1. Field of the Invention
The subject invention relates to a work support apparatus for re-grinding a cutting insert around a corner, between edges thereof.
2. Description of the Prior Art
The typical work support is supported on a chuck and used in combination with a surface grinder to grind the cutting surfaces into the cutting insert. An example of such a work support apparatus is shown in the U.S. Pat. No. 5,168,661 to Pedersen et. al., (“the '661 patent.”)
The '661 patent discloses a work support apparatus that includes a work holder for supporting the cutting insert. The work holder is secured to a work spindle that is journaled for rotation in a work head. The work head is rotatably mounted to a base for rotation about a pivot axis extending upwardly from the base. The base is mounted to a table, which is movable in perpendicular and parallel directions relative to the surface grinder. The surface grinder is movable vertically relative to the table. A plurality of electric motors controls the movement of the table and surface grinder, and an operator controls the electric motors. The cutting insert is ground by rotating the gear about the pivot axis and into engagement with the surface grinder.
When using a work support apparatus as disclosed in the '661 patent to grind cutting inserts, the radius of the corner is determined by the distance between the pivot axis and the surface grinder. If a different radius is desired, an alternative work support having a different relative spacing between the pivot axis and the surface grinder must be installed on the table.
The subject invention provides a work support apparatus for re-grinding a cutting insert around a corner between edges. The work support apparatus includes a base. A support lever is pivotably attached to the base for rotation about a pivot axis. The pivot axis extends upwardly from the base. A carrier post extends upwardly from the support lever in spaced relationship to the pivot axis. An insert holder is disposed on the carrier post and extends along a holder axis perpendicular to the pivot axis. The insert holder supports the cutting insert such that the pivot axis extends therethrough. An adjustable device interconnects the insert holder and the carrier post for adjusting the position of the insert holder along the holder axis relative to the pivot axis for determining the radius of the corner of the cutting insert to be re-ground into the cutting insert.
The subject invention also provides a method of re-grinding a cutting insert around a corner between edges. The method comprises the steps of pre-positioning the cutting insert in a datum position relative to the pivot axis, moving the cutting insert into kissing engagement with a grinding wheel to a start position, moving the cutting insert away from the grinding wheel, and moving the cutting insert back into engagement with the grinding wheel and past the start position to grind the corner. The method further includes the step of adjusting the position of the cutting insert a pre-determined distance from the datum position such that the pivot axis extends through the cutting insert to pre-determine the radius of the corner to be ground.
Accordingly, the subject invention provides a work support apparatus for grinding a cutting insert that is adjustable to provide for grinding differing radii on the cutting insert without using different work supports for the different radii. The subject invention is therefore a more efficient and cost effective work support apparatus for re-grinding cutting inserts.
Other advantages of the present invention will be readily appreciated, as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:
Referring to the figures, wherein like numerals indicate like or corresponding parts throughout the several views, a work support apparatus is generally shown at 20 in
The work support apparatus 20 further includes an indexing device, generally shown at 38, for positioning the insert holder 32 in a datum position parallel to and spaced radially from the pivot axis P. As best shown in
As best shown in
Referring to
When operating the work support apparatus 20, an operator moves the insert holder 32 forward from the stop plate 40 to place a shim between the locating surface 46 and the stop plate 40. The operator will then move the insert holder 32 back toward the stop plate 40 tightly sandwiching the shim between the locating surface 46 and the stop plate 40.
As best shown in
Referring back to
Referring to
The carrier post 30 and the support lever 26 define a threaded bore 80 therebetween. An adjustment screw 82 is in threaded engagement with the threaded bore 80. The adjustment screw 82 axially adjusts the carrier post 30 by threading the adjustment screw 82 inwardly or outwardly from within the threaded bore 80. The carrier post 30 is adjusted along the longitudinal axis L of the carrier post guide 76 for centering the insert holder 32 on the holder axis H.
As best shown in
The work support apparatus 20 includes at least one stop 92 attached to the base 24 for limiting rotation of the support lever 26 about the pivot axis P. Preferably, the work support apparatus 20 includes a first stop 94 and a second stop 96 disposed on each side of the support lever 26 to limit rotation of the support lever 26 in both a clockwise and a counterclockwise direction.
Referring back to
The work support apparatus 20 includes a handle 120 attached to the support lever 26 for operating the work support apparatus 20. The handle 120 is attached to the support lever 26 by a handle fastener 122 passing through the support lever 26 and into threaded engagement with the handle 120.
The work support apparatus 20 as described above is intended for use with a magnetic chuck. The work support apparatus 20 can be used to re-grind a variety of different shaped cutting inserts 22, including square and triangular inserts. A different insert holder 32 is used for the different shaped cutting inserts 22.
The subject invention also provides a method of re-grinding a cutting insert 22 around a corner between a first and a second edge of the cutting insert 22. When operating the work support apparatus 20, the operator must first determine the stock removal thickness necessary to sharpen the cutting insert 22. This is the necessary amount of material to be removed to grind a sharp corner. Next, the operator must determine the existing radius of the cutting insert 22 to be ground. It is preferable to use radius gauges or and optical comparator to determine the existing radius. A proposed radius is then calculated by adding the stock removal thickness to the existing radius. A shim thickness is calculated by an equation specific to the shape of the cutting insert. As shown in the Figures, for a triangular cutting insert, the shim thickness is calculated by multiplying the proposed radius by two. The cutting insert 22 is initially positioned in a datum position parallel to and spaced radially from the pivot axis P. The shim is inserted between the locating surface 46 on the insert holder 32 and the stop plate 40 to move the insert holder 32 from the datum position to a grinding position. The cutting insert 22 is positioned in the insert holder 32 firmly against the locating edges and securely clamped in place.
The work support apparatus 20 is positioned on the magnetic chuck in either the horizontal position if the operator is grinding a negative cutting insert 22 or the inclined position if the operator is grinding a positive cutting insert 22. The corner of the cutting insert 22 is positioned in the lower right quadrant of the surface grinder. The operator then advances the cutting insert 22 inward towards the surface grinder until the cutting insert 22 is in kissing engagement with the surface grinder in a start position. At least one dog stop 92 is placed for repeating the start position. The cutting insert 22 is then withdrawn from the surface grinder. To sharpen the cutting insert 22, the surface grinder is activated and the operator urges the cutting insert 22 back into the surface grinder while rotating the cutting insert 22 back and forth about the pivot axis P until the corner is re-ground.
The foregoing invention has been described in accordance with the relevant legal standards; thus, the description is exemplary rather than limiting in nature. Variations and modifications to the disclosed embodiments may become apparent to those skilled in the art and do come within the cope of the invention. Accordingly, the scope of legal protection afforded this invention can only be determined by studying the following claims. In addition, the reference numerals in the claims are merely for convenience and are not to be read in any way as limiting.
This application claims the benefit of U.S. provisional patent application Ser. No. 60/565,456, filed on Apr. 26, 2004, the disclosure of which is hereby incorporated by reference.
Number | Date | Country | |
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60565456 | Apr 2004 | US |