Abrasive tool making process – material – or composition – With carbohydrate or reaction product thereof
Patent
1989-05-26
1990-12-11
Schmidt, Frederick R.
Abrasive tool making process, material, or composition
With carbohydrate or reaction product thereof
B24B 4104
Patent
active
049760718
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
My invention relates to a clamping device or chuck for axially clamping a tool and, more particularly, to a clamping device for a tool used in a portable powered hand tool, e.g. for a grinding disk in a portable grinding machine.
My invention is based on a chuck for axially clamping a tool, especially a disk-shaped tool or tool disk, on a flange of a driven spindle comprising a clamping nut which is provided with an internal thread and which can be screwed onto an end-side threaded step of the spindle, and a clamping member which is positioned axially between the tool on one side and the clamping nut on the other side and can press the tool against the flange. A clamping fixture of the said type has been disclosed (German Patent Specification No. 3,012,836) in which the clamping member consists of an element which is roughly hat-shaped in cross-section and is axially supported against the flange of the clamping nut via a helical spring. When the clamping nut is screwed on and tightened, the hat-shaped clamping element is pressed axially against the tool via the axially compressed spring, and the tool is thereby tightened against the flange on the spindle side, the end face of a cylindrical extension of the clamping nut coming to bear directly on a facing axial side of the flange on the spindle side and, during further tightening of the clamping nut, the flange on the spindle side being tightened together with the clamping nut. This is to ensure in an angle grinder that the grinding disc is mounted with a definite contact pressure and that this contact pressure remains at the right level. This clamping device is also intended to permit a quick and simple replacement of the grinding disk and at the same time avoid overloading of the powered hand tool, in particular the angle grinder. This is because, if the torque acting on the grinding disk is too great, the grinding disc stops, while the flange and also the clamping nut having the clamping member perform a relative movement thereto. The effect of the clamping nut automatically tightening further in operation, which otherwise makes it considerably more difficult to loosen the clamping nut when changing the grinding disk, is counteracted with this clamping fixture. Nonetheless, loosening of the clamping nut is here only possible with the assistance of a special auxiliary tool. The spindle, depending on the design of the machine, must be appropriately counterheld by a second auxiliary tool, e.g. a spanner.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a clamping device for axially clamping a tool, especially a grinding disk, in which a tool change can be made without an aixiliary tool such as a spanner. Another object is to be able to easily modify existing power tools.
In keeping with these objects and with others which will become apparent hereinafter, the clamping member is held on the clamping nut so as to be movable relative to the clamping nut between a clamping position and a loosened position and has at least one pressing surface dropping axially in a direction of motion from the clamping position to the loosened position.
In the clamping device according to the invention having the characterizing features of the main claim, the following advantages result. A tool change is made possible without any auxiliary tool. This tool change, in addition, can be performed quickly and safely. A further advantage is that powered hand tools already existing can also be changed over without special redesign. For example, a simple exchange of the clamping nut is sufficient for this purpose. Since, when the clamping member is transferred from the clamping position into the release position, the axial clamping force of the clamping fixture is reduced and removed to such an extent that axial force no longer acts on the thread, the spindle, in the release position, when the clamping nut is unscrewed further by hand, is no longer loaded by a torque. Only the thread friction of the relieved thread
REFERENCES:
patent: 526420 (1894-09-01), Thomas
patent: 946152 (1910-01-01), Peglar
patent: 1226029 (1917-05-01), Tessmer
patent: 1539057 (1925-05-01), Ridderstrom
patent: 2157345 (1939-05-01), Nelson
patent: 2454309 (1948-11-01), Davis
patent: 2518112 (1950-08-01), Anthony
patent: 2815052 (1957-12-01), Krasnow
patent: 2908303 (1959-10-01), Schmidt
patent: 3528203 (1970-09-01), Franklin et al.
patent: 4237659 (1980-12-01), Welsch et al.
patent: 4622123 (1986-11-01), Nejame, Jr.
patent: 4706963 (1987-11-01), Geuss
Robert & Bosch GmbH
Schmidt Frederick R.
Striker Michael J.
Watson Bruce P.
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