Adjustable support fixture

A fixture for supporting a workpiece having a surface to be milled by a milling tool in a predetermined position while being milled, the fixture comprising:

• a substantially horizontal platen tiltable to a limited extent relative to its horizontal plane, the platen having an upper surface and fastening means for affixing the workpiece to the upper surface with the surface to be milled facing upwardly,
• means for establishing a plane above the platen in a cutting plane of the milling tool,
• spaced means located under the platen actuatable in unison to raise the platen and the workpiece thereon to move the workpiece surface to be milled into engagement with the means establishing the plane,
• means to lock the platen in the last named position to maintain the workpiece surface in the cutting plane of the milling tool, and;
• track means supporting the means for establishing the plane for movement horizontally relative to the platen.

Means to accurately locate a surface on a workpiece in the plane of a cutting head of a milling machine comprising:

• a workpiece support platen including means to locate and support a workpiece having an upwardly facing surface to be milled thereon,
• means to establish a plane for the surface to be milled including a carriage movable between a position spaced from the platen and a position aligned with and extending above the platen, said carriage having at least two members located thereon and having means to adjust the positions thereof on the carriage to establish a plane in the cutting plane of the cutting head,
• means to support the platen from beneath for vertical movement including a plurality of vertically adjustable lifting devices at spaced locations below the platen, said vertically adjustable devices being simultaneously actuatable to apply vertical lifting force to the platen and to the workpiece supported thereon,
• other means under the platen actuatable to lock the platen in a fixed position independently of the lifting devices, and
• track means including means on the carriage engageable therewith for movably supporting the carriage for movement therealong between a position aligned with the platen and a position spaced therefrom.

Means to accurately locate a relatively flat surface on a workpiece in a cutting plane of a workpiece cutting tool comprising:

• a workpiece support platform having upper and lower surfaces and means on the upper surface for supporting a workpiece having its relatively flat surface facing upwardly,
• said support platform being located in position to have the workpiece cutting tool move thereabove,
• means to establish a plane in the cutting plane of movement of the cutting tool above the platform,
• means to support and vertically move the platform including a plurality of vertically adjustable hydraulic devices positioned at spaced locations below the platform, each hydraulic device having means engagable with the lower surface of the platform,
• means for applying hydraulic pressure to the hydraulic devices to move the platform and the workpiece supported thereon in an upward direction whereby the flat surface of the workpiece is moved against the means establishing the plane in the cutting plane of movement of the cutting tool,
• other means engagable with the lower surface the platform for locking the platform in a position with the flat surface of the workpiece engaging the means establishing the plane independently of the hydraulic devices, and
• means for moving the means establishing the plane out of engagement with the flat surface of the workpiece so that the cutting tool can be moved across and cut the flat workpiece surface.

Means to accurately locate a relatively flat surface on a workpiece in a plane of a workpiece cutting tool comprising:

• a workpiece support platform having upper and lower surfaces and means on the upper surface for supporting a workpiece having its relatively flat surface facing upwardly, said support platfrom being located in position to have the workpiece tool move thereacross,
• means to establish a plane of movement of the cutting tool above the platform,
• means to support and move the platform including a plurality of vertically adjustable hydraulic devices at spaced locations below the platform, each hydraulic device having means engageable with the underside of the platform,
• means for applying hydraulic pressure to the hydraulic devices to move the platform and the workpiece supported thereon in an upward direction whereby the flat surface of the workpiece is moved against the means establishing a plane in the cutting plane of the cutting tool,
• other means engageable with the underside of the platform for locking the platform in a position with the flat surface of the workpiece engaging the means establishing the plane independently of the hydraulic means, and
• means for moving the means establishing the plane in the cutting plane out of engagement with the flat surface of the workpiece so that the cutting tool can be moved across to trim the flat workpiece surface.

A fixture for supporting a workpiece having a surface to be machined by a machine tool that moves in a planar cutting path, the fixture including means for aligning and maintaining the workpiece surface in substantially coplanar orientation relative to the cutting path of the machine tool so as to enable precise and accurate removal of an amount of surface material necessary to make the surface planar, the fixture comprising:

• a platen having a support surface and a surface opposite thereto, the platen being tiltable about the plane of the support surface, means on the support surface including means for restraining the workpiece when mounted thereto with the surface to be machined facing away from the support surface,
• movable means for establishing a plane coplanar with the cutting path when the means for establishing the plane are aligned with the platen,
• means for moving the platen when the workpiece is mounted thereto and when the means for establishing the plane are aligned therewith causing the surface to be machined to bear against the means for establishing the plane and thereby become coplanar with the established plane, and
• locking means for restraining movement of the platen with the workpiece surface coplanar to the cutting path of the machine tool.

A fixture for supporting a workpiece having a surface to be machined by a machine tool that moves in a planar cutting path, the fixture including means for aligning and maintaining the workpiece surface in substantially coplanar orientation relative to the cutting path of the machine tool so as to enable precise and accurate removal of an amount of surface material necessary to make the surface planar, the fixture comprising:

• a platen having a support surface and a surface opposite thereto, the platen being tiltable about the plane of the support surface, means on the support surface including means for restraining the workpiece when mounted thereto with the surface to be machined facing away from the support surface,
• means for establishing a plane coplanar with the cutting path, the means including a calibration block mountable on the support surface of the platen and having an upper surface adapted to establish the cutting plane of the machine tool, and a carriage assembly movable between a position spaced from the platen and a position aligned with the platen, the carriage assembly including adjustable members engageable with the upper surface of the calibration block when the carriage assembly is aligned with the platen,
• means for moving the platen when the workpiece is mounted thereon and the carriage assembly is aligned therewith causing the surface to be machined to bear against the adjustable members and thereby become coplanar with the established plane, and
• locking means for restraining movement of the platen with the workpiece surface coplanar to the cutting path of the machine tool.

A method for supporting a workpiece having a surface to be machined by a machine tool that moves in a planar cutting path, bringing the surface into substantially coplanar orientation relative to the cutting path, and retaining the surface in said orientation so as to enable precise and accurate removal by the machine tool of an amount of surface material necessary to make the surface planar, the method comprising the steps of:

• mounting the workpiece on a support surface of a platen tiltable about the plane of the support surface, the workpiece being oriented so that the surface to be machined faces away from the support surface,
• aligning plane-establishing means adjacent to the surface to be machined, the plane-establishing means establishing a plane that is coplanar with the cutting path of the machine tool,
• driving the platen toward the plane-establishing means until the surface to be machined bears against the plane-establishing means, the platen tilting as needed to bring the surface to be machined into coplanar alignment with the established plane,
• restraining movement of the platen to maintain the surface to be machined in coplanar orientation with the established plane, and
• removing the plane-establishing means from the surface to be machined.

A method for adjusting and operating a fixture for supporting a workpiece having a surface to be machined by a machine tool that moves in a planar cutting path, bringing the surface into substantially coplanar orientation relative to the cutting path, and retaining the surface in said orientation so as to enable precise and accurate removal by the machine tool of an amount of surface material necessary to make the surface planar, the method comprising the steps of:

• placing a calibration block having a planar surface adapted to establish the planar cutting path of the machine tool on a support surface of a platen tiltable about the plane of the support surface so that the planar surface of the calibration block faces away from the support surface of the platen,
• bringing the machine tool from a home position into engagement with the upper surface of the calibration block and setting the machine tool accordingly to establish its planar cutting path,
• returning the machine tool to its home position,
• aligning movable means having adjustable members with the calibration block,
• fixedly adjusting the adjustable members against the upper surface of the calibration block,
• moving the movable means from alignment with the calibration block,
• removing the calibration block from the support surface of the platen,
• mounting the workpiece on a support surface of a platen tiltable about the plane of the support surface, the workpiece being oriented so that the surface to be machined faces away from the support surface,
• aligning the movable means with the platen, the adjustable members establishing a plane that is coplanar with the cutting path of the machine tool,
• driving the platen toward the plane-establishing means until the surface to be machined bears against the adjustable members, the platen tilting as needed to bring the surface to be machined into coplanar alignment with the cutting path of the machine tool,
• restraining movement of the platen to maintain the surface to be machined in coplanar orientation with the cutting path, and
• moving the movable means from alignment with the platen.