., the clay prefers NH 4 + to Ca ++ . This is the reason that NH 4 + is only very slowly released by flushing the clay with water containing only neutral, dissolved salts.
In accordance with the present invention, the contaminated space (a "pore volume") of the formation is treated with a halogenated restoration fluid preferably comprising chlorinated water and/or a hypochlorite solution, e.g., NaOCl, to decompose ammonium ions in the formation to components, e.g., N 2 ,H 2 O, which, in turn, offer no contamination threat to the formation. The restoration fluid is injected into one of the wells previously used in the leach operation and fluids are produced from another until the ammonia concentration in the produced fluids reaches an acceptable level. The produced fluids are made up with additional chlorine and/or hypochlorite solution for recycle as fresh restoration fluid. When the ammonia content of the produced fluids drops below an ecologically satisfactory level, e.g., 3 parts per million indicating that substantially all of the ammonium ions have been removed or converted in the formation, injection of the restoration fluid is stopped and the restoration of the formation is complete.
As stated above, there are equilibria existing between NH 4 + in the clay and NH 4 + in the formation water, see Equation (2), and also between NH 3 and NH 4 + in the formation water, the latter being:
NH.sub.4.sup.+ +OH.sup.- ⃡NH.sub.3 +H.sub.2 O (3)
when chlorine (Cl 2 ) in the restoration fluids contacts the NH 3 in the formation water, the following sequence of reactions occur: ##EQU1##
The effect of Cl 2 is to react away the ammonia to break it from re-equilibration with NH 4 + , which in turn reequilibrates with clay. That is, as the NH 3 and hence NH 4 + , see Equation (3), in the formation water is decomposed, NH 4 + from the clay replaces the converted NH 4 + in the water and there the NH 4 + becomes NH 3 which, in turn, is contacted and decomposed by more chlorine from the restoration fluid. Sufficient chlorinated restoration fluid is injected until substantially all NH 4 + in the formation is decomposed. This is determined by monitoring the NH 3 concentration in the produced fluids.
The NH 3 concentration in the produced fluids during the early part of the operation will be relatively high and decreases to a value almost undetectable in the final stages. However, even the early produced fluids can be used to make up fresh restoration fluid for recycle by adding chlorine and/or hypochlorite thereto to bring it back up to strength if it is so desired. The added chlorine attacks the NH 3 in the produced fluid during makeup in the same manner as that which occurs in the formation to decompose the NH 3 in the produced fluids. This permits a "closed cycle" to be used during the restoration operation which eliminates the necessity of excessive handling and/or disposal of large quantities of ammonia-contaminated produced fluids at the surface.
The chlorinated restoration fluid can be made up at the surface prior to injection into a well by bubbling chlorine gas into water and/or the produced fluids in a mixing tank. Also, if a hypochlorite, e.g., NaOCl, is used, this solid compound can also be dissolved into water and/or produced fluids in a mixing tank at the surface. If chlorine gas is used, it can also be mixed with the water and/or produced fluids downhole in the well just before the restoration fluid enters the contaminated formation. A method and apparatus for mixing a gas and a liquid at a downhole location is fully described in copending U.S. application Ser. No. 846,863, filed Oct. 31, 1977.
In order to improve the rate efficiency of the present process, the pH of the chlorinated water and/or hypochlorite restoration fluid can be adjusted with a base, e.g., Ca(OH) 2 or NaOH, to a value of 7 to 13. At the higher pH, more NH 4 + from the clay is converted faster to NH 3 , see Equation (3). In addition, the reaction produces HCl, see Equation (4), and this acid tends to neutralize the base used to adjust the pH. Although chloride is preferred, other halogens, such as bromide and iodine, will also convert NH 4 + in the same manner and may be used in the restoration fluid if the situation dictates. Fluorine will also react with the NH 4 + but, due to undesirable side reactions in many actual restoration operations, it is likely to be the least preferable of the halogens in most field operations.
To further illustrate the invention, the following experimental data is set forth:
Three columns were packed with 18 cc (23.4g) each of rich uranium, clay-containing ore from South Texas with 100-200 mesh fine quartz at both the top and the bottom to insure uniform flow of the liquid through the bed.
Each column was first loaded with NH 4 + by passing 2.8 bed volume (BV) of simulated leach solution with the following nominal composition:
______________________________________ Grams per literComponent (g/l)______________________________________NaCl 5.0NH.sub.4 HCO.sub.3 3.0NH.sub.4 OH 5.8______________________________________
The pH of the solution was 9.44 and the actual NH 3 content was found to be 2670 ppm.
The loaded columns were then flushed with 1.4 BV of brine solution (5 g/l of NaCl, pH=8), simulating the connate water normally present in the natural formation.
The three columns were then restored as follows:
(1) Control (column #1): The column was flushed using the restoration fluid containing 20 g/l of NaCl at pH=10.
2) Continuous injection of chlorinated water (column #2): The column was continuously flushed with the chlorinated water described above.
(3 Slug injection of chlorinated water (column #3): To simulate slug injection, 2.8 BV of the chlorinated water was injected. This was followed by injection of substantially chlorine-free water which could be connate water in an actual operation. The chlorinated water used in both columns #2 and #3 was prepared by saturating a brine solution having 20 g/l of NaCl with Cl 2 at atmospheric pressure with the pH of the chlorinated solution adjusted from 2 to 10 using a caustic solution.
The process was followed by collecting samples every 1.4 BV analyzing for pH and NH 3 NH 3 was determined using an ammonia electrode, Orion Model 95-10, manufactured by Orion Research Inc. This is a method acceptable to Federal and State agencies.
The chlorine content of the chlorinated water was not analyzed. If it were really saturated, the chlorine content would be estimated to be 0.045 mole/l or 3.2 g/l.
The results of the above experiments are plotted on the graph of the Figure with the ammonia content of the effluents, i.e., produced fluids, being plotted against the total bed volumes of restoration fluid passed through a respective column. It can be seen that after injection of 4 BV of chlorinated restoration fluid in the continuous mode (column #2 in graph), the NH 3 content in the effluent was down from 2000 ppm to 1 ppm. To achieve a level of 5 ppm, less than 3 BV was required. On the other hand, the NH 3 content of the effluent of the control run (column #1 in graph) was still 100 ppm after 4 BV of the restoration fluid.
In column #3 (column #3 in graph), the restoration fluid was switched to chlorine-free solution after injection of 2.8 BV of chlorinated restoration fluid. The ammonia content of the effluent at total BV of 5 (2.8 and 2.2 for chlorinated and chlorine-free solutions, respectively) was 3 ppm. This indicates that the chlorinated restoration fluid can be injected in the form of a slug followed by a chlorine-free flushing fluid, e.g., connate water, to substantially reduce the cost of the restoration operation.
The chemistry involved in the present process is not completely understood. The stoichiometry from the above equations indicates that it takes 1.5 mole of Cl 2 to decompose 1 mole of NH 3 or 6.3 pounds of Cl 2 per pound of NH 3 . In actual field operations it may take somewhat more chlorine to compensate for potential side reactions. However, the experimental data revealed that a lesser amount, i.e., approximately 3 pounds of chlorine per pound NH 3 , was actually needed. This indicates that the actual conditions of the formation to be restored need to be considered in finalizing the amounts of chlorine needed to be added to a particular restoration fluid.
The present invention provides a safe and relatively quick method for restoring an ammonium-contaminated, clay formation which does not require excessive handling and/or disposal of contaminated produced fluids at the surface. Further, since chlorine is used in disinfecting municipal water supplies, the present invention offers little, if any, ecological risks even if the restoration fluid flows outside the contaminated area.
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A method of treating a subterranean formation which has undergone an in situ leaching operation which utilzed an ammonium solution as the lixiviant. In such a leach operation, ammonium ions will exchange into the clay in the formation and will present a threat of contamination to any ground waters that may be present in the formation. The present method involves flushing the formation with a halogenated restoration fluid, e.g., chlorinated water having a halogen therein which reacts with ammonia within the formation to decompose the ammonia to nitrogen. The halogenated restoration fluid can be continuously injected or it can be injected as a slug followed by a relatively halogen-free solution to complete the operation. The ammonia concentration of the produced fluids is monitored and when it drops below a desired value, the method is complete.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application Ser. No. 60/811,041, filed Jun. 5, 2006, which is incorporated herein in its entirety by reference.
FIELD OF INVENTION
[0002] The invention relates to a highly efficient approach to prepare at least 99% pure curcumin from technical grade (typically about 70% by weight) curcumin. This invention focuses on the difference in reactivity between 4-phenolic groups with or without the presence of methoxy group on its adjacent position. This invention relates to readily available phenol protecting groups to guide a selective recrystallization of curcumin in the presence of other curcuminoids of similar physical properties. This invention further relates to preparation of at least 99% pure curcumin, which may be suitable for pharmaceutical use.
BACKGROUND
[0003] Curcumin (1) is a natural product isolated in abundance from Curcuma species, in particular, Curcuma longa (Zingiberaceae) Linn. See Park and Kim, J. Nat. Prod. 65: 1227 (2002) and U.S. Pat. No. 5,861,415. Recently, it has attracted considerable attention due to its antioxidant (Kawanishi et al., Antioxid. Redox Signal. 7: 1728 (2005)), antiinflamatory (Chianani-Wu, J. Altern. Complement Med. 9: 161 (2003)), antiviral (Vajragupta et al., Bioorg. Med. Chem. Lett. 15: 3364 (2005) and Ranjan et al., J. Sur. Res. 87: 1 (1999)), antifungal (Kim et al., J. Agric. Food Chem. 51: 1578 (2003)), antibacterial (Foryst-Ludwig et al., Biochem. Biophys. Res. Commun. 316: 1065 (2004)), anticancer (Lee et al., Antioxid. Redox Signal. 7: 1612 (2005)), chemopreventive activities (Duvoix et al., Cancer Lett. 223: 181 (2005)), and in particular, its ability to protect neuronal cells from beta-amyloid insult (Park and Kim, J. Nat. Prod. 65: 1227 (2002) and Yang et al., J. Biol. Chem. 280, 5892 (2005)), suggesting a potentially important drug candidate to prevent and/or treat Alzheimer's Disease.
[0004] Although curcumin (1) can be readily synthesized (Nurfina et al., Eur. J. Med. Chem. 32: 321 (1997)), isolation from the natural resources using recrystallization techniques remains the most economically viable supply method (U.S. Pat. No. 5,861,415), however with notable challenges. Curcumin (1) is typically prepared in about 70% purity as a mixture of curcuminoids, such as demethoxycurcumin (2), bis-demethoxycurcumin (3), and other minor curcuminoids constituting the remaining composition. Because of the similar physical properties of these curcuminoids, large scale preparation of at least 99% pure curcumin using conventional chromatographic or recrystallization technique remains a challenge. It was envisioned a simple chemical modification of phenol groups on these curcuminoids using a phenol protecting group may alter the physiochemical properties of these curcuminoids to favor a selective recrystallization of curcumin (1) to achieve>99% purity.
[0005] A protecting group's chemoselectivity based on the difference in electrosteric environment around the reaction site may be a useful tool in separating a mixture of compounds with similar physical properties. Acetyl, THP (tetrahydropyran) ether, and TBDMS (t-butyldimethylsilyl) ether are representative examples of widely used phenol protecting groups. See Greene and Wuts, Protective Groups in Organic Synthesis, 2 nd ed. 1991. It was reasoned that reaction rate of these protecting groups on phenol functionality at a 4-position could be influenced by electrosteric environment attributed by methoxy group on an adjacent 3-position. Removal of phenol protecting groups under mild reaction conditions has been reported. See Greene and Wuts, Protective Groups in Organic Synthesis, 2 nd ed. 1991. Herein is disclosed a simple chemical modification method that yields at least 99% pure curcumin from a mixture of curcuminoids (1-3).
SUMMARY OF INVENTION
[0006] The present invention relates to method of obtaining at least about 90% pure curcumin from technical grade (about 70% by weight) curcumin, which can be suitable for pharmaceutical use. The difference in reactivity between 4-phenolic groups with or without the presence of methoxy group on its adjacent position can be manipulated to allow for curcumin isolation from a mixture of curcumin and curcuminoids having similar properties. Thus, disclosed herein are methods of purifying curcumin using readily available reagents which provide phenol protecting groups and selectively recrystallizing curcumin in the presence of other curcuminoids of similar physical properties.
[0007] In one aspect, the disclosure provides a method of obtaining purified curcumin comprising the steps of (a) admixing impure curcumin comprising curcumin and curminoids and having a curcumin purity up to about 75% by weight, a reagent which provides a phenol protecting group, and an optional catalyst under condition sufficient to control reactivity of the hydroxyl groups of the curcuminoids and the reagent which provides a phenol protecting group to form a mixture of curcumin and at least one curcuminoid having at least one phenol protecting group; (b) crystallizing the mixture of step (a) in at least one organic solvent to form curcumin crystals having a curcumin purity of at least about 90% by weight. In some embodiments, the curcumin crystals have a purity of at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or at least about 99.5% by weight. In various embodiments, the crystallization step can be repeated to increase the purity of the curcumin crystals.
[0008] Another aspect is to provide a method to obtain a purified curcumin composition having a purity of at least about 99% comprising the steps of: (1) obtaining an impure curcumin composition such as a commercially available curcumin composition having a purity of about 50 to about 70%; (2) dissolving the impure curcumin in an appropriate solvent, examples of which include, but are not limited to, DMF, acetonitrile, dichloromethane, ethylene dichloride, DMSO, acetone and the like; (3) adding an appropriate phenol protecting groups to the reaction at various temperature to control the reaction rate, such as from about −50° C. to reflux condition; (4) adding an appropriate catalyst such as pyridine p-toluenesulfonate (PPTS) or dimethylaminopyridine (DMAP) to assist the reaction; (5) quenching the reaction by adding water or appropriate solvent and/or reagent to the reaction mixture, (6) adding an appropriate organic solvent, examples including, but not limited to, ethyl acetate, dichloromethane, chloroform, ethylene dichloride, or ethers; (7) washing the said organic solution to remove water soluble substance from the organic layer and repeating the step as needed; (8) removing the said solvent under vacuum or steady stream of air; (9) dissolving the reaction residue in a minimum amount of appropriate hot organic solvent, examples including, but not limited to, methanol, ethanol, acetone, methyl ethyl ketone, isopropyl alcohol, acetic acid, water, ethyl acetate, ethylene dichloride, dichloromethane, or mixtures thereof; (10) slowly cooling the solution down to room temperature to initiate the recrystallization of curcumin, which can further be induced by placing the recrystallizing solution in a refrigerator and slowly evaporating the solvent to increase the yield of curcumin; (11) collecting the crystals using vacuum filtration; (12) rinsing the crystals with cold solvent and further drying the crystals; and (13) optionally repeating the recrystallization step to obtain curcumin with higher purity as needed. According to one aspect of the invention a purified curcumin composition having a purity of greater than 99% is obtained in the presence of other curcuminoids.
[0009] The invention further provides methods of obtaining a purified curcumin composition having a purity of at least 99% by weight, said method comprising the steps of utilizing phenol protecting groups to alter the chemophysical properties of other curcuminoids to favor the preparation of pure curcumin in the presence of other curcuminoids.
[0010] The impure or crude curcumin can comprise curcumin and other curcuminoids. Other curcuminoids can constitute demethoxycurcumin, bis-demethoxycurcumin, calebin-A, 1-hydroxy-1,7-bis(4-hydroxy-3-methoxyphenyl)-6-heptene-3,5-dione, 1,7-bis(4-hydroxyphenyl)-1-heptene-3,5-dione, 1,7-bis(4-hydroxyphenyl)-1,4,6-heptatrien-3-one, 1,5-bis(4-hydroxy-3-methoxyphenyl)-1,4-pentadien-3-one, and other curcuminoids of minor composition.
[0011] The invention provides methods of obtaining a purified curcumin composition having a purity of greater than 99% said method where phenol protecting groups are in a form of ethers selected from the following list but not limited to: methyl, methoxymethyl, methylthiomethyl, t-butylthiomethyl, (phenyldimethylsilyl)methoxymethyl, benzyloxymethyl, p-methoxybenzyloxymethyl, (4-methoxyphenoxy)methyl, guaiacolmethyl, t-butoxymethyl, 4-pentenyloxymethyl, siloxymethyl, 2-methoxyethoxymethyl, 2,2,2-trichloroethoxymethyl, bis(2-chloroethoxy)methyl, 2-(trimethylsilyl)ethoxymethyl, tetrahydropyranyl, 3-bromotetrahydropyranyl, tetrahydrothiopyranyl, 1-methoxycyclohexyl, 4-methoxytetrahydropyranyl, 4-methoxytetrahydrothiopyranyl, 4-methoxytetrahydrothiopyranyl S,S-dioxido, 1-[(2-chloro-4-methyl)phenyl]-4-methoxypiperidin-4-yl, 1,4-dioxan-2-yl, tetrahydrofuranyl, tetrahydrothiofuranyl, 2,3,3a,4,5,6,7,7a-octahydro-7,8,8-trimethyl-4,7-methanobenzofuran-2-yl, 1-ethoxyethyl, 1-(2-chloroethoxy)ethyl, 1-methyl-1-methoxyethyl, 1-methyl-1-benzyloxyethyl, 1-methyl-1-benzyloxy-2-fluoroethyl, 2,2,2-trichloroethyl, 2-trimethylsilylethyl, 2-(phenylselenyl)ethyl, t-butyl, allyl, p-chlorophenyl, p-methoxyphenyl, 2,4-dinitrophenyl, benzyl, p-methyoxybenzyl, 3,4-dimethoxybenzyl, o-nitrobenzyl, p-nitrobenzyl, p-halobenzyl, 2,4-dichlorobenzyl, p-cyanobenzyl, p-phenylbenzyl, 2- and 4-picolyl, 3-methyl-2-picolyl N-oxido, diphenylmethyl, p,p′-dinitrobenzhydryl, 5-dibenzosuberyl, triphenylmethyl, α-naphthyldiphenylmethyl, p-methoxyphenyldiphenylmethyl, di(p-methoxyphenyl)phenylmethyl, tri(p-methoxyphenyl)methyl, 4-(4′-bromophenacyloxy)phenyldiphenylmethyl, 4,4′,4″-tris(4,5-dichlorophthalimidophenyl)methyl, 4,4′,4″-tris(levulinoyloxyphenyl )methyl, 4,4′,4″-tris(benzoyloxyphenyl)methyl, 3-(imidazol-1-ylmethyl)bis(4′,4″-dimethoxyphenyl)methyl, 1,1-bis(4-methoxyphenyl)-1′-pyrenylmethyl, 9-anthryl, 9-(9-phenyl)xanthenyl, 9-(9-phenyl-10-oxo)anthryl, 1,3-benzodithiolan-2-yl, benzisothiazolyl S,S-dioxido, and the like.
[0012] According to one aspect of the invention a method of obtaining a purified curcumin composition having a purity of at least 99% by weight is provided where phenol protecting groups are in a form of a silyl ether. The silyl ether can be selected from: trimethylsilyl, triethylsilyl, triisopropylsilyl, dimethylisopropylsilyl, diethylisopropylsilyl, dimethylthexylsilyl, t-butyldimethylsilyl, t-butyldiphenylsilyl, tribenzylsilyl, tri-p-xylylsilyl, triphenylsilyl, diphenylmethylsilyl, t-butylmethoxyphenylsilyl, and the like.
[0013] Also provided by the invention is a method of obtaining a purified curcumin composition having a purity of at least 99% by weight said method where phenol protecting groups are in a form of esters selected from the following list but not limited to: formate, benzoylformate, acetate, chloroacetate, dichloroacetate, trichloroacetate, trifluoroacetate, methoxyacetate, triphenylmethoxyacetate, phenoxyacetate, p-chlorophenoxyacetate, p-P-phenylacetate, 3-phenylpropionate, 4-oxopentanoate (levulinate), 4,4-(ethylenedithio)pentanoate, pivaloate, adamantoate, crotonate, 4-methoxycrotonate, benzoate, p-phenylbenzoate, 2,4,6-trimethylbenzoate (mesitoate), 2-iodobenzoate, 4-azidobutyrate, 4-nitro-4-methylpentanoate, o-(dibromomethyl)benzoate, 4-(methylthiomethoxy)butyrate, 2-(methylthiomethoxymethyl)benzoate, 2,6-dichloro-4-methylphenoxyacetate, 2,6-dichloro-4-(1,1,3,3-tetramethylbutyl)phenoxyacetate, 2,4-bis(1,1-dimethylpropyl)phenoxyacetate, chlorodiphenylacetate, isobutyrate, monosuccinoate, (E)-2-methyl-2-butenoate (Tigloate), o-(methoxycarbonyl)benzoate, p-P-benzoate, α-naphthoate, dimethylphosphinothioyl, 2,4-dinitrophenylsulfenate, and the like.
[0014] Also provided by the invention is a method of obtaining a purified curcumin composition having a purity of at least 99% by weight said method where phenol protecting groups are in a form of carbonates selected from the following list but not limited to: methyl, 9-fluorenylmethyl, ethyl, 2,2,2-trichloroethyl, 2-(methylthiomethoxy)ethyl, 2-(trimethylsilyl)ethyl, 2-(phenylsulfonyl)ethyl, 2-(triphenylphosphonio)ethyl, isobutyl, vinyl, allyl, p-nitropheny, benzyl, p-methoxybenzyl, 3,4-dimethoxybenzyl, o-nitrobenzyl, p-nitrobenzyl, S-benzyl thiocarbonate, 4-ethoxy-1-naphthyl, methyl dithiocarbonate.
[0015] The invention also provides a method of obtaining a purified curcumin composition having a purity of at least 99% by weight said method where phenol protecting groups are in a form of sulfonates and others selected from the following list but not limited to: sulfate, methanesulfonate (mesylate), benzylsulfonate, tosylate, 2-formylbenzenesulfonate, nitrate, borate, alkyl N,N,N′,N′-tetramethylphosphorodiamidate, N-phenylcarbamate and the like.
[0016] The invention also provides a method of obtaining a purified curcumin composition having a purity of at least 99% by weight said method using recrystallization technique in the presence of other phenol protecting groups attached curcuminoids. According to one aspect of the invention the recrystallization solvent systems are selected from singly, or in a mixture of but not limited to: methanol, ethanol, acetone, methyl ethylketone, isopropyl alcohol, acetic acid, water, ethyl acetate, ethylene dichloride, dichloromethane, and the like. According to one aspect of the invention a method of obtaining a purified curcumin composition having a purity of at least 99% by weight is provided wherein said curcuminoids are dissolved in minimum amount of said solvent(s) at a temperature above room temperature. According to another aspect of the invention a method of obtaining a purified curcumin composition having a purity of at least 99% by weight is provided wherein the dissolved curcuminoids are slowly cooled to room temperature and slowly evaporating the solvent to induce recrystallization of curcumin. More preferably the recrystallizing curcuminoids are placed in a refrigerator to further assist the recrystallization to increase the yield of curcumin.
[0017] The purified curcumin composition having a purity of at least 99% by weight can be obtained wherein the curcumin crystals are collected by vacuum filtration or wherein the collected curcumin crystals are dried and collected.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 depicts the structures of various curcuminoids including curcumin (1); demethoxy curcumin (2); and bis-demethoxy curcumin (3); and
[0019] FIG. 2 depicts a scheme for the protection and deprotection of curcuminoids.
DETAILED DESCRIPTION OF THE INVENTION
[0020] The present invention provides an improved strategy for obtaining highly purified (at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or at least 99.5% purified) curcumin compositions. In some cases, a phenol protecting group is used to modify a curcuminoid in the presence of curcumin to allow for purification of curcumin from the curcumin/curcuminoid mixture. Typically, the phenol protecting group is an ether, a silyl ether, a carbonate, or a sulfonate. In some specific cases, the phenol protecting group is a THP ether, acetyl, and/or TBDMS ether.
[0021] The methoxy group of the 3-position of a curcuminoid may influence the reaction rate of adjacent phenol group on 4-position such that curcuminoids 2 and 3 will predominantly acquire the protecting groups on their 4-phenol functionality, thus altering their physical properties to favor the crystallization of curcumin (1).
[0022] As used herein, the term “reagent which provides a phenol protecting group” is a reagent which reacts with a phenol (hydroxyl group on an aromatic moiety) to provide a protecting group. A protecting group is a moiety which masks the functional group being protect (here a phenol hydroxyl group) and which can then be removed to unmask the function group. Nonlimiting examples of protecting groups for phenols include ethers, esters, silyl ethers, carbonates, sulfonates, and the like. A reagent which provides a protecting group typically has reactive functionality which allows reaction between the reagent and the functional group to be protected. For example, a silyl chloride can be used to transform a phenol to a silyl ether. Other examples of reagents which provide a phenol protecting group can be found in Greene and Wuts, Protective Groups in Organic Synthesis, 2 nd ed. 1991.
[0023] Specific nonlimiting examples of protecting groups methyl, methoxymethyl, methylthiomethyl, t-butylthiomethyl, (phenyldimethylsilyl)methoxymethyl, benzyloxymethyl, p-methoxybenzyloxymethyl, (4-methoxyphenoxy)methyl, guaiacolmethyl, t-butoxymethyl, 4-pentenyloxymethyl, siloxymethyl, 2-methoxyethoxymethyl, 2,2,2-trichloroethoxymethyl, bis(2-chloroethoxy)methyl, 2-(trimethylsilyl )ethoxymethyl, tetrahydropyranyl, 3-bromotetrahydropyranyl, tetrahydrothiopyranyl, 1-methoxycyclohexyl, 4-methoxytetrahydropyranyl, 4-methoxytetrahydrothiopyranyl, 4-methoxytetrahydrothiopyranyl S,S-dioxido, 1-[(2-chloro-4-methyl)phenyl]-4-methoxypiperidin-4-yl, 1,4-dioxan-2-yl, tetrahydrofuranyl, tetrahydrothiofuranyl, 2,3,3a,4,5,6,7,7a-octahydro-7,8,8-trimethyl-4,7-methanobenzofuran-2-yl, 1-ethoxyethyl, 1-(2-chloroethoxy)ethyl, 1-methyl-1-methoxyethyl, 1-methyl-1-benzyloxyethyl, 1-methyl-1-benzyloxy-2-fluoroethyl, 2,2,2-trichloroethyl, 2-trimethylsilylethyl, 2-(phenylselenyl)ethyl, t-butyl, allyl, p-chlorophenyl, p-methoxyphenyl, 2,4-dinitrophenyl, benzyl, p-methyoxybenzyl, 3,4-dimethoxybenzyl, o-nitrobenzyl, p-nitrobenzyl, p-halobenzyl, 2,4-dichlorobenzyl, p-cyanobenzyl, p-phenylbenzyl, 2- and 4-picolyl, 3-methyl-2-picolyl N-oxido, diphenylmethyl, p,p′-dinitrobenzhydryl, 5-dibenzosuberyl, triphenylmethyl, α-naphthyldiphenylmethyl, p-methoxyphenyldiphenylmethyl, di(p-methoxyphenyl)phenylmethyl, tri(p-methoxyphenyl)methyl, 4-(4′-bromophenacyloxy)phenyldiphenylmethyl, 4,4′,4″-tris(4,5-dichlorophthalimidophenyl)methyl, 4,4′,4″-tris(levulinoyloxyphenyl)methyl, 4,4′,4″-tris(benzoyloxyphenyl)methyl, 3-(imidazol-1-ylmethyl)bis(4′,4″-dimethoxyphenyl)methyl, 1,1-bis(4-methoxyphenyl)-1′-pyrenylmethyl, 9-anthryl, 9-(9-phenyl)xanthenyl, 9-(9-phenyl-10-oxo)anthryl, 1,3-benzodithiolan-2-yl, and benzisothiazolyl S,S-dioxido, trimethylsilyl, triethylsilyl, triisopropylsilyl, dimethylisopropylsilyl, diethylisopropylsilyl, dimethylthexylsilyl, t-butyldimethylsilyl, t-butyldiphenylsilyl, tribenzylsilyl, tri-p-xylylsilyl, triphenylsilyl, diphenylmethylsilyl, t-butylmethoxyphenylsilyl, formate, benzoylformate, acetate, chloroacetate, dichloroacetate, trichloroacetate, trifluoroacetate, methoxyacetate, triphenylmethoxyacetate, phenoxyacetate, p-chlorophenoxyacetate, p-P-phenylacetate, 3-phenylpropionate, 4-oxopentanoate (levulinate), 4,4-(ethylenedithio)pentanoate, pivaloate, adamantoate, crotonate, 4-methoxycrotonate, benzoate, p-phenylbenzoate, 2,4,6-trimethylbenzoate (mesitoate), 2-iodobenzoate, 4-azidobutyrate, 4-nitro-4-methylpentanoate, o-(dibromomethyl)benzoate, 4-(methylthiomethoxy)butyrate, 2-(methylthiomethoxymethyl)benzoate, 2,6-dichloro-4-methylphenoxyacetate, 2,6-dichloro-4-(1,1,3,3-tetramethylbutyl)phenoxyacetate, 2,4-bis(1,1-dimethylpropyl)phenoxyacetate, chlorodiphenylacetate, isobutyrate, monosuccinoate, (E)-2-methyl-2-butenoate (Tigloate), o-(methoxycarbonyl)benzoate, p-P-benzoate, α-naphthoate, dimethylphosphinothioyl, 2,4-dinitrophenylsulfenate, methyl, 9-fluorenylmethyl, ethyl, 2,2,2-trichloroethyl, 2-(methylthiomethoxy)ethyl, 2-(trimethylsilyl)ethyl, 2-(phenylsulfonyl)ethyl, 2-(triphenylphosphonio)ethyl, isobutyl, vinyl, allyl, p-nitropheny, benzyl, p-methoxybenzyl, 3,4-dimethoxybenzyl, o-nitrobenzyl, p-nitrobenzyl, S-benzyl thiocarbonate, 4-ethoxy-1-naphthyl, methyl dithiocarbonate, sulfate, methanesulfonate (mesylate), benzylsulfonate, tosylate, 2-formylbenzenesulfonate, nitrate, borate, alkyl N,N,N′,N′-tetramethylphosphorodiamidate, and N-phenylcarbamate.
[0024] The conditions sufficient to control reactivity of the hydroxyl (phenol) groups of the curcumin and curcuminoids can be chosen by the person of skill in the art, in view of the present disclosure. The concentration of the reagents, use of an optional catalyst (such as DMAP or PPTS), temperature of the reaction, and/or reaction time can be selected to provide appropriate selectivity for a 4-hydroxyl next to a 3-methoxy group. The temperature of the reaction can be about −50° C. to reflux. Specific temperatures include, but are not limited to, about −50° C. to about 0° C., about 10° C. to about 25° C., about 30° C. to about 100° C., about 50° C. to about 90° C., about 50° C. to about 85° C., about 55° C. to about 80° C., or about 65° C. to about 75° C. In some cases, the temperature is above room temperature (typically about 25 to about 27° C.).
[0025] The organic solvent suitable for the crystallization step can be any solvent that is compatible with the curcumin, curcuminoid, and protected curcuminoid mixture. Typically, the organic solvent is methanol, ethanol, acetone, methyl ethylketone, isopropyl alcohol, acetic acid, water, ethyl acetate, ethylene dichloride, dichloromethane, or mixtures thereof. Other organic solvents contemplated include ethyl acetate, dichloromethane, chloroform, ethylene dichloride, or ethers. In some cases, the crystallization includes cooling the mixture to below room temperature to facilitate the formation of curcumin crystals. In specific cases, the temperature is less than about 15° C., less than about 10° C., less than about 4° C., less than about 0° C., less than about −10° C., or less than about −20° C.
[0026] In various cases, the crystals of curcumin can be collected. Collection of crystals can be via any known technique, and include via filtration. In some cases, the crystals are filtered and dried. Filtration can be via any known means, including gravity, vacuum, and the like.
EXAMPLES
[0027] The present invention is further explained by the following examples which should not be construed by way of limiting the scope of the present invention.
Example 1
[0028] For this study 4:1:1 mixture of previously isolated curcuminoids 1, 2, and 3 were used. See Park and Kim, J. Nat. Prod. 65: 1227 (2002). Approximately 3.2 equivalent of protecting reagents were used to selectively capture the phenol functionality on 4-position without methoxy group at the adjacent position (Scheme 1 in FIG. 2 ).
[0029] The first batch of (4:1:1) curcuminoid mixture was reacted with dihydropyran (DHP) in dimethylformamide (DMF) in the presence of PPTS as catalyst overnight. See Greene and Wuts Protective Groups in Organic Synthesis, 2 nd ed. 1991. After aqueous work up, recrystallization of curcumin (1) was induced using hot acetone/H 2 O system (2×) to afford >99% curcumin in 79% yield. The second batch of (4:1:1) curcuminoid mixture was reacted with acetic anhydride in triethylamine/DMF in the presence of DMAP as catalyst overnight. See Greene and Wuts Protective Groups in Organic Synthesis, 2 nd ed. 1991. Aqueous work up and recrystallization using hot acetone/H 2 O system described above afforded >99% curcumin in 72% yield. The third batch of (4:1:1) curcuminoid mixture was reacted overnight with TBMDSCl in diisopropylethylamine/DMF. See Greene and Wuts Protective Groups in Organic Synthesis, 2 nd ed. 1991. Aqueous work up and recrystallization using hot acetone/H 2 O system afforded >99% curcumin in 84% yield.
[0030] The remaining residues were subjected to protecting group removal condition without isolation: PPTS/ethanol system for THP ether, K 2 CO 3 /methanol system for acetyl, and 1,1,3,3-tetramethylguanidine(TMG)/acetonitrile (CH 3 CN) system for TBDMS ether protecting groups (Oyama and Kondo, Org. Lett. 5: 209 (2003). The resulting residues were purified using column chromatography over silica gel to afford curcuminoids in various yields to confirm the efficacy of the method.
[0031] Of the THP ether protecting group work up, the overall yield of curcumin (1) was 87% while the overall curcuminoid yield was 88%. Of the acetyl protecting group work up, the overall yield of curcumin (1) was 90% and the overall curcuminoid yield also was 90%. Of the TBDMS protecting group work up, the overall yield of curcumin (1) was 88% while the overall curcuminoid yield was 90%. Table 1 shows curcuminoid yields from this procedure.
[0000]
TABLE 1
Curcuminoid recovery yield from 4-phenol group protection,
recrystallization of curcumin (1), deprotection, and chromatographic
isolation using (4:1:1) curcuminoid mixture (600 mg)
Protecting Group
Yield (%)
Compounds
1*
2
3
Overall yield (%)
THP
(79/87)
90
89
88
Acetyl
(72/90)
91
88
90
TBDMS
(84/88)
93
90
89
*Note: The yields are presented as (recrystallization/overall).
Example 2
[0032] Table 2 shows curcuminoid yields from processing of commercially available about 70% technical grade curcumin. The composition of about 70% technical grade curcumin was assumed to be a mixture of 70%, 20%, and 5%, curcuminoid 1, 2, and 3, respectively, and 5% unknown impurity based on a previous report (U.S. Pat. No. 5,861,415). The reactions were carried out as for Example 1. The results confirmed that this procedure is a simple and effective method to obtain >99% pure curcumin from a technical grade curcumin containing a mixture of curcuminoids that are similar in physiochemical properties.
[0033] Procedures using bulky protecting groups (THP ether and TBDMS ether) afforded higher curcumin (1) yield from recrystallization. The chromatographic isolation of products after removal of protecting groups and aqueous work up further confirmed the efficacy of this procedure. The overall curcuminoid yields remained comparable but were less than that of investigation using pure curcuminoids (Table 1), suggesting the influence of unidentified impurities in the technical grade. The purity of isolated curcuminoids was established based on their isolated yields, 1 HNMR spectral data, and mixed melting point analyses. Curcumin (1) mixed with about 2% curcuminoids 2 or 3 afforded melting point about 1° C. lower and wider range (about 1 to about 1.5° C.) than that of pure curcumin. All curcumin (1) obtained from recrystallization afforded sharp melting point of 183.5-184° C.
[0000]
TABLE 2
Curcuminoid recovery yield from 4-phenol group protection,
recrystallization of curcumin (1), deprotection, and chromatographic
isolation using technical grade curcumin (1.0 g)
Protecting Group
Yield (mg)
Compounds
1*
2
3
Overall yield (w/w %)
THP
(460/604)
158
28
79
Acetyl
(410/626)
148
26
80
TBDMS
(456/616)
162
32
81
*Note: The yields are presented as (recrystallization/overall).
Experimental Details for Examples 1 and 2
[0034] Materials and Instruments. All solvents and reagents were purchased from Aldrich and used without further purification. Compounds 1, 2, and 3 isolated from Curcuma longa were used. The 1 H NMR (300 MHz) and 13 CNMR (75 MHz) spectra were measured in DMSO-d6 or acetone-d6 using Bruker 300 MHz spectrometer. The chemical shifts are reported in δ (ppm) relative to TMS. Melting points were determined in open capillary tubes with a Thomas-Hoover apparatus and were uncorrected.
[0035] A General Procedure for Preparation of THP ether. To an anhydrous DMF solution (100 mL) containing compounds (600 mg) 1, 2, and 3 (4:1:1) was added 3.1 equiv. anhydrous DHP and catalytic amount of PPTS (20 mg) at room temperature and stirred overnight under N 2 atmosphere.
[0036] A General Procedure for Preparation of Acetate. To an anhydrous DMF solution (100 mL) containing compounds (600 mg) 1, 2, and 3 (4:1:1) was added 3.5 equiv. anhydrous triethylamine, catalytic amount of DMAP (20 mg), and acetic anhydride (3.1 equiv.) at 0° C., warmed to room temperature, and stirred overnight under N 2 atmosphere.
[0037] A General Procedure for Preparation of Silyl ether. To an anhydrous DMF solution (100 mL) containing compounds (600 mg) 1, 2, and 3 (4:1:1) was added 3.5 equiv. anhydrous diisopropylethylamine, and TBDMSCl (3.1 equiv.) at room temperature, and stirred overnight under N 2 atmosphere.
[0038] A General Procedure for Aqueous Work up and Recrystallization of Curcumin (1). The reaction mixture was added H 2 O (200 mL) and extracted with ethyl acetate (100 mL×4). The organic layers were combined, washed with H 2 O (50 mL×3). The combined aqueous layer was extracted with ethyl acetate (50 mL×2). The organic layers were combined, dried (MgSO 4 ), filtered, and the solvent was removed under vacuum. The resulting residue was dissolved in minimum amount of hot acetone, dropwisely added H 2 O to induce precipitation, reheated to re-dissolve, slowly cooled at room temperature and placed in a refrigerator to induce crystallization of curcumin (1). The crystals were filter collected dried, and recrystallized using acetone/H 2 O system as before to afford >99% pure curcumin. The purity of curcumin was confirmed by 1 H NMR and mixed melting point comparison.
[0039] A General Procedure for Removing THP Group. To an ethanol solution (50 mL) containing the residue (200 mg) was added PPTS (20 mg) at room temperature, stirred overnight, added H 2 O (20 mL), and the solvent was reduced to ˜50% volume under stream of air. To the residue was added ethyl acetate (100 mL), washed with H 2 0 (50 mL×3). The aqueous layers were combined and washed with ethyl acetate (50 mL×2). The organic layers were combined, dried (MgSO 4 ), filtered, and the solvent was removed under vacuum. The residue was column chromatographed over silica gel using gradient ethylacetate/pet ether/isopropyl alcohol.
[0040] A General Procedure for Removing Acetyl Group. To a methanol solution (50 mL) containing the residue (200 mg) was added K 2 CO 3 (20 mg) at room temperature, stirred overnight, added dropwise 10% AcOH to neutralize K 2 CO 3 , added H 2 O (20 mL), and the solvent was reduced to ˜50% volume under stream of air. To the residue was added ethyl acetate (100 mL), washed with H 2 O (50 mL×3). The aqueous layers were combined and washed with ethyl acetate (50 mL×2). The organic layers were combined, dried (MgSO 4 ), filtered, and the solvent was removed under vacuum. The residue was column chromatographed over silica gel using gradient ethylacetate/pet ether/isopropyl alcohol.
[0041] A General Procedure for Removing Silyl ether Group. To a CH 3 CN solution (50 mL) containing the residue (200 mg) was added 1,1,3,3-tetramethylguanidine (100 mg), H 2 O (0.5 mL) and stirred at 50° C. for two hours. The reaction mixture was cooled to room temperature, added H 2 O (20 mL), and the solvent was reduced to ˜50% volume under stream of air. To the residue was added ethyl acetate (100 mL), washed with H 2 O (50 mL×3). The aqueous layers were combined and washed with ethyl acetate (50 mL×2). The organic layers were combined, dried (MgSO 4 ), filtered, and the solvent was removed under vacuum. The residue was column chromatographed over silica gel using gradient ethylacetate/pet ether/isopropyl alcohol.
[0042] Curcumin 1
[0043] Yellow crystals; mp 183.5-184° C.; 1 H NMR (300 MHz, DMSO-d 6 ) δ7.56 (2H, d, J=15.8 Hz, H-1 and H-7), 7.32 (2H, d, J=1.5 Hz, H-2′ and H-2″), 7.15 (2H, dd, J=8.2 and 1.5 Hz, H-6′ and H-6″), 6.83 (2H, d, J=8.2 Hz, H-5′ and H-5″), 6.76 (2H, d, J=15.8 Hz, H-2 and H-6), 6.05 (1H, s, H-4), 3.84 (6H, s, OCH 3 -3′ and OCH 3 -3″) ppm; 13 C NMR (75 MHz, DMSO-d 6 ) δ184.1 (C-3 and C-5), 150.2 (C-4′ and C-4″), 148.8 (C-3′ and C-3″), 141.6 (C-1 and C-7), 127.2 (C-1′ and C-1″), 124.0 (C-6′ and C-6″), 121.9 (C-2 and C-6), 116.6 (C-5′ and C-5″), 112.1 (C-2′ and C-2″), 101.8 (C-4), 56.5 (OCH 3 -3′ and OCH 3 -3″) ppm.
[0044] Demethoxycurcumin 2
[0045] Yellow powder; mp 181-182 ° C.; 1 H NMR (300 MHz, acetone-d6) δ7.62 (1H, d, J=15.3 Hz, H-7), 7.61 (1H, d, J=15.3 Hz, H-1), 7.57 (2H, d, J=8.1 Hz, H-2″ and H-6″), 7.35 (1H, d, J=1.8 Hz, H-2′), 7.18 (1H, dd, J=8.1 and 1.8 Hz, H-6′) 6.91 (2H, d, J=8.1 Hz, H-3″ and H-5″), 6.88 (1H, d, J=8.1 Hz, H-5′), 6.73 (1H, d, J=15.3 Hz, H-6), 6.67 (1H, d, J=15.3 Hz, H-2), 5.99 (1H, s, H-4), 3.93 (3H, s, OCH 3 -3′) ppm; 13 C NMR (75 MHz, acetone-d 6 ) δ188.4 (C-3 and C-5), 160.4 (C-4″), 150.0 (C-4′), 148.8 (C-3′), 141.2 (C-7), 141.0 (C-1), 130.8 (C-2″ and C-6″), 128.2 (C-1″), 127.8 (C-1′), 123.7 (C-6′), 122.4 (C-6), 122.1 (C-2), 116.8 (C-3″ and C-5″), 116.2 (C-5′), 111.7 (C-2′), 101.5 (C-4), 56.4 (OCH 3 -3′) ppm.
[0046] Bisdemethoxycurcumin 3
[0047] Yellow needles; mp 232-233 ° C.; 1 H NMR (300 MHz, acetone-d 6 ) δ7.62 (2H, d, J=15.6Hz, H-1 and H-7),7.58 (4H, d, J=8.4 Hz, H-2′, H-2″, H-6′and H-6″), 6.91 (4H, d, J=8.4 Hz, H-3′, H-3″, H-5′ and H-5″), 6.68 (2H, d, J=15.6 Hz, H-2 and H-6), 5.99 (1H, s, H-4) ppm; 13 C NMR (75 MHz, acetone-d 6 ), δ 184.0 (C-3 and C-5), 160.0 (C-4′ and C-4″), 140.8 (C-1 and C-7), 130.6 (C-2′, C-2″, C-6′ and C-6″), 126.9 (C-1′ and C-1″), 121.4 (C-2 and C-6), 116.5 (C-3′, C- 3″, C-5′ and C-5″), 101.6 (C-4) ppm.
REFERENCES
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Park, S.-Y.; Kim, D. S. H. L., Discovery of natural products from Curcuma longa that protect cells from beta-amyloid insult: a drug discovery effort against Alzheimer's disease. J. Nat. Prod. 2002, 65, 1227.
Majeed, M.; Badmaev, V.; Rajendran, R., Bioprotectant composition, method of use and extraction process of curcuminoids. 1999, U.S. Pat. No. 5,861,415.
Kawanishi, S.; Oikawa, S.; Murata, M., Evaluation for safety of antioxidant chemopreventive agents. Antioxid. Redox Signal. 2005, 7, 1728.
Chianani-Wu, N., Safety and anti-inflammatory activity of curcumin: a component of turmeric ( Curcuma longa ). J. Altern. Complement Med. 2003, 9, 161.
[0052] Vajragupta, O.; Boonchoong, P.; Morris, G. M.; Olson, A. J., Active site binding modes of curcumin in HIV-1 protease and integrase. Bioorg. Med. Chem. Lett. 2005, 15, 3364.
Ranjan, D.; Johnston, T. D.; Reddy, K. S.; Wu, G.; Bondada, S.; Chen, C., apoptosis mediates inhibition of EBV-transformed lymphoblastoid cell line proliferation by curcumin. Enhanced J. Sur. Res. 1999, 87, 1. Kim, M.-K.; Choi, G.- J.; Lee, H.-S., Fungicidal property of Curcuma longa L. rhizome-derived curcumin against phytopathogenic fungi in a greenhouse. J. Agric. Food Chem. 2003, 51, 1578. Foryst-Ludwig, A.; Neumann, M.; Schneider-Brachert, W.; Naumann, M., Curcumin blocks NF-kB and the motogenic response in Helicobacter pylori-infected epithelial cells. Biochem. Biophys. Res. Commun. 2004, 316, 1065. Lee, K. W.; Kim, J.-H.; Lee, H. J.; Surh, Y.-J., Curcumin inhibits phorbol ester-induced up-regulation of cyclooxygenase-2 and matrix metalloproteinase-9 by blocking ERK1/2 phosphorylation and NF-kB transcriptional activity in MCF10A human breast epithelial cells. Antioxid. Redox Signal. 2005, 7, 1612. Duvoix, A.; Blasius, R.; Delhalle, S.; Schnekenburger, M.; Morceau, F.; Henry, E.; Dicato, M.; Diederich, M., Chemopreventive and therapeutic effects of curcumin. Cancer Lett. 2005, 223, 181. Yang, F.; Lim, G. P.; Begum, A. N.; Ubeda, O. J.; Simmons. M. R.; Ambegaokar, S. S.; Chen, P.; Kayed, R.; Glabe, C. G.; Frautschy, S. A.; Cole, G. M., Curcumin inhibits formation of amyloid b oligomers and fibrils, binds plaques, and reduces amyloid in vivo. J. Biol. Chem. 2005, 280, 5892. Nurfina, A. N.; Reksohadiprodjo, M. S.; Timmerman, H.; Jenie, U. A.; Sugiyanto, D.; van der Goot, H., Synthesis of some symmetrical curcumin derivatives and their anti-inflammatory activity. Eur. J. Med. Chem. 1997, 32, 321. Greene, T. W.; Wuts, P. G. M. Protective Groups in Organic Synthesis, 2 nd ed. 1991, John Wiley & Sons, Inc. and references sited therein. Oyama, K.; Kondo, T., A novel and convenient chemoselective deprotection method for both silyl and acetyl groups on acidic hydroxyl groups such as phenol and carboxylic acid by using a nitrogen organic base, 1,1,3,3-tetramethylguanidine. Org. Lett. 2003, 5, 209.
[0062] All patents, publications and references cited herein are hereby fully incorporated by reference. In case of conflict between the present disclosure and incorporated patents, publications and references, the present disclosure should control.
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This invention describes a preparation of at least 99% by weight pure curcumin from less pure grades of curcumin utilizing phenol protecting groups to favor a selective recrystallization of curcumin in the presence of demethoxycurcumin and bis-demethoxycurcumin and other curcuminoids of minor composition.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of International Patent Application No. PCT/CN2006/003641 with an international filing date of Dec. 28, 2006, designating the United States, now pending, and further claims priority benefits to Chinese Patent Application No. 200610013230.7 filed Feb. 28, 2006. The contents of all of the aforementioned applications, including any intervening amendments thereto, are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to a decorating lamp, and particularly to a seven-color light-emitting module and a seven-color decorating lamp string comprising the same.
[0004] 2. Description of the Related Art
[0005] With fast development of economy and improvement in living standard and cultural quality, decorating lamps are of great importance for decoration of high buildings, entertainment places, roads, shops, and especially sceneries in festivals and grand gathering places in cities. However, a conventional decorating lamp string comprises a monochromatic lamp and a bicolor lamp, decorating and illumination effects of which are not ideal, some of which have complex structure, high processing cost and power consumption, some of which have poor waterproof, impact resistance and electrical performance, and thus use effect and lifetime thereof are affected.
[0006] At present, some oversea products employ three-color self-flashing LEDs to overcome drawbacks in decoration and illumination caused by the monochromatic lamp and the bicolor lamp. However, since interelectrode voltage of the three-color self-flashing LED cannot be effectively regulated in a range of rated voltage, it always operates in an abnormal state, which not only affects use effect and lifetime, but also makes it impossible to serially connect tens of three-color self-flashing LEDs to city power. Therefore, present circuit design usually employs a transformer to step down or decreases the number of three-color self-flashing LEDs to prevent the interelectrode voltage from exceeding the rated voltage. However, this makes the circuit complex in structure, causes a limited application range since few lamps can be connected for a lamp string, and affects aesthetic appearance and use of the decorating lamp string since a step down transformer is employed. In addition, since the lampshade is not firm enough and improper designed, it is prone to be broken due to impact and squeezing; since the lampshade uses transparent materials, light-mixing and light-emitting effect are poor, and aesthetic appearance is affected. Besides, as one three-color self-flashing LED is opened and does not operate, the rest of the three-color self-flashing LEDs serially connected thereto will not emit light, and the lamp string cannot operate normally.
SUMMARY OF THE INVENTION
[0007] In view of the above-described problems, it is one objective of the invention to provide a seven-color light-emitting module and a seven-color decorating lamp string comprising the same that feature good color-mixing effect and transparency, high anti-break strength, significant waterproof effect, low power consumption, safe and reliable performance, convenient use, long life, simple manufacture and wide applications.
[0008] A seven-color light-emitting module of the invention comprises a lampshade and a lamp socket; wherein the lampshade is made of ivory-white light-transmission plastics or synthetic resin with good color-mixing effect and transparency, a three-color self-flashing LED, a Zener diode, a current-limiting resistor and a printed circuit board (PCB) sealed in the lampshade are disposed on the lamp socket, the three-color self-flashing LED is connected with the PCB, and both ends of the three-color self-flashing LED are parallel connected to the Zener diode, one or both ends of the Zener diode are serially connected to the current-limiting resistor, and the lampshade is filled with materials like transparent epoxy resin or silicon glue.
[0009] The PCB is a double-side PCB, and the Zener diode and the current-limiting resistor disposed thereon are piece components.
[0010] One or two three-color self-flashing LEDs are disposed in the lampshade.
[0011] A transparent sealing layer for sealing the three-color self-flashing LED, the PCB and the piece components on the PCB are disposed in the lampshade.
[0012] A thickness of the lampshade is 2-12 mm, and usually 5-10 mm.
[0013] A positioning hole is axially disposed on a side wall at the bottom of the lampshade.
[0014] The lampshade may be sphere, column, rectangle, rhombus, lantern, or any other shapes of heads of various cartoon animals.
[0015] The lampshade and the lamp socket can be integrally formed into sphere, column, rectangle, rhombus, lantern, or any other shapes of heads of various cartoon animals.
[0016] A seven-color decorating lamp string of the invention comprises a plug, and a power supply and a plurality of seven-color light-emitting modules connected via wires; wherein the power supply comprises a house filled with materials like epoxy resin or silicon glue and a rectifying and filter circuit connected to a printed circuit board (PCB); the seven-color light-emitting module comprises a lampshade, a lamp socket, and a three-color self-flashing LED, a Zener diode, a current-limiting resistor and the PCB disposed on the lamp socket and sealed in the lampshade.
[0017] The three-color self-flashing LED is connected with the PCB, and both ends of the three-color self-flashing LED are parallel connected to the Zener diode; one or both ends of the Zener diode are serially connected to the current-limiting resistor; and the lampshade is filled with materials like transparent epoxy resin or silicon glue.
[0018] The rectifying and filter circuit is a half-wave rectifying circuit, a structure of which is: one end of the power input is serially connected to a rectifying diode and an anti-surge resistor, a discharging resistor and a filtering capacitor are parallel connected between the other end of the anti-surge resistor and the other end of the power supply, and a circuit comprising a plurality of serial-connected seven-color light-emitting modules is parallel connected between both ends of the filtering capacitor.
[0019] The rectifying and filter circuit is a full-wave rectifying circuit, a structure of which is: one end of the power input is serially connected to a dividing capacitor and then to an alternating input end of a silicon rectifying bridge, a cathode of the silicon rectifying bridge is serially connected to an anti-surge resistor, a discharging resistor and a filtering capacitor are parallel connected between the other end of the anti-surge resistor and an anode of the silicon rectifying bridge, and a circuit comprising a plurality of serial-connected seven-color light-emitting modules is parallel connected between both ends of the filtering capacitor.
[0020] A plurality of said seven-color decorating lamp strings can be connected altogether in structure to form a lamp string.
[0021] Advantages of the invention comprise:
1. Since the lampshade is made of ivory-white light-transmission plastics or synthetic resin with good color-mixing effect and transparency, light emitted from the seven-color decorating lamp string composed of the light-emitting module is soft and colorful, meanwhile, the seven-color decorating lamp string has high intensity, heat tolerance as well as long lifetime, and is not easily damaged or deformed. 2. Space in the enclosing cover of the power supply and the lampshade of the seven-color light-emitting module is filled with materials like epoxy resin or silicon glue, components and solder joints therein can be tightly fixed and sealed very well. Thus the invention features high tolerance to water pressure and significant waterproof performance, and applications thereof are enhanced. 3. By using the Zener diode, (1) an interelectrode voltage of the three-color self-flashing LED is regulated in a range of rated voltage, so that it operates in a more reasonable state, and thus a lifetime of the lamp string is prolonged; (2) If the three-color self-flashing LED emits light with different colors or does not work, redundant current will be bypassed; (3) If a three-color self-flashing LED in the lamp string is opened and does not emit light, the lamp string will still operate properly; (4) A large and expensive step-down transformer that is used in a normal lamp string is omitted, which simplifies overall design of the lamp string. Meanwhile, the number of seven-color light-emitting modules forming the seven-color decorating lamp string is expanded to several hundreds or even thousands. 4. To some extent, the dividing capacitor and the silicon rectifying bridge allows for free setting of the number of seven-color light-emitting modules in each seven-color decorating lamp string, which makes applications of the invention even wider. 5. Since the double-side PCB and the piece components are employed in the lampshade of the seven-color light-emitting module, a size of the seven-color light-emitting module is reduced, a structure and a process thereof are more simple, product quality is improved, processing cost is decreased, large-scaled production is implemented, and the product is novel, simple and beautiful.
[0031] Since a three-color self-flashing LED that is capable of emitting light with seven colors is used in the seven-color light-emitting module, If two three-color self-flashing LEDs are selected in the seven-color light-emitting module, two groups of combinations both with seven different colors can be formed, and therefore more colors can be generated, which makes the decorating lamp more colorful and a dreaming effect more remarkable.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] FIG. 1 is a circuit diagram of the invention;
[0033] FIG. 2 is a circuit diagram of the invention as a dividing capacitor is used;
[0034] FIG. 3 illustrates a scenario where a lamp socket is columnar and a lampshade is sphere;
[0035] FIG. 4 illustrates a scenario where a lamp socket is disciform and a lampshade is columnar and has a circle top;
[0036] FIG. 5 illustrates a scenario where a lamp socket and a lampshade are molded into a sphere shape;
[0037] FIG. 6 illustrates a scenario where a wire passes through a side portion of a columnar lamp socket;
[0038] FIG. 7 illustrates a scenario where a lamp socket is columnar and a lampshade is lantern-shaped; and
[0039] FIG. 8 is a sectional view of a seven-color light-emitting module in FIG. 3 .
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0040] Detailed description of a seven-color light-emitting module and a seven-color decorating lamp string comprising the same will be given below with reference to accompanying drawings and embodiments.
[0041] As shown in FIGS. 1-8 , the seven-color decorating lamp string of the invention comprises a plug 1 , a power supply 2 and a plurality of seven-color light-emitting modules 3 connected via a wire 4 . Each of the seven-color light-emitting modules 3 comprises a lampshade 31 , a lamp socket 32 , a three-color self-flashing LED D 2 , a Zener diode Dw, a current-limiting resistor R 3 and a printed circuit board (PCB), the PCB being connected to the three-color self-flashing LED D 2 , both ends of the three-color self-flashing LED D 2 being parallel connected to the Zener diode Dw, one or both ends of the Zener diode Dw being serially connected to the current-limiting resistor R 3 , and the seven-color light-emitting modules 3 being connected together via the wire 4 .
[0042] In this embodiment, the power supply 2 may employ different structure.
[0043] For example, the power supply 2 comprises an enclosing cover (not shown), a PCB (not shown), a rectifying diode D 1 , a surge-proof resistor R 1 , a discharging resistor R 2 and a filtering capacitor C 1 . As shown in FIG. 1 , one end of a power input is serially connected to the rectifying diode D 1 and the surge-proof resistor R 1 , so as to perform half-wave rectification; The charging resistor R 2 and the filtering capacitor C 1 are parallel connected between the other end of the surge-proof resistor R 1 and the other end of the power input, so as to generate a pulsatile DC voltage; and a circuit comprising a plurality of serial-connected seven-color light-emitting modules 3 is parallel connected between both ends of the filtering capacitor C 1 .
[0044] In another example, the power supply 2 comprises an enclosing cover, and a dividing capacitor C 0 , a silicon rectifying bridge D 0 , a surge-proof resistor R 1 , a discharging resistor R 2 and a filtering capacitor C 1 disposed in the enclosing cover. As shown in FIG. 2 , the power input is serially connected to the dividing capacitor C 0 and then to an alternating input end of the silicon rectifying bridge D 0 , so as to perform full-wave rectification; a cathode of the silicon rectifying bridge D 0 is serially connected to the anti-surge resistor R 1 ; the discharging resistor R 2 and the filtering capacitor C 1 are parallel connected between the other end of the anti-surge resistor R 1 and an anode of the silicon rectifying bridge D 0 , so as to generate a pulsatile DC voltage; and a circuit comprising a plurality of serial-connected seven-color light-emitting modules 3 is parallel connected between both ends of the filtering capacitor C 1 .
[0045] For the seven-color light-emitting module 3 in the seven-color decorating lamp string, since the Zener diode Dw is parallel connected between a cathode and an anode of the three-color self-flashing LED D 2 , compared with products in the art, electric properties of the invention are improved as follows:
1. An interelectrode voltage of the three-color self-flashing LED D 2 is regulated in a range of rated voltage, and prevented from operating in an abnormal voltage state that may reduce lifetime of the three-color self-flashing LED D 2 , and thus a lifetime of the seven-color decorating lamp string is prolonged. 2. As the three-color self-flashing LED D 2 emits homogeneous light, polychromatic light and three-color light, redundant current in the circuit is bypassed (Characteristics of the three-color self-flashing LED: operating current when emitting homogeneous light, polychromatic light and three-color light is different, the least current is consumed as red homogeneous light is emitted), so that the three-color self-flashing LED D 2 always operates in a normal state, and lifetime thereof is prolonged. 3. If a three-color self-flashing LED D 2 is opened and does not emit light, current of the seven-color decorating lamp string is bypassed, and voltage distribution of the other three-color self-flashing LEDs D 2 are not affected and emit light as usual, so that the entitle circuit operates normally and reliability of the invention is improved.
[0049] The Zener diode Dw allows the seven-color decorating lamp string to be directly connected to city power, and therefore a step-down transformer that is used in the prior art is omitted, which simplifies structure of the invention, reduces cost, offers easy use, improves aesthetic appearance and enhances applications.
[0050] The dividing capacitor C 0 in the power supply 2 is capable of selecting capacitors with different capacitance and withstanding voltage, according to power input voltage and the number of serial-connected three-color self-flashing LEDs; as a ratio between an overall voltage of the serial-connected three-color self-flashing LEDs and the power input voltage is appropriate, the dividing capacitor C 0 and the silicon rectifying bridge D 0 are no longer needed.
[0051] The lampshade 31 employs ivory-white light-transmission plastics or synthetic resin (for example, polypropylene, polyethylene, polycarbonate and so on) with good color-mixing effect and transparency. A thickness of the lampshade 31 can be set in a range of 2-12 mm according to a diameter thereof and the number of three-color self-flashing LEDs D 2 disposed therein, and preferably 5-10 mm as better transparency and color-mixing effect are required. The lampshade 31 is capable of uniformly mixing polychromatic light and three-color light emitted by the three-color self-flashing LED D 2 , so as to generate a single and uniform effect of composite light.
[0052] In order to improve insulation, waterproof and impact performance of the seven-color decorating lamp string, space in the enclosing cover of the power supply and the lampshade 31 is filled with transparent materials 34 like epoxy resin or silicon glue.
[0053] An objective of filling the enclosing cover of the power supply 2 with materials 34 like epoxy resin or silicon glue is to coat printed circuit boards of voltage-dividing, rectifying, filtering and discharging components and all solder joints, so as to realize insulation from the air and special waterproof effect.
[0054] Moreover, by way of filling the lampshade 31 with materials 34 like epoxy resin or silicon glue and installing the lamp socket 32 , it is possible to coat the three-color self-flashing LED D 2 , printed circuit boards having voltage regulating and current limiting components, as well as all solder joints, so as to effectively improve waterproof and impact performance.
[0055] To highlight waterproof effect of the light-emitting module and to insulate all components disposed therein and all the solder joints from the air, a transparent coating layer (not shown) capable of sealing one or two three-color self-flashing LEDs D 2 and printed circuit boards of welding components thereon.
[0056] A pair of positioning holes 33 are axially disposed on a side wall at the bottom of the lampshade 31 (as shown in FIG. 8 ), as materials like epoxy resin or silicon glue are introduced, redundant remainders overflow from the lampshade 31 , enter the positioning holes 33 and are solidified, and a material 34 with two protruding columns is formed. Thus, adhesion and sealing are realized, PCBs and electronic components in the lampshade 31 are fixed, and the lampshade 31 is prevented from detaching from the lamp socket 32 .
[0057] The lampshade 31 is molded into a sphere, column, rectangle, rhombus, lantern, or any other shapes of heads of various cartoon animals. For example, a closed sphere-shaped lampshade 31 can construct a sphere-shaped seven-color decorating lamp string, the lamp socket 32 connected to the lampshade 31 may be molded into a columnar shape (as shown in FIGS. 3 and 6 ), a disc shape (as show in FIG. 4 ) and so on; the lampshade 31 connected to the lampshade 32 may be molded into a columnar shape with a circle top (as show in FIG. 4 ); the lampshade 31 and the lamp socket 32 may be integrally molded into a sphere, column, rectangle, rhombus, lantern, or any other shapes of heads of various cartoon animals, for example a sphere shape (as shown in FIG. 5 ). The disc-shaped lamp socket 32 is adhered to the surface of objects like buildings, which improves stability, decorative quality and consistency. The sphere-shaped seven-color decorating lamp string is applicable to places like fountains and pools as an underwater ornament, as well as both sides of roads, shops, buildings and various entertainment places.
[0058] The lampshade 31 connected to the lamp socket 32 is a lantern-shaped, both ends of the lampshade 31 are connected to a pair of lamp sockets 32 , and the lamp socket 32 is connected to wire 4 to form a reticular lamp string and a reticular seven-color decorating lamp (as shown in FIG. 7 ). The reticular seven-color decorating lamp is novel and has significant decorating effect.
[0059] One or two three-color self-flashing LEDs D 2 may be alternatively disposed in the lampshade 31 . As two three-color self-flashing LEDs D 2 are used, two groups of combinations both with seven different colors can be formed, after being mixed and transmitted by the lampshade 31 , more colors can be generated. If the lamp string is used for decorating buildings, novel and beautiful characteristics thereof will be highlighted, the decorated buildings will be more colorful, and a dreaming effect will be more remarkable.
[0060] The PCB in the lampshade 31 or on the lamp socket 32 is a double-side PCB, the Zener diode Dw and the current-limiting resistor R 3 disposed thereon are piece components. This arrangement simplifies the manufacturing process, reduces a size of the light-emitting module 3 , which decreases processing cost, and improves reliability, production rate and aesthetic appearance of products.
[0061] The seven-color light-emitting modules of the invention may be connected together to form a seven-color decorating lamp string by passing the wire 4 through the bottom of the lamp socket 32 or side portions thereof (as shown in FIG. 6 ). A plurality of the seven-color decorating lamp strings can be connected altogether in different manners, so as to form a lamp string with hundreds to thousands of seven-color light-emitting modules, which are more splendid and beautiful.
[0062] While particular embodiments of the invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the invention in its broader aspects, and therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of the invention.
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A seven-color light emitting module and a seven-color decorating lamp string comprising the same. The seven-color light emitting module includes a lampshade made of a transparent plastic or synthetic resin, and a lamp socket on which three colors self-flashing light emitting diode, a zener diode, a current limiting resistance and a double-side printed circuit board (PCB) are sealed. The three colors light emitting diodes connect with PCB and connect with the zener diode in parallel. One end of the zener diode or two ends of the zener diode connects with the current limiting resistance in series. A transparent epoxy resin or silicon glue is filled in the lampshade. The seven-color decorating lamp string include a power supply plugs, a power supply module which has a PCB and a rectifying and filter circuit connected by wires and a plurality of said seven colors light emitting modules
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a DDFSE (Delayed Decision Feedback Sequence Estimator) for estimating a transmission signal from a signal having undergone transmission path distortion caused by frequency selective fading due to a multipath effect in a radio channel in high-speed digital communication and, more particularly, to a delayed decision feedback sequence estimation diversity receiver which improves its signal estimation ability by combining antenna diversity with a DDFSE.
2. Description of the Prior Art
As a conventional apparatus designed to determine an optimal reception timing so as to estimate a transmission signal from reception signals having undergone transmission path distortion by using a DDFSE, the delayed decision feedback sequence estimation receiver disclosed in Japanese Unexamined Patent Publication No. 11-8573 is known.
The DDFSE is a signal estimator which has the merits of both an MLSE (Maximum Likelihood Sequence Estimator) having high signal estimation ability and a DFE (Decision Feedback Equalizer) with a small computation amount.
FIG. 1 is a block diagram showing the arrangement of a conventional DDFSE with a timing control function.
Assume that a reception signal 201 is a complex baseband signal expressed in a two-dimensional form. A transmission path estimator 202 is a block for obtaining the characteristics of a transmission path in the form of an impulse response. In general, the transmitting side sends a training signal before transmission of data, and the receiving side receives the training signal having undergone transmission path distortion, thereby obtaining transmission path characteristics.
An estimation region detector 203 performs a computation to find the timing at which the signal estimation ability is maximized. A DDFSE 204 performs signal estimation on the basis of the impulse response sequence obtained by the transmission path estimator 202 and the optimal timing obtained by the estimation region detector 203 .
If the impulse response sequence obtained by the transmission path estimator 202 has undergone transmission path distortion, it has a temporally wide waveform like the one shown in FIG. 2 . In this case, this signal is expressed in the form of a discrete signal sampled at a symbol period T of the transmission signal. FIG. 2 shows how the distortion spreads over a time 6 T (signal components a 2 , a 3 , and a 6 to a 10 are not shown because their amplitudes are regarded as 0).
Assume that the DDFSE with the timing control function is configured to perform transmission path estimation in 11 symbol periods. More specifically, the DDFSE performs signal estimation equivalent to an MLSE computation in the first three symbol periods, and cancels a component corresponding to the succeeding three symbol periods by a computation equivalent to a DFE computation.
The estimation region detector 203 can find an optimal timing by the following computation.
Let P be the power component used for signal estimation, which falls within a 3-symbol range (MLSE region), Q be the power component to be canceled, which falls within a 3-symbol range (DFE region), and R be the power in the remaining 5-symbol range (outside the estimation region). In this case, as P increases, the signal estimation ability increases. Q is irrelevant to the signal estimation ability because it is canceled. As R increases, the signal estimation ability decreases. As an evaluation function, we define:
Z=P/R (1)
The signal estimation ability is maximized at the timing at which Z of equation (1) is maximized.
In general, an impulse response in a transmission path can be obtained accurately only within certain limits on the receiving side owing to the influences of noise and computation errors. For this reason, the signal component in the DFE region which should be completely canceled ideally is not completely canceled and left as a distortion component. This phenomenon becomes noticeable as the signal component in the MLSE region decreases and the signal component in the DFE region increases.
A decision feedback loop exists in the DDFSE. Once an error is made in signal estimation, therefore, the erroneous estimation result circulates within the loop, and a burst-like error called error propagation may occur. This error propagation is likely to occur as the component in the DFE region becomes large. In order to cope with this situation, the evaluation function expressed by equation (1) must be modified to determine the timing at which higher signal estimation ability can be obtained. To this end, we define an evaluation function given by:
Z=P /( R+αQ ) (2)
In equation (2), the coefficient α is a coefficient determined in accordance with the computation precision of an impulse response.
In the transmission path impulse response sequence shown in FIG. 2 ., the timings represented by:
P =( a 0 ) 2 +( a 1 ) 2 +( a 2 ) 2 (3)
Q =( a 3 ) 2 +( a 4 ) 2 +( a 5 ) 2 (4)
R =( a 6 ) 2 +( a 1 ) 2 +( a 8 ) 2 +( a 9 ) 2 +( a 10 ) 2 (5)
are obtained as optimal timings for signal estimation by using either equation (1) or (2).
If signal components that are received with delays are larger than other components as shown in FIG. 3 , the timings obtained by equations (1) and (2) may differ from each other. In using equation (2), the timings are matched to delayed components that are received with delays by adjusting the coefficient a as per:
P =( a 3 ) 2 +( a 4 ) 2 +( a 5 ) 2 (6)
Q =( a 6 ) 2 +( a 7 ) 2 +( a 8 ) 2 (7)
R =( a 9 ) 2 +( a 10 ) 2 +( a 0 ) 2 +( a 1 ) 2 +( a 2 ) 2 (8)
This is because the estimation ability can be improved by performing signal estimation using a 4 and a 5 while regarding a 0 and a 1 as distortion components rather than by performing signal estimation using a 0 and a 1 with small amplitudes.
FIG. 4 shows the arrangement of this estimation region detector 203 .
A power calculator 701 obtains the power level of each symbol, which is the square value (the sum of the square value of a real part and the square value of an imaginary part) of each symbol, of the complex impulse response sequence output from the transmission path estimator 202 , and inputs the respective power levels to shift registers 702 a to 702 j.
An adder 703 obtains a power value P of the signal component in the MLSE region. An adder 704 obtains a power value Q of the signal component in the DFE region. An adder 705 obtains a power value R of a signal component outside the estimation region for the DDFSE 204 .
Equations (3) and (6) are calculated by the adder 703 . Equations (4) and (7) are calculated by the adder 704 . Equations (5) and (8) are calculated by the adder 705 .
The power values P, Q, and R obtained by the adders 703 , 704 , and 705 are used by an evaluation function calculator 706 to perform a computation based on equation (2). The evaluation function calculator 706 calculates equation (2) over 11 symbol periods, and detects the timing at which the value of Z is maximized. The evaluation function calculator 706 then outputs this timing to the DDFSE 204 .
In this manner, the DDFSE with the timing control function obtains the timing for signal estimation by using an evaluation function like equation (2), thereby obtaining an optimal timing for the DDFSE.
However, the following problem arises in the prior art described above.
In a transmission path impulse response sequence like the one shown in FIG. 3 , if a 0 and a 1 are received in the MLSE region as optimal timings, a 4 and a 5 received in the DFE region are canceled by a 0 and a 1 having small amplitudes. At this time, if a slight error is included in a 0 or a 1 , the error is amplified when a 4 and a 5 are canceled, resulting in a deterioration in signal estimation ability.
If the values of a 4 and a 5 are large, the probability of occurrence of error propagation, i.e., continuous occurrence of errors upon occurrence of an error in signal estimation, increases. This also leads to a deterioration in signal estimation ability.
If a 4 and a 5 are received in the MLSE region, since a 0 and a 1 are received in neither the MLSE region nor the DFE region, these values are not effectively used for signal estimation and treated as distortions. This becomes a factor that degrades the signal estimation ability. That is, high signal estimation ability can be obtained by selecting neither of the former timing and the latter timing.
When a relatively large power component is set in the DFE region, as shown in FIG. 2 , error propagation occurs more easily than when a large power component is not set in the DFE region. Therefore, a deterioration in signal estimation ability cannot be avoided.
SUMMARY OF THE INVENTION
The present invention has been made in consideration of the above situation in the prior art, and has as its object to provide a delayed decision feedback sequence estimation diversity receiver which can obtain high signal estimation ability.
In order to achieve the above object, according to the first aspect of the present invention, there is provided a delayed decision feedback sequence estimation diversity receiver characterized in that signals are received by two or more antennas, impulse response sequences in the respective transmission paths are obtained from the respective reception signals, components having the largest amplitude values among delayed wave components that are received with delays in these impulse response sequences are detected, and the impulse response sequences are combined so as to cancel the detected delayed wave components to generate a new impulse response sequence.
According to the second aspect of the present invention, there is provided a delayed decision feedback sequence estimation diversity receiver characterized in that signals are received by using two or more antennas, and the respective reception signals are combined so as to cancel components having the largest amplitude values among delayed wave components received with delays, thereby generating a new reception signal.
According to the third aspect of the present invention, there is provided a delayed decision feedback sequence estimation diversity receiver characterized in that signal estimation is performed by receiving a newly generated impulse response sequence and a newly generated reception signal and performing a computation for delayed decision feedback sequence estimation.
As is obvious from the respective aspects described above, according to the delayed decision feedback sequence estimation diversity receiver of the present invention, the overall power of delayed wave components is decreased by canceling components having the largest amplitudes among delayed wave components which cause a deterioration in signal estimation in a DDFSE by using a delayed wave canceler.
As a consequence, the power of delayed wave components which cause a deterioration in the DDFSE decreases, and hence the signal estimation ability of the DDFSE can be improved.
The above and many other objects, features and advantages of the present invention will become manifest to those skilled in the art upon making reference to the following detailed description and accompanying drawings in which preferred embodiments incorporating the principle of the present invention are shown by way of illustrative examples.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing the arrangement of a conventional delayed decision feedback sequence estimation diversity receiver having a timing control function;
FIGS. 2 and 3 are charts for explaining conventional impulse response sequences in transmission paths;
FIG. 4 is a block diagram showing the detailed arrangement of an estimation region detector in the prior art;
FIG. 5 is a block diagram showing a delayed decision feedback sequence estimation diversity receiver according to an embodiment of the present invention;
FIG. 6 is a block diagram showing the detailed arrangement of a delayed wave detector in the embodiment of the present invention in FIG. 5 ;
FIG. 7 is a block diagram showing the detailed arrangement of a delayed wave canceler according to the embodiment of the present invention in FIG. 5 ; and
FIGS. 8 and 9 are charts for explaining the impulse response sequences output from the delayed wave canceler according to the embodiment of the present invention in FIG. 5 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A preferred embodiment of the present invention will be described below with reference to the accompanying drawings.
FIG. 5 is a block diagram showing the arrangement of a delayed decision feedback sequence estimation diversity receiver according to an embodiment of the present invention.
Referring to FIG. 5 , the delayed decision feedback sequence estimation diversity receiver includes transmission path estimators 103 and 104 for respectively obtaining transmission path complex impulse response sequences from complex baseband reception signals 101 and 102 input through input terminals T 1 and T 2 and received by two independent antennas.
The delayed decision feedback sequence estimation diversity receiver of the present invention includes delayed wave detectors 105 and 106 for detecting the positions and magnitudes of components having the largest amplitudes among delayed wave components from the complex impulse response sequences respectively obtained by the transmission path estimators 103 and 104 , a delayed wave canceler 107 for outputting an impulse response sequence obtained by canceling a component having the largest amplitude among delayed wave component sequences in the impulse response sequences output from the transmission path estimators 103 and 104 on the basis of the output signals from the delayed wave detectors 105 and 106 , and a delayed wave canceler 108 for outputting a complex baseband reception signal obtained by canceling a component having the largest amplitude among delayed wave components in the reception signals input through the input terminals T 1 and T 2 .
The delayed decision feedback sequence estimation diversity receiver also includes an estimation region detector 109 for determining an optimal timing for signal estimation from the impulse response sequence output from the delayed wave canceler 107 , and a DBFSE 110 for performing signal estimation by receiving the output signals from the delayed wave canceler 107 , estimation region detector 109 , and delayed wave canceler 108 .
The overall operation of this embodiment will be described next with reference to the arrangement shown in FIG. 5 .
In this case, a 11-bit pseudo-random code is used as a training signal to allow the transmission path estimators 103 and 104 to obtain impulse response sequences based on multipath distortion in transmission paths during a 11-symbol period. As regions that can be estimated by the DDFSE (Delayed Decision feedback Sequence Estimator) 110 , a maximum likelihood sequence estimation region (MLSE region) and decision feedback equalization region (DFE region), each corresponding to three symbols, will be described below.
A transmission path is estimated on the transmitting side when a training signal is transmitted. The training signal generated from a 11-bit pseudo-random code on the transmitting side is input as the reception signal 101 through the input terminal T 1 . The transmission path estimator 103 obtains an impulse response sequence in the transmission path by performing a correlation computation between the reception signal 101 and a 11-bit pseudo-random code identical to that on the transmitting side.
As the 11-bit pseudo-random code, a Barker code (+1, +1, +1, −1, −1, −1, +1, −1, −1, +1, −1) is used, and the received training signal is represented by r(n). In this case, an output signal h(n) from the transmission path estimator 103 is given by
h ( n )=r( n− 10)+ r ( n− 9)+ r ( n− 8)− r ( n− 7)− r ( n− 6)− r ( n− 5)+ r ( n− 4)− r ( n− 3)− r ( n− 2)+ r ( n− 1)− r ( n ) (9)
where n is an integer having a symbol period.
This output signal h(n) becomes an impulse response sequence in the transmission path. Since a baseband reception signal is generally a two-dimensional signal, the signal given by equation (9) is also a two-dimensional signal.
The transmission path estimator 104 receives the reception signal through the input terminal T 2 , which is received by using an antenna different from that used for the reception signal 101 , and performs a correlation computation with a 11-bit pseudo-random code in the same manner as described above, thereby obtaining an impulse response sequence in the transmission path.
Assume that the impulse response sequence obtained by the transmission path estimator 103 from the reception signal is the sequence shown in FIG. 2 , and the impulse response sequence obtained by the transmission path estimator 104 from the reception signal 102 is the sequence shown in FIG. 3 .
The delayed wave detector 105 detects the timing, real component, and imaginary component of a 4 in FIG. 2 which is the component having the largest amplitude in the delayed wave sequence. In this case, the timing is represented by m 1 , and the component is represented by p 1 +j×q 1 . Note that j is an imaginary unit.
FIG. 6 shows an example of the arrangement of the delayed wave detector 105 .
The two-dimensional impulse response sequence value input from the transmission path estimator 103 is shifted at a symbol cycle by using shift registers 801 a to 801 e.
The magnitudes of impulse responses at three symbols, i.e., the fourth to sixth symbols, of the signal input from the transmission path estimator 103 are compared with each other.
The impulse response value at the fourth symbol is output from the shift register 801 c , and its power level is obtained by a power calculator 802 . The impulse response value at the fifth symbol is output from the shift register 801 d , and its power level is obtained by a power calculator 803 . The impulse response value at the sixth symbol is output from the shift register 801 e , and its power level is obtained by a power calculator 804 .
The power levels at the fourth, fifth, and sixth symbols, respectively obtained by the power calculators 802 , 803 , and 804 , are compared by a comparator 805 to determine a specific symbol at which the highest level is obtained. The corresponding information (timing m 1 ) is output to a selector 806 . The selector 806 outputs the component (p 1 +j×q 1 ) having the largest amplitude among the components at the fourth, fifth, and sixth symbols in the impulse response sequence.
The other delayed wave detector 106 has the same arrangement as that of the delayed wave detector 105 . The delayed wave detector 106 obtains the timing, real component, imaginary component of a 4 in FIG. 3 . In this case, the timing is represented by m 2 , and the component is expressed by p 2 +j×q 2 as a complex number.
The delayed wave canceler 107 generates an impulse response sequence by canceling the largest component of a delayed wave using the output signals from the delayed wave detectors 105 and 106 . This computation is performed as follows.
The impulse response sequence output from the transmission path estimator 103 is represented by h 1 ( k ), and the impulse response sequence output from the transmission path estimator 104 is represented by h 2 ( k ). In this case, k represents the timing of symbol periods and takes an integer from 0 to 10. Letting dm be the difference between a timing m 1 and a timing m 2 , the computation by the delayed wave canceler 107 is expressed as
h 1 ( k )×( p 2 + j×q 2 )− h 2 ( k−dm )×( p 1 + j×q 1 ) (10)
In mathematical expression (10), (k−dm) is the remainder of 11.
The computation result on mathematical expression (10) becomes a new impulse response sequence. FIG. 8 shows such a case.
When the component having the largest amplitude among delayed wave components is canceled, the ratio of a delayed component to a corresponding direct wave component increases, and high signal estimation ability can be obtained.
FIG. 7 shows an example of the arrangement of the delayed wave canceler 107 .
A computation based on mathematical expression (10) can be performed by using a complex multiplier 901 , complex multiplier 902 , and complex subtractor 903 , and an impulse response sequence obtained by canceling the delayed wave component having the largest amplitude can be output.
The new impulse response sequence is obtained by the delayed wave canceler 107 . A new reception signal must be obtained accordingly. Letting S 1 ( k ) be the reception signal 101 , and S 2 ( k ) be the reception signal 102 , the output signal from the delayed wave canceler 108 is given by
S 1 ( k )×( p 2 + j×q 2 )− S 2 ( k−dm )×( p 1 + j×q 1 ) (11)
The delayed wave canceler 108 can be implemented by the same arrangement as that of the delayed wave canceler 107 .
In order to perform signal estimation in the DDFSE 110 , an optimal timing must be determined. If only three components have certain amplitude values as shown in FIG. 8 , it is not difficult to find a timing so as to set a 0 and a 1 in the MLSE region. If, however, eight components have certain amplitudes as shown in FIG. 9 , the present invention requires the same function as that of the estimation region detector 203 in FIG. 1 , which is used in the prior art. As this function, the estimation region detector 109 obtains an optimal timing based on the impulse response sequence newly obtained by the delayed wave canceler 107 .
The DDFSE 110 performs signal estimation upon receiving the impulse response sequence output from the delayed wave canceler 107 , the reception signal output from the delayed wave canceler 108 , and the timing signal output from the estimation region detector 109 . The estimation result is output as a decision result 111 from an output terminal T 3 (shown in FIG. 5 ).
Only the preferred embodiment of the present invention has been exemplified above. However, the present invention is not limited to this. Persons skilled in the art easily recognize that various changes and modifications can be made within the spirit and scope of the invention.
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A delayed decision feedback sequence estimation diversity receiver includes a section for extracting a plurality of reception signals by using a plurality of antennas when estimating a transmission signal from reception signals having undergone transmission path distortion, a section for combining impulse response sequences in transmission paths while canceling delayed wave components having the largest amplitudes in delayed wave component sequences in impulse response sequences in the respective transmission paths, and a section for performing signal estimation on the basis of a new impulse response sequence generated by combining the impulse response sequences. A delayed decision feedback sequence estimation method is also disclosed.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a perform and a fabrication method for a fiber-reinforced corner fitting that has continuous fibers connecting all sides.
[0003] 2. Background of the Invention
[0004] The use of reinforced composite materials to produce structural components is now widespread, particularly in applications where their desirable characteristics for being lightweight, strong, tough, thermally resistant, self-supporting and adaptability to being formed and shaped are sought. Such components are used, for example, in the aeronautical, aerospace, satellite, and battery industries, as well as for recreational uses such as in racing boats and autos, as well as countless other applications. A three-dimensional fabric may generally comprise fibers with each kind of fiber extending along a direction perpendicular to the other fibers, that is along the X, Y and Z axial directions.
[0005] Typically components formed from such fabrics consist of reinforcement materials embedded in matrix materials. The reinforcement component may be made from materials such as glass, carbon, ceramic, aramid (e.g., KEVLAR®), polyethylene, and/or other materials which exhibit desired physical, thermal, chemical and/or other properties, chief among which is great strength against stress failure. Through the use of such reinforcement materials, which ultimately become a constituent element of the completed component, the desired characteristics of the reinforcement materials such as very high strength, are imparted to the completed composite component. The constituent reinforcement materials may typically be woven, knitted or otherwise oriented into desired configurations and shapes for reinforcement preforms. Usually, particular attention is paid to ensure the optimum utilization of the properties for which these constituent reinforcing materials have been selected. Generally, such reinforcement preforms are combined with matrix 5 material to form desired finished components or produce working stock for the ultimate production of finished components.
[0006] After a desired reinforcement preform has been constructed, matrix material may be introduced and combined with the preform, so that the reinforcement preform becomes encased in the matrix material such that the matrix material fills the interstitial areas between the constituent elements of the reinforcement preform.
[0007] The matrix material may be any of a wide variety of materials, such as epoxy, polyester, vinyl-ester, ceramic, carbon and/or other materials, which also exhibit desired physical, thermal, chemical and/or other properties. The materials chosen for use as the matrix may or may not be the same as that of the reinforcement preform and may or may not have comparable physical, thermal, chemical or other properties. Typically, however, they will not be of the same materials or have comparable physical, thermal, chemical or other properties as the reinforcement preform, since a usual objective sought in using composites in the first place is to achieve a combination of characteristics in the finished product that is not attainable through the use of one constituent material alone. When combined, the reinforcement preform and the matrix material may then be cured and stabilized in the same operation by thermosetting or other known methods, and then subjected to other operations toward producing the desired component. It is significant to note that after being so cured, the then solidified masses of the matrix material are normally very strongly adhered to the reinforcing material (e.g., the reinforcement preform). As a result, stress on the finished component, particularly via its matrix material acting as an adhesive between fibers, may be effectively transferred to and borne by the constituent material of the reinforcement preform.
[0008] Frequently, it is desirable to produce components in configurations other than simple geometric shapes such as plates, sheets, rectangular or square solids, etc. For instance, complex three-dimensional components require complex three dimensional preforms. One way to achieve a complex component is to combine basic geometric shapes into the desired more complex forms. One such typical combination is made by joining components made as described above at an angle (typically a right-angle) relative to each other to form lateral and transverse stiffeners. Usual purposes for such angular arrangements of joined components are to create desired shapes to form reinforced structures that include one or more end walls or “T” intersections for example. Another purpose for joining components is to strengthen the resulting combination of reinforcement preforms and the composite structure which it produces against deflection or failure when exposed to exterior forces such as pressure or tension. Therefore, it is important to make each juncture between the constituent components, i.e. the stiffener and the base platform or panel portion, as strong as possible. Given the desired very high strength of the reinforcement preform constituents per se, weakness of the juncture becomes, effectively, a “weak link” in a structural “chain” if not joined appropriately.
[0009] Various methods have been used in the past for joining composite components or reinforcement preforms to produce a reinforced complex structure. It has been proposed to form and cure a panel element and an angled stiffening element separate from each other, with the latter having a single panel contact surface or being bifurcated at one end to form two divergent, co-planar panel contact surfaces. The two components are then joined by adhesively bonding the panel contact surface(s) of the stiffening element to a contact surface of the other component by thermosetting or by an adhesive material. However, when tension is applied to the cured panel or the skin of the composite structure, loads at unacceptably low values often result in “peel” forces which separate the stiffening element from the panel at their interface.
[0010] The use of metal bolts or rivets at the interface of such components has also been used but is unacceptable because such additions at least partially destroy and weaken the integrity of composite structures themselves, add weight, increase cost and introduce differences in the coefficient of thermal expansion as between such elements and the surrounding material.
[0011] Other approaches to solving this problem have been based on the concept of introducing high strength fibers across the joint area through the use of such methods as stitching one of the components to the other and relying upon the stitching thread to introduce such strengthening fibers into and across the juncture site. One such approach is shown in U.S. Pat. No. 4,331,495 and its method divisional counterpart, U.S. Pat. No. 4,256,790. These patents disclose junctures having been made between a first and second composite panels made from adhesively bonded fiber plies. The first panel is bifurcated at one end to form two divergent, co-planar panel contact surfaces in the prior art manner, that have been joined to the second panel by stitches of uncured flexible composite thread through both panels. The panels and thread are then “co-cured”: i.e., cured simultaneously.
[0012] However, this process requires the preform to be constructed in multiple steps as well as requires the introduction of a third yarn or fiber into the preform.
[0013] Another example of an intersecting configuration is set forth in U.S. Pat. No. 6,103,337, the disclosure of which is incorporated herein by reference. This reference discloses a means for joining a reinforcement preform with a preform panel to form a three-dimensional reinforcement preform. The two individual preforms are joined to each other at the junction by means of reinforcing fibers in the form of threads or yarns. Once the two preforms are joined or stitched together, matrix material is introduced to the preforms. However, while this process has many advantages, it does require that the preforms be individually woven or constructed and subsequently stitched together in a separate step. Furthermore, an additional yarn or fiber is needed to connect the preforms.
[0014] Another method to improve upon junction strength is set forth in U.S. Pat. No. 5,429,853. However, this method is similar to previously described methods because separately constructed distinct elements are joined together by the stitching of a third yarn or fiber between the two.
[0015] While the prior art has sought to improve upon the structural integrity of the reinforced composite and has achieved some success, there exists a desire to improve thereon and to address the problem through an approach different from the use of adhesives or mechanical coupling of the separate panel and stiffener elements. In this regard, one approach might be by creating a woven three-dimensional structure on specialized machines. However, the expense involved is considerable and rarely is it desirable to have a weaving machine directed to creating a simple structure.
[0016] Another approach is to weave a two-dimensional structure and fold it into shape so that the panel is integrally stiffened, i.e. yarns are continuously interwoven between the planar base or panel portion and the stiffener. However, this typically results in distortion of the preform when the preform is folded. The distortion occurs because the lengths of fiber as-woven are different than what they should be when the preform is folded. This causes dimples and ripples in areas where the as-woven fiber lengths are too short, and buckles in the areas where fiber lengths are too long. These distortions cause undesirable surface anomalies and reduce the strength and stiffness of the component. While this may be relieved by cutting and darting, such procedures are undesirable since they are labor intensive or otherwise may compromise the integrity of the preform.
[0017] U.S. Pat. No. 6,446,675, the disclosure of which is incorporated herein by reference, solves the problem with distortion that occurs upon folding a two-dimensional woven preform by adjusting the lengths of the fibers during weaving such that some fibers are too short in some areas and others too long in other areas. Upon folding the preform, the lengths of the fibers are equalized, providing for a smooth transition at the fold. However, this woven preform is only capable of providing reinforcement or stiffening in one direction, which is parallel to the warp fiber direction.
[0018] Another approach for constructing stiffened panels is set forth in U.S. Pat. No. 6,019,138 which discloses a method for making stiffened panels with reinforcing stiffeners in both the warp and fill directions. As disclosed, this method achieves reinforcement in two directions through over weaving, or simply weaving high spots into the panel portion of the preform. Using this method will limit the height of the stiffener that can be achieved. Further, this method requires that the preform be woven using three yarns. The third yarn, which binds the stiffener to the panel portion of the preform, is only periodically woven between the two. Therefore, the stiffener is not completely integrally woven with the panel portion which results in a joint that is weaker than a fully integrally woven joint.
[0019] A further approach can be found in U.S. Pat. No. 6,733,862, the disclosure of which is incorporated herein by references. The '862 patent describes a fabric suitable as the reinforcement for a three dimensional composite structure. The fiber reinforcement is one that may be woven on conventional weaving machinery. It starts off as a woven two dimensional structure that is then formed into a three dimensional structure, particularly one having deep draws. To provide for this, the reinforcing fabric is woven in a manner that, in portions of the weave, the warp and weft or fill fibers are laid on each other and do not interlock. In this portion the fibers can move independently and slide past one another when the fabric is drawn or folded into shape. If the portion is a rectangular or square shape, it can be collapsed in such a manner that both the warp and weft fibers fold upon themselves and each other to align in an unidirectional manner which creates a corner which acts as a compression column in the final structure.
[0020] Thus, three-dimensional preforms which can be processed into fiber reinforced composite components are desirable because they provide increased strength relative to two-dimensional laminated composites. These preforms are particularly useful in applications that require the composite to carry out-of-plane loads. However, even the most advanced heretofore known structures, such as those described in the '862 patent, only have continuous reinforcing fibers in two of the three planes of any corner feature.
[0021] Accordingly, a need exists for a woven corner preform or fitting that provides reinforcement in three directions that can be woven using a conventional loom and provides for reinforcing fibers in all three planes of the corner fitting. Further there exists a need for integration of such a corner fitting into a larger preform or structure.
SUMMARY OF THE INVENTION
[0022] It is the object of the present invention to improve upon the prior art preforms discussed above.
[0023] It is another object of the present invention to provide a corner fitting and a method of forming a corner fitting having continuous fibers connecting all sides.
[0024] It is another object of the present invention to provide a corner fitting and a method of forming a corner fitting having continuous fibers connecting all sides that is formed from a flat woven fabric.
[0025] One aspect of the present invention is a corner fitting including steps of providing a flat woven fabric including a first woven portion having first and second direction woven fibers or yarns, a second woven portion having first direction fibers and removable or sacrificial second direction fibers adjacent the first woven portion, and a third semi-woven portion having first direction fibers, with said first direction fibers selectively engaged by the sacrificial second direction fibers. Wherein upon removal of the sacrificial second direction fibers, the first direction fibers of the third semi-woven portion replace the sacrificial second direction fibers of the second woven portion and form a corner fitting having continuous fibers connecting all sides.
[0026] A further aspect of the present invention is a method of forming a corner fitting including steps of providing a flat woven fabric including a first woven portion having first and second direction woven fibers, a second woven portion having first direction fibers and sacrificial second direction fibers adjacent the first woven portion, and a third semi-woven portion having first direction fibers, with said first direction fibers selectively engaged by the sacrificial second direction fibers. The method further comprising steps of folding the flat woven fabric in at least one direction, and removing the sacrificial second direction fibers, wherein during removal the second direction fibers are replaced in the second woven portion by the first direction fibers of the third semi-woven portion and form a corner fitting having continuous fibers connecting all sides.
[0027] Once the corner fitting is created, it can them be made into a composite in any known manner or incorporated into a larger preform or structure which in turn is made into a composite.
[0028] The various features of novelty which characterize the invention are pointed out in particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying descriptive matter in which preferred embodiments of the invention are illustrated in the accompanying drawings in which corresponding components are identified by the same reference numerals.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] For a more complete understanding of the invention, reference is made to the following description and accompanying drawings, in which:
[0030] FIG. 1 is an isometric view of a corner fitting according to the present invention;
[0031] FIG. 2 is a plan view of a flat woven corner fitting according to the present invention;
[0032] FIG. 3 is an isometric view of the flat woven corner fitting of FIG. 2 ;
[0033] FIG. 4 depicts the flat woven corner fitting of FIG. 2 after a first fold;
[0034] FIG. 5 depicts the flat woven corner fitting of FIG. 2 after a second fold;
[0035] FIG. 6 depicts the flat woven corner fitting of FIG. 2 during fiber transfer;
[0036] FIG. 7 depicts the flat woven corner fitting of FIG. 2 after the fiber transfer is complete;
[0037] FIG. 8 depicts the final structure of the flat woven corner fitting of FIG. 2 ;
[0038] FIGS. 9 depict an actual prototype flat woven corner fitting of the type shown in FIG. 2 ;
[0039] FIGS. 10-11 depict the folding and weaving process of the flat woven corner fitting of FIG. 9 ;
[0040] FIG. 12 depicts the final structure of the flat woven corner fitting of FIG. 9 ;
[0041] FIG. 13 depicts the implementation of a corner fitting as reinforcing member; and
[0042] FIG. 14 depicts an integrated corner fitting as part of a larger preform or structure.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0043] The present invention is a fiber reinforced corner preform or fitting and a method of forming a fiber-reinforced corner fitting that has continuous fiber connecting all sides. A corner fitting 10 is shown in FIG. 1 . The corner fitting 10 consists of three sides 12 , 14 , and 16 that are mutually perpendicular. Such fittings are often used to reinforce corners where several independent pieces are joined together. They are very common in aerospace structures at rib/spar/skin intersections in wings, and at frame/stringer/skin intersections in the fuselage.
[0044] In composite structures, it is beneficial to have the corner fitting made from the same material as the other components, because all of the parts will have similar coefficients of thermal expansion. It is also desirable that the fitting has continuous fiber connecting each side. This can be accomplished by overlapping and bonding three ‘L’ shaped components, but the bond lines in the resulting fitting are weak areas that will typically be the initial points of failure. Accordingly, the fiber-reinforced corner fitting of the instant application is directed to an integrally woven preform that has continuous fibers around all three corners.
[0045] Fabrication of the corner fitting is done in three steps. First, a flat preform 20 , as shown in FIG. 2 , is woven using a conventional loom. Next, the flat preform is loaded into a fixture and fiber from one area of the preform is drawn into another section, as will be described in detail below. Finally, the removable or sacrificial fiber is trimmed away, leaving the final corner fitting 110 shown in FIG. 8 . The second step is referred to as a ‘fiber transfer’ step, and is shown in detail in FIGS. 3-8 .
[0046] The initial flat preform 20 is shown schematically in FIG. 2 . The flat preform 20 can be described with reference to primary fiber woven into the flat preform 20 that will remain in the corner fitting 110 , and sacrificial or secondary fibers that will be removed in forming the corner fitting 110 .
[0047] FIG. 2 depicts sections A 1 and A 2 . Sections A 1 and A 2 are woven with primary fiber in the warp and weft directions. These sections form the upper left 116 and lower sides 112 of the corner fitting 110 shown in FIG. 8 .
[0048] Section B 1 has primary fiber in the warp direction and sacrificial fiber in the weft direction. Weft fibers float over most warp fibers, but make a loop around one (and only one) specific warp fiber. Since the weft fibers loop around only one warp fiber it will be referred to as being semi-woven. This warp fiber will eventually be transferred into the position of the sacrificial weft in section B 2 to form the upper right side 114 of the corner fitting 110 shown in FIG. 8 . Section B 2 has primary fiber in the warp direction weaving with sacrificial fiber in the weft direction. The warp fiber in section B 1 will eventually replace this weft fiber.
[0049] Section C 1 contains unwoven primary fiber in the warp direction; there is no weft fiber in this section. This excess fiber will eventually be trimmed away. Section C 2 has sacrificial fiber in the warp direction weaving with sacrificial fiber in the weft direction. This section stabilizes section B 2 during the fiber transfer and is eventually trimmed away. An isometric view of the flat preform is shown in FIG. 3 .
[0050] A note on the woven sections of the initial preform, there are really no restrictions to the type of fiber that is used or on the basic weaving pattern. The initial preform could even be a multi-layered design. More complicated design may make the fiber transfer process more difficult, however, these are nonetheless considered within the scope of the instant invention.
[0051] As shown in the progression from FIG. 3 to FIG. 5 , initial forming of the corner fitting 110 is accomplished by folding along the two fold lines identified in FIG. 3 , shown as 22 and 24 respectively. Completion of folds along lines 22 and 24 is illustrated in FIGS. 4 and 5 , respectively.
[0052] As shown in FIG. 5 , the fitting is in position to facilitate the fiber transfer step. Fiber transfer is accomplished by pulling each of the sacrificial weft fibers 26 in section B 2 out of the preform 20 . When this is done, the warp fibers 28 in section B 1 will be pulled into the locations that were occupied by the sacrificial weft fibers 26 . A specific warp fiber 28 in section B 1 will then occupy the position in section B 2 that was originally occupied by the sacrificial weft fiber 26 that was looped around it. This process is shown in the progression from FIG. 5 to FIG. 7 The final step in the forming process is to trim away the excess fiber at 28 a . This consists of the warp fibers from section B 1 that have been pulled completely through section B 2 , and all of section C 2 , (labeled 30 ), as shown in FIG. 7 . The resulting corner fitting 110 is shown in FIG. 8 . As can be seen in this figure, there is continuous fiber around all comers. The corner fitting 110 may then itself be made into a composite and used as a strengthening element or incorporated into a larger preform or structure which is made into a composite or otherwise used as desired.
EXAMPLE
[0053] A prototype preform has been woven to validate this approach. This preform was woven using a combination of aramid, carbon, and glass fibers to demonstrate the applicability of the approach to a variety of fibers, and to clarify the fiber paths in the resulting preform. Note, while the fibers used were those listed and could be typical reinforcing fibers aforementioned used in composite structures, this invention is applicable to fibers made of any material suitable for the purpose and accordingly is not limited to the material mentioned herein. This preform was woven on a conventional shuttle loom. The flat woven preform is shown in FIG. 9 . A grid has been superimposed thereon so that the regions A 1 -C 2 defined in FIG. 2 , can be easily identified.
[0054] The preform shown in FIG. 9 was woven using a plain weave pattem. This pattern was chosen because it includes more crimp than other common patterns, such as twills or satins, and presents the most difficult challenge for the fiber transfer process in a single layer fabric. As previously mentioned, any weave pattern could be used. The only pattern that cannot change is in section B 1 where each weft fiber must loop around a single warp fiber. In addition, the loops must progress in length from the lower left corner of section B 1 to the upper right.
[0055] The preform shown in FIG. 9 was loaded into a forming fixture/fiber transfer aid, which folds it into shape and prepared sections B 1 and B 2 of the fiber transfer process. A prototype preform loaded into the fixture is shown in FIGS. 10 and 11 .
[0056] FIG. 10 shows the preform prior to the fiber transfer. FIG. 11 shows the preform during the fiber transfer. The caul plates help stabilize various portions of the preform during the fiber transfer and help minimize distortion. After completing the fiber transfer process, the sacrificial fiber was trimmed away, resulting in the corner fitting shown in FIG. 12 . Note the continuous aramid fibers 120 , carbon fibers 122 , and glass fibers 124 around the various corners.
[0057] The corner fitting shown in FIG. 12 was woven on a machine, but the fiber transfer was accomplished by hand. The individual steps required to fold the preform and extract the sacrificial weft are readily automated. For, example, in a production environment, the flat preforms can be woven continuously and wound onto a roll. This roll of flat preforms could then be loaded into a second machine that accomplishes the folding, fiber transfer, and final trimming. It can thereafter be made into a composite structure itself or incorporated into a larger preform structure which is then formed into a composite.
[0058] The present invention has been described primarily herein with respect to the formation of a corner fitting. In application such a corner fitting may be used in situations where it is desirable to reinforce a joint of two or more sections of an apparatus. For example in the aerospace industry there is often need to reinforce the joint between a skin material and an instance where both longitudinal and transverse stiffeners are supporting the skin. Such an example is shown in FIG. 13 , where a skin material 200 includes an integral stringer 202 . To help support the skin 200 a support 204 is attached to the skin 200 . A mouse hole 206 in the support allows the support to be placed over the stringer 202 of the skin 200 . To reinforce these joints a corner fitting 208 is applied to one or more sides of the intersection of the stringer 202 and the support 204 .
[0059] Another embodiment of the present invention is shown in FIG. 14 , where the support 210 is formed by the process described above and has integral within its design a corner 208 formed with continuous fibers across the intersections of the three planes of the corner. As can be readily appreciated the increased strength from this design allows for an elimination in some instances of a reinforcement corner as shown in FIG. 13 .
[0060] Although a preferred embodiment of the present invention and modifications thereof have been described in detail herein, it is to be understood that this invention is not limited to this precise embodiment and modifications, and that other modifications and variations may be effected by one skilled in the art without departing from the spirit and scope of the invention as defined by the appended claims.
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A corner fitting and a method of forming a corner fitting including steps of providing a flat woven fabric including a first woven portion having first and second direction woven fibers, a second woven portion adjacent the first woven portion having first direction fibers and sacrificial second direction fibers and a third semi-woven portion having first direction fibers selectively engaged by the sacrificial second direction yarns. The method further comprising steps of folding the flat woven fabric in at least one direction, and removing the sacrificial second direction fibers, wherein during removal, the sacrificial second direction fibers are replaced in the second woven portion by the first direction fibers of the third semi-woven portion and form a corner fitting having continuous fibers connecting all sides.
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BACKGROUND OF THE INVENTION
This invention relates to a fabric selvage end cut prevention cutter guide in a shuttleless loom, e.g., a fluid jet type loom such as of the air jet picking type, and more particularly it relates to a cutter guide adapted to protect and guide a fabric selvage end so as to prevent the cutting of the fabric selvage end which is liable to occur when the ends of inserted weft threads are cut.
Fabrics produced by shuttleless looms have a fringed selvage at the fabric selvage end (or edge), the presence of which fringed selvage tends to detract from their market value as it makes them look unfavorable in comparison with fabrics which are produced by ordinary looms and which have no fringed selvage so that the selvage line can be distinctly and neatly exhibited. Therefore, to make them look as favorable as possible to increase their market value, it has been desired that the fringed selvage be trimmed as short as possible. To this end, it has been proposed to position the cutter as close to the fabric selvage end as possible so as to allow the cutting of weft threads to be effected in close proximity to the fabric selvage end. However, since a fabric being woven is influenced by such factors as warp thread tension, fabric take-up tension, and the temperature and humidity in the weaving room, whereby the fabric width changes more or less during weaving, there is a fear that if the fabric width increases, the fabric selvage end is caught by the blades of the cutter installed in close proximity thereto and is thereby cut. Therefore, it has been common practice to effect the cutting of inserted weft threads by installing the cutter at a position excessively remote from the fabric selvage end to the extent that the fabric selvage end is not cut. As a result, the fringed selvage lengthens and has its threads entwined with each other, detracting from the aesthetic value of the fabric and forming an obstacle to the subsequent treatment; it has been impossible to expect to eliminate such drawbacks.
SUMMARY OF THE INVENTION
An object of the invention is to provide a cutter guide, intended to eliminate the aforesaid drawbacks in looms of the described type, wherein in forming a fringed selvage on a selvage end of a fabric by cutting weft threads after insertion in a shuttleless loom, a fabric selvage end guide is provided at a fabric selvage end in close proximity to a cutter, the position of the guide being adjusted to accommodate a change in the width of a fabric being woven, so as to keep the guide in contact with the fabric selvage end, whereby the distance between the fabric selvage end and the cutter can be minimized.
According to this invention, a cutter guide is installed in such a manner that a fabric selvage end guide is positioned at a location where it contacts the fabric selvage end at a predictable minimum of fabric width to cope with a change in fabric width which takes place during weaving, whereby even if the fabric width increases, the fabric selvage end guide prevents the fabric selvage end from being caught by the cutter, and since the fabric selvage end travels in contact with the fabric selvage end guide as it is suppressed by the latter without being influenced by a change in fabric width, the distance between the fabric selvage end at the cutter position and the cutter is maintained at a constant value. Further, since the cutter integral with the fabric selvage end guide is positioned as close to the fabric selvage end as possible, the threads of the fringed selvage are trimmed short and neat and the selvage looks very good, increasing the market value of the woven fabric and making it possible to maintain the improved external appearance of the selvage during the subsequent treatment.
According to this invention, since it is only necessary to provide a conventional cutter with a fabric selvage end guide integrally therewith, the cutter guide is simple in construction and easy to manufacture. Further, the cutter guide is capable of preventing fabric selvage end cut and allowing a fringed selvage to be easily trimmed short and neat. Thus, the invention is of highly practical use.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a cutter guide assembly according to this invention installed in position; and
FIG. 2 is a plan view showing schematically the relationship of the operative elements to illustrate how a fringed selvage is trimmed.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Usually, a shuttleless loom such as an air jet type loom, as shown in FIG. 1, is so arranged that inserted weft threads are cut by a cutter 1 adjacent a fabric selvage end to form a fringed selvage 12 at the fabric selvage end.
As shown in FIG. 1, the cutter 1 comprises upper and lower blades 1a and 1b, one of which is fixed, the other being movable (in the illustration, the upper blade being fixed), and a fabric selvage end guide 4 is interposed between said cutter 1 and a plate-like bracket 3 having a shaft 2 for fixing said cutter, thus forming an integral cutter guide assembly a.
The aforesaid fabric selvage end guide 4 is in the form of a plate formed at its front end with a guide groove cut like an acute angle and opening in the same direction as the opening and closing angle formed between the upper and lower blades 1a and 1b of the cutter 1 during cutting operation. The cutter guide assembly a is so positioned that the lateral surface of the fabric selvage end guide 4 is contacted at A with a fabric selvage end 11, as shown, which corresponds to a predictable minimum of fabric width when the fabric width changes during weaving, so as to introduce a plurality of uncut weft threads 12a into the guide groove 5.
As a result of this arrangement, the distance between the fabric selvage end 11 and the cutter 1 is maintained substantially at the shortest constant distance, and the fabric selvage end 11 travels in contact with the fabric selvage end guide 4 irrespective of a change in fabric width and will not be cut by the cutter 1, while the latter cuts the fringed selvage 12 to a minimum of length for uniform trimming to a constant length. That is, even if the fabric width decreases during weaving, since the fabric selvage end guide 4 is positioned where it contacts the fabric selvage end 11 corresponding to a predictable minimum of fabric width, the fabric selvage end 11 remains in contact with the fabric selvage end guide 4, so that there is no possibility of the fringed selvage becoming longer. Further, when the fabric width increases, the fabric selvage end 11 is contacted deep with the fabric selvage end guide 4, but at the cutting position of the cutter 1 a further approach to the cutter 1 is suppressed, so that the cut length of the fringed selvage 12 is constant, being the same as when the fabric width decreases.
In addition, in the above embodiment the fabric selvage end guide is in the form of a plate cut to form a V-shaped guide groove so as to have the function of easily and positively introducing uncut weft threads into the opening defined by the two blades 1a and 1b of the cutter. However, this fabric selvage end guide may be formed of a plate so that its front end is positioned adjacent the cutting point of the cutter. Further, when the fabric selvage end guide is installed between the cutter and the cutter fixing plate, besides being mounted on a cutter attaching shaft, it may be attached to the cutter attaching plate-like bracket or the bracket 3 itself may be configured to serve as a fabric selvage end guide. No matter what form it may take, it is only necessary that it be capable of being positioned as close to the fabric selvage end as possible without causing any trouble to the operation of the cutter and of positivly and easily introducing uncut weft threads at the fabric selvage end into the cutter section.
In addition, the fabric selvage end guide, besides being in the form of a plate, may be in the form of a bar or a rectangular prism, which is used as such or after being cut to form a groove for introducing uncut weft threads thereinto.
The embodiment of this invention will now be outlined. The guide groove 5 cut in the fabric selvage end guide 4 is so positioned that, as shown in FIGS. 1 and 2, the acute angle tip A of the groove is located at a point deviated about 1.5 mm from the cutting point C of the cutter 1 (the crossing point of the cutting edges of blades 1a and 1b) in the direction of travel of the fabric. The open groove width of the guide groove 5 at the intersection B between a cutting point line 6 extending from the cutting point C in the direction of the fabric width and the guide groove 5 is smaller than the maximum open width of the cutter 1. This arrangement makes reliable the introduction of uncut weft threads 12a to the cutting point C of the cutter. Further, the fabric selvage end guide 4 together with the cutter 1 is positioned to contact the fabric selvage end 11 corresponding to a predictable minimum of fabric width.
Let y be the distance from the beating point D to the acute angle tip A of the cut guide groove 5 of the fabric selvage end guide, x be the maximum change in fabric width, B be the intersection between the cutting point line 6 and a line extending from the lateral surface of the fabric selvage end guide 4, and Δx be the amount of change in the length of the fringed selvage 12.
Then, since y=105 mm, x=4 mm, and AB'=1.5 mm, the amount of change in the length of the fringed selvage is given by
Δx=1.5×4/105≈0.6≈0
and BC=B'C, so that it is constant.
That is, the fabric selvage end B point on the cutting point line 6 is located substantially on the extension line from the lateral surface of the fabric selvage end guide nearer to the fabric selvage end. Thus, since the cutter guide is installed at a position where the fabric selvage end guide contacts the fabric selvage end at a minimum of fabric width in consideration of the amount of change in fabric width, the fabric selvage end guide accommodates or controls a change in fabric width so as to keep substantially constant the distance between the cutting point of the cutter and the fabric selvage end, thus making it possible to trim the fringed selvage as short as possible at a constant value without the danger of cutting the fabric selvage end.
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A cutter guide wherein a fabric selvage end guide is provided at a fabric selvage end in close proximity to a cutter, and in forming a fringed selvage on a selvage end of a fabric by cutting weft threads after insertion in a shuttleless loom, the position of the guide being adjusted to accommodate a change in the width of a fabric being woven, so as to keep the guide in contact with the fabric selvage end, whereby the distance between the fabric selvage end and the cutter can be minimized.
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BACKGROUND OF THE INVENTION
There are many cases wherein it is necessary to determine the structure of the sea bed in a limited region. One case is where piles are to be driven into the sea bed to support a construction project such as columns of an offshore hydrocarbon loading platform or of various types of structures that are to lie offshore. If the seabed below a certain depth is consolidated (firm and secure) then piles driven therein will remain stationary, while if piles are driven into soft subsea soil then the piles are not as secure and soil strength must be considered. There is also the costly refusal of the pile by the presence of boulders. One way to determine the condition of the sea bed is to produce samples of the sea bed using core drills, which range in diameter between about 5 centimeters (2 inches) and 30 centimeters (12 inches). Another way is to conduct insitu cone tests. In insitu cone tests, a cone containing sensors is driven into the seabed and seabed characteristics at that location are measured. These two methods will sometimes be collectively referred to herein as seabed penetration measurement, by a seabed data penetrator. Since offshore core drilling and insitu cone tests are expensive and difficult to conduct, only a limited number of locations are drilled or interrogated by a cone. This leads to uncertainty about the condition of the sea bed. For example, if the core sample shows rock material extending down from a predetermined depth, there is uncertainty as to whether the rock is bedrock or is part of a boulder, or is part of a discontinuous hard pan layer.
The seabed can take the form of soft sedimentary lenses, boulders and/or cobble stones, a glacial till (clay, sand, gravel, and boulders intermingled), hard pan (compacted clay soil), mud layers, gas hydrates and gaseous sediments, and frozen soil. Many of these seabed materials are of different conditions when lying in situ (in the sea bed) than when present in a core sample, as where liquid and/or gas escape and/or very fine particulates drop out of the core or the temperature changes. It is possible to analyze the seabed by acoustic (sonar and seismic) apparatus wherein the sound is directed at the sea bed and the echoes are detected. The echoes indicate the reflectivity, attenuation, back-scatter, and velocities of sound at selected frequencies in the materials, from which the characteristics of the sea bed can be estimated. The interpretation of such acoustic sea bed characteristics is a more reliable presentation of the spatial extend of the layers than from a core sample or insitu core test alone. Acoustic imaging can cover a much wider area and at lower cost. It can also provide for lateral confirmation of the physical core properties.
SUMMARY OF THE INVENTION
In accordance with one embodiment of the present invention, a method and apparatus are provided for imaging a sea bed by imaging it, which enables the more accurate evaluation of a region lying under a seabed surface area of more than one square meter. The method includes the use of a core drill or insitu geotechnical cone to produce detailed information about a small volume of the sea floor. The same core drill or cone is used to support and accurately locate a wide area acoustic imaging apparatus during its movement to obtain acoustic data about a large area of the seabed. The acoustic apparatus includes a clamping carriage that can slide down the shank of the core drill (or cone) and then clamp to the core drill. An arm is supported on a frame that is, in turn, supported on the carriage. The arm extends radially away from the drill and holds at least one set of transducers. These transducers include an acoustic generator that produces acoustic radiation and an acoustic detector that detects acoustic radiation that represents echoes from the seabed.
With the core drill (or cone) lying adjacent to, or preferably against the sea floor, before or after a core sample has been drilled, the acoustic generator on the arm is operated to produce acoustic echoes, with the output of the detector recorded. After acoustic readings have been taken at a plurality of locations along the arm, the carriage is rotated around the core drill as in increments of 15°, with acoustic readings taken at each angular position. As a result, a large and more accurate assessment of the sea bed is made, based on both the core sample and the acoustic imaging. A general assessment of the sea bed over the considerable area that has been acoustically imaged, is made more definite by comparing the assessment at areas acoustically similar to where the core sample was taken, to the actual core sample.
The novel features of the invention are set forth with particularity in the appended claims. The invention will be best understood from the following description when read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation view of a seabed evaluation apparatus of the invention in an installation configuration, with the arms projecting upward from the clamping carriage.
FIG. 2 is a side elevation view of the apparatus of FIG. 1 , with the arms deployed to imaging positions.
FIG. 3 is a view of a map of the seabed at a particular depth.
FIG. 4 is an isometric view showing the acoustic characteristics of a seabed at vertically spaced planes, and also showing a drill core.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a seabed evaluation complex 10 for evaluating a seabed region 18 , which includes a core drill 12 that extends along a primarily vertical axis 14 and an acoustic interrogation apparatus, or acoustic imaging apparatus 16 . The core drill is of the usual type that includes a hollow drilling portion 20 and a shank 22 . The shank is rotated or pounded down by Equipment (not shown) at the sea surface, while the core drill is lowered into the seabed 24 and thereafter pulled up to the surface so a core sample can be recovered. Instead of penetrating the seabed with a core drill, the seabed can be penetrated by an insitu Geotechnical cone, which is a device with sensors that is pounded or otherwise inserted into the seabed. Both devices can be referred to as a seabed data penetrator, which penetrates deep (at least one meter) into the seabed to gather data. The acoustic apparatus 16 of FIG. 1 includes a clamping carriage 26 that is centered on the drill axis and that can clamp (i.e. fix itself) to the drill. The apparatus also includes a rotatable frame 28 that is rotatable about the carriage. The acoustic apparatus also includes a pair of arms 30 , 32 that are pivotally connected to the frame at primarily horizontal axes 34 , 36 that are circumferential to the drill axis.
FIG. 1 . shows the acoustic imaging apparatus 16 during the course of its installation to allow acoustic reading to be taken. The walls of a passage 29 that surround a core drill hollow drilling portion 20 serves as a locator part that locates the imaging apparatus with respect to a core hole 66 . The arms 30 , 32 have been pivoted up so they extend primarily vertically and parallel to the drill axis to facilitate sliding them down along the drill. With the carriage lower end 38 lying against the sea bed surface 40 ( FIG. 2 ), the arms are pivoted down to the configuration of FIG. 2 . At least one transducer set 42 which includes an acoustic generator 44 and an acoustic detector 46 is established at a particular position along each arm 30 , 32 , such as at the radially outer end of each arm. Applicant notes that FIG. 2 shows two modes for the transmission and reception of acoustic energy. One mode is the use of multiple acoustic detectors 46 whose positions (e.g. fixed on the carriage 26 ) do not change and with applicant repeatedly repositioning only the acoustic generators 44 . In the other mode, co-located transmitter(s) and receptor(s) move along the arm.
With the acoustic generator 44 at a selected position on the arm, the acoustic generator is energized by electronic signals such as short pulses, to produce acoustic waves that penetrate into the seabed 24 . To penetrate to a depth of up to 10's of meters, applicant produces acoustic waves of a frequency that is typically 1 KHz to 50 KHz. The acoustic waves generate echoes which are detected by the detectors 46 . The times after acoustic transmission when various parts of an echo are detected and the amplitudes of the detected echo parts indicate many characteristics of the seabed. These include the density at various depths (which can indicate rock or soil), and the locations of the top and bottom of boulders (where there are strong reflections) and other materials in the sea bed. The acoustic generator produces a beam that interrogates (produces images of) a tall column-shaped location under the seabed surface.
Each acoustic generator is repeatedly moved along an arm 30 , 32 to image many column-like volumes spaced along the arm. After all locations along one arm position are interrogated, the arm is pivoted, as by 15°, about the drill axis 14 . At each rotational position, the seabed is insonified (echoes are detected from transmitted sonic pulses) at a plurality of positions of the acoustic generator along each arm. The result is a two-dimensional map such as shown at 50 in FIG. 3 for each of a plurality of depths under the seabed surface. Each arm 30 , 32 ( FIG. 2 ) has a length of more than 0.5 meter, so the area of the seabed surface under which the seabed is insonified, is more than one square meter (more than 10 square feet). Preferably, each arm has a length of a plurality of meters, so the area of the seabed under which the seabed is acoustically examined is a plurality of 10's of square meters.
In one example, the drill core indicates rock at location 54 , while the map 50 of FIG. 3 indicates rock at 56 which form boulders because they have small horizontal dimensions. The map 50 indicates a wide expanse of rock at 58 which could be bedrock and which could be further interrogated. Sometimes even the core sample is deceiving as where it contains material that changes state under pressure or contains fluids or has been blocked by large particulates during the sampling. FIG. 4 shows the physical core 52 which extends about 20 meters below the seabed surface 40 , and shows four acoustic images taken at 5 meter intervals. The acoustic images indicate fine sand at 51 , course sand at 53 , boulders at 56 and fine clay at 55 .
It is important that the positions of locations on the acoustic examination map 50 be accurately correlated to the position of the core sample(s) at 52 for that volume of the sub-seabed. The correlation should be within an inch (2.5 centimeters) in perpendicular lateral directions, and also be accurate in a vertical direction. The acoustic imaging apparatus 16 shown in the figures enables such close correlation of positions.
After applicant lowers the drill ( FIG. 1 ) to the seabed (and usually after a core is drilled), applicant positions a passage 29 in the carriage 26 so it receives the drill 12 . Then, applicant lowers the carriage along the drill until the carriage lower end 38 lies against the seabed 24 as in FIG. 2 . An umbilical 62 extends from a facility at the sea surface down to the carriage. The umbilical is used to lower the carriage until the carriage lower end contacts the sea floor. A cable 64 also extends to the sea surface. A clamp 65 on the carriage is then operated to clamp the carriage to the drill, at the drill shank. The drill 12 preferably lies in contact with the seabed at the walls of a core hole 66 that has been drilled or that is to be drilled, to accurately position the acoustic apparatus with respect to the core hole. With the carriage fully lowered, a winch 68 is operated to lower the arms 30 , 32 until they are horizontal, as shown in FIG. 2 . Applicant can use a single arm 30 , or can use two arms to interrogate more rapidly.
With the arms lowered, the acoustic generators 44 are energized and the echoes are detected by the receivers 46 . After each acoustic insonification by detecting the echoes, the transducer(s) is moved along the arm 30 , 32 to a new position. The column-shaped volumes imaged by the transducers 44 , 46 usually overlap. After sounding a series of volumes lying under the length of the arm, the arm 30 , 32 is rotated to a new position. Data from the interrogation apparatus is stored in a data file 48 although it can be transmitted to a recorder at the sea surface. An actuator apparatus typically formed by an electric motor 70 with gear set 72 or pneumatic or hydraulic actuator, rotates the frame 28 on which the arms 30 , 32 are mounted, about the carriage 26 that is, clamped to the drill. Each rotation angle is preferably about 15° and proceeds in typically twelve to twenty-four steps to provide twenty-four angularly spaced arm positions for the two arms. However, if an area of special interest is found (e.g. 58 in FIG. 3 ) the frame may be rotated in steps of perhaps 1°.
In a system that applicant has designed, the arms 30 , 32 each had a length of 7 meters. As a result, a volume of the sea bed was acoustically interrogated which lay under a sea floor area of 68 square meters. The arms were located above the seabed by a distance A of more than a Meter, and actually was about 3 meters above the sea floor, which allowed the pulse initially generated by the generator 44 to produce sound waves of a frequency of 1 KHz to 20 KHz in a broadening beam that passed into the seabed.
The ability to precisely position the transducers 42 , enables applicant to employ synthetic aperture sonic techniques to augment the analysis of the seabed. In synthetic aperture sonic techniques, applicant, detects and co-locates the phases of returned (reflected and/or refracted) signals, or echoes, in addition to their amplitude and time of detection (after transmittal), which enables a more precise analysis of seabed characteristics.
Thus, the invention provides a method and apparatus for analyzing a seabed volume that lies under an area of more than one square meter of the sea bed surface. The invention involves the penetration of over one meter of the seabed by a seabed data penetrator, and the acoustic imaging, or interrogation, of a volume in the sea bed that lies around the location where the seabed penetration was made to gather data from a hole in the seabed. This allows the evaluation of a large volume of the sea bed, using only one or a limited number of core drillings and/or insitu cones. This is accomplished by using the acoustic interrogation to evaluate the lateral extent of layers in the seabed and by cross-correlating with the core sample and/or data from the cone to check that acoustic iterations between the two sources of information produce a final consistent calibrated interpretation of conditions of the seabed. Accurate information about the location of the core sample with respect to the locations where the acoustic evaluation data were taken, is assured by positioning the acoustic transducer(s) on an apparatus that is mounted on the core drill, with the bottom of the carriage placed in contact with the seabed while the core drill lies in contact with the sea bed at the location where the core was taken or is to be taken. This is accomplished by mounting the transducers on an arm(s) that rotates about the axis of the drill.
Although particular embodiments of the invention have been described and illustrated herein, it is recognized that modifications and variations may readily occur to those skilled in the art, and consequently, it is intended that the claims be interpreted to cover such modifications and equivalents.
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A seabed region ( 18 ) that lies under a seabed surface area of over one square meter, is analyzed by comparing a core sample taken near the middle of the region and/or data from a geotechnical insitu cone penetrometer installed at the middle of the region, to an acoustic analysis of the region. Locations of the acoustic analysis are precisely correlated to the location of the core test sample or cone test by mounting an acoustic imaging apparatus ( 16 ) that holds acoustic transducers ( 44, 46 ), on a carriage ( 26 ) that is positioned on the core drill ( 12 ) or cone penetrometer barrel staff. The carriage of the acoustic imager apparatus is clamped to the core drill when the core drill is not rotating. An arm ( 30 and/or 32 ) is supported on the carriage through a frame ( 28 ), with at least one acoustic generator ( 44 ) and one acoustic echo detector ( 46 ) mounted on the arm. The arm can be rotated to positions lying about the drill axis ( 14 ) to accurately scan a wide area.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application makes reference to, and claims priority to and the benefit of, U.S. provisional application Ser. No. 60/224,733 filed Aug. 11, 2000.
INCORPORATION BY REFERENCE
The above-referenced U.S. provisional application Ser. No. 60/224,733 is hereby incorporated herein by reference in its entirety.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
N/A
BACKGROUND OF THE INVENTION
Current data communication systems rarely approach highest possible rate, i.e., the rate corresponding to Shannon channel capacity. For example, voiceband modems complying with ITU-T recommendation V.90 employ uncoded modulation for downstream transmission. The nominal downstream rate of 56 kbit/s is thereby almost never achieved, although under practical channel conditions the capacity rate can exceed 56 kbit/s.
The difference between the signal-to-noise ratio (SNR) required to accomplish a given rate with a given practical coding and modulation scheme and the SNR at which an ideal capacity-achieving scheme could operate at the same rate is known as “SNR gap to capacity”. At spectral efficiencies of 3 bit per signal dimension or higher, uncoded modulation with equiprobable PAM (pulse amplitude modulation) and QAM (quadrature amplitude modulation) symbols exhibit an SNR gap of 9 dB at a symbol error probability of 10 −6 . In the case of V.90 downstream transmission, the SNR gap can correspond to a rate loss of up to 12 kbit/s.
This overall 9 dB gap is generally comprised of a “shaping gap” portion and a “coding gap” portion. The “shaping gap” portion (approximately 1.5 dB) is caused by the absence of constellation shaping (towards a Gaussian distribution). The remaining “coding gap” portion (approximately 7.5 dB) stems from the lack of sequence coding to increase signal distances between permitted symbol sequences.
Two different techniques are used, generally in combination, to reduce the overall 9 dB gap. The first technique addresses the “coding gap” portion, and uses one of several coding techniques to achieve coding gains. One of these techniques is trellis-coded modulation. More recent techniques employ serial- or parallel-concatenated codes and iterative decoding (Turbo coding). These latter techniques can reduce the coding gap by about 6.5 dB, from 7.5 dB to about 1 dB.
Once a coding gain is achieved, the second technique, referred to as shaping, can be used to achieve an even further gain. This type of gain is generally referred to as a shaping gain. Theoretically, shaping is capable of providing an improvement (i.e., shaping gain) of up to 1.53 dB.
Two practical shaping techniques have been employed in the prior art to achieve shaping gains, namely, trellis shaping and shell mapping. With 16-dimensional shell mapping, such as employed in V.34 modems, for example, a shaping gain of about 0.8 dB can be attained. Trellis shaping can provide a shaping gain of about 1 dB at affordable complexity. Accordingly, between 0.5 and 0.7 dB of possible shaping gain remains untapped by these prior art shaping methods.
Further limitations and disadvantages of conventional and traditional approaches will become apparent to one of skill in the art, through comparison of such systems with the present invention as set forth in the remainder of the present application with reference to the drawings.
BRIEF SUMMARY OF THE INVENTION
Aspects of the present invention may be found in a method of communicating data in a communication system. The method generally comprises accepting and randomizing (scrambling) data from a source of user data, such as a computer, for example. The randomized data are accumulated until a Huffman codeword is recognized, at which time the Huffman codeword is mapped into a channel symbol. Then the channel symbol is applied to an input of a communication channel. In the field of source coding, the above operation is known as Huffman decoding.
The encoding operation described above may be combined with further channel encoding operations such as, for example, trellis coded modulation or some form of serial- or parallel-concatenated coding to achieve coding gain in addition to shaping gain. In addition, channel symbols can be modulated in various ways before they are applied to the input of the communication channel.
In one embodiment of the invention, the channel encoding operation described above is performed in combination with a framing operation to achieve transmission of data at a constant rate.
Next, on the receiver side of the communication channel, a channel symbol is received from an output of the communication channel after suitable demodulation and channel decoding. Once obtained, the channel symbol is converted into the corresponding Huffman codeword. The data sequence represented by concatenated Huffman codewords is de-randomized (descrambled) and delivered to a sink of user data.
In one embodiment of the invention, a deframing operation is performed, which provides for data delivery to the data sink at constant rate.
The method of the present invention results in a symbol constellation and a probability distribution of symbols in this constellation that exhibits a shaping gain of greater than 1 dB. The shaping gain may be, for example, 1.35 dB or 1.5 dB, depending on the specific design
In general, a communication system according to the present invention comprises a communication node that performs a “Huffman decoding” operation to generate channel symbols with a desired probability distribution.
These and other advantages and novel features of the present invention, as well as details of an illustrated embodiment thereof, will be more fully understood from the following description and drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is a block diagram of a generic communication system that may be employed in connection with the present invention.
FIG. 2 illustrates additional detail regarding the transmitters of FIG. 1 according to the present invention.
FIG. 3 shows shaping gain versus rate for PAM and QAM sq constellations of different sizes, in accordance with the present invention.
FIG. 4 plots shaping gains versus rate for square and lowest-energy 1024-QAM constellations, in accordance with the present invention.
FIG. 5 depicts the mean and standard deviation of the rate in bit/dimension and the shaping gain accomplished for a nominal rate of R=4 bit/dimension with QAM le constellations of different sizes, in accordance with the present invention.
FIG. 6 illustrates a 128-QAM le constellation with Huffman shaping for a nominal rate of 3 bit/dimension, in accordance with the present invention.
FIG. 7 illustrates one embodiment of a generic method for achieving constant rate and recovering from bit insertions and deletions.
FIG. 8 illustrates the probability of pointer overflow as a function of framing buffer size in accordance with the present invention.
FIG. 9 illustrates one embodiment of the design of a Huffman code in accordance with the present invention.
FIG. 10 is a block diagram of one embodiment of a communication system that operates in accordance with the method of present invention.
FIG. 11 is another embodiment of the design of a Huffman code in accordance with the present invention, when a framer/deframer is utilized.
FIG. 12 is a block diagram of another embodiment of a communication system that operates in accordance with the method of present invention, utilizing a framer/deframer.
FIG. 13 illustrates one operation of a system that employs Huffman shaping in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a block diagram of a generic communication system that may be employed in connection with the present invention. The system comprises a first communication node 101 , a second communication node 111 , and a channel 109 that communicatively couples the nodes 101 and 111 . The communication nodes may be, for example, modems or any other type of transceiver device that transmits or receives data over a channel. The first communication node 101 comprises a transmitter 105 , a receiver 103 and a processor 106 . The processor 106 may comprise, for example, a microprocessor. The first communication node 101 is communicatively coupled to a user 100 (e.g., a computer) via communication link 110 , and to the channel 109 via communication links 107 and 108 .
Similarly, the second communication node 111 comprises a transmitter 115 , a receiver 114 and a processor 118 . The processor 118 , like processor 106 , may comprise, for example, a microprocessor. The second communication node 111 is likewise communicatively coupled to a user 120 (again a computer, for example) via communication link 121 , and to the channel 109 via communication links 112 and 113 .
During operation, the user 100 can communicate information to the user 120 using the first communication node 101 , the channel 109 and the second communication node 111 . Specifically, the user 100 communicates the information to the first communication node 101 via communication link 110 . The information is transformed in the transmitter 105 to match the restrictions imposed by the channel 109 . The transmitter 105 then communicates the information to the channel 109 via communication link 107 . The receiver 114 of the second communication node 111 next receives, via communication link 113 , the information from the channel 109 , and transforms it into a form usable by the user 120 . Finally, the information is communicated from the second communication node 111 to the user 120 via the communication link 121 .
Communication of information from the user 120 to the user 100 may also be achieved in a similar manner. In either case, the information transmitted/received may also be processed using the processors 106 / 118 .
FIG. 2 illustrates additional detail regarding the transmitters of FIG. 1 according to the present invention. The functions of transmitter 201 may be decomposed into those of a source encoder 203 and a channel encoder 205 . Generally, the source encoder 203 is a device that transforms the data produced by a source (such as the user 100 or user 120 of FIG. 1 ) into a form convenient for use by the channel encoder 205 . For example, the source may produce analog samples at a certain rate, such as, for example, 8000/s, as in a telephone application. The source encoder 203 then may perform the function of analog-to-digital conversion, converting each analog sample into an 8-bit binary code. The output of the source encoder 203 then would be a binary sequence of digits presented to the input of the channel encoder 205 at a rate of 8×8000=64,000 bit/s. The output of the source encoder 203 is passed to the channel encoder 205 , where the data are transformed into symbols that can be transmitted on the channel. For example, the data may be transformed using pulse-amplitude modulation (PAM), whereby successive short blocks of data bits of length N are encoded as analog pulses having one of 2 N allowable amplitudes.
In most communication systems, the data presented to the channel encoder are assumed to be completely random. This randomness is normally assured by the inclusion of a scrambler designed into the system. In the previous example of PAM, random data would lead to each 2 N of the allowable amplitudes being equally likely. That is, each of them occurs with probability 2 −N . It turns out that employing equally likely pulse amplitudes leads to a small inefficiency in the use of the power in the signal that is transmitted into the channel. In fact, as mentioned above, if the amplitude distribution can be made more nearly Gaussian, then up to 1.53 dB of transmitted power can be saved for the same level of error performance at the receiver.
Accordingly, a shaping function is provided in FIG. 2 by a shaper 207 , which alters the statistical distribution of the values presented to modulator 209 . Shaping the transmitted signal generally means controlling the distribution of transmitted signal values to make the signal appear more Gaussian in character. The shaper 207 comprises a Huffman decoder 211 and a mapper 213 . The design of the Huffman decoder 211 depends upon the characteristics of the channel.
In the Huffman decoder 211 , the sequence of scrambled binary data bits is parsed into Huffman codewords. The codewords are then mapped into modulation symbols. The Huffman code is designed to let the modulation symbols assume approximately a sampled Gaussian distribution.
Unlike trellis shaping or shell mapping, Huffman shaping is not a constant-rate-encoding scheme. Moreover, decoding errors can lead to bit insertion or deletion in the decoded binary data sequence. This may be acceptable for many systems, such as, for example, those in which variable-length packets are transmitted in burst mode with an Ethernet-like medium access protocol. In some cases, continuous transmission at constant rate is desirable, such as, for example, those involving variable-rate encoded voice and video streams over constant rate channels. A constant rate and recovery from bit insertions and deletions may be achieved, and the framing overhead may be kept to a value equivalent to a SNR penalty of ≈0.1 dB, for example, utilizing the method of the present invention.
The following mathematical foundation of Huffman shaping is based upon M-ary PAM data transmission, but the concept clearly applies to two- and higher-dimensional modulation as well.
Let A M be a symmetric M-ary PAM constellation of equally spaced symbols. Adjacent symbols are spaced by 2, and M may be even or odd (usually M will be even):
A M ={a i =−( M −1)+2 i, 0 ≦i≦M− 1}
e.g.: A 8 ={−7,−5,−3,−1,+1,+3,+5,+7}, A 5 ={−4,−2,0,+2,+4} (1)
If symbols are selected independently with probabilities p={p i , 0 ≦i≦M −1}, the symbol entropy H(p)(=rate) and the average symbol energy E(p) become:
H ( p ) = - ∑ i = 0 M - 1 p i log 2 p i bit / symbol
( p i = 1 M ∀ i : H ( p ) = H M = log 2 M ) , ( 2 ) E ( p ) = ∑ i = 0 M - 1 p i a i 2 ( 3 ) ( M - PAM , p i = 1 M ∀ i : E ( p ) = E M = M 2 - 1 3 ) .
Shaping gain G s (p) expresses a saving in average symbol energy achieved by choosing symbols from A M with probabilities p rather than selecting equiprobable symbols from a smaller constellation A M′ , where M′=2 H(p) (M′<M, ignoring that M′ may not be an integer):
G S ( p ) = E M ′ E ( p ) = 2 2 H ( p ) - 1 3 × E ( p ) . ( 4 )
The maximum shaping gain is obtained by the probability distribution p={tilde over (p)}, which minimizes E(p) subject to the constraints R=H(p) and
∑ i = 0 M - 1 p i = 1.
Differentiation of
J ( p ) = ∑ i = 0 M - 1 p i a i 2 + λ 1 ( - ∑ i = 0 M - 1 p i log 2 p i - R ) + λ 2 ( ∑ i = 0 M - 1 p i - 1 ) ( 5 )
with respect to the probabilities P i yields the conditions
( ∂ J ( p ) ∂ p i ) p = p ~ = a i 2 - λ 1 ln 2 ( ln p ~ i + 1 ) + λ 2 = 0 ,
for 0 ≤ i ≤ M - 1. ( 6 )
The parametric solution of (6), with the Lagrange multipliers λ 1 , λ 2 transformed into the new variables α,s, becomes
p ~ i = exp ( - 1 + ln 2 λ 1 ( a i 2 + λ 2 ) ) = α exp ( - s a i 2 ) , 0 ≤ i ≤ M - 1. ( 7 )
The optimum distribution {tilde over (p)} is thus found to be a Gaussian distribution sampled at the symbol values of A M . This solution can also be obtained by maximizing the rate R=H(p) subject to the constraints E(p)=S and
∑ i = 0 M - 1 p i = 1.
The value of α follows from
∑ i = 0 M - 1 p i = 1.
The value of s may be chosen to achieve a given rate R≦log 2 (M) or a given average symbol energy S≦E M .
If M and R are increased, the optimum shaping gain tends towards the ultimate shaping gain G s ∞ =πe/6=1.423 (1.53 dB). This gain can be derived as the ratio of the variance of a uniform density over a finite interval and the variance of a Gaussian density, both with the same differential entropy.
One can see that (7) does not only hold for regular symmetric PAM constellations, but gives the optimum shaping probabilities for arbitrary one- and higher-dimensional symbol constellations as well.
In general, given a sequence of M-ary source symbols which occur independently with probability distribution p, a traditional Huffman coding approach encodes the source symbols into binary codewords of variable lengths such that (a) no codeword is a prefix of any other codeword (prefix condition), and (b) the expected length of the codewords is minimized.
An optimum set of codewords is obtained by Huffman's algorithm. More particularly, let a i be a source symbol that occurs with probability p i . The algorithm associates a i with a binary codeword c i of length l i such that 2 −l i ≈p i . The algorithm guarantees that
∑ i = 0 M - 1 2 - l i = 1
(Kraft's inequality is satisfied with equality), and that the expected value of the codeword length,
L = ∑ i = 0 M - 1 p i l i ,
approaches the entropy of the source symbols within one bit [10]:
H ( p )≦ L<H ( p )+1. (8)
In the limit for large H(p), the concatenated Huffman codewords yield a binary sequence of independent and equiprobable zeroes and ones with rate R=L≅H(p) bit per source symbol. However, for certain probability distributions L may be closer to H(p)+1 than H(p) because of quantization effects inherent in the code construction. If H(p) is small, the difference between L and H(p) can be significant. The rate efficiency may be improved by constructing a Huffman code for blocks of K>1 source symbols. Then, (8) takes the form H(p)≦L(K)/K=L≦H(p)+1/K, where L(K) is the expected length of the Huffman codewords associated with K-symbol blocks. The code comprises M K codewords and the rate expressed in bit per source symbol will generally be within 1/K bit from H(p).
With the Huffman shaping method of the present invention, the traditional encoding approach is reversed. A Huffman code is generated for the optimum probability distribution {tilde over (p)} of the modulation symbols in a given M-ary constellation. In the transmitter, the sequence of data bits is suitably scrambled so that perfect randomness can be assumed. The scrambled sequence is buffered and segmented into Huffman codewords, as in traditional Huffman decoding. A codeword c i is encountered with probability 2 −l i ≈{tilde over (p)} i and mapped into modulation symbol a i . In the receiver, when a symbol a i is detected codeword c i is inserted into the binary output stream.
For the general case of K-dimensional modulation (K=1: PAM, K=2: QAM), it is appropriate to express rates and symbol energies per dimension, while a i , {tilde over (p)} i , and l i relate to K-dimensional symbols.
The mean value {overscore (R)} h and the standard deviation σ R h of the number of bits encoded per symbol dimension become
R h = 1 K ∑ i = 0 M - 1 2 - l i l i bit / dimension ( ≈ 1 K H ( p ~ ) ) , ( 9 ) σ R h = 1 K ∑ i = 0 M - 1 2 - l i ( l i - KR h ) 2 . ( 10 )
The average symbol energy per dimension S h and the shaping gain G s h of the Huffman-shaped symbol sequence are given by
S h = 1 K ∑ i = 0 M - 1 2 - l i a i 2 energy per dimension ( ≈ 1 K E ( p ~ ) ) , ( 11 ) G s h = 2 2 R _ h - 1 3 × E h . ( 12 )
The corresponding quantities obtained with optimum shaping probabilities {tilde over (p)} will be denoted, respectively, by {tilde over (R)} and σ {tilde over (R)} (bit/dimension), {tilde over (S)} (energy per dimension), and {tilde over (G)} s (optimum shaping gain).
For numerical evaluations, uncoded modulation with M-PAM (M=2 m) and M-QAM (M=4 m) constellations have been considered. The M-QAM constellations are either square constellations M-QAM sq =√{square root over (M)}−PAM×√{square root over (M)}−PAM, or lowest-energy constellations M-QAM le comprising the M points in the set {(1+2i,1+2k), i,k εZ} nearest to the origin. The symmetries of the symbol constellations are enforced on the Huffman codes. In the PAM case, m codewords are constructed for positive symbols and then extended by a sign bit. Similarly, in the QAM case m codewords are constructed for symbols in the first quadrant and extended by two quadrant bits. The results of different numerical evaluations are depicted in FIGS. 3 , 4 , and 5 .
FIG. 3 shows shaping gain versus rate for PAM and QAM sq constellations of different sizes, in accordance with the present invention. The solid curves indicate the shaping gains obtained with the optimum shaping probabilities {tilde over (p)}. Every rate in the interval 1≦R≦log 2 (M)/K can be accomplished (bit per dimension). The shaping gains vanish at R=1 (constellations reduced to BPSK or QPSK) and R=log 2 (M)/K (equiprobable M-QAM). The optimum shaping gains practically reach the ultimate shaping gain of 1.53 dB at R=4 bit per dimension for ≧32-PAM and ≧1024-QAM sq constellations. With the Huffman shaping method of the present invention, not every rate can be realized because of quantization effects in the construction of Huffman codes. For PAM, shaping gains of up to ≈1.35 dB are achieved at some rates above 3 bit per dimension. The effects of quantization are significantly reduced in the QAM cases. With ≧256-QAM sq constellations shaping gains within 0.1 dB from the ultimate shaping gain of 1.53 dB are consistently obtained at rates above 3 bit per dimension.
FIG. 4 plots shaping gains versus rate for square and lowest-energy 1024-QAM constellations, in accordance with the present invention. Minor differences occur in the region of diminishing shaping gains, at rates above 4.5 bit/dimension. The shaping gain of equiprobable 1024-QAM le (R=5 bit/dimension) is 0.2 dB.
FIG. 5 depicts the mean and standard deviation of the rate in bit/dimension and the shaping gain accomplished for a nominal rate of R=4 bit/dimension with QAM le constellations of different sizes, in accordance with the present invention. The nominal rate is at least closely achieved with Huffman shaping (with optimum shaping it is exactly achieved). The standard deviation increases with increasing constellation size to a final value of ≈1 bit/dimension. The optimum shaping gain and the Huffman shaping gain increase rapidly when the initial 256-QAM constellation is enlarged. The respective final shaping gains of ≈1.5 dB and ≈1.4 dB are practically achieved with M=512 (512-QAM le : 1.495 dB and 1.412 dB, 1024-QAM le : 1.516 dB and 1.432 dB).
FIG. 6 illustrates a 128-QAM le constellation with Huffman shaping for a nominal rate of 3 bit/dimension, in accordance with the present invention. The codeword lengths ranging from 5 to 12 bits are indicated for the first-quadrant symbols. {overscore (R)} h =2.975 (σ R h =0.919) bit/dimension and G s h =1.378 dB ({tilde over (G)} s =1.443 dB) are achieved. The symbol energies, optimum shaping probabilities, codeword probabilities and lengths, and the codewords of the first quadrant symbols are listed below. The codewords for the first-quadrant symbols end with 00.
TABLE 1
Huffman code words tabulated against
their index
i
|a i | 2
{tilde over (p)} i
p h i = 2 −l i
l i
c i
0
2
0.03872
0.03125
5
00000
1
10
0.02991
0.03125
5
10000
2
10
0.02991
0.03125
5
01100
3
18
0.02311
0.03125
5
11100
4
26
0.01785
0.01563
6
010000
5
26
0.01785
0.01563
6
001100
6
34
0.01379
0.01563
6
110000
7
34
0.01379
0.01563
6
101100
8
50
0.00823
0.00781
7
1010000
9
50
0.00823
0.00781
7
0101100
10
50
0.00823
0.00781
7
0101000
11
58
0.00636
0.00781
7
1101100
12
58
0.00636
0.00781
7
1101000
13
74
0.00379
0.00391
8
10101100
14
74
0.00379
0.00391
8
10101000
15
82
0.00293
0.00195
9
001001000
16
82
0.00293
0.00195
9
001000100
17
90
0.00226
0.00195
9
001010100
18
90
0.00226
0.00195
9
001010000
19
98
0.00175
0.00195
9
001011100
20
106
0.00135
0.00098
10
0010011100
21
106
0.00135
0.00098
10
0010011000
22
122
0.00081
0.00049
11
00100000100
23
122
0.00081
0.00049
11
00100000000
24
130
0.00062
0.00049
11
00101101000
25
130
0.00062
0.00049
11
00101100100
26
130
0.00062
0.00049
11
00101100000
27
130
0.00062
0.00049
11
00100001100
28
146
0.00037
0.00024
12
001000010100
29
146
0.00037
0.00024
12
001000010000
30
162
0.00022
0.00024
12
001011011000
31
170
0.00017
0.00024
12
001011011100
FIG. 7 illustrates one embodiment of a generic method for achieving constant rate and recovering from bit insertions and deletions. Data frames of N b bits are embedded into symbol frames of N s modulation symbols. Every sequence of bits transmitted within a symbol frame begins with a S&P (synch & pointer) field of n sp =n s +n p bits, where n s is the width of a synch subfield and n p is the width of a pointer subfield. The synch subfield enables the receiver to acquire symbol-frame synchronization. In principle, sending a known pseudo-random binary sequence with one bit (n s =1) in every S&P field is sufficient (as in T1 systems). The pointer subfield of the n th symbol frame expresses the offset in bits of the n th data frame from the S&P field.
With reference to FIG. 7 , in the 1 st symbol frame, the 1 st data frame follows the S&P field with zero offset. The S&P field and 1 st data frame are parsed into Huffman codewords, which are then mapped into modulation symbols indexed by 1,2,3, . . . N s . The end of the 1 st data frame is reached before the N s th modulation symbol has been determined. The data frame is padded with fill bits until the N s th modulation symbol is obtained. The 2 nd data frame follows the S&P field of the 2 nd symbol frame again with zero offset. Now the last symbol of the 2 nd symbol frame is found before the 2 nd data frame is completely encoded. The S&P field of the 3 rd symbol frame is inserted and encoding of the remaining part of the 2 nd data frame is then continued, followed by encoding the 3 rd data frame. The pointer in the S&P field indicates the offset of the 3 rd data frame from the S&P field. The 3 rd data frame can again not completely be encoded in the 3 rd symbol frame. The 4 th data frame becomes completely encoded in the 4 th symbol frame and is padded with fill bits, and so on. The pointer information in the S&P fields enables a receiver to recover from bit insertion and deletion errors.
To determine the overhead in framing bits per symbol, first let B n be the number of bits that are encoded into the N s symbols of the n th symbol frame. As mentioned above, the mean and standard deviation of the number of bits encoded per symbol dimension are R h and σ R h , respectively, as given by (9) and (10). Then B=N s KR h is the mean and σ B =√{square root over (N s K)}σ R h the standard deviation of B n . For large N s , the probability distribution of B n will accurately be approximated by the Gaussian distribution
Pr ( B n = x ) ≅ 1 2 πσ B exp ( - ( x - B ) 2 2 σ B 2 ) , x = 0 , 1 , 2 , 3 , … ( 13 )
Next, let P n be the pointer value in the S&P field of the n th symbol frame. The pointer values will remain bounded if B>n sp +N b . Equivalently, the average number of fill bits per frame, n fill , is nonzero:
n fill =B− ( n sp +N b )>0. (14)
Moreover, in a practical implementation the pointer values remain limited to the values that can be represented in the n p -bit pointer subfield i.e. 0≦P n ≦2 n p −1. Parameters are chosen such that the probability of P n >2 n p −1 becomes negligible. From FIG. 7 , one can verify the recursive relation
P n = { 0 if n sp + P n - 1 + N b ≤ B n - 1 n sp + P n - 1 + N b - B n - 1 otherwise . ( 15 )
The temporal evolution of the pointer probabilities then becomes
Pr ( P n = 0 ) = ∑ x ≥ 0 Pr ( P n - 1 = x ) Pr ( B n - 1 ≥ n sp + N b + x ) , ( 16 ) Pr ( P n = y ) = ∑ x ≥ 0 and
x ≥ y - n sp - N b Pr ( P n - 1 = x ) Pr ( B n - 1 = n sp + N b + x - y ) ,
y = 1 , 2 , 3 , … . ( 17 )
(equation (17) changed to fit within page margins)
The steady-state distribution Pr(P=x)=Pr(P n→∞ =x) can be determined numerically (mathematically speaking, Pr(P=x) is the eigensolution of (16) and (17) associated with eigenvalue one). Pr(P=x) and Pr(P≧x) are plotted in FIG. 8 for the following case.
Lowest-energy 512-QAM, nominal rate R=4 bit/dimension Huffman code design:
→R h =4.015, σ R h =0.927 bit/dimension; shaping gain G s h =1.412 dB. Assume N s =512 QAM symbols/symbol, N b =4094 bit/data frame, n sp =12 (n s =1, n p =11) →B=4111.36, σ B =29.66, n fill =5.36 bit/symbol frame.
The pointer field allows for a maximum pointer value of 2047. FIG. 6 shows that Pr(P>2047) is well below 10 −10 . The pointer values exhibit a Paréto distribution, i.e., log(Pr(P≧x)) decreases linearly for large x.
A framing overhead of (n sp +n fill )/N s =0.034 bit/QAM symbol is found, which is equivalent to an SNR penalty of 0.102 dB. The final net shaping gain becomes 1.412−0.102=1.310 dB.
Based on the above mathematical foundation of Huffman shaping, in one embodiment of the invention, the method of the present invention may generally comprise two parts. The first is related to the design of the Huffman code to be employed on a given channel, and the second is related to the operation of the Huffman shaper in the transmitter. While the above mathematical foundation of Huffman shaping assumes a PAM implementation; extension to higher-dimensional modulation are also possible.
FIG. 9 illustrates one embodiment of the design of a Huffman code in accordance with the present invention. The modulation scheme is characterized by parameters M, α, and s (see (7) and accompanying text above) acquired in block 901 , from which are derived the constellation levels {a i ;i=0,1, . . . , M−1} also in block 901 . The probability p i is then calculated for each a i in step 903 for i=0,1, . . . , M−1. Finally, a Huffman code for the symbols {a i } and their corresponding probabilities {p i } is constructed in block 905 .
FIG. 10 is a block diagram of one embodiment of a communication system that operates in accordance with the method of present invention. Upon completion of the construction of the Huffman code in FIG. 9 , a Huffman shaper is employed. Referring to FIG. 10 , Huffman shaper 1001 is loaded with information from a table similar to Table 1 above. The Huffman shaper information comprises one entry for each valid Huffman codeword and a corresponding entry for the channel symbol into which that Huffman codeword is mapped. The information is also sent to the receiver, using means available in the training procedure for the system. Then Huffman shaping proceeds during data transmission.
Specifically, referring again to FIG. 10 , data source 1003 generates (typically binary, but this is not required) data symbols at an adjustable rate controlled by the Huffman shaper 1001 . The data symbols are converted to pseudo-random form in a scrambler 1005 . The Huffman shaper 1001 generally comprises two parts, namely, a Huffman parser 1007 and a mapper 1009 . The Huffman parser 1007 accumulates outputs from the scrambler 1005 , symbol by symbol (e.g., bit by bit), until it accumulates a valid Huffman codeword. This codeword forms the input to the mapper 1009 . The mapper 1009 generates the channel symbol that corresponds to the Huffman codeword and passes the channel symbol to modulator 1011 , under the control of the modulator clock 1013 . The modulator clock 1013 defines the timing of the system. If required by the modulator clock 1013 , the Huffman shaper 1001 controls the rate at which it accumulates output symbols from the scrambler 1005 , in order to meet the demands of the modulator clock 1013 .
Slicer/decision element 1015 maps the symbol received from the channel 1017 into its best estimate of the channel symbol transmitted by the remote transmitter. The Huffman encoder 1019 maps the estimated received channel symbol into a Huffman codeword, which is passed to the descrambler 1021 . The descrambler 1021 inverts the operation of the scrambler 1005 , and the resulting received sequence of data symbols is passed to the user 1023 .
The Huffman shaper 1001 is modeled as being able to control the rate at which data are input to the shaper (see reference numeral 1025 of FIG. 10 ). More colloquially, present-day communication systems often operate in an environment where a large buffer of data are available for transmission, and data can be removed from that buffer at any rate appropriate for the transmission medium. Therefore, ascribing an adjustable rate capability to the Huffman shaper 1001 does not burden the method of the present invention with functionality that is not already present in practical situations.
As described above, a system that employs Huffman shaping carries a variable number of bits per modulation symbol. Therefore channel errors can introduce data in the receiver that is incorrect bit-by-bit, and that actually may contain the wrong number of bits as well. That is, referring to FIG. 10 , if a channel symbol different from the one introduced at the input to the modulator 1011 is received at the output of the slicer/decision element 1015 , then both the bits and the number of bits passed to the Huffman encoder 1019 may be incorrect. To compensate for this potential effect, a framer/deframer may be introduced.
FIG. 11 is another embodiment of the design of a Huffman code in accordance with the present invention, when a framer/deframer is utilized. Again, a PAM implementation is assumed, but extensions to higher-dimensional modulation are also possible. Referring to FIG. 11 , the modulation scheme is characterized by parameters M,α,s,N b ,N s ,n s , and n p acquired in block 1001 , from which are derived the constellation levels {a i ;i=0,1, . . . , M−1} (block 1101 ). Parameters N b ,N s ,n s , and n p define, respectively, the number of data bits, the number of modulation symbols, the number of synch bits, and the number of pointer bits in each symbol frame. The probability p i then is calculated for each a i in block 1103 for i=0,1, . . . ,M−1. Finally, a Huffman code for the symbols {a i } and their corresponding probabilities {p i } is constructed in block 1105 .
FIG. 12 is a block diagram of another embodiment of a communication system that operates in accordance with the method of present invention, utilizing a framer/deframer. Upon completion of the construction of the Huffman code in FIG. 11 , a Huffman shaper is employed. Referring to FIG. 12 , Huffman shaper 1201 is loaded with information from a table similar to Table 1 above. The Huffman shaper information consists of one entry for each valid Huffman codeword and a corresponding entry for the channel symbol into which that Huffman codeword is mapped. A framer 1203 is loaded with parameters N b ,N s ,n s , and n p . The information is also sent to the receiver using means available in the training procedure for the system. In the receiver a deframer 1205 is loaded with the same parameters, N b , N s , n s , and n p . Then Huffman shaping proceeds during data transmission.
Specifically, referring to FIG. 12 , data source 1207 generates data symbols at an adjustable rate controlled by the Huffman shaper 1201 . The data symbols are converted to pseudo-random form in a scrambler 1209 . The scrambler 1209 output is collected in the framer 1203 , which arranges transmitted data in groups of N b bits per symbol frame, N s modulation symbols per symbol frame, n s synch bits per frame and n p pointer bits per frame as discussed above. The Huffman shaper 1201 generally comprises of two parts, a Huffman parser 1211 and the mapper 1213 . The Huffman parser 1211 accumulates outputs from the framer 1203 , symbol by symbol, until it accumulates a valid Huffman codeword. This codeword forms the input to the mapper 1213 . The mapper 1213 generates the channel symbol that corresponds to the Huffman codeword and passes the channel symbol to the modulator 1215 under the control of the modulator clock 1217 . The modulator clock 1217 defines the timing of the system. If required by the modulator clock 1217 , the Huffman shaper 1201 controls the rate at which it accumulates output symbols from the scrambler 1209 in order to meet the demands of the modulator clock 1217 (see reference numeral 1218 in FIG. 12 ).
The slicer/decision element 1219 maps the symbol received from the channel 1221 into its best estimate of the channel symbol transmitted by the remote transmitter. The Huffman encoder 1223 maps the estimated received channel symbol into a Huffman codeword. In this embodiment, switch 1225 is in position A. The deframer 1205 is able to distinguish individual received modulation symbols by means of the demodulator clock 1227 signal from the demodulator 1229 . It uses the received symbol frame as well as the synch and pointer bits to construct a serial data stream corresponding to the output of the scrambler 1209 . This output is passed to the descrambler 1231 , which inverts the operation of the scrambler 1209 , and the resulting received sequence of data symbols is passed to the user 1233 .
In still another embodiment of the invention, the Huffman code constructed in a slightly modified fashion. This embodiment uses a one-dimensional form of the Huffman code described above. Specifically, a Huffman code is constructed for only the positive modulation symbols. After a Huffman code word has been collected in the transmitter by the Huffman decoder, the decoder uses its next input bit to define the sign of the modulation symbol corresponding to the collected Huffman code word. An inverse procedure is applied in the receiver. Again, a PAM implementation is assumed, but extension to higher-dimensional modulation is also possible.
Referring to FIG. 11 , the modulation scheme is characterized by parameters M,α, s, N b ,N s ,n s , and n p acquired in block 1101 , from which are derived the constellation levels {a i ;i=0,1, . . . , M−1}(block 1101 ). Parameters N b ,N s ,n s and n p define, respectively, the number of data bits, the number of modulation symbols, the number of synch bits, and the number of pointer bits in each symbol frame. The probability p i is then calculated for each nonnegative a i in block 1103 for i=0,1, . . . , M−1. Finally, a Huffman code for the nonnegative symbols {a i } and their corresponding probabilities {p i } is constructed in block 1105 .
Upon completion of the construction of the Huffman code in FIG. 11 , a Huffman shaper is employed. Referring to FIG. 12 , Huffman shaper 1201 is loaded with information from a table similar to Table 1 above. The Huffman shaper information consists of one entry for each valid Huffman codeword and a corresponding entry for the channel symbol into which that Huffman codeword is mapped. The framer 1203 is loaded with parameters N b ,N s ,n s , and n p . The information is also sent to the receiver using means available in the training procedure for the system. In the receiver the deframer 1205 is loaded with the same parameters, N b ,N s ,n s , and n s . Then Huffman shaping proceeds during data transmission.
Specifically, data source 1207 generates data symbols at an adjustable rate controlled by the Huffman shaper 1201 . The data symbols are converted to pseudo-random form in scrambler 1209 . The scrambler 1209 output is collected in the framer 1203 , which arranges transmitted data in groups of N b bits per symbol frame, N s modulation symbols per symbol frame, n s synch bits per frame and n p pointer bits per frame, as discussed above. The Huffman shaper 1201 generally comprises two parts, the Huffman parser 1211 and the mapper 1213 . The Huffman parser 1211 accumulates outputs from the framer 1203 , symbol by symbol, until it accumulates a valid Huffman codeword. The Huffman parser 1211 then accumulates one additional input bit and appends it to the Huffman codeword. This Huffman codeword with the appended bit forms the input to the mapper 1213 . The mapper 1213 generates the channel symbol that corresponds to the Huffman codeword, and uses the appended bit to define the sign of the channel symbol. It then passes the channel symbol to the modulator 1215 under the control of the modulator clock 1217 .
The slicer/decision element 1219 maps the magnitude of the symbol received from the channel 1221 into its best estimate of the magnitude of the channel symbol transmitted by the remote transmitter. It also estimates the sign of the received symbol. The channel symbol magnitude is passed to the Huffman encoder 1223 , which maps the estimated received channel symbol magnitude into a Huffman codeword and presents the output at the A input of switch 1225 . The sign of the received symbol is presented at the B input of switch 1225 by means of connection sign information 1235 . Switch 1225 , normally in the A position; is switched to the B position after each received Huffman code word, in order to accept the sign information 1235 from the slicer/decision element 1219 . The deframer 1205 is able to distinguish individual received modulation symbols by means of the demodulator clock 1227 signal from the demodulator 1229 . It uses the received symbol frame as well as the synch and pointer bits to construct a serial data stream corresponding to the output of the scrambler 1209 . This output is passed to the descrambler 1231 , which inverts the operation of the scrambler 1209 , and the resulting received sequence of data symbols is passed to the user 1233 .
FIG. 13 illustrates one operation of a system that employs Huffman shaping in accordance with the present invention. A transmitter 1301 accepts user data (block 1303 ). The transmitter 1301 may also perform a framing operation ( 1307 ) to provide a means to recover from possible errors that may be introduced in the channel.
The transmitter 1301 then implements Huffman shaping. Specifically, the transmitter 1301 accumulates source data until a Huffman codeword is recognized (block 1309 ), and then maps the resulting Huffman codeword into a channel symbol (block 1311 ). The transmitter then performs a modulation operation (block 1313 ), which optionally includes sequence coding to increase the signal distances between permitted symbol sequences. Finally, the modulated signal is applied to the input of the communications channel (block 1315 ).
The receiver 1317 accepts the received signal from the channel output (block 1319 ), and demodulates it (block 1321 ). Demodulation generally includes such operations as timing tracking and equalization. The received signal is then subjected to a decision operation, which may optionally include sequence decoding (block 1323 ). The Huffman shaping (blocks 1309 and 1311 ) is inverted by applying the received signal to the input of a Huffman encoder (block 1325 ). The receiver 1317 then performs a deframing operation (block 1327 ), and communicates the received data to the user (block 1331 ).
Based on the foregoing discussion, it should be apparent that in one embodiment of the invention, once data is received from a data source, the sequence of binary data bits is randomized by a scrambling operation and bits are mapped into channel symbols such that the channel symbols occur with a probability distribution suitable for achieving shaping gain. This is accomplished by accumulating scrambled data bits until a Huffman codeword is recognized, at which time the Huffman codeword is mapped into a channel symbol. Then the channel symbol is applied to the input of a communication channel. The probability of recognizing in the scrambled data sequence a particular Huffman codeword of length L bits is 2 −L . Hence, the channel symbol associated with that particular Huffman codeword will be transmitted with probability 2 −L . Note that this channel encoding operation via Huffman codes corresponds in the field of source coding to Huffman decoding.
In one embodiment of the invention, the channel encoding operation described above is performed in combination with a framing operation to achieve transmission of data at a constant rate. In addition, channel symbols can be modulated in various ways before they are applied to the input of the communication channel.
Next, on the receiver side of the communication channel a channel symbol is obtained at the demodulator output. The channel symbol is converted into the corresponding Huffman codeword. The sequence of bits represented by concatenated Huffman codewords is descrambled and delivered to the data sink. The described channel decoding operation corresponds in the field of source coding to Huffman encoding.
In one embodiment of the invention, a deframing operation is performed, which provides for data delivery to the data sink at constant rate. In addition, the deframing operation limits the effect of channel demodulation errors, which can cause a temporal shift of the received binary data sequence. This shift can occur when a channel symbol is erroneously decoded whose associated Huffman codeword differs in length from the Huffman codeword associated with the correct channel symbol.
The method of the present invention results in a symbol constellation and a probability distribution of symbols in this constellation that exhibits a shaping gain of greater than 1 dB. The shaping gain may be, for example, 1.35 dB or 1.5 dB, depending on the specific design. More specifically, for PAM constellations, shaping gains of up to ≈1.35 dB are achieved for some rates. For QAM constellations, shaping gains within 0.1 dB from the ultimate shaping gain are consistently obtained for rates of >3 bit per dimension.
In general, a communication system according to the present invention comprises a communication node that performs a Huffman decoding operation to generate channel symbols with a desired probability distribution.
Many modifications and variations of the present invention are possible in light of the above teachings. Thus, it is to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as described hereinabove.
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In a communication system, Huffman coding techniques are used to obtain shaping gains for an improvement in data transmission rates. More particularly, a novel method of Huffman shaping is described that achieves a shaping gain of greater than 1 dB. The shaping gain results in a higher data rate transmission in a communication system where transmitted power is constrained.
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[0001] The present application claims priority under 35 U.S.C. §119(a) to Korean application number 10-2014-0120794, filed on Sep. 12, 2014, in the Korean Intellectual Property Office, which is incorporated herein by reference in its entirety as set forth in full.
BACKGROUND
[0002] 1. Technical Field
[0003] The present invention relates to a data pattern detecting device capable of detecting a specific pattern of data, a semiconductor device including the same, and an operating method thereof.
[0004] 2. Related Art
[0005] A data storage device, such as an SSD (Solid State Drive), which includes a nonvolatile semiconductor memory device such as a NAND flash memory device, substitutes for an existing data storage device such as a hard disk.
[0006] Efficient use of data storage space is required in data storage devices such as SSDs. For example, when data of a specific pattern (a “patterned data”) is frequently used, only information representing the patterned data is stored instead of storing the patterned data itself. Therefore, the data storage device saves storage space.
[0007] The NAND flash memory device may perform read and write operations by units of pages and may perform erase operations in units of blocks. The size of pages is normally 4096 bytes (4 KB), but since the information representing the patterned data is very small, it is possible to save storage space.
[0008] Conventionally, an excessive amount of resources is used for detecting patterned data, resulting in degradation of overall data storage device performance. Therefore, a device and a method of detecting patterned data more efficiently are desirable.
SUMMARY
[0009] A data pattern detecting device capable of easily detecting patterned data, a semiconductor device including the same, and an operating method thereof are described herein.
[0010] In one embodiment of the present invention, a data pattern detecting device may include: a length comparison unit suitable for comparing lengths of compressed input data and compressed reference data; and a data comparison unit suitable for comparing the compressed input data and the compressed reference data.
[0011] In another embodiment of the present invention, a semiconductor device may include: a memory cell array; and a control device suitable for controlling the memory cell array for input and output of data requested from a host, wherein the control device comprises: a pattern detecting device suitable for determining whether the data requested from the host has a specific data pattern; an address mapping table suitable for storing a logical address and a physical address corresponding to the logical address for the data of the memory cell array; and a control unit suitable for allocating a specific physical address for the data, which is to be written into the memory cell array in response to a request from the host and has the specific data pattern.
[0012] In another embodiment of the present invention, a method for operating a semiconductor device may include: compressing data requested to be written; determining whether the data requested to be written has a specific data pattern; and allocating a specific physical address for the data requested to be written and having the specific data pattern, wherein the determining comprises: comparing lengths of a compressed input data and a compressed reference data; and comparing the compressed input data and the compressed reference data, and wherein the compressed input data is obtained by compressing the data requested to be written, and wherein the compressed reference data is obtained by compressing the specific data pattern.
[0013] The present invention provides a data pattern detecting device capable of easily determining whether inputted data has a specific pattern, a semiconductor device including the same, and an operating method thereof. Consequently, as the specific pattern occupies a large space before it is compressed, it is possible to reduce the data storage space that is consumed. Instead of reading data of the specific pattern from a memory cell array and outputting the data, the data of the specific pattern can be directly generated and outputted, so that reading performance can be improved.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Features, aspects, and embodiments are described in conjunction with the attached drawings, in which:
[0015] FIG. 1 is a block diagram illustrating a data pattern detecting device according to an embodiment of the present invention;
[0016] FIG. 2 is a block diagram illustrating a semiconductor device according to an embodiment of the present invention;
[0017] FIG. 3 is a data structure diagram illustrating an address mapping table shown in FIG. 2 ;
[0018] FIG. 4 is a data structure diagram illustrating a physical page shown in FIG. 2 ;
[0019] FIG. 5 is a data structure diagram illustrating a write buffer shown in FIG. 2 ;
[0020] FIG. 6 is a flowchart illustrating a write operation of a semiconductor device according to an embodiment of the present invention;
[0021] FIG. 7 is a flowchart illustrating a read operation of a semiconductor device according to an embodiment of the present invention; and
[0022] FIG. 8 and FIG. 9 are graphs illustrating the effects of the present invention.
DETAILED DESCRIPTION
[0023] Hereinafter, a data pattern detecting device, a semiconductor device including the same, and an operating method thereof according to the present invention will be described in detail with reference to the accompanying drawings through an exemplary embodiment.
[0024] FIG. 1 is a block diagram Illustrating a data pattern detecting device 100 according to an embodiment of the present invention.
[0025] The data pattern detecting device 100 may detect patterned data, and output a detection flag signal.
[0026] The data pattern detecting device 100 may include a compression unit 110 , a length comparison unit 120 , a data comparison unit 130 , a flag generation unit 140 , and a storage unit 150 .
[0027] The compression unit 110 may compress inputted data to be stored, and may output compressed data.
[0028] The length comparison unit 120 may compare the lengths of the compressed data and compressed reference data stored in the storage unit 150 , which is a compressed representation of a specific data pattern. When the lengths of the compressed data and compressed reference data are equal, the length comparison unit 120 enables a length comparison signal SL.
[0029] When the length of the compressed data is different from the length of the compressed reference data, the inputted data before the compression is not equal to the specific data pattern, which is represented by the compressed reference data. Accordingly, the data comparison unit 130 may not be activated.
[0030] When the length of the compressed data is equal to the length of the compressed reference data, the inputted data before the compression may have a chance to be the same as the specific data pattern, but it is not possible to conclude that the inputted data is the same as the specific data pattern. For example, in the case in which the size of a page is 4 KB and a compression algorithm is the LZF (Lempel-Ziv-Free), when all data in the page is 0 and 1, the lengths after compression are the same as 54 bytes in the two cases.
[0031] When the length comparison unit 120 determines that the length of the compressed data is equal to the length of the compressed reference data, the data comparison unit 130 may compare the compressed reference data with the compressed data. When the compressed reference data is equal to the compressed data, the data comparison unit 130 may enable a data comparison signal SD.
[0032] The flag generation unit 140 may enable a detection flag when both of the length comparison signal SL and the data comparison signal SD are enabled.
[0033] The specific data pattern represented by the compressed reference data may vary according to design, and the following description will be provided for an example of zero data, that is, when the specific data pattern is all “0”.
[0034] For example, the page size stored in a NAND flash memory device is 4096 bytes (4 KB). It is quite burdensome in view of occupying area and operation time for the data comparison unit 130 to compare each bits of inputted page data and reference page data of 4096 bytes (4 KB) in order to determine whether the inputted page data is the zero page data, thereby degrading the performance of the data pattern detecting device.
[0035] However, according to an embodiment of the present invention, the data pattern detecting device 100 may compress the inputted page data thereby reducing the size of the inputted page data. As described above, when compressed by the LZF algorithm, 4096 bytes (4 KB) of the inputted page data may be reduced to 54 bytes.
[0036] Consequently, the occupying area and the operation time of the data comparison unit 130 can be considerably reduced. The data comparison unit 130 may be realized using logic gates.
[0037] FIG. 2 is a block diagram illustrating a semiconductor device 1000 according to an embodiment of the present invention.
[0038] The semiconductor device 1000 may perform read and write operations in response to requests from a host 10 . The semiconductor device 1000 may be a NAND flash memory device. The host 10 may operate under the control of an operating system therein.
[0039] The semiconductor device 1000 may include a memory cell array 300 , which is divided in units of physical pages 310 , and a control device 200 , which controls the memory cell array 300 and inputs/outputs data to/from the memory cell array 300 .
[0040] The memory cell array 300 may store data in the physical pages 310 . The data may be compressed or non-compressed.
[0041] The size of the physical page 310 may be different from the size of a logical page. For example, the size of the logical page provided from the host may be 4 KB and the size of the physical page 310 may be 8 KB. In this case, a single physical page may include two non-compressed logical pages.
[0042] The control device 200 may include a control unit 210 , an address mapping table 220 , the pattern detecting device 100 , a decompression unit 230 , a write buffer 240 , and a read buffer 250 .
[0043] The control unit 210 may generally control various operations of the NAND flash memory device with the FTL (Flash Translation Layer) such as read, write, garbage collection, and ware leveling. Since the general operation of the FTL is well-known, a detailed description thereof will be omitted.
[0044] The address mapping table 220 may manage logical addresses requested from the host 10 and physical addresses corresponding to the logical addresses. The relationship between the logical and physical addresses may be updated during the garbage collection, the ware leveling and the like.
[0045] The pattern detecting device 100 may include the compression unit 110 that compresses the inputted data as described above. The pattern detecting device 100 may determine whether the Inputted data to be written is the same as the specific data pattern represented by the compressed reference data.
[0046] The decompression unit 230 may decompress and output the compressed data from the memory cell array 300 in response to a read request from the host 10 .
[0047] The write buffer 240 may temporarily store the inputted data in the physical pages 310 of the memory cell array 300 .
[0048] The read buffer 250 may temporarily store data read from the physical pages 310 .
[0049] FIG. 3 illustrates a data structure illustrating the address mapping table 220 shown in FIG. 2 .
[0050] The address mapping table may include a logical address field LPA, a bypass flag field BPF, an index field INDEX, and a physical address field PPA.
[0051] The logical address field LPA may store the logical address of data in the memory cell array 300 . When the index of the address mapping table 220 can be identified by the logical address transmitted from the host 10 , the logical address field LPA may not be separately stored.
[0052] The bypass flag field BPF may store 1 when data stored in the physical pages 310 is not compressed, and may store 0 when the data stored in the physical pages 310 is compressed. The compression performance may depend on the type of data, and the size of a compressed data may be greater than the original data, and in this case the data is stored non-compressed.
[0053] For example, when original data is compressed and the length of the compressed data is more than 95% of the length of the original data, the original data may be stored non-compressed and the bypass flag and its corresponding logical address is set to 1.
[0054] FIG. 3 illustrates that the stored data of the logical addresses 80 to 82 is compressed and the stored data of the logical addresses 83 and 84 is non-compressed.
[0055] The physical address field PPA may indicate the addresses of the physical pages 310 corresponding to the logical addresses.
[0056] As described above, the sizes of the physical pages 310 may be larger than those of the logical pages. Accordingly, a single physical page 310 may store a plurality of logical pages. Thus, index information may be used in order to identify a plurality of logical pages stored in the single physical page 310 . The index field INDEX may store such index information.
[0057] For example, in FIG. 3 , since the index of the logical address 80 is “0”, data of the index “0” may be the first one of the compressed data stored in the physical address 100 . Furthermore, since the index of the logical address 84 is “1”, data of the index “1” may be the second one of the non-compressed data stored in the physical address 200 .
[0058] FIG. 4 illustrates a data structure illustrating the physical page 310 shown in FIG. 2 .
[0059] (a) and (b) of FIG. 4 illustrate the structures of the uncompressed and compressed logical pages stored in the physical page 310 , respectively.
[0060] In the present embodiment, since the size of the logical page is 4 KB and the size of the physical page is 8 KB, the single physical page 310 may store two logical addresses 311 and 312 and sequentially correspond to indexes 0 and 1, as shown in (a) of FIG. 4 .
[0061] In the case of non-compressed data, no further data other than the logical page data may be required.
[0062] However, in the case of compressed data, the size of compressed data may be different, and separate meta data for identifying the compressed data may be required.
[0063] (b) of FIG. 4 shows three (3) of the compressed logical pages 317 to 319 (page “#0” to “#2”), the lengths 314 to 316 (“2030”, “2045”, and “3028” bytes) of the compressed logical pages 317 to 319 , and the number 313 (“3”) of the compressed logical pages 317 to 319 in the physical page 310 .
[0064] The length data 314 indicates the length of the 0 th compressed logical page 317 , the length data 315 indicates the length of the first compressed logical page 318 , and the length data 314 indicates the length of the second compressed logical page 319 .
[0065] As such, it is possible to identify the compressed logical page data through the physical addresses and the meta data.
[0066] FIG. 5 is a block diagram illustrating the write buffer 240 shown in FIG. 2 .
[0067] The write buffer 240 may include a first write buffer 241 and a second write buffer 242 .
[0068] The first write buffer 241 may temporarily store the non-compressed logical page, and may have the same structure as the uncompressed logical pages stored in the physical page 310 illustrated in (a) of FIG. 4 . The first write buffer 241 may store two non-compressed logical pages 241 - 1 and 241 - 2 .
[0069] The second write buffer 242 may temporarily store the compressed logical page, and may have the same structure as the compressed logical pages stored in the physical page 310 illustrated in (b) of FIG. 4 . The second write buffer 242 may store compressed logical pages 242 - 5 to 242 - 7 and meta data 242 - 1 to 242 - 4 corresponding to the compressed logical pages 242 - 5 to 242 - 7 . The meta data may include the number 242 - 1 of the compressed logical pages, and the lengths 242 - 1 to 242 - 4 of the compressed logical pages.
[0070] FIG. 6 is a flowchart illustrating the writing operation of the semiconductor device 1000 according to an embodiment of the present invention.
[0071] The writing operation of the semiconductor device 1000 may be generally controlled by the control unit 210 .
[0072] When a writing request is provided from the host 10 as well as input data to be written in the memory cell array 300 and the logical address for the input data, the compression unit 110 of the pattern detecting device 100 may compress the input data (S 110 ).
[0073] Next, the pattern detecting device 100 may compare the compressed input data and the compressed reference data, which is a compressed representation of the specific data pattern, as described above with reference to FIG. 1 (S 120 ).
[0074] Then, the pattern detecting device 100 may determine whether the input data has the same pattern as the specific data pattern of the compressed reference data ( 5130 ).
[0075] When the input data has the same pattern as the specific data pattern of the compressed reference data, the pattern detecting device 100 may allocate a physical address for the compressed input data (S 140 ). In this case, a specific value, for example, “0”, may be allocated as the physical address for the compressed input data. Furthermore, it is not necessary to store the compressed input data in the physical page 310 .
[0076] When the input data does not have the same pattern as the specific data pattern of the compressed reference data, the pattern detecting device 100 may determine whether the size of the compressed input data is smaller than a threshold value ( 5150 ). For example, the pattern detecting device 100 may determine whether the size of the compressed input data is less than 95% of the size before compression.
[0077] When the size of the compressed input data is larger than the threshold value, the pattern detecting device 100 may select the original input data as the data to be written in the memory cell array 300 (S 151 ), and when the size of the compressed input data is not larger than the threshold, the pattern detecting device 100 may select the compressed input data as the data to be written in the memory cell array 300 (S 152 ).
[0078] Then, the pattern detecting device 100 may determine whether there is space for the data to be written in the write buffer 240 (S 160 ). For example, when the original input data is selected as the data to be written, the pattern detecting device 100 may determine whether there is space for the original input data in the first write buffer 241 , and when the compressed input data is selected as the data to be written, the pattern detecting device 100 may determine whether there is a space for the compressed input data in the second write buffer 242 .
[0079] When there is no spare space in the write buffer 240 , the pattern detecting device 100 may move data stored in the write buffer 240 to the memory cell array 300 ( 5170 ), and may store the data to be written into the write buffer 240 (S 180 ).
[0080] When there is space for data to be written in the write buffer 240 , the pattern detecting device 100 may store the data to be written into the write buffer 240 (S 180 ).
[0081] When the data to be written is the original input data, the pattern detecting device 100 may store the data to be written into the first write buffer 241 , and when the data to be written is compressed input data, the pattern detecting device 100 may store the data to be written in the second write buffer 242 .
[0082] FIG. 7 is a flowchart illustrating a reading operation of the semiconductor device 1000 according to an embodiment of the present invention.
[0083] The reading operation of the semiconductor device 1000 may be generally controlled by the control unit 210 .
[0084] When a reading request is provided from the host 10 as well as the logical address for the stored data to be read from the memory cell array 300 , the control unit 210 may find the physical address corresponding to the requested logical address by referring to the address mapping table 220 (S 210 ).
[0085] Next, the control unit 210 may determine whether or not the data to be read has the specific data pattern based on the physical address. The compressed reference data representing the specific data pattern may be stored in the memory cell array 300 with a specific physical address, namely the physical address having the specific value “0” as described above.
[0086] When the requested data has the specific data pattern, the control unit 210 generates the specific data pattern instead of reading data from the memory cell array 300 , and may transfer the generated specific data pattern to the host 10 ( 230 ) in response to the read request.
[0087] When the requested data does not have the specific data pattern, the control unit 210 may read the requested data, which may be compressed or non-compressed, from the physical page 310 of the memory cell array 300 based on the physical address corresponding to the requested logical address (S 240 ).
[0088] The read data may be temporarily stored in the read buffer 250 .
[0089] Then, the control unit 210 may decompress the read data, and may transfer the decompressed data to the host (S 250 ) in response to the read request.
[0090] FIG. 8 is a graph illustrating the effects of the present invention.
[0091] In the graph of FIG. 8 , the performance when specific data pattern detection is applied is compared to the performance without pattern detection in a NAND flash memory device employing a scheme of compressing and storing page data.
[0092] In the graph, the horizontal axis denotes the type of benchmark and the vertical axis denotes the write amplification factor (WAF). The write amplification factor indicates the ratio of data that has been actually written in the memory cell array 300 by the control unit 210 with respect to the size of data requested to be written by the host 10 .
[0093] As illustrated in FIG. 8 , when the specific data pattern detecting operation is performed, since the specific data pattern is not stored, the write amplification factor is further reduced. For example, in the case of a Linux benchmark, when the specific data pattern detecting operation is performed, the write amplification factor is reduced by about 14%, compared with the case in which the zero page detecting operation is not performed.
[0094] FIG. 9 is another graph Illustrating the effects of the present invention.
[0095] In the graph of FIG. 9 , the number of read, write, and compress release operations when detecting the specific data pattern is compared with the number of read, write, and compress releases without pattern detection in the NAND flash memory device employing a scheme of compressing and storing page data.
[0096] Since the reading of the specific data pattern is not generated directly after writing is generated, actual user workload of about 12 hours after the installation of Window 7 has been extracted in order to measure actual performance. Through the extracted workload, the number read, write, and compress release operations have been measured with and without specific data pattern detection.
[0097] As illustrated in FIG. 9 , when detecting specific data patterns, the number read operations is reduced by about 2% and the number of write and compress releases is reduced by about 4%, compared to when specific data pattern detection is not employed.
[0098] In the reading operation, when detecting the specific data pattern, the data of the specific data pattern is generated and outputted instead of actually reading data. In the writing operation, when detecting the specific data pattern, since data is not actually written, such results are obtained.
[0099] When reading and writing data in which the specific data pattern occupies a large part, as compared with data used in experiments, the reduction of required storage space is expected to be higher.
[0100] While certain embodiments have been described above, it will be understood to those skilled in the art that the embodiments described are examples only. Accordingly, the data pattern detecting device, the semiconductor device including the same, and the operating method thereof described herein should not be limited based on the described embodiments. Rather, the data pattern detecting device, the semiconductor device including the same, and the operating method thereof described herein should only be limited in light of the claims that follow when taken in conjunction with the above description and accompanying drawings.
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A pattern detecting device includes a length comparison unit suitable for comparing lengths of compressed input data and compressed reference data; and a data comparison unit suitable for comparing the compressed input data and the compressed reference data.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of U.S. patent application Ser. No. 10/101,346, filed Mar. 20,2002, entitled “Method for Curing Cyanoacrylate Adhesive”, which is currently pending, which is a continuation-in-part of U.S. patent application Ser. No. 10/077,852, filed Feb. 20, 2002, entitled “Method for Curing Cyanoacrylate Adhesive”, which is abandoned.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates broadly to a method of treating stabilized cyanoacrylate adhesives prior to their application to a substrate, particularly with reference to medical procedures using such adhesives.
[0004] 2. Description of the Prior Art
[0005] Medical interest in cyanoacrylate polymers has been apparent since at least the mid-nineteen sixties as evidenced by numerous reports on its use as a tissue bonding agent. Collins et al. reported on the effectiveness of homologous chain cyanoacrylates for bonding of biological substrates. J. A. Collins, et al., ARCH SURG. Vol. 93, 428 September 1966; F. Leonard et al., J.A.P.S. Vol. 10: 1617, 1966. Both articles report the observation of high rates of polymerization with longer chain esters than with the methyl or ethyl monomers. There appeared to be more biocompatability with the longer chains as noted by the ease of spreading monomer films on bio-substrates. This contrasted with in vitro polymerizations where the lower homologues reacted much faster. There was particular interest in the degradation of these polymers as they related to possible harmful effects that would preclude their use in surgery.
[0006] Woodward et al. reported histotoxicity of these monomers in rat tissue. S. C. Woodward, et al., ANN. SURG. Vol. 162, July 1965. The study involved in situ polymerization of three cyanoacrylate monomers: methyl, hexyl, decyl. It was reported that histotoxic effects were greatest with methyl and decreased with the other two monomers.
[0007] The same group reported on the use of radioactive methyl cyanoacrylate for monitoring routes for the loss of the polymer. J. J. Cameron et al., SURGERY, Vol. 58, August 1965; C. H. McKeever, U.S. Pat. No. 2,912,454, Nov. 10, 1950. Results indicated that the polymer was degraded and excreted principally through the urine and feces. Analysis of the animal's organs revealed no signs of radioactivity. This implied no degradation products were incorporated into any of the animal's metabolic pathways. By analogy to poly-vinylidene cyanide, they noted that the cyanoacrylate polymer degraded in the presence of water and more so in the presence of bases. The first observed degradation product turned out to be one of the starting materials, i.e., formaldehyde. In vitro studies have shown that the polymers degrade via hydrolytic scission in homogeneous as well as heterogeneous conditions. F. Leonard et al., J.A.P.S., Vol. 10: 259, 1966. These degradation products were confirmed to be formaldehyde and the corresponding cyanoacetate. The conditions of solution degradation affected the consequent rates, namely, under neutral conditions rates decreased as the homologous series was ascended while alkaline conditions increased all rates.
[0008] The same study reported that the hydroxyl group was evident in the polymer as the initiating species. This was concluded from infrared spectral data that displayed hydroxyl group absorption at 3600 cm(−1). Further support for this is the noted suppression of the OH as water is replaced with methanol and the observed methoxy absorption at 1100 cm (−1). Preferential initiation was shown to occur with NH2 containing substances such as pyridine, cysteine, alanine, and glycine in aqueous solutions. This suggested that in vivo adhesion was more than a mechanical interlocking of the solid polymer with the tissue. This appears to be the case as it was noted that typical polymer solvents were not effective in solvating tissue-bound polymer.
[0009] From this it appears that in vivo studies of degradation do not necessarily correspond to in -vitro conditions. Part of the degradation mechanism relies on the conditions of the polymer for hydrolytic scission. The chemical bonding of the polymer excludes this surface from hydrolytic activity. A mechanism of degradation was proposed that suggests an action similar to unzipping in acrylics, however, the difference being that the monomer is not regenerated. The proposed mechanism necessitates the presence of the hydroxyl as well as the presence of water.
[0010] An unusual effect was reported regarding the aqueous degradation of isobutyl cyanoacrylate. R. H. Lehman et al., ARCH SURG. Vol. 93: 441, 1966. Of the monomers tested (methyl, propyl, butyl, isobutyl, heptyl, octyl), it was the only one that degraded more rapidly than any of the unbranched homologues, with the exception of the methyl monomer.
[0011] A second study reported that in vivo experimentation gives credence to the chain scission mechanism by hydrolysis. M. Yonezawa et al., YUKI GOSEI KAGAKU KYOKAISHI, Vol. 25, 1967. When beta-(14) carbon tagged cyanoacrylate is implanted in rats, radioactive urea is isolated from urine. This suggests that tagged formaldehyde is released, converted to carbon dioxide and in turn reacts with ammonia to produce urea. F. Leonard, ADHES. BIOL. SYS. 1970.
[0012] Rates of degradation on ethyl, butyl, and hexyl cyanoacrylates were evaluated with regards to molecular weights, concentrations, and side chain structures. W. R. Vezin et al., J. PHARM. PHARMACOL., Vol. 30, 1978, Suppl. The method employed buffered systems of pH ranges from 5.97 to 7.88. As expected, the rates increased with increasing pH. Scanning electron microscopy of the degraded polymer indicated that reaction occurs at the surfaces and not internally through diffusion. It was postulated that the greater the length of the—alkyl side chain, the more protection provided to the labile hydroxyl end of the polymer chain. This in turn would provide greater resistance to degradation of the polymer. Degradation rates do in fact correspond to chain length protection. The relative rates of degradation for hexyl, butyl, and ethyl were, respectively, 1.0, 1.36, 9.55.
[0013] The same group reported on a study whereby degradation rates were retarded by increasing the chain length of the polymer. W. R. Vezin et al., J. BIOMED. MAT. RES., Vol. 93, 1980. Very small quantities of impurities in the monomers had a significant impact on the final outcome of the degree of polymerization. Further to this study, within the ethoxyethyl system, longer chain length enhanced the degradation resistance of the resultant polymer.
[0014] A comparative study of ethyl cyanoacrylate and polyurethane in-situ generated adhesives and coatings was reported in U.S. Pat. No. 4,057,535 to Lipatova et al. The study claimed the superiority of the polyurethane structure due to high flexibility and compatibility with the treated tissues. The single comparison was made with incised tissue and consequent application between the wound edges. Inferiority of this application for the cyanoacrylate was readily evident, but true topical applications were not compared. Of eleven examples given, four were of a topical method, yet no data was presented as no application of the ethyl or any other homologue was done conjunctively for comparative efficacy. A further deficiency of this patent is the practicality of use. No indication is given for a device to properly apply the two part system and appears to indicate an at-site preparation.
[0015] Another patent, U.S. Pat. No. 5,192,536 to Robinson overcomes the issue of the apparent difficulties associated with the invention disclosed in U.S. Pat. No. 4,057,535 by taking preformed polyurethane and dissolving it in a rapidly evaporating solvent such as tetrahydrofuran. The composition is designed to form a “membrane-like cover over the wound” and “assists in maintaining closure of the wound”. Again no comparative studies were reported.
[0016] U.S. Pat. No. 3,995,641 to Kronenthal et al. discusses the novelty of modified cyanoacrylates, namely, carbalkoxyalkyl cyanoacrylates. The patent discloses their usefulness as a tissue adhesive in surgical applications. The presumed superiority of these products was attributable to the rapid hydrolytic decay and concurrent low degree of histotoxicity. Since no data is presented regarding formaldehyde evolution, it is presumed that the hydrolysis mechanism does not scission the polymer to generate it.
[0017] U.S. Pat. No. 5,254,132 to Bartley et al. discloses the use of a hybrid method of surgical application of cyanoacrylates. It discloses a combination of sutures and adhesive such as to be mutually isolated from each other, but to both support the re-growth of the tissue in the wound area. The '132 patent addresses the issue of insuring no contact of adhesive in the suture area so as to assure no inclusions of the cyanoacrylate. The disclosed method appears to be awkward and cumbersome, and requires a very effective and controlled dispensing of the adhesive without contacting the suture. Additional concern is indicated as a suggestion is made to employ a solvent (acetone) if any surgical instrument happens to be bonded inadvertently to the treated area.
[0018] U.S. Pat. No. 5,328,687 to Leung et al. attacks the formaldehyde issue by incorporating a formaldehyde scavenger, such as, sodium bisulfite. The various compositions were evaluated via in-vitro experimentation. The examples presented all had a presumably excessive level of scavenger. The representative compositions had loadings of 20% of a scavenging agent that was designed to offset formaldehyde emissions that were at 0.1%. As indicated previously, in-vitro and in vivo conditions are not identical and certainly not in this instance. The in-vitro conditions presented in the '687 patent do not factor in the dynamic conditions in living tissue. The surgically treated area would be under continuous and changing fluids as the organ attempts to bring in the necessary biocomponents to heal the traumatized tissue. As such, it would not be expected that the scavenger/formaldehyde ratio would be maintained as it was in the in-vitro state. It could be speculated that the use of such high loadings of any fluid solubilized additives would contribute to greater formaldehyde emissions. This can be assumed to be a consequence of dissolution of the additives resulting in cavities in the polymer, thereby promoting greater surface area for hydrolytic degradation.
[0019] U.S. Pat. No. 5,403,591 to Tighe et al. relates to the use of cyanoacrylates for treatment of skin irritations that progress to ulcerations. It would be assumed that these conditions could be considered wound formations, e.g., see U.S. Pat. No. 3,995,641.
[0020] U.S. Pat. Nos. 5,928,611 to Leung, 5,981,621 to Clark et al., 6,099,807 to Leung, 6,217,603 to Clark et al. describe methods of inducing cure of cyanoacrylates bypassing the adhesive through a porous applicator tip containing substances that initiate the polymerization. These substances co-elute and dissolve into the adhesive as it is forced through the porous tip.
[0021] U.S. Pat. No. 6,143,352 to Clark et al. describes methods of altering the pH environment of cyanoacrylates in order to attenuate or accelerate the rate of hydrolytic degradation by uses of acid and alkaline additives. The formulation of acidic modifiers is problematic as they tend to inhibit the primary characteristic of these materials, namely, rapid cure on application to tissue. Data is presented on effects of acidic compositions on previously cured cyanoacrylates, not on in situ applied compositions.
[0022] All of these methods rely on the addition of various compositions to affect the accelerated cure onto a desired substrate. These compositions may induce polymerization by creating a greater number of initiation sites and or orientation of the monomer for more facile polymerizations. Other plausible mechanisms can be evoked, but the fact remains that the added materials become a part of the composition (undesirable for many medical applications). As such, these chemical inclusions may elicit unfavorable reactions in the cured state. In particular, the use of pH-based accelerators may contribute to the alkaline hydrolysis of the cyanoacrylate polymer.
[0023] This is particularly undesirable in medical applications of the cyanoacrylates as the hydrolysis results in the evolution of formaldehyde. A certain level of formaldehyde can be tolerated by tissue as it is able to dispose of reasonable concentrations. A solution proposed in the prior art has been increasing the chain length of the cyanoacrylate monomer side group; in particular, that it be alkyl so as to impart hydrophobic character to the resulting polymer.
[0024] The prior art methods and compositions have been able to achieve a synthesis of the octyl cyanoacrylate at economic levels for applications in the medical field, although improbable for uses in commercial applications due to reaction yields. A number of methods have been attempted to improve yields. Yin-Chaos Tseng et al., BIOMATERIALS, Vol 11, 1990. The variables looked at included: azeotropes, temperature and formaldehyde/cyanoacetate ratio. Other methods have also included assessment of different catalysts for the condensation reaction. Regardless of the methods tried, yields become increasingly smaller as the cyanoacetate pendant group becomes larger.
[0025] An attempt to improve yields is reported in U.S. Pat. No. 6,245,933 to Malofsky. This method attempts to avoid yield losses by producing the high yield cyanoacrylate prepolymers of the lower homologues (methyl & ethyl) and then proceed through a transesterification with a longer chain alcohol such as the octyl. Three reported examples with 2-octanol gave yields ranging from 21.8% to 36.2% of crude monomer.
[0026] From this, it can be seen that high yields are difficult and no doubt subsequent work-up to medically acceptable products result in even lower product output. The difficulty with methods such as discussed above, is the undesirable side products that are difficult to remove from the main stream. In particular, it is difficult to achieve complete transesterification reactions on polymeric moieties because of steric obstruction. As a consequence, purity is compromised as the initial cyanoacrylate prepolymer is not completely reacted and the lower homologue co-distills with the desired product.
[0027] Other additives have been used to attenuate various properties, such as modulus (elasticity, viscosity, thermal resistance, etc. Each and every additive becomes a substance that must be removed by the surrounding tissue, which generally does not assist in recovery of the damaged area. In that regard, the addition of these additives must weigh the effect of property improvements against the effect on tissue compatibility.
[0028] In contrast to additives for the cured adhesives are additives formulated into the synthesized monomers. The synthetic route for monomer production relies on two principal groups of stabilizers. The first group is chosen from substances capable of preventing free radical polymerization and the second group inhibits the anionic polymerization.
[0029] The critical step in the production of these monomers relies on the high temperature thermal degradation of the polymer generated from the formaldehyde-cyanoacetate reaction. These temperatures span the range of 150° C. to excesses of 200° C. Under ideal conditions, this polymer will undergo a clean unzipping reaction that releases the cyanoacrylate monomer. This begins to take place in the lower temperature regions and must be gradually elevated to extract the increasingly difficult boiling off of the monomer. Elevation of the temperature is necessary as byproducts form and increasingly hamper the volatilization of the desired monomer.
[0030] In order to prevent the thermal reversal of the monomer back to polymer as it is generated and exits the body of fluid polymer in the reaction vessel, retarders or inhibitors are added at the beginning of this process. These substances react with free radicals to form a stable unreactive species, thereby halting the thermal polymerization typical of vinyl monomers. Quinones are the most often used substances in this group. Typical, but not exclusive, are hydroquinone and methyl ether hydroquinone. The presence of these additives is most critical in the monomer-polymer mix in the reaction vessel. Once the monomer is vaporized, it is quickly cooled to ambient conditions as it is distilled over to a suitable receiver.
[0031] The second group of stabilizers are used to prevent the anionic polymerization of the monomer in the reaction vessel as well as the vapor and collected liquid monomer in the receiver. Those knowledgeable in the art are quite familiar with these substances. Typical, and again, not exclusive, are the sulfonic acids and sulfur dioxide. In general, acidic substances are chosen to effect stabilization not only during the production of these monomers but further for stabilization during storage.
[0032] A fine line exists in the levels of these anionic stabilizers. If there is insufficient loading of these acids during the polymer unzipping to monomer, the vaporized and condensing monomer will begin to repolymerize throughout the system. On the other hand, if too much anionic stabilizing takes place in the distilled monomer, the desired repolymerization is not easily accomplished. This is evidenced by those patents cited above that deal with the loading of alkaline substances and other anion polymer promoting initiators in a porous tip. These additives are necessary to overcome the excessive levels of anionic stabilizers that co-distill during the distillation of monomer.
[0033] In the manufacture of the lower homologues such as the methyl, ethyl, and butyl monomers, the degradation of the polymer to monomer is much more effective and gentle, requiring lower levels of these anionic stabilizers. The resultant distilled monomers are thereby stabilized sufficiently and in some cases additional acid is charged, usually under 100 parts per million, to effect a useful shelf life for commercial applications.
[0034] These lower homologues are, as are all of the cyanoacrylates (with some exceptions such as the difunctional ones), distilled under vacuum conditions. The typical vacuum is in the 0.5 mm H to 2.0 mm Hg. As the molecular weight of these monomers increases, the required vacuum conditions become more critical. In order to effectively distill the higher molecular weights, the vacuum conditions must continue beyond the range of approximately 0.5 mm Hg. Higher distillation temperatures with poor vacuum conditions results in increasing levels of undesirable byproducts, and consequent poor yields and inferior product.
[0035] As a typical example, it is necessary to achieve a vacuum in the range of approximately 0.01 mm Hg to 0.05 mm Hg for the octyl monomer and higher homologues in order to effectively distill the monomers in a nondestructive process. This, however, is the crux of the problem in the isolation of these monomers as confronted in the prior art methods and systems.
[0036] The lower homologues and typical anionic stabilizers have a sufficiently large difference in their respective boiling points, such that very little stabilizer is co-distilled with the monomer. This, however, becomes an increasingly important issue as the vacuum levels proceed to better distill over the higher boiling monomers like the octyl, decyl and so on. The consequence then is that increasing levels of the stabilzer co-distill along with the desired monomer. The resultant isolated monomer is excessively loaded with anionic stabilizer(s) thus requiring the devices referred to above.
[0037] In addition, and as generally discussed above, prior art methods for the synthesis of cyanoacrylate monomers generally require the addition of acids and free radical inhibitors during the monomer synthesis. The free radical inhibitors prevent premature polymerization during the thermal unzipping reaction as well as the follow-up distillation step(s). The acid additives are necessary to prevent premature polymerization during workup and storage of these compositions. However, and as discussed above, as the chain lengths become increasingly longer, higher temperatures are necessary to effect the unzipping reaction. A direct unintended result is that excessive levels of acid are necessary with the consequent overstabilization of the distilled product.
[0038] It, therefore, becomes necessary to negate this overstabilization in order to facilitate the anionic polymerization. To date, all means of effecting this have been by pretreatment of the substrate with, for example, alkaline and/or organic soluble amines that are intended to initiate the anionic polymerization by dissolution into the adhesive. Though not specifically stated, this approach is apparently based on the view that as the mass of the side chain group increases, the polymerizability drops off. This is apparent, as all current techniques rely on overriding the excess stabilizer levels. Alternative methods employ a solution of these initiators being sprayed over the adhesive after it has been applied to the substrate. The other variant of this soluble initiator method are those referenced above incorporating the initiator in the porous applicator tip. As those skilled in the art certainly appreciate, neither of these approaches is desirable for medical procedures.
[0039] With the foregoing in mind, a need currently exists for a method by which cyanoacrylate adhesives may be rapidly cured without contaminants or extraneous additive. The present invention provides such a method.
SUMMARY OF THE INVENTION
[0040] It is, therefore, an object of the present invention to provide a method for increasing the shelf life of a cyanoacrylate adhesive by increasing the stability of the adhesive. The method includes treating packaging for containment of the cyanoacrylate adhesive or precursors to the cyanoacrylate adhesive with a strong acid. The cyanoacrylate adhesive or precursor to the cyanoacrylate adhesive is then introduced to the packaging.
[0041] It is also an object of the present invention to provide a method wherein the strong acid is hydrofluoric acid.
[0042] It is another object of the present invention to provide a method for increasing the shelf life of a cyanoacrylate adhesive including the step of treating the cyanoacrylate adhesive with a stabilizing compound.
[0043] It is a further object of the present invention to provide a method for increasing the shelf life of a cyanoacrylate adhesive including the step of treating the cyanoacrylate adhesive with at least one acid stabilizing compound of selenic or selenous acids.
[0044] It is still another object of the present invention to provide a method of plasticization of a cured polymer with an ester of tocopheral, and more particularly, tocopherol acetate.
[0045] It is also an object of the present invention to provide a method wherein the ester of tocopherol has a concentration in the range of approximately 5% to approximately 15% by weight.
[0046] It is another object of the present invention to provide a method for increasing the shelf life of a cyanoacrylate adhesive including the step of treating the cyanoacrylate adhesive with selenic acid.
[0047] It is still another object of the present invention to provide a method for increasing the shelf life of a cyanoacrylate adhesive. The method is achieved by treating the cyanoacrylate adhesive with structures functionalized with both free radical and anionic inhibition in the same molecule. Typical, but not exclusive, the treating compounds are titration indicators, also referred to as acid-base indicators. The levels of limitations are defined as sufficient to provide practical shelf life as well as acceptable utility in cyanoacrylate applications.
[0048] Other objects and further scope of applicability of the present invention will become apparent from the detailed descriptions given herein; it should be understood, however, that the detailed descriptions, while indicating preferred embodiments of the invention, are given byway 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 such descriptions.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0049] The detailed embodiments of the present invention are disclosed herein. It should be understood, however, that the disclosed embodiments are merely exemplary of the invention, which maybe embodied in various forms. Therefore, the details disclosed herein are not to be interpreted as limited, but merely as the basis for the claims and as a basis for teaching one skilled in the art how to make and/or use the invention.
[0050] As discussed above, the present invention generally relates to a method for curing reactive monomeric cyanoacrylates to undergo macromolecular formations via appropriate modification of anionic stabilizer levels in a manner permitting utilization of the resulting adhesives in the treatment of human, or animal, tissue and/or flesh, required to be otherwise sealed or sutured, or otherwise protected from its surroundings. While certain distinctions may be drawn between the usage of the terms “flesh” and “tissue” within the scientific community, the terms are used herein interchangeably as referring to a general substrate upon which those skilled in the art would understand the present adhesive to be utilized within the medical field for the treatment of patients. Without being bound to a specific mechanism, such modification of the anionic stabilzer levels chemically and/or physically removes stabilizing agents so the present method allows for reformulation of compositions capable of reasonable cure speeds without external anionic initiators.
[0051] The present method generally includes the steps of providing a long shelf life stable adhesive composition comprising cyanoacrylate adhesive and excess stabilizing agent(s), removing excess stabilizing agent(s) from the adhesive composition, re-stabilizing and presenting a substrate to receive at least a portion of the cyanoacrylate adhesive composition and applying the cyanoacrylate adhesive portion to the substrate.
[0052] Cyanoacrylate adhesives that may be used in accordance with the present invention, comprise one or more monomers having the following general structure:
CH2=(CN)—C(O)—R
[0053] Without encumbering the body of this patent with specific examples of moieties, reference is made to the numerous patents delineating the myriad of groups that can be represented by the moiety designated as R, many representative examples being given in the cited references. With this in mind, these, as well as other moieties, may be employed without departing from the spirit of the present invention. In the case of difunctional cyanoacrylates, R would be bound to two reactive groups. These are, therefore, intended to define and be included by general reference to such prior art and by those knowledgeable thereof.
[0054] As discussed above in the Background of the Invention, the various methods for the synthesis of these monomers generally require the addition of acids and free radical inhibitors during the monomer synthesis. The free radical inhibitors prevent premature polymerization during the thermal unzipping reaction as well as the follow-up distillation step(s). The acid additives are necessary to prevent premature polymerization during work-up and storage of these compositions.
[0055] However, as the chain lengths become increasingly longer, higher temperatures are necessary to effect the unzipping reaction. A direct unintended result is that excessive levels of acid are necessary with the consequent overstabilization of the distilled product. It, therefore, becomes necessary to negate this overstabilization in order to facilitate anionic polymerization of the adhesive composition.
[0056] Prior art techniques rely upon pretreatment of the substrate with, for example, alkaline and/or organic soluble amines that are intended to initiate the anionic polymerization by dissolution into the adhesive. This approach is apparently based on the view that as the mass of the side chain group increases, the polymerizability drops off. This is apparent, as all current techniques rely on overriding the excess stabilizer levels. Alternative prior art methods employ a solution of these initiators being sprayed over the adhesive after it has been applied to the substrate. The other variant of this soluble initiator method are those referenced above incorporating the initiator in the porous applicator tip.
[0057] Since the difficulty in polymerization of these longer chain moieties is due to excessive acid levels, in accordance with the present invention the acids are removed rather than neutralized. As noted above, polymerization is achieved by the addition of initiators to overcome the stabilizing effects of these acids and so remain in the resultant polymer matrix. The concept of acid removal is also the focus of a co-pending U.S. patent application Ser. No. 09/982,226, filed Dec. 19, 2001, which is incorporated herein by reference. The '226 application describes the use of acid removing particulates during the coincidental application of these adhesives. The utility of this method is limited by a period of time in which the adhesive can be applied. It would be most desirable to have a greater degree of freedom in time to apply these adhesives.
[0058] This present method achieves this goal by removing stabilizers in cyanoacrylate adhesives prior to their application to substrates. This renders the resultant purified compositions highly susceptible to polymerizations when applied to the substrates. Again, without being bound to any single specific mechanism, this process relies on a combination of physical adsorption/absorption, chemical reaction, and hydrogen bonding of the acid group(s) onto particulate surfaces. It is necessary to have the acid removing particulate substances, in fluid contact with the excessively stabilized monomer(s), be insoluble or otherwise isolatable from the monomers, such as by filtration, centrifugation, phasing out, membrane separation, or other appropriate isolating mechanism. The requisite is the isolation of the acids or other stabilizers from the monomers.
[0059] Substances exhibiting these mechanisms encompass polymers capable of forming hydrogen bonds with the stabilizing acids. These polymeric materials can have carbonyl, hydroxyl, amide, carboxylic, amine, ether, anhydride, ester, urethane, sulfone or other structures or combination structures capable of coupling or otherwise fixing the acid stabilizer to the isolatable substances. These polymeric materials can also be inorganic such as silicates. Other contemplated particulates are those in which the stabilizers are selectively trapped in zeolytic substances or otherwise caged in molecular sieves.
[0060] Chemical isolation can be achieved by, for example, reactive contact with anhydride structures such as on copolymers containing maleic anhydride. It is postulated that the anhydride structure reacts to form an anhydride link with the mobile (stabilizing) acid and a carboxylic group, both being bound to the polymer chain; an example for this being maleic anhydride copolymers of styrene and ethylene.
[0061] Physical removal of the excess stabilizers may be accomplished by such substances as activated carbon, which appears to rely on adsorption of the stabilizer(s) as a result of the high surface area and polar surface structures.
[0062] These mechanisms of treatment are not meant to be mutually exclusive, but can, in fact, be acting by any and all combinations to remove the excessive stabilizers. A typical example is the use of activated carbon, which has oxidation structures that are likely to participate in hydrogen bonding as well as physical adsorption. A further example is the use of more than one substance, such as polymer(s) and inorganic(s) in a single treatment or sequential or multiple treatments.
[0063] To most effectively use stabilized cyanoacrylate adhesives for medical applications in accordance with the invention, they are stored in a device that houses a crushable ampoule containing such adhesives. Such ampoule containing devices may be constructed of any number of materials that can be shaped or molded or otherwise fabricated to contain the adhesive and ampoule. The application devices are preferably manufactured from such materials as to effect a resilient wall capable of transmitting pressure to the crushable ampoule without loss of its containment properties. These application devices advantageously further comprise a filtering component and nozzle for application of the filtered adhesive to the substrate, for example, tissue of the patient being treated. Examples of application devices which may be used in accordance with the present method are disclosed in detail in the '226 application which, as discussed above, is incorporated herein by reference.
[0064] The application devices can also be designed to apply the product in a continuous manner. An example of such a device is one that incorporates a reservoir of the appropriate adhesive feeding through a valving mechanism, thereby providing a source of adhesive without an ampoule.
[0065] In multi-application uses the properly treated cyanoacrylate is contained in appropriate vessels such as glass or high-density polyethylene. These containers may be pretreated so as to effect useful shelf life. Reference again is made to those familiar with the art and patents delineating the various methods to achieve this treatment. Typically a container would hold 2-5 grams of product to provide many topical applications with appropriate disposable applicators such as pipettes.
[0066] In a preferred embodiment, one of the above described devices houses 2-octyl cyanoacrylate which has been previously treated with poly(vinyl pyrrolidone/vinyl acetate) copolymer. The ampoule is crushed and the contents are then expressed through the appropriate filter and dispenser tip onto the substrate, specifically human, or animal tissue, or skin. The application is accomplished in such fashion as to prevent encapsulation of adhesive by any surrounding tissue. Though ultimately these inclusions are degraded and excreted, it is most desirable to minimize this occurrence to maximize reconstitution of the surrounding tissue. The need to assure this minimization was noted in U.S. Pat. No. 3,667,472 which pointed out the requisite to bridge the wound without diffusing into it. This was accomplished by bringing the wound edges together followed by application so as to effect a bridging over the wound to circumvent necrosis and irritation by this technique.
[0067] A second preferred embodiment utilizes the above-described devices containing decyl cyanoacrylate.
[0068] A third preferred embodiment utilizes the above-described devices containing dodecyl cyanoacrylate.
[0069] A fourth preferred embodiment includes the above with combinations of cyanoacrylate monomers to achieve control over the rate of hydrolytic degradation so as to improve compatibility with tissue by control of formaldehyde emissions.
[0070] In accordance with a preferred embodiment, the invention employs vinyl pyrrolidone polymers and copolymers to remove stabilizers from the cyanoacrylate adhesives formulation. These particulate agents are combined with the monomer adhesive in mutual contact until the adhesive is destabilized, whereupon the adhesive becomes isolated from the destabilizing agent by various means such as to effect isolation of the adhesive from the destabilizing component. Once isolated, the adhesive is restabilized at reduced levels so as to effect timely cure rates in the 5 seconds to approximately one minute range. It should further be understood that these particulate agents may have some degree of solubility and therefore may pass through along with the adhesive onto the substrate. It is only a requisite that enough excess stabilizer is left behind so as to provide the desirable speed of cure. It should also be understood that re-stabilization is also desirable in order to provide a balance between speed of cure and shelf life. It should be further understood that oligomeric or low molecular weight fractions may indeed be somewhat soluble in the cyanoacrylate adhesives but still be effective in producing a desirable adhesive composition.
[0071] A novel improvement in shelf life of these adhesives has been observed with the use of stabilizers having both phenolic and acidic functionalities in the same structure. These types of substances are typically recognized as acid-base indicators or titration indicators. The following compounds are contemplated for use in accordance with a preferred embodiment of the present invention: thymol blue, trisulphonated napthol, phenolsulfonapthalein, pyrochatechol violet, acid yellow, bromophenol blue, phenol red, and cresol red. An additional benefit is the inherent color imparted to some of the compositions utilizing the stabilizers. These can serve as visual indicators of coverage on the substrate. The concentrations of these dual function stabilizers are expected to be effective in ranges typically associated with sulfur dioxide, sulfonic acids, and other acids as well as in the ranges associated with the phenolic stabilizers for these monomers as is known in the art. They may further act synergistically with stabilizers of the prior art.
[0072] Advantageously, the device of the invention is one that (a) delivers the cyanoacrylate adhesive of convenient viscosity, (b) contains a porous segment for the containment of the ampoule and other components so as to permit the release of the adhesive with no particulate components being released onto the substrate to which it is applied, (c) delivers the adhesive through a nozzle applicator tip configured for appropriate application onto the substrate, and (d) can be used with other monomer formulations prior to application to effect the desired result such as polymerizations to produce various thermoplastic and thermoset resins of both organic and inorganic nature.
[0073] All of preferred embodiments disclosed in accordance with the present invention should be understood to further include all of the various additives useful in the alteration and improvement to cyanoacrylate adhesives as would make them suitable for placement into the above devices, substrates, and modifications to these and similar devices. These can include plasticizers, stabilizers, surface insensitive additives, tougheners, thickeners, adhesion promoters, other monomers, comonomers, and other such compositions as would be evident to those familiar with the cyanoacrylate adhesives art.
[0074] The following preferred examples further disclose the new method and display its effectiveness.
EXAMPLE 1
[0075] A quantity of particulate destabilizing agent (5 grams) in the form of vinyl pyrrolidone vinyl acetate copolymer is blended with (25 grams) 2-octyl cyanoacrylate for a period of 24 hours. The resultant slurry is filtered to effectively remove the destabilizing agent and is restabilzed at a level to achieve the desired cure speed for the following test. In particular, 6 grams of the treated monomer is blended with 0.012 grams of pretreated monomer. A glass ampoule is charged with 0.5 grams of treated monomer and sealed with a gas flame. The ampoule is inserted into a tubular device referred to as a Tandem Dropper supplied by James Alexander Company of Blairstown, N.J., that also provided unsealed ampoules. In order to filter matter dispensed from the dispenser tip of the Tandem Dropper, it is plugged internally with a small wad of polyester fiber also supplied by James Alexander Company. The dispenser tip press fits onto the end of the Tandem Dropper after insertion of the sealed ampoule.
[0076] The assembled device is squeezed to effect rupture of the ampoule. Pressure is applied so as to exude a drop of adhesive through the filtering tip. The drop is applied to skin and timed to determine when the film has undergone cure to a non-tacky surface. The 2-octyl cyanoacrylate undergoes cure in 10-20 seconds upon application to skin on the back of the hand. This contrasts with untreated 2-octyl cyanoacrylate which shows no sign of cure up to 3 minutes whereupon the test is terminated.
EXAMPLE 2
[0077] A 10 milliliter glass vial is charged with 0.5 grams of activated charcoal Calgon WPX, sourced from Calgon Carbon Corp. of Pittsburgh Pa. Followed by this is a 6.0 gram charge of 2-octyl cyanoacrylate which is mixed for a period of 30 minutes. The resulting dispersion is filtered to isolate the cyanoacylate into a small ampoule. A test of cure speed on skin of the isolated monomer results in the formation of a protective film in 10 to 20 seconds in a manner similar to example 1 above.
EXAMPLE 3
[0078] A 3 milliliter test tube is charged with 0.016 grams of anhydrous potassium carbonate and 2.030 grams of 2-octyl cyanoacrylate which is then sealed and shaken for approximately 2 hours. It is stored for 17 days. A sample is removed and applied to the skin with a consequent film cure in a range of 110 to 120 seconds.
EXAMPLE 4
[0079] Example 3 is repeated with a higher loading of the anhydrous carbonate: 0.27 grams and 2.46 grams of 2-octyl cyanoacrylate. The test tube is stored for 15 days whereupon a test of cure exhibits film formation in 120 seconds.
EXAMPLE 5
[0080] A 50 milliliter flask is charged and sealed with 1.5 grams of polyvinyl alcohol granules (BP-05) and 18.5 grams of 2-octyl cyanoacrylate. The dispersion is intermittently shaken for a period of 48 hours due to the more coarse nature of the polymer. A sample is taken and tested on skin to show a cure of film in 90 to 100 seconds.
EXAMPLE 6
[0081] A flask is charged and sealed with 1.0 grams of ethylene-vinyl acetate copolymer RP251 (Wacker Polysystems) and 18.5 grams of 2-octyl cyanaocrylate. The dispersion is intermittently shaken for 48 hours prior to the skin test. Upon testing the treated monomer cured in approximately 100 seconds
EXAMPLE 7
[0082] Example 6 is repeated with RP140, a vinyl acetate homopolymer. The resultant treated monomer gave a cure after 130 seconds.
EXAMPLE 8
[0083] A 10 milliliter flask is charged and sealed with 1.0 grams of poly(methyl methacrylate) (Rhohadon M449, Rohmtech Inc.) and 6 grams of 2-octyl cyanaocrylate. After intermittent shaking for 24 hours, the dispersion is filtered and the isolated monomer is tested to reveal a film formation in 30 to 35 seconds.
EXAMPLE 9
[0084] A 10 milliliter flask is charged and sealed with 1.0 grams of styrene-maleic anhydride copolymer (SMA-3000, Atochem Inc.) and 6 grams of 2-octyl cyanoacrylate. Subsequent isolation of the monomer after 24 hours of treatment gave a cured film on skin in approximately 65 seconds.
EXAMPLE 10
[0085] A 10 milliliter flask is charged and sealed with 0.5 grams of zinc oxide (AZO66, US Zinc Products Inc.) and 6 grams of 2-octyl cyanoacrylate. After shaking the dispersion for 30 minutes, subsequent filtration and testing on skin gave a cure in 50 to 60 seconds.
EXAMPLE 11
[0086] A 10 milliliter flask is charged and sealed with 0.5 grams of “Hydrosource” (1-2 mm average diameter particles) polyacrylamide (Castle International) and 6.0 grams of 2-octyl cyanoacrylate. Subsequent testing after 4 hours of mixing gave a 30 second cure on skin.
EXAMPLE 12
[0087] A 10 milliliter flask is charged and sealed with 1.6 grams of glass spheres (Class 4A size 203 from Cataphote Corp.) and 4.4 grams of 2-octyl cyanoacrylate. The mix was shaken for 2 hours prior to testing. The sampled droplet was spread on skin giving a 60 second cure.
EXAMPLE 13
[0088] A 10 milliliter flask is charged and sealed with 1.6 grams of pulverized polyimide resin (Dupont Kapton 700HPP-ST film) and 4.4 grams of 2-octyl cyanoacrylate. The mix was shaken overnight prior to testing. An isolated sample gave a skin surface cure of 120 seconds.
EXAMPLE 14
[0089] A two ounce, opaque polyethylene bottle is charged with 0.57 grams of vinyl pyrrolidone vinyl acetate copolymer and 30 grams of 2-octyl cyanoacrylate. The container is shaken for five minutes and stored for 3 months. A sample was taken and passed through a 0.2 micron filter with a 1 milliliter syringe. Application onto skin gave a very rapid cure of 10-15 seconds with noticeable warmth due to the more rapid polymerization.
[0090] As evidenced by the last example, these additives can be left in contact with the cyanoacrylate with no apparent detriment to the shelf life and cure of the final product. It is further evident that these products can be kept without the need to isolate and store in glass ampoules. This further leads to the capability of large reservoirs of product to be dispensable through a disposable fibrous or porous tip. This is particularly advantageous in procedures where quantities necessary exceed the capacity of the crushable ampoules. The only limitations to the various treatments is the ability to isolate a practical level of cyanoacrylate monomer, i.e., that concentrations even at levels creating slurries can be filtered off to achieve economic quantities. These examples serve to show the extensive applicability of the primary requisite: to remove excessive stabilizer(s). No other references have addressed this issue, as those knowledgeable in the science and art of this technology have always understood the need to add, not remove, these stabilizing substances. It has not previously been recognized that the synthesis and isolation of these long chain side group cyanoacrylates results in excessive levels of these stabilizers. The preceding examples are intended to show the various types of cyanoacrylate insoluble materials that can perform the extraction of stabilizers. They are therefore intended to exemplify, not define the limits, of applicable substances.
[0091] As those skilled in the art will certainly appreciate, a method and composition enhancing shelf life and stability would be highly advantageous, particularly for use with cyanoacrylate-based adhesives used in medical procedures. It has been found that the cyanoacrylate adhesive produced through implementation of the present invention, as well as their precursors, exhibit greater shelf life stability when subjected to treatment with strong acids. The treatment described herein may be employed alone or in combination with other known antioxidants and/or stabilizers typically used with cyanoacrylates.
[0092] In accordance with a preferred embodiment, hydrofluoric acid is used to improve the shelf life of cyanoacrylate adhesives, as well as their precursors, produced in accordance with the present invention. The improvement in shelf life is effected by applying hydrofluoric acid to packaging for the containment of the cyanoacrylate adhesive compositions in accordance with the present invention. The packaging may be in the form of any used for cyanoacrylates, typically including glass, metal, plastic and combinations thereof. As Example 15 below will serve to show, treatment of the packaging in this manner stabilizes the monomers, extending the period of time before complete polymerization occurs and thereby extending the shelf life of the compositions.
[0093] A method for improving the plasticity of the resulting adhesive includes the addition of tocopherol acetate, or other esters of tocopherol. Tocopherol acetate, a form of vitamin E, effects a more flexible cured product. This added benefit is particularly useful in medical adhesives where common movement contort body surfaces.
[0094] The tocopherol additive may be incorporated into the cyanoacrylate adhesive composition in concentrations of approximately 5% to approximately 15% by weight. In accordance with a preferred embodiment, the concentration of tocopherol ester added is approximately between 5% and 10% by weight to impart necessary or desirable flexibility to the product.
[0095] Further to the application of esters of tocopherol to cyanoacrylate compositions in accordance with the present invention, compounds of selenic acid or selenous acid may be added to cyanoacrylate adhesives to improve shelf life of the resulting cyanoacrylate adhesive. Those skilled in the art will appreciate other strong acids that may be utilized without departing from the spirit of the present invention. The selenic acid is preferably added in a concentration typical of acid stabilizers used in the art. Typically, the concentration used is approximately 10 ppm to several hundred ppm, but most preferably in the range of 20 ppm to 200 ppm. In addition, the selenic acid may be combined with other known stabilizers and antioxidants.
[0096] By treating the cyanoacrylate adhesive in this manner stabilizing is effected by the use of entities exhibiting both acid functionality and phenolic structures in the same molecule. The cyanoacrylate adhesive may be further treated with prior art stabilizers.
[0097] While the packaging treatments, tocopherol acetate treatments, selenic acid treatments and phenolic free radical stabilizer(s) treatments are employed with cyanoacrylate compositions as previously described in accordance with the present invention, it is contemplated these treatment methods may be employed with other cyanoacrylates without departing from the spirit of the present invention.
[0098] The following examples serve to demonstrate the advantageous increase in shelf life through the treatments described above. The first example demonstrates improved stability when using strong acids, in particular, hydrofluoric acid, in the treatment of packaging for containment of cyanoacrylates. The second example demonstrates improved plasticity in a like manner, as well as increased viscosity, through addition of tocopherol acetate. The final example exposes the effectiveness of the new class of dual functionality stabilizers disclosed above. These examples are intended to illustrate the invention without, however, limiting the scope thereof.
EXAMPLE 15
[0099] Glass ampoules suitable for containment of cyanoacrylate polymers in accordance with the present invention were treated with hydrofluoric acid at a concentration of 6.75% for a period of 5 minutes. The ampoules were then rinsed prying to drying in an oven at 120° C. A series of untreated ampoules were added to the collection as controls. Each ampoule, treated and untreated, was then loaded with 0.5 cc of treated octyl cyanoacrylate and heat sealed. The ampoules then underwent sterilization at 160° C. for 60 minutes followed by an ageing period at 95° C. A viscosity check was performed after 4 days. The untreated ampoules contained completely polymerized compositions. Those ampoules treated with hydrofluoric acid each recorded a viscosity of 52 cPs.
EXAMPLE 16
[0100] Selenic acid and tocopherol acetate, respectively at 29 ppm and 5% in octyl cyanoacrylate in accordance with the present invention, was aged in glass ampoules treated as described above with reference to Example 15. A viscosity check following 4 days of storage revealed untreated ampoules containing a product having a viscosity of 298 cPs and treated ampoules containing a fluid product of indeterminate viscosity exhibiting softness when touched. The results indicate use of both an antioxidant/stabilizer in combination with tocopherol acetate provides a more compliant film as subjectively observed in comparison with comparable compositions from the first group of examples above.
EXAMPLE 17
[0101] Thymol blue and sulfur dioxide were blended into 2-octyl cyanoacrylate at 46 and 13 ppm, respectively. This composition was compared to one having 75 ppm sulfur dioxide and a third composition of 60 ppm sulfur dioxide and 46 ppm sulfuric acid. Heat ageing of the compositions resulted in a distinct visual difference in fluidity (no viscosity was determined). The fluidity was highest with the thymol composition and least with the sulfur dioxide/sulfuric acid system. This is particularly relevant as the thymol system has a total of 59 ppm acid versus the second with a total of 106 ppm acid.
[0102] While the preferred embodiments have been shown and described, it will be understood that there is no intent to limit the invention by such disclosure, but rather, is intended to cover all modifications and alternate constructions falling within the spirit and scope of the invention as defined in the appended claims.
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A new adhesive method using an adhesive composition including cyanoacrylate adhesive and a stabilizing agent to join together portions of a substrate, particularly useful in suturing and similar medical procedures, is disclosed. It is based on the discovery that remarkable improvements are obtained by adding a step of removing stabilizing agent from such adhesive compositions in the manufacturing process with the prior known steps of (a) providing an adhesive composition including cyanoacrylate adhesive and a stabilizing agent, (b) presenting a substrate to receive at least a portion of such cyanoacrylate adhesive and (c) applying such portion to the substrate. Devices for use in performing the method are described.
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FIELD OF INVENTION
This invention relates to a novel composition for protecting hair from damage by thermal processes such as curling and straightening devices. A method for applying a polymer system to the hair and the heat treatment of hair containing such polymers is also described.
BACKGROUND OF THE INVENTION
A hair fiber is composed of three major sections: cuticle (the outermost layer), cortex, and medulla. It is well understood that treatments requiring heating the hair by contact with hot surfaces damages the hair fiber. More specifically heating causes significant damage to the cuticle, or outermost layer of the hair shaft. The cuticle is composed of flattened keratinized material that is arranged in a scale like fashion. The cuticle can be further broken down into endocuticle, exocuticle, and epicuticle. For the purpose of this invention we are concerned with the protection of the epicuticle. The epicuticle is a heavily keratinized protein rich structure which is associated with lipids. It is this layer which gives hair the ability to repel water. This is the outermost layer that can be easily damaged by curling and straightening tools. The cuticle scales can be easily damaged, resulting in de-cementation and lifting, vertical cracking, shear band formation, bulges, and craters. All of the types of damage described above result in removal of portions of the cuticle exposing the inner most layers of the hair resulting in split ends, breakage and dullness of the hair fiber. Curling irons and straightening irons that come in direct contact of the hair fiber typically have surface temperatures above 150° C. At these elevated temperatures, the hair cuticle endures a significant amount stress resulting in loss of the cuticle or protective coating, thus resulting in the fiber being more hydrophilic in nature.
With each repeated heating cycle the hair becomes more damaged to the point of splitting, breaking, frizzing or just losing its luster and full body look of healthy hair. Many conditioners are sold commercially to repair or mask the affects of deleterious processes such as curling or straightening, and there is still a very strong need for a method to prevent the damage from occurring.
Currently there are several additive ingredients in the market which claim thermal protection for the hair. These additives range from silicones to plasticizers and some polymeric systems have been used to deliver or carry these materials. However, the majority of these additives can only be used under specific conditions and have poor compatibility with solvents and propellants; therefore, it is difficult to incorporate them in hair styling products such as hairsprays. Aside from additives, there are very few existing polymers which provide thermal protection to a certain extent, but these polymers are not used too often due to their lack of performance or toxicity issues. Accordingly, there still exists a need for a polymeric system that can provide the thermal protection and be applied as a hairspray or styling aid.
SUMMARY OF THE INVENTION
It has now been found that certain polymers systems containing acrylate monomers can stop or at least minimize the damage to hair normally associated with thermal processing. Accordingly, in an aspect of the invention, the invention relates to a method of minimizing cuticle damage to human hair that is subjected to a thermal process of greater than 150° C. The method comprises contacting the hair with an anhydrous alcohol solution of a polymer composition prior to subjecting same to the thermal process. The polymer comprises greater than about 10 weight percent of at least one acrylate monomer, wherein the acrylate monomer is acrylic or methacrylic acid.
In another aspect, the invention is directed to a method for protecting hair from damage when the hair is contacted with a heated surface. The method comprises applying a formulation to the hair prior to contacting same with a heated surface. The formulation comprises an anhydrous alcohol solution of a polymer comprising greater than 10 weight percent of an acrylate monomer wherein the acrylate monomer is acrylic acid or methacrylic acid, and wherein the heated surface has a temperature of greater than about 150° C.
In yet another aspect, the invention relates to a formulation for protecting hair from thermal damage resulting from contacting the hair with a heated surface, wherein the heated surface has a temperature of greater than about 150° C. The formulation contains an anhydrous alcohol solution of a polymer which comprises greater than 10 weight percent of at least one acrylate monomer. The acrylate monomer is acrylic acid or methacrylic acid. The formulation is effective in attaining a wetting force of less than about 4.0×10 −4 mN for the hair subsequent to contacting same with the heated surface.
BRIEF DESCRIPTION OF THE DRAWING
The invention is best understood from the following detailed description when read in connection with the accompanying drawings. Included in the drawings are the following figures:
FIG. 1 is an SEM image showing a virgin hair fiber with no heat treatment.
FIG. 2 is an SEM image showing an untreated virgin hair fiber after 12 heat cycles.
FIG. 3 is an SEM image showing a virgin hair fiber treated with a polymer composition according to an embodiment of the present invention after heat treatment.
FIG. 4 is an SEM image showing a virgin hair fiber treated with a polymer composition not according to an embodiment of the present invention after heat treatment.
DESCRIPTION OF THE INVENTION
As noted above, certain polymer systems containing acrylate monomers have been found that can stop or at least minimize the damage to hair normally associated with thermal processing. For purposes of this invention, thermal processing is any hair treatment where the hair is directly contacted with a hot surface. Some non-limiting examples of these processes are curling irons, and straightening irons. In an embodiment of the invention, the hair is contacted with a heated surface in which the heated surface has a temperature of greater than about 150° C. In another embodiment, the heated surface has or is heated to a temperature greater than about 200° C.
The polymers of this invention can be any type of polymers which is made of or modified to contain an acrylate monomeric repeat unit. The polymers of this invention can be anionic, cationic or amphoteric and non-ionic. Non-limiting examples of acrylate monomers are acrylic acid, methacrylic acid, methylacrylate, methacrylate and the like. In the case where the monomer is acrylic or methacrylic acid, the acid group can be neutralized with typical reagents such as triethanol amine (TEA), AMP, sodium carbonate, sodium hydroxide or the like. In one embodiment of this invention the polymer is a copolymer of acrylate or methacrylate monomers
The polymers of this invention can also be used in combination with one or more other polymers typically found in hair care products such as, but not limited to (listed as NCI names) VA/Crotonates/Vinyl Neodecanoate Copolymer, Polyquaternium-55, Acrylates/Octylacrylamide Copolymer, Acrylates/Hydroxyesters Acrylates Copolymer, Acrylates/Octylacrylamide/Diphenyl Amodimethicone Copolymer, Acrylates/C1-2 Succinates/Hydroxyacrylates Copolymer, Octylacrylamide/Acrylates/Butylaminoethyl Methacrylate Copolymer, Polyacrylate-12, Ammonium VA/Acrylates Copolymer, Acrylamide/Sodium Acryloyldimethyltaurate/Acrylic Acid Copolymer, Ethylene/VA Copolymer, Acrylates/Steareth-20 Methacrylate Copolymer, Polyvinyl Acetate, PEG-150/Stearyl Alcohol/SMDI Copolymer, PVP/VA/Itaconic Acid Copolymer, PEG-150/Decyl Alcohol/SMDI Copolymer, Hydrolyzed Wheat Protein/PVP Crosspolymer, VA/Crotonates Copolymer, PVP VP/Methacrylamide/Vinyl Imidazole Copolymer, VP/Acrylates/Lauryl Methacrylate Copolymer, Polyurethane-1, Acrylates/VP Copolymer, Polyacrylate-22 Styrene/VP Copolymer, Polyquatemium-72, Vinyl Caprolactam/VP/Dimethylaminoethyl Methacrylate Copolymer, Hydroxypropyltrimonium Hydrolyzed Corn Starch, Acrylates/Acrylamide Copolymer, Sodium Laneth-40 Maleate/Styrene Sulfonate Copolymer, Acrylates/Amino acrylates/C10-30 Alkyl PEG-20 Itaconate Copolymer, Polyester-5, Acrylates/C10-30 Alkyl Acrylate Crosspolymer, VA/Butyl Maleate/Isobornyl Acrylate Copolymer, Acrylates/C12-22 Alkyl Methacrylate Copolymer, Acrylates/C1-2 Succinates/Hydroxyacrylates Copolymer, Acrylates Copolymer, Isobutylene/Ethylmaleimide/Hydroxyethylmaleimide Copolymer, Acrylates/Vinyl Isodecanoate Crosspolymer, Polyimide-1, Acrylates/Vinyl Neodecanoate Crosspolymer, Butyl Ester of PVM/MA Copolymer, Acrylates/VP Copolymer, PVM/MA Copolymer, Butyl Methacrylate/DMAPA Acrylates/Vinylacetamide Crosspolymer, Stearylvinyl Ether/MA Copolymer, Starch/Acrylates/Acrylamide Copolymer, Isopropyl Ester of PVM/MA Copolymer, VP/Acrylates/Lauryl Methacrylate Copolymer, Polyvinyl Methyl Ether, VP/DMAPA Acrylates Copolymer, Calcium/Sodium PVM/MA Copolymer, VP/Vinyl Caprolactam/DMAPA Acrylates Copolymer, AMP-Acrylates/Allyl Methacrylate Copolymer, Ethyl Ester of PVM/MA Copolymer, Polyacrylate-14, Polyacrylate-2 Crosspolymer, Sodium Polystyrene Sulfonate, Polyurethane-14 (and) AMP-Acrylates Copolymer, Polyurethane-2, Butyl Acrylate/Ethylhexyl Methacrylate Copolymer, and Butyl Acrylate/Styrene Copolymer. The official chemical description of each of these chemical names can be found in the INCI dictionary or at they website (www.ctfa.org).
In an embodiment of the invention, the polymer comprises greater than about 10 weight percent of at least one acrylate monomer. In another embodiment, the polymer comprises greater than 50 weight percent of at least one acrylate monomer. The percent of acrylate monomer in the polymer is defined as a weight percent of the acrylate monomer based on the weight of the total monomer(s) present.
In an embodiment of the invention, the polymer is contacted is damaged. The damage may be measured as a wetting force as defined by the Wetting Force Measurement described below. In an embodiment of the invention, the damage to the hair is measured as an average wetting force of less than about 4.0×10 −4 mN of the hair after the thermal process. In another embodiment, damage is measured as an average wetting force of less than about 3.0×10 −4 mN of the hair.
One aspect of this invention is that the polymer can be sprayed onto the hair. While polymers of the type described herein are typically applied to the hair by spraying, it is novel to apply these polymers to the hair before the hot iron is used. In one embodiment of this invention the polymers are sprayed by a pump onto the hair from a solvent chosen from the group consisting of water, methanol, ethanol, isopropanol, acetone, or methyl acetate. In another embodiment the solvent to be sprayed is water or isopropanol. In yet another embodiment the solvent for spraying is ethanol. Alternatively the formulations can be sprayed by means of a pressurized device containing a propellant (aerosol). In addition to any solvent in the formulation, the polymers must be compatible with the propellants used. In an embodiment of this invention the propellants are chosen from the group consisting of hydrocarbon, dimethyl ether, and 1,1-difluoroethane.
In another embodiment of the current invention the polymer system can be deposited onto the hair from a shampoo formulation. In yet another embodiment the polymer can be deposited onto the hair from a cream rinse formulation. In either of these embodiments the hair can either be dried first and then heat treated or the heat treatment can be accomplished directly on the wet hair.
One skilled in the art would recognize that other ingredients can also be added. Such non-limiting examples are colorants, fillers, pigments, dyes, fragrances, surfactants, plasticizers, sunscreens, emollients.
EXPERIMENTAL
Preparation of Hair Samples and Heat Treatment:
A flat iron configured to the highest heat setting possible and allowed to heat up to operational temperature (approximately 210° C.). A sample hair tress is hydrated in water for 5 minutes and excess water squeezed out of the tress and combed through to relieve any tangles present. A spray solution containing 1% polymer solids is then applied to the tress and then the flat iron is applied to the tress in a vertical motion starting from the top and ending at the bottom, repeating this heating process for 5 minutes. The tress is allowed to cool for 1-2 minutes before applying 1.5 cc of shampoo to the tress. The shampoo is worked in for about one minute and then rinsed with warm tap water for an additional minute to make sure that all excess polymer and shampoo is washed off. Comb through the tress to relieve tangles once again, and then place the tress in a 45° C. oven for 15 minutes to allow the tress to dry completely. Pre-wet the tress once again for 1-2 minutes and then repeat the entire process for 12 cycles.
Wetting Force Measurement:
Once all the samples have been prepared and heat treated, they were then measured in terms of wetting force utilizing the KRUSS K14 tensiometer. The KRUSS K14 contains a microbalance in which it submerges a single fiber of material into a liquid and measures the wetting force of that fiber only during the instance when the fiber breaks the surface of the liquid. The fiber was only submerged to a depth of 3 mm. Within the time of submersion, the KRUSS K14 gathered an average of 400 values in units of mili-newtons (mN) in correspondence to the depth. For each of the 12 tress samples, individualized 1 inch fibers were precisely cut and then measured with the KRUSS K14. In support of statistical purposes, 12 fibers of each sample were tested. The average of all 12 fibers of each sample was calculated.
TABLE 1
Wetting Force Measurements
Sample
Average Wetting
#
Polymer (solvent)
Force (10 −4 ) mN
1
Control (no heat, no polymer)
−0.6088
2
Heat control (no polymer)
7.93328
3
Luviset PUR
7.34064
4
Luviset PUR (water)
7.33811
5
FLEXAN ® II***
6.88329
6
Mirustyle XHP***
6.14537
7
Luvimer 100P
5.41103
8
DynamX ® (water)
4.97542
9
DynamX ®
4.38711
10
Luvimer 100P (water)
3.96864
11
AMPHOMER ® (ethanol)
2.27584
12
AMPHOMER ® (water)
1.45294
***Solutions delivered through a pump spray, while all others were delivered through an aerosol
The above table shows that the polymers that contain acrylate monomers (samples 10 to 12) have the lowest wetting energies after heat treatment. The lower the wetting energy represents a more hydrophobic hair fiber and less damaged hair cuticle due to the action of the polymer treatment. Less damage to the cuticle relates to better feel, higher sheen and overall smoother hair cuticle.
Specifications
Trade Name INC Name AMPHOMER ® Octylacrylamide/Acrylates/Butylaminoethyl Methacrylate Copolymer DynamX ® Polyurethane-14 (and) AMP-Acrylates Copolymer FLEXAN ® II Sodium Polystyrene Sulfonate Luvimer 100P Acrylates Copolymer Luviset P.U.R. Polyurethane - 1 Mirustyle XHP Aqua (and) Sodium Laneth-40 Maleate/Styrene Sulfonate Copolymer
Qualatative Analysis (SEM)
Twelve hair tresses were formed from the same lot of hair for control purposes. Each hair tress was labeled correspondingly to the labels associated with the formulations listed above. The polymers that have been aerosolized were formulated in two different systems: one containing all water and the other containing all ethanol. This was done as a control to determine whether the polymers would perform differently in various solvent environments. Representative SEMs are shown in FIGS. 1-4 to illustrate the visual damage associated with thermal processing.
Virgin Control (No Polymer, No Heat Treatment)
The first SEM image as shown in FIG. 1 is the virgin hair fiber with no heat treatment. From this photomicrograph it can be seen that the hair used for this study was in relatively good condition prior to being used for testing. This photo shows the cuticle having a nice uniform scale-like structure. This can be used a baseline photo to compare the rest of the micrographs for damage.
Heat Control (No Polymer Applied but Exposed to 12 Heat Cycles)
The photomicrograph of FIG. 2 shows extensive damage and loss of the cuticle. Portions of the cuticle are broken off while other areas show thermal cracks and craters. The jagged edges and pitting are also representative of the damage done by the heating process. It is the presence of these flakes, cracks and pitting that causes the increase in wetting energy and loss of desirable aesthetics.
Amphomer (Water)
FIG. 3 is a photomicrograph of a sample showing the cuticle with minimal damage and maintained uniform scale like structure of the hair fiber. This represents the protection that would be obtained with acrylate containing polymers of this invention.
Luviset PUR (Water)
The photomicrograph of FIG. 4 shows the cuticle with the melted polymer attached, yet there is still pitting and damage to the cuticle observed. The presence of the melted polymer, even after shampooing, will leave the hair feeling plastic and un-natural.
FIGS. 1-4 represent Scanning Electron Microscope (SEM) images of the surface of a single fiber of each tress sample in which polymer and heat have been applied to. All the images presented above are shown at a 10,000× magnification. The purpose for these images was to obtain a correlation between the condition of the cuticle and the quantitative data obtained through wetting force analysis shown previously. Hair samples were taken from the same hair tresses that were treated for the wetting force analysis.
Although the invention is illustrated and described herein with reference to specific embodiments, the invention is not intended to be limited to the details shown. Rather, various modifications may be made in the details within the scope and range of equivalents of the claims and without departing from the spirit of the invention.
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This invention details a method for providing thermal protection to human hair by applying an aerosolized polymer system to the hair before heat treatment. It has been found that acrylate polymers provide good protection from the damaging affects of curling irons and straightening irons and afford improvements in the look and feel of the treated hair.
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BACKGROUND
[0001] The present invention generally relates to a pothead assembly.
[0002] A typical subterranean well includes submersible equipment to which wet electrical connections are made. For example, referring to FIG. 1 , a production system 10 of a subterranean well may include a tubular string 12 that extends inside a casing string 14 and through a production zone 20 of the well. The string 12 typically has a central passageway for purposes of communicating well fluid to the surface of the well. To aid in producing this well fluid, the string 12 may include a submersible pump 22 .
[0003] The submersible pump 22 may operate from power that is provided from the surface of the well by one or more electrical cables 16 . For example, for a three-phase pump, three electrical cables 16 may extend from the surface of the well along the string 12 to the pump 22 .
[0004] Due to the very nature of its operation, the submersible pump 22 is surrounded by well fluid. A connection assembly 25 , or pothead, is used to connect the electrical power cables 16 to the motorhead of the pump 22 . The sealed connections formed by the pothead 25 should ideally maintain their integrity even in the relatively high temperature and pressure that are present in the well. The integrity of the sealed connections may be affected by the relative movement that occurs between the cables 16 and the submersible pump 22 .
[0005] Thus, there exists a continuing need for a pothead that maintains its integrity in the wellbore environment.
SUMMARY
[0006] In an embodiment of the invention, a connector that is usable with a well includes a flange member and a tube. The flange member is adapted to form a connection with a submersible component. The tube is adapted to connect to the flange member and receive a cable that has a conductor that is surrounded by an insulative layer. The tube is crimped into the insulative layer.
[0007] In another embodiment of the invention, a technique that is usable with a well includes connecting an outer jacket of a cable to a flange member; attaching the flange member to a submersible component; and forming a crimped connection between the flanged member and an insulative layer of the cable.
[0008] In yet another embodiment of the invention, a system that is usable with a well includes a submersible component, a cable, a flange member and a tube. The cable has a conductor that is surrounded by an insulative layer. The flange member is adapted to form a connection with the submersible component. The tube is adapted to connect the flange member to the submersible component and receive the cable. The tube is crimped into the insulative layer of the cable.
[0009] Advantages and other features of the invention will become apparent from the following description, drawing and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a schematic diagram of a pumping system of the prior art.
[0011] FIG. 2 is an exploded cross-sectional view illustrating a pothead assembly according to an embodiment of the invention.
[0012] FIG. 3 is a cross-sectional view illustrating a connection between a tube of the pothead assembly and an exposed connection end of an electrical cable according to an embodiment of the invention.
[0013] FIGS. 4, 5 and 6 depict a flow diagram illustrating a technique to assemble the pothead assembly according to an embodiment of the invention.
DETAILED DESCRIPTION
[0014] Referring to FIG. 2 , an embodiment 30 of a pothead assembly in accordance with the invention is constructed to form mechanical and sealed connections between motor lead extensions and a motorhead of a submersible component (a submersible pump, for example) inside a well (a subterranean or subsea well). In some embodiments of the invention, the pothead assembly 30 includes a flange insert 32 that sealably attaches to a housing 200 of the submersible component. The flange insert 32 includes a protruding section 34 that is generally coaxial with a longitudinal axis 190 of the pothead assembly 30 and is constructed to be inserted into a mating opening 202 of the housing 200 .
[0015] When the protruding section 34 is inserted into the opening 202 , an O-ring 36 (that circumscribes the longitudinal axis 190 and resides in an annular groove of the protruding section 34 ) forms a seal between the flange insert 32 and the housing 200 . As described further below, the flange insert 32 provides a structure of the pothead assembly 30 , which is used to both seal one or more electrical cables 100 (one cable being depicted in FIG. 2 ) to the housing 200 as well as provide mechanical connections between the cable 100 and the housing 200 .
[0016] More specifically, in some embodiments of the invention, the flange insert 32 includes openings 42 (openings 42 a and 42 b depicted in FIG. 2 , as examples) through which (as described below) sealed connections are formed between the cables 100 and the submersible component. More specifically, these sealed connections allow motor lead extension connectors 104 (one connector 104 being depicted in FIG. 2 ) to be electrically connected to associated electrical receptacles (not shown) of a motorhead of the submersible component, in some embodiments of the invention. As depicted in FIG. 2 , the openings 42 are each eccentric with respect to the longitudinal axis 190 of the pothead assembly 30 , in some embodiments of the invention.
[0017] For purposes of illustrating the pothead assembly 30 by way of a specific example, the connection of the electrical cable 100 through the opening 42 a is depicted in FIG. 2 and described below. It is noted that other electrical cables 100 may be connected in a similar manner (and thus, extend through the other openings 42 ) in some embodiments of the invention. For example, in some embodiments of the invention, the pothead assembly 30 may be used to connect three electrical cables 100 to the submersible component, and these three cables 100 may supply, for example, three-phase power to the submersible component.
[0018] As depicted in FIG. 2 , the electrical cable 100 extends through the opening 42 a so that when the pothead assembly 30 is fully assembled, an exposed end 102 of the electrical cable 100 is contained in the opening 42 a . The terminology “exposed” means that a protective and electrically conductive outer jacket (not depicted in FIG. 2 ) of the cable 100 is removed, exposing a dielectric, or electrically insulative, layer 112 (a PEEK layer, for example) of the cable 100 . As shown in FIG. 2 , the insulative layer 112 surrounds an inner electrical wire 114 of the cable 100 .
[0019] The openings 42 receive flared tubes 70 (flared tubes 70 a and 70 b , depicted as examples in FIG. 2 ) that are sealed (as described below) to the flange insert 32 . As depicted in FIG. 2 , the opening 42 a receives a flared tube 70 a that is coaxial with the axis 190 . As its name implies, each flared tube 70 includes a flared opening 74 . The flared opening 74 facilitates insertion of the exposed end 102 of the cable 100 into the flared tube 70 and also facilitates insertion of a small tube 80 (a thin-walled tube made from Monel, for example) into the flared tube 70 .
[0020] More particularly, in some embodiments of the invention, the small tube 80 has an outer diameter that is closely sized to the inner diameter of the flared tube 70 and an inner diameter that is closely sized to the outer diameter of the exposed end 102 of the cable 100 . Therefore, in the fully assembled state of the pothead assembly 30 , the exposed end 102 of the cable 100 extends through and is sealed to (as described below) the small tube 80 ; the small tube 80 is located inside and is sealed to the flared tube 70 ; and the flared tube 70 is at least partially recessed into the opening 42 and sealed to the main body of the flange insert 32 .
[0021] As described further below, in the assembly of the pothead assembly 30 , each tube 80 is slid onto the exposed end 102 of the respective cable 100 , and then the small tube 80 is radially crimped so that the resultant annular grooves that are formed from the crimping extend into the insulative layer 112 of the cable 100 . These annular grooves secure the cable 100 to prevent relative movement between the cable 100 and the pothead assembly 30 . Additionally, as further described below, the crimping of the small tube 80 to the cable 100 provides a redundant seal around the exposed end 102 of the cable 100 .
[0022] Referring to both FIGS. 2 and 3 , as a more specific example, in some embodiments of the invention, the exposed end 102 of the cable 100 may be configured in the following manner before being inserted into the flared tube 70 . The small tube 80 is first slid over the exposed end 102 so that, in accordance with some embodiments of the invention, one end 141 of the small tube 80 abuts or at least comes in close proximity to a lead jacket 140 of the cable 100 , as depicted in FIG. 3 . Thus, the junction of the lead jacket 140 and the free end 102 forms the beginning of the remaining 110 fully encased portion of the cable 100 , which extends toward the surface of the well. The lead jacket 140 , as shown in FIG. 3 , circumscribes the insulative layer 112 .
[0023] The small tube 80 may be crimped at one or more locations. For example, as depicted in FIG. 3 , in some embodiments of the invention, the crimping may form at least two annular grooves 82 in the small tube 80 , and these annular grooves 82 circumscribe the electrical wire 114 and extend into (as depicted at reference numerals 83 ) the insulative layer 112 . Near the end 141 of the tube 80 , a seam 142 may be formed for purposes of mechanically connecting and sealing the tube 80 to the lead jacket 140 . For example, in some embodiments of the invention, the seam 142 may be a solder seam. However, other types of seams may be formed between the tube 80 and the lead jacket 140 , in other embodiments of the invention.
[0024] In some embodiments of the invention, each annular groove 82 may be formed using a pipe cutter that has a sufficiently dull blade so that as the pipe cutter is rotated about the tube 80 , the pipe cutter forms the annular groove 82 in the wall of the tube 80 instead of cutting through the wall. Other techniques may be used to crimp the tube 80 and form one or more of the annular grooves 82 , in other embodiments of the invention.
[0025] At an end 84 of the tube 80 opposite from the end 141 that abuts the lead jacket 140 , the tube 80 is designed to be inserted into the flared tube 70 (see FIG. 2 ). Furthermore, at this end 84 of the tube 80 , a mechanical and sealed connection may be formed between the exterior surface of the tube 80 and the surrounding surface of the flared tube 70 . As a more specific example, in some embodiments of the invention, a solder seam may be formed between the exterior surface of the tube 80 (at the end 84 ) and the interior surface of the flared tube 70 , where the flared tube 70 extends from the opening 42 . For example, a 95/5 solder may be used in conjunction with an inorganic acid flux to solder each small tube 80 inside its associated flared tube 70 , in some embodiments of the invention.
[0026] Referring to FIG. 2 , among the other features of the pothead assembly 30 , in some embodiments of the invention, another fluid seal may be formed between the insulative layer 112 and the flange insert 32 . More specifically, in accordance with some embodiments of the invention, the flange insert 32 includes an O-ring chamber 52 that includes annular O-ring grooves 50 that are each sized to receive one of the O-rings 60 . Thus, each O-ring groove 50 and the corresponding O-ring 60 (when installed in the groove 50 ) are concentric with the opening 42 .
[0027] For each opening 42 , an annular shoulder 45 defines an inner stop for the opening 42 to limit the distance in which the flared tube 70 may be inserted into the opening 42 from an exterior face 38 (i.e., the face of the flange insert 32 opposite from the face that contacts the housing 200 ) of the flange insert 32 . Each O-ring groove 50 is located behind each associated annular shoulder 45 for purposes of positioning the O-ring 60 to extend around the insulative layer 112 of the cable 100 . Thus, referring also to FIG. 3 , when the exposed end 102 of the cable 100 is inserted through the flanged insert 32 , the O-ring 60 closely circumscribes the insulative layer 112 between the end 84 of the tube 80 and the connector 104 .
[0028] Referring back to FIG. 2 , for purposes of retaining the O-rings 60 within the O-ring grooves 50 , in some embodiments of the invention, the pothead assembly 30 includes an O-ring cover 81 that is constructed to be closely received in the O-ring chamber 52 . The O-ring cover 81 , in turn, includes openings 82 that are coaxial with the openings 42 (when the cover 81 is assembled to the flange insert 32 ) but are sized to retain the O-rings 60 inside the O-ring chamber 52 . Thus, the connector 104 and a portion of the free end 102 extend beyond the opening 82 so that an appropriate electrical connection (a connection into a motorhead of the submersible component, for example) may be made with the electrical connector 104 .
[0029] In some embodiments of the invention, the pothead assembly 30 may include a housing 90 that attaches to the exterior face 38 of the flange insert 32 . More specifically, the housing 90 includes a recessed portion 91 that is inset to mate with the flange insert 32 that fits therein. The connector housing 90 is generally coaxial with the longitudinal axis 190 of the pothead assembly 30 when the pothead assembly 30 is assembled, and the housing 90 includes an inner chamber 94 that circumscribes the above-described connections between the electrical cables 100 and the tubes 70 and 80 . After the above-described connections have been made between the tubes 70 and 80 and the electrical cable 100 , the chamber 94 may be filled with a sealant, such as a stainless steel epoxy (as an example).
[0030] Among the other features of the pothead assembly 30 , in some embodiments of the invention, the connector housing 90 may include one or more openings 92 for purposes of accepting bolts (not shown in FIG. 2 ) to attach the flange insert 32 to the connector housing 90 . Furthermore, in some embodiments of the invention, the flange insert 32 may include one or more openings 56 , and the housing 200 may include one or more openings 205 , all of which may be used for purposes of receiving bolts to connect the flange insert 32 to the housing 200 .
[0031] Referring to FIG. 4 , to summarize, in accordance with embodiments of the invention, a technique 300 may be used to assemble the pothead assembly 30 . Pursuant to the technique 300 , the lead jackets 140 of the electrical cables 100 are terminated to form the exposed ends 102 , as depicted in block 302 . The connectors 104 are also attached to the exposed ends 104 . Next, the small tubes 80 are slid over the exposed ends 102 so that the lead jackets 140 contact or at least come near the ends 141 of the tubes 80 , pursuant to block 304 . It is noted that in other embodiments of the invention, the tube 80 may have (at least near the end 141 ) an inner diameter that is sized to closely slide over the end of the lead jacket 140 . Thus, many variations are possible and are within the scope of the appended claims.
[0032] Continuing with the description of the technique 300 , after the tubes 80 are slid onto the exposed ends 102 , sealed connections are formed between the tubes 80 and the lead jackets 140 , pursuant to block 306 . For example, in some embodiments of the invention, solder seams may be formed between the tubes 80 and the lead jackets 140 . The tubes 80 are then crimped to engage the insulative layers 112 , as depicted in block 308 .
[0033] The technique 300 includes sliding the connector housing 90 onto the electrical cables 100 past the exposed ends 102 , as depicted in block 310 . It is noted that block 310 , as well as other blocks depicted in the technique 300 , may be performed in a different order, in that the order that is shown pursuant to the technique 300 is merely for illustrating one out of many possible embodiments of the invention.
[0034] Referring to FIG. 5 , the technique 300 includes forming (block 314 ) sealed connections between the flared tubes 70 and the flange insert 32 . For example, in some embodiments of the invention, the flared tubes 70 may be inserted into the openings 40 and then soldered to the surrounding body of the flange insert 32 . The exposed ends 102 of the cables 100 are inserted (block 316 ) through the flared tubes 70 and through the openings 50 and 52 so that the tubes 80 are partially inserted into the flared tubes 70 . In this position, sealed connections may then be formed between the tubes 70 and 80 , as depicted in block 318 . As a more specific example, in some embodiments of the invention, the tubes 70 and 80 may be soldered together using 95/5 solder and inorganic acid flux.
[0035] O-rings 60 may then be inserted (block 320 ) over the exposed ends 102 that extend from the flange insert 32 so that the O-rings 60 reside in the annular O-ring grooves 50 . Subsequently, the O-ring cover 81 may be placed in the O-ring chamber 52 and assembled to the flange insert 32 to secure the O-rings 60 in place, as depicted in block 324 . Next, in accordance with some embodiments of the invention, the housing 90 is assembled (block 328 ) to the flange insert 32 , and the cavity 94 of the housing 90 is filled (block 332 ) with a sealant, such as stainless steel epoxy, for example. Other sealants may be used, in other embodiments of the invention.
[0036] While the present invention has been described with respect to a limited number of embodiments, those skilled in the art, having the benefit of this disclosure, will appreciate numerous modifications and variations therefrom. It is intended that the appended claims cover all such modifications and variations as fall within the true spirit and scope of this present invention.
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A connector that is usable with a subterranean well includes a flange member and a tube. The flange member is adapted to form a connection with a submersible component. The tube is adapted to connect to the flange member and receive a cable that has a conductor that is surrounded by an insulative layer. The tube is crimped into the insulative layer.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] There are not any pending applications that cross-reference this application.
FIELD OF THE INVENTION
[0002] The field of this invention is the heating ventilation and cooling (HVAC) industry where fluids are the medium for the heating and cooling. Fluids that are sent from boilers or chillers are routed through piping structures which need to be balanced in terms of pressure and flow in order to even distribute the hot or cold fluids into air handler units which deliver temperature controlled air. In this industry, quarter-turn ball valves are usually used which present a host of problems and restrictions on their location and use.
BACKGROUND OF THE INVENTION
[0003] This device is used in piping system in large HVAC systems where the control of the amount of flow is desired. Currently, most controls that regulate the flow in piping systems are based on the principle shown in the quarter-turn ball valve, where the operator can have complete shutoff or full flow within a 90° turn of the handle. In the field of power assisted actuators, most all of the manufactures design them for the same quarter-turn application as well. Generally in this industry, a full port or more commonly known full bore ball valve is incorporated into the piping structures. This valve has an over-sized ball so that the hole in the ball is the same size as the pipeline resulting in lower friction loss.
[0004] There are many problems with the basic ball valve involve it's inability to regulate evenly as the valve is opened or closed. This means that simply opening the ball valve a certain percentage of the total range, say 50% for example, does not equate to 50% of the total flow of the valve. This non-linear relationship between the percentage open and percentage of flow creates problems in setting the flow into a particular section of the piping system. This is because of the shape of the insert being circular. This non-linear problem can be greatly improved with the additional of a parabolic or other characterized insert into the ball opening itself.
[0005] In the disclosed invention, a venturi tubes is used to calculate pressure differential and thus fluid flow. With a ball valve, to the nature of the throttling or jetting aspects of the ball as it rotates at low percentages of openness, it is very difficult to accurately measure flow anywhere near the valve. This leads to oversizing of the pump and running the pump at a higher pump rate to compensate for the inefficiencies of a ball valve. A venturi is used whenever low pressure loss and high accuracy is desired, and due to the nature of the valve disclosed herein, the length of straight piping is greatly reduced as the pressure differential measuring means are located directly upon the valve as this valve incorporates a venturi. Due to the low pressure loss, a venturi saves the user many dollars and frequently pays for itself in one year of continuous operation by greatly reducing pumping cost.
[0006] Other problems associated with ball valves is the amount of force necessary to open or especially close the valve when under pressure as the flow of fluid fights against the closing or opening of the valve. Especially when one is trying to barely crack open the valve to let in only a minimal amount of flow. Also, due to the characteristics of the flow opening and exit of the ball itself, at low flow rates, that is a tremendous amount of cavitation and noise exist if the pressure differential is substantial across the ball itself. The critical flow in a ball valve is encountered when delta P (the differential pressure) is 0.15 P, which is far below the usual figure of 50% of absolute inlet pressure. Another issue is the handle to adjust the opening of the ball itself, as it must be located in a position where the user can access it. In piping structures where many pipes are located and space is at a premium, the knuckles of more than one person has been wracked against the piping structure when attempting to access and adjust a ball valve. Where pressures are significant, the size and length of the handle becomes a critical aspect of the operation of the valve and the need for space can drastically increase.
[0007] The current state of the art can be found to use ceramic disks that have angular segments removed that allow for the flow of fluids. These ceramic disks are used to regulate the flow of fluids in many applications, such as high end water faucets and shower fixtures. U.S. Pat. No. 7,841,362 issued to Kim on Nov. 30, 2012 shows the use of multiple disks in a faucet or water control valve, where temperature and flow are controlled. This disclosure is typical of the faucet style of control valves, where two sources of fluid are mixed and flow is controlled. These valves have the discharge of fluid through a spout which is basically perpendicular to the flow of the fluid. Prior art does exist to detail that ceramic disks can be used to supply and discharge fluids as well as U.S. Pat. No. 7,373,950 issued to Huang on May 20, 2008 demonstrates where a single set of disks control the mixing of hot and cold water from two distinct sources and regulates the outbound flow of water through the same disks.
[0008] One of the deficiencies of the current state of the industry as well as the prior art is that a valve, that can go to complete shutoff and maximum flow with a 90 degree rotation about the axis of fluid flow, cannot also be capable of measuring the differential pressure between the inlet and outlet of the valve. Current ball valve technology, which through the use of parabolic or other inserts to the ball can approach a more linear relation between the percentage of openness of the ball to the percentage of maximum flow through the valve, does not have the capabilities to have a pre-set Cv in association with the ball valve.
[0009] Additionally, due to the surfaces upon which the fluids impact upon when the ball valve is turned and due to the close tolerances required to prevent fluids from leaking past the ball portion of the valve, it is imperative that the fluids be free from any hard impurities that can scratch or mar the surface of the ball and that can damage the exposed O-Rings. Furthermore, since the O-Rings are exposed to the fluids on a daily basis, the chance for O-Ring degradation due to reactions with the fluids is greatly enhanced, leading to failure and leakage. To prevent this possible degradation, some manufactures use Teflon seals which facilitate a sealing function as well as creating a surface with less friction than O-rings.
[0010] Another issue with using ball valves is that the user most still incorporate a venturi and high and low pressure test probes to measure the flow of the fluid. Since cavitation and throttling may occur with the use of a ball valve, the venturi must be location a sufficient distance away from the ball valve in order to more accurately measure the flow. This could cause problems in the reading and adjusting the flow in a particular section of a piping structure.
[0011] It is an object of this invention to create a device that will enable the user to adjust the flow of fluid in a piping structure where space is at a premium and where accuracy of the fluid flow is critical.
[0012] It is a further object of this invention to provide the user with a valve whose adjustment is axially relation to the flow of fluid. This axial relationship provides for a more compact unit and which more accurately controls the flow using linearly related flow control disks.
[0013] It is a further object of this invention to provide a device with which the user can measure the differential pressure as the device is being operated so that flow can be accurately measured at the actual valve as it is being adjusted. It is desirable that the space required for this measurement be compact in nature and close to the body of the valve for the most accurate measurement as well as being compact for the tight spaces that it will likely be experiencing.
[0014] It is a further object of this invention to provide an embodiment of this device where be a Cv can be set for this valve, through the use of flow control disks, whereby the user has an axially controlled valve with a set maximum Cv, said valve being able to go to complete shutoff.
[0015] Accordingly, it is the goal of this invention to create an adjustable valve that is axially related to the fluid flow, containing port to determine the actual flow of the fluid, that has the aforementioned characteristics of simplicity, accuracy, adaptability to current uses and safety.
BRIEF SUMMARY OF THE INVENTION
[0016] Accordingly, this application discloses a valve that is adjusted axially along the axis of the flow of fluid. This valve is adjusted by the rotation of the body of the valve where the valve is part of a piping structure. Along with the adjustment portion, there is also the addition of two test ports for high pressure and low pressure measurement, said ports being integral with the rotational member. The valve rotates through 180° from a complete shutoff to maximum flow and back to complete shutoff within the 180°. The valve is able to be rotated simply by hand control and does not need any tool due to the design of the interface between the control disks and the minimal need for 0-rings interference. Furthermore, the valve has a set screw that is attached to an external boss, which is used to lock the valve in place and prevent any unwanted rotation. The valve either has a stop at 180°, so that the user cannot continue past 180° or the valve does not have a stop and allows the user to then complete the rotation for the full 360°. As stated, test ports are integral with the rotating member so that there is an instant feedback of the pressure differential between the high side and the low side of the valve so that one can calculate flow. Since this valve design does not permit increases in cavitation or turbulent flow in the piping system, it is possible to measure the pressure differential at a location that is very close to the actual adjustment means, which is one of the drawbacks with normal ball valves.
[0017] The valve has two control disks, one stationary and one that is movable and it is the interface between openings on both disks that allow the user to select a particular flow rate. Due to the smoothness of the disks, which are preferably made of ceramic materials, the friction moment is greatly reduced even under high pressure fluid flow.
[0018] As an embodiment the user can incorporate an adjustable Cv control disk into the valve so that the maximum Cv or maximum flow rate can be established for the valve. This allows the user to set the flow rate and also allows the system to be able to anticipate the maximum flow coming out of the valve.
[0019] Another embodiment is the addition of a larger Cv control surface which will enable the valve to rotate through up to a total of 300° of rotational movement. This allows a user to more finitely adjust the valve over a larger rotational range and can accommodate higher Cv values. The 300° degrees of rotation is not a limiting factor this invention, but rather a range of motion that will be most suitable for the application in HVAC piping structures.
BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS
[0020] In FIG. 1 , in a view of the valve where the viewer is looking into the test ports of the device. This will be called the upper view.
[0021] In FIG. 2 , the view is of the inlet side of the valve with the test ports pointing downwardly.
[0022] In FIG. 3 , the view is of the outlet side of the valve with the test ports pointing downwardly.
[0023] In FIG. 4 , an upper oblique view of the valve is shown with the outlet of the valve being exposed.
[0024] In FIG. 5 , a side profile view of the valve is shown with a cutaway view through the body of the valve is shown detailing the inlet portion of the valve and the first metering section.
[0025] In FIG. 6 , a side profile view of the valve is shown with a cutaway view through the body of the valve is shown detailing the regulating means and the outlet portion of the valve.
[0026] In FIG. 7 through FIG. 10 , is a series of views looking at the valve from the inlet side, where the valve has been adjusted to various flow amounts, as shown as a percentage of total flow. One can observe the different regulating means as they interact with one other by the difference in the cross hatching.
[0027] In FIG. 11 , a detail of only the outlet portion of the valve is shown along with the primary flow control regulating means.
[0028] In FIG. 12 , a detail of only the outlet portion of the valve is shown along with the secondary flow control regulating means, where the primary flow control regulating means has been removed from the view for clarity.
[0029] In FIG. 13 , an oblique view of the valve is shown where the outlet portion has been removed and only the primary flow control regulating means is shown.
[0030] In FIG. 14 , an oblique view of the valve is shown where the outlet portion has been removed and the primary flow control regulating means is also removed to detail the inner bore of the body of the valve
[0031] In FIG. 15 and FIG. 15A , the primary flow control disk is shown in a frontal and an oblique view respectively, where the disk is used in an application where the valve is capable of complete shutoff every 180° degrees.
[0032] In FIG. 16 and FIG. 16A , the secondary flow control disk is shown in a frontal and an oblique view respectively, where the disk is used in an application where the valve is capable of complete shutoff every 180° degrees.
[0033] In FIG. 17 and FIG. 17A , the variable Cv or variable flow regulating control disk is shown in a frontal and an oblique view respectively, where the disk is used in an application where the valve is capable of complete shutoff every 180° degrees.
[0034] In FIGS. 18 and 18A , the primary flow control disk is shown where the embodiment of having a range of motion greater than 180°.
[0035] In FIG. 19 and FIG. 19A , the variable Cv or variable flow regulating control disk is shown in a frontal and an oblique view respectively, where the disk is used in an where the embodiment of having a range of motion greater than 180°.
DETAILED DESCRIPTION OF THE INVENTION
[0036] This invention as disclosed in the drawings has the principle use in the HVAC environment but there exists no limiting language to prevent this invention to be practiced in other fields of use. The invention consists of three main elements, inlet section, a body and an outlet portion. This invention is an adjustable valve that is adjusted axially to the flow of the fluid, with the further embodiments of ports that are designed to report differential pressure through the valve and whereby the Cv of the valve can be set and still have the valve go to complete shutoff.
[0037] In FIG. 1 , the valve is shown with its three main sections; a central body 100 , an inlet portion 200 and an outlet portion 300 . Shown in this view are differential pressure measurement means, shown as ports 102 for high side pressure and port 103 for low side pressure. It is disclosed that this invention will function without ports 102 and 103 as the measurement of differential pressure across this valve can be done through the use of other independent devices. It can be seen in this FIG. 1 that high side pressure test port 107 is at the base of high side pressure monitoring port 102 . Similarly, low side pressure test port 106 is located at the base of low-pressure test port 103 . Both ports 102 and 103 are internally adapted, by threads or other means, to accept industry standard pressure probes, which can include those probes that are capable of measuring pressure and temperature. Located between inlet portion 200 and high pressure port 102 is set screw boss 104 therein located on boss 104 is threaded set screw through hole 112 . It is the procedure for the user to adjust the device to the desired flow, and then use the set screw to lock it in place preventing further rotation. Located appurtenant to outlet 300 is angular displacement index 105 which corresponds in 90° increments to major angle indicator 106 . It is the relation of the increments on index 105 to angular displacement guide 310 that is located on outlet portion 300 , so that the user can reference the amount of rotation that has been accomplished through a number of degrees. Guide 310 is located upon the hex-nut 301 . Both outlet hex-nut 301 and inlet hex-nut 201 are shown as hexagonal connecting members, but there is nothing in this application that defines and/or limits the shape or size of either of the flanges. Body 100 is defined as a cylindrical member 101 that can either have a smooth or polygonal exterior surface. Inlet portion 200 and outlet portion 300 defined the two ends of the cylindrical member 101 , where the inlet portion 200 is defined as the proximal end and the outlet portion 300 is defined as the distal portion.
[0038] It is in FIG. 2 , that the valve is shown with inlet portion hex-nut 201 facing the observer. As references one can see set screw boss 104 and high pressure test port 102 . In this view primary control disk 113 is seen in its closed position. The opening that defines inner bore 203 is defined as sharing a common central axis to the cylindrical member 101 . Inlet lead-in bevel 206 allows the operator to more accurately insert the connecting member into the body. It is noted that the piping system connection means are located at the distal end of inlet section 200 and outlet portion 300 respectively, are not adapted to any particular piping structure connecting means. In this embodiment of this invention, connection means are internally threaded couplings which have a described hexagonal external interface, which is commonly known in the plumbing industry as inlet hex nut 201 and outlet hex nut 301 , which are located at the distal end of inlet section 200 and outlet portion 300 respectively. This device, though commonly using national pipe thread threads, can be adapted to a piping system by a sweated or swaged joints or any other common plumbing practice joinery. In FIG. 3 we see the opposite end from FIG. 2 as hex-nut 301 is shown, and low-pressure port 103 is shown for reference. Secondary control disk 315 is shown and primary control disk 113 is shown as well. It is the relationship between the two that details that is in a closed position as the two control disks are diametrically opposed in their position. Interior bore 303 has a common bore that is coincident to bore 203 and outlet lead in bevel 317 assists the operator in inserting the piping joints. FIG. 4 is an oblique view of the upper portion of the valve. Reference is made throughout this application as the upper portion of the valve as being that portion containing the high pressure and low pressure ports 102 and 103 . FIG. 4 details the outlet bore 303 along with lead in bevel 317 along hex-nut 301 .
[0039] FIG. 5 is a cutaway version of the valve which details the inlet portion as well as the first half of the main body. Lead-in bevel 206 is located about the entrance of bore 203 . Further interiorly located in the center of opening of bore 203 is stepped down region 207 which provides entrance to the venturi 204 . The venturi is a commonly used device in the plumbing industry. The venturi allows for the measurement of the volumetric flow rate of the fluid going through the valve as there is a direct relationship between the high side and the low side pressure difference and the fluid speed through the valve, where fluid flow increases as the cross-sectional area decreases, which is based on Bernoulli's principles. This step down from bore 203 to the entrance of venturi 204 is shown as rough steps which is common for manufacturing to create a bore pattern using smooth sides and sharp corners as that is the shape of the boring tool. There is nothing that prevents the disclosure of a smoother transition between board 203 and venturi 204 . Venturi wall 209 is a conically described section which terminates at the proximal end of inlet portion 200 along inlet portion termination wall 208 . Inlet portion 200 fits into main body 100 along the common bore between the two parts. Along the interior of inlet portion 200 is snap ring groove 211 which holds snap ring 202 , said snap ring 202 secures the inlet portion 200 onto body 100 . Inlet portion 200 butts against body 100 along the joint between the interior flange wall 210 and body exterior collar 121 . Distal portion 109 of body 101 contains O-ring groove 124 . The O-ring that sits in O-Ring groove 124 is not shown so as to maintain the clarity of the drawing. Venturi 204 terminates into low-pressure sensing ring as part of body 101 . It is seen in FIG. 5 high-pressure testing port 107 is in direct contact and relations there with circular venturi sensing ring 108 so that the low pressure can be measured. High-pressure port 102 is shown with smooth walls but is designed to adapt to any size and or connection type, including the common NPT thread, that is available on the testing probes. Though desirable to remain located with the valve, the testing probes can be removed and used on other applications. After the fluid passes through sensing ring 108 it is throttled down through throttling area 110 after which the now higher pressure fluid flows into interior channel 111 prior to the fluid de-throttling into primary control disk 113 . The fluid flow through interior channel 111 is at a higher pressure than it was going through the low-pressure sensing ring. It is at the end of channel 111 that low-pressure sensing port 106 is seen on FIG. 6 .
[0040] FIG. 6 details the outlet and of the valve. Primary control disk 113 is placed upon O-ring that is compressed upon in O-ring groove 126 by disk 113 as disk 113 is tightly fit and secured into primary disk enclosure 130 , where the purpose of the O-ring is to seal the disk preventing blow-by of the fluids as well as to promote contact with the secondary flow control disk 315 through the compressive and expansive characteristics of a circular sectioned O-Ring. Again the O-ring is excluded for purposes of clarity. Primary control disk 113 has two locating tabs 117 located 180° opposite along the exterior of the primary control disk 113 . Tabs 117 of primary disk 113 are securely located into primary disk securement slots 125 located on body 101 as more clearly seen in FIGS. 13 and 14 . FIG. 6 also shows rotation stop 312 which is placed to prevent rotation of the body 100 past a set number of degrees, which in this case would be 180°. The valve uses the rotation stop as a convenience versus a necessity as there is no harm to the valve should the user completely rotate the body 360° except for issues with the differential pressure probes.
[0041] Outlet portion 300 has centered through it bore 303 which has a common axis with bore 203 and channel 111 , lead-in bevel 317 being centered about bore 303 , which has a similar step down region 305 that has sharp side, again referring to common tooling nomenclature of the industry. Region 305 steps down into central outlet bore 304 which is in fluid communication with secondary control disk 315 . Secondary control disk 315 also has locking flanges 308 which slide into slot 316 which holds disk 315 in place. As with the primary control disk 113 , secondary control disk 315 also is tightly fit and secured into secondary disk enclosure 321 and compresses upon an O-ring that fits into O-ring groove 306 , the O-ring is not shown for purposes of clarity and adapts the characteristics of sealing and compressive resistance as the O-Ring provides to the primary control disk 113 . It can be shown that snap ring 316 sits in groove 302 of the outlet portion 300 and interfaces with body 101 through snap ring channel 119 . This snap ring secures outlet portion 300 into body 100 . Located interiorly from snap ring 316 is O-ring groove 116 which provides additional sealing for outlet portion 300 , as before O-ring is not shown for purposes of clarity. All O-rings used in this device are common O-rings with a circular cross-section that are used in the industry, constructed of a material that does not degrade in the presence of the proposed fluids going through the about. In this case buna-nitrile, silicon or EPDM O-rings can be used, as water is the proposed fluid. Proximal edge 318 of outlet portion 300 butts up against outside flange wall 121 and there is a close fit tolerance between interior bore wall 307 of outlet portion 300 and the interior wall 123 of body 101 . Though it is shown on FIG. 6 that primary control disk 113 and secondary control disk 315 are not in contact, this is for purposes of clarity of the drawing. In actual application O-rings that are contained in O-ring grooves 126 and 306 will maintain the control disks in constant contact. Furthermore the pressure and flow of the water will push the to do is to gather further preventing any leakage between the deaths The two control disks are ground smooth and have a surface roughness of no greater than 0.2 of a micrometer.
[0042] FIGS. 7 , 8 , 9 and 10 show the relationship between the primary and the secondary control disks 113 and 315 respectively. Being viewed from the inlet hex-nut 201 as the valve body rotates one can see how the primary control disk shown with the wavy lines rotates through the stationary secondary control disk shown with the straight lines.
[0043] FIG. 11 is a view of the outlet portion 300 as can be seen the interior bore wall 307 defines the piece. Snap ring groove 302 a shower and at the proximal and the distal and is defined by termination wall 313 . Primary control disk 113 , though not being part of the outlet portions 300 , is shown for reference only. One can see the tab 117 as well as the defined opening 120 . Shown in this view is rotation stop 312 which can be used if the purchaser of the product wants only 180° rotation or any specified angle as we will see later that the maximum rotation is 300°. The maximum of 300° rotation is not a limiting feature of this invention. The shape of the openings in the secondary disk 315 can be adapted to any finite number of degrees, but it found that in the practicing of this invention in the HVAC industry, approximately 300 degrees of rotation would be the most adaptable to the application of this invention. Rotation more than 330 degrees might cause issues with test probes inserted into the test ports 102 and 103 along with problems associated with the secondary disk 315 . It is important that the user be able to have a positive stop to know when the valve is flowing at its maximum or minimum valves. FIG. 12 is the same view as FIG. 11 scans primary control disk 113 . Secondary control disk 315 is shown flush with termination wall 313 as disk 315 is positioned into disk enclosure 321 , where disk enclosure 321 contains O-ring groove 306 . Secondary control disk 315 being held in place by tabs 308 which fit in the slot 316 . As can be observed between FIG. 11 and FIG. 12 the opening 120 of primary control desk 113 interfaces with the closed portion of secondary control disk 315 . This would be in the closed state.
[0044] FIG. 13 is a view of the body and inlet portion distally related to the bore of the body. As can be seen the outlet portion 300 has been removed so that we can observe the inside of body 101 . Primary control disk 113 can be seen with tab 117 . FIG. 14 shows a view of slot 125 as it is cut into the bore of the body 101 , termination shelf 127 is shown in FIG. 13 along O-ring groove 116 and snap ring 119 . Rotational stop 118 , interfaces with rotation stop 312 , is located at the proximal edge 121 of body 101 . Rotational stop 118 works in conjunction with rotation stop 312 providing the user a positive stop to know when the user has fully opened or closed the valve. In this particular example rotation stop 312 interfaces with rotational stop 118 and provides the user with an approximate 300° rotation. In other embodiments the rotation stop 312 and rotational stop 118 can limit the user to 180° of rotation. In embodiment of the valve has a tactile feel so that each incremental rotation through guide 105 of the valve can have an indent and detent combination so that the user can feels the rotation and notice that each tactile bump represents a number of degrees.
[0045] FIGS. 15 and 15A shows a detail the primary control disk where there are two openings. The primary control disk 113 that has two 90° angular sections or openings in the face of the disk. FIGS. 16 and 16A show the matching secondary control disk 315 having two 90° angular sections or openings in the face of the desk. FIGS. 15 and 16 disclose disks with two 90° circular segments where the radius of the segment is less than the radius of the disk. The radius and chord sections of each of the circular segment on the primary and secondary control disk must be coincident. The segments are cut out of the where the operator has 180° to go between any of the two extremes, such as 180° from shut off to shut off or 180° from full-flow to full flow. There is no limit to the number of angular sections on a particular disk so long as the disk has an equal number of closed sections that will interface with a similar number of sections on the secondary disk so that the valve can completely shut off the flow of fluids through the valve.
[0046] FIGS. 17 and 17A show the variable Cv disk 415 that can be used as an embodiment to this device. The Cv is defined by the geometry of the arc's radius and chord. As can be seen disk 415 works with primary disk 113 , where that the design of disk 415 is unique to a defined Cv or maximum flow. The variable Cv Disk 415 has a crescent shaped arcs where the major arc has a defined diameter based on the diameter of disk and a minor arc of lesser diameter is tangentially placed against first arc, and the surface area of the opening defines the maximum flow. Disk 415 is factory set for example to 5 gallons per minute, so that the maximum flow through the valve is set by the disk 415 . The rotation of this style of desk is 180°. The interface between Cv disk 415 and primary disk 113 , is that disk 113 rotates about the fixed Cv disk regulating flow up to the maximum flow rate as described by the arcs through a rotation of 180°.
[0047] FIGS. 18 and 19 detail an embodiment where a set of disks selected by the user sets a particular Cv from the factory and the valve can rotate up to 300°. With this increase in angular rotation, a more finite adjustability is introduced into the valve and the design of secondary disk 415 A allows for a more linear relationship between the percentage of the valve opening to the percentage of maximum flow of fluids through the valve. Disk 113 A is similar in function as primary disk 113 and disk 415 A is similar in design and function as secondary disk 415 . The radius of the major arc is less than the radius of the secondary disk 415 A and the minor arc is not tangentially located but is more centrally located and is defined mathematically according to the surface area desired based on the maximum Cv or flow rate required of the valve. The valve body, using rotation stops 118 and 312 , allows the user a finer control of the valve through the entire adjustment range of up to 300°.
[0048] Another embodiment, not shown on the drawings is the addition of a piezometer ring or averaging annulus ring in place of low pressure sensing ring 108 . This piezometer ring is used when the valve is not located on a length of pipe that is sufficiently for a distance to accurately measure the pressure differential with a regular circular cylindrically shaped venturi sending ring 108 . The concept of the piezometer ring is to create a much finer ability to more accurately sensing the low pressure so that the valve can operate with a higher degree of accuracy.
[0049] It can be appreciated by those appropriately skilled in the art that changes, modifications or embodiments can be made to this invention without departing from the spirit, principles, theories, ideas or conceptions that have been disclosed in the foregoing. It is herein recognized that the embodiments disclosed by this description of the best mode of practicing this invention, which will be hereafter described in their full breadth in the claims and equivalents thereof.
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A rotationally adjustable valve is disclosed whereby the user is able to control the flow of fluids from complete shutoff to maximum flow by rotating the body of the valve, said rotation being axial to the flow of the fluid. Additionally, the user is able to attach high and low pressure test probes directly to the valve, as it is rotatably adjusted, so that additional equipment is not required next to the valve. An embodiment of this invention includes the use of an adjustable Cv disk to set the maximum flow of the valve, rather than just create a simple 180° on/off, very similar to a current 90° ball valve that this device will replace. All of the problems associated with the ball valve have been minimized including creating a linear relationship between the percentage open of the valve and the percentage of maximum flow of the valve.
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