Abrasive tool making process – material – or composition – With ester-type wax – bituminous material – or tarry residue
Reexamination Certificate
2000-06-12
2003-04-15
Koslow, C. Melissa (Department: 1755)
Abrasive tool making process, material, or composition
With ester-type wax, bituminous material, or tarry residue
C051S307000, C051S309000, C051S295000, C051S295000, C252S062520, C252S074000, C252S570000, C252S572000
Reexamination Certificate
active
06547842
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a polishing material comprising a fluid containing grinding particles, a grinding material (particularly grinding particle body for abrasion-grinding in which reversible phase transition between liquid and solid states is possible at normal temperatures (0-65° C.)), polishing method, and a polishing apparatus with which to move a polishing material relative to a work thereby giving a polish to the work.
2. Prior Art
With the rapid development of technological innovation, demand for high quality industrial products becomes acute; and processed objects (to be referred to as “work” hereinafter) such as industrial products or parts requiring abrasion-polishing or abrasion-grinding come to have a complicated shape which often requires finest and minutest precision for processing. However, the last finishing process of such a work where the finest surface polishing or the maximum precision of groundwork is required is generally achieved even today by human hands. Therefore, if this manually achieved process could be substituted for by a machine-operated process or a process enabling the reduction of labor cost, it would be beneficial because it would reduce cost involved in processing, or time required for the process. Further, the manually-operated process has a precision limit in the finest surface polishing no matter how skilled the hands may be.
To meet such a situation, studies on a method for enabling the high-precision surface polishing of a work using a soft lapping stone have been continued. This is a polishing method using a polishing stone comprising of a soft polymer material such as polyvinyl acetal, sodium alginate or the like, as a bonding agent. The polishing based on soft lapping like this has been mainly used for the fine surface polishing of a silicone wafer required for fabrication of an integrated circuit.
The inventors of this Application proposed a polishing method which consists of using a magnetic fluid containing grinding particles whose orientation can be controlled by a magnetic field, immersing a work in the magnetic fluid, and vibrating or rocking the magnetic fluid with respect to the work while a magnetic field with a specified intensity being applied to the fluid. The polishing method based on the use of a magnetic fluid includes, for example, those disclosed by Japanese Patent Laid-Open Nos. 1-135466, 4-336954 and 4-41173.
However, with such a polishing method, the strains given by grinding particles on the surface of work are so small that their polishing effect is weak, because the polishing material is a highly fluidic liquid. Because of this, this method is not suitable for a process requiring abrasion-grinding, or a process requiring coarse polishing introduced before fine polishing, although it may be utilized for the uniform surface polishing of the entire surface of a work during the final process.
This conventional technique uses a magnetic fluid, puts it under a magnetic field having a specified intensity, and polishes a work while controlling the orientation of grinding stone particles, but poses a problem when used for polishing a work requiring high-precision polishing in a direction in a tri-dimensional space.
To meet this inconvenience, the present inventors paid attention to the fact that a fluidic abrasive containing grinding store can vary its form freely in accordance with the shape of the surface to be ground, and can polish even the surface of a cleft or a narrow, recessed surface rejecting the access of human hands or a tool. However, because the fluidic abrasive exerts a less pressure against the surface of a work than a solid abrasive that is otherwise the same in configuration, it is not suitable for rapid grinding or coarse polishing. Therefore, they proposed a polishing material which combines the merits of both fluidic and solid abrasives, that is, a material capable both of polishing a surface having a complicated shape, and of achieving highly effective polishing. Use of this proposed polishing material consists of injecting fluidic abrasive stone containing grinding particles into a work, solidifying it at a low temperature, and moving the thus obtained solid abrasive relative to the surface of work, thereby achieving polishing or grinding of the latter. The conventional abrasive stone includes metal bond abrasives, resin bond abrasives, electrical bond abrasives, gelatin texture abrasives, etc. However, because they have been prepared to take a certain shape before they are used, it is difficult to freely vary their shape in accordance with the surface to which they are applied.
Actually, the method for polishing or grinding a work on the basis of a mechanical force imposed by a solid J abrasive with a specific shape is limited to abrasion grinding or coarse polishing because it does not allow high precision polishing. Further, polishing with an apparatus incorporating a solid abrasive has been conventionally used for polishing of a two-dimensional surface and hardly used for polishing of a surface having a tridimensional expanse because of the structural rigidity inherent to such a solid abrasive.
Further, polishing by the method of immersing a fluid containing grinding particles to the surface of a work to be polished, and moving the fluid with respect to the surface thereby to give a polish on the surface has a very weak effect, because the polishing material is a highly fluidic liquid, and the contact pressure exerted by the grinding particles against the surface to be polished is small. Because of this, this method is not suitable for a process requiring abrasion-grinding, or a process requiring coarse polishing introduced before fine polishing, although it may be utilized for the uniform surface polishing of the entire surface of a work during the final process. This conventional method consisting of using a magnetic fluid, putting it under a magnetic field having a specified intensity, and polishing a work while controlling the orientation of grinding stone particles poses a problem when a work requiring high-precision polishing must be polished in a direction in a tri-dimensional space.
Furthermore, the polishing material solidifies when exposed to low temperatures close to −15° C. while the atmospheric temperature prevalent during polishing is close to −30° C. This temperature difference requires some adjustment when the method is to be put into practice.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a grinding particle body in which the phase transition from a liquid abrasive to a solid abrasive occurs in a temperature range facilitating practicality, and which enables polishing or grinding at normal temperatures.
Another object of this invention is to orientate grinding particles in a specific direction by utilizing the orientation characteristic of a grinding particle orientation material, and externally applying an electric or magnetic field to the grinding particles, thereby improving the grinding and polishing properties of the particles.
The present invention provides a polishing material which not only retains the merits of a fluid grinding stone containing grinding particles, that is, the property of freely changing its shape in accordance with the shape of the surface to be polished, and the property of invading into a narrow closed recessed surface inaccessible to human hands or a tool, but is also provided with the merit of a solid grinding stone, that is, the property of enabling rapid abrasion-grinding or coarse polishing, and a method using such a material. To achieve this object, this method is configured such that a fluid containing grinding particles is solidified or gelatinized in accordance with the shape of a work, and the resulting solid or gel material is moved relative to the work, thereby polishing or grinding the work.
Further, the invention provides a polishing material wherein the fluid containing grinding particles is a magnetic fluid capable of controlli
Edamura Kazuya
Shibata Isao
Umehara Noristugu
Armstrong Westerman & Hattori, LLP
Koslow C. Melissa
Nisca Corporation
LandOfFree
Polishing material, grinding particle body for... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Polishing material, grinding particle body for..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Polishing material, grinding particle body for... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3076260