Machine tool extension table and method for installing same

An extension table for a machine tool of the type that comprises a machine table that is substantially fixed during processing of a workpiece and that defines a reference plane, said extension table comprising:

• a beam having a lower surface which defines a beam plane, said beam comprising an inner portion and an outer portion;
• a ledge mounted to the lower surface of the outer portion of the beam to extend outwardly from at least one side of the beam, said ledge defining an upper surface substantially parallel with the beam plane;
• means for mounting the inner portion of the beam on the machine table with the beam positioned above the reference plane such that the outer portion of the beam is cantilevered from the machine table with the beam plane substantially parallel with the reference plane;
• said beam having sufficient rigidity to ensure that the upper surface of the ledge is maintained substantially coplanar with the reference plane when the beam is loaded only with the ledge;
• a leg;
• and
• means for adjustably securing the leg to the outer portion of the beam to support the beam against downward deflection when loaded with a workpiece.

A pair of extension tables for a jointer of the type having an infeed table that defies an infeed reference plane and an outfeed table that defines an outfeed reference plane, said pair of extension tables comprising:

• an infeed beam and an outfeed beam, each having a respective lower surface which defines a respective beam plane, each beam comprising a respective inner portion and a respective outer portion;
• an infeed ledge and an outfeed ledge, each mounted to the lower surface of the outer portion of the respective beam to extend outwardly from at least one side of the respective beam, each ledge defining an upper surface substantially parallel with the respective beam plane;
• means for mounting the inner portion of the infeed beam on the infeed table with the infeed beam positioned above the infeed reference plane such that the outer portion of the infeed beam is cantilevered from the infeed table with the infeed beam plane substantially parallel with the infeed reference plane;
• means for mounting the inner portion of the outfeed beam on the outfeed table with the outfeed beam positioned above the outfeed reference plane such that the outer portion of the outfeed beam is cantilevered from the outfeed table with the outfeed beam plane substantially parallel with the outfeed reference plane;
• said beams having sufficient rigidity to ensure that the upper surfaces of the infeed and outfeed ledges are substantially coplanar with the infeed and outfeed reference planes, respectively, when the beams are loaded only with the ledges;
• a pair of legs;
• and
• means for adjustably securing a respective one of the legs to the outer portion of each of the beams to support the beams against downward deflection when loaded with a workpiece as the workpiece is moved from the infeed ledge to the infeed table and from the outfeed table to the outfeed ledge.

An extension table for a machine tool of the type having a machine table that is substantially fixed during processing of a workpiece and that defines a reference plane, said extension table comprising:

• a center beam and at least one end beam, each having a respective lower surface which defines a respective beam plane;
• at least one ledge each mounted to the lower surface of a respective one of the end beams to extend outwardly from at least one side of the end beam, each ledge defining an upper surface substantially parallel with the respective beam plane;
• means for mounting the center beam on the machine table with the lower surface of the center beam resting on the machine table and the beam plane of the center beam substantially parallel with the reference plane;
• and
• means for releasably coupling each of the end beams to a respective end of the center beam such that each of the end beams is cantilevered from the center beam with the beam planes of each of the beams substantially parallel;
• said beams and said beam coupling means having sufficient rigidity to ensure that the upper surface of each of the ledges is maintained substantially coplanar with the reference plane when each of the end beams is loaded only with the respective ledge;
• at least one leg;
• and
• means for adjustably securing each of the legs to a respective end beam to support the end beam against downward deflection when loaded with a workpiece.

An extension table for a machine tool of the type that comprises a machine tool that comprises a machine table that is substantially fixed during processing of a workpiece, said table defining a workpiece feed direction and a reference plane, said extension table comprising:

• a beam having a lower surface which defines a beam plane, said beam comprising an inner portion and an outer portion;
• a ledge mounted to the lower surface of the outer portion of the beam to extend outwardly from at least one side of the beam, said ledge extending along the feed direction along the beam for a distance of at least about two feet to support the workpiece continuously as it slides on the ledge along the feed direction;
• means for mounting the inner portion of the beam on the machine table with the beam positioned above the reference plane such that the outer portion of the beam is cantilevered from the machine table with the beam plane substantially parallel with the reference plane;
• said beam having sufficient rigidity to ensure that the upper surface of the ledge is maintained substantially coplanar with the reference plane when the beam is loaded only with the ledge.

A method of installing an extension table on a machine tool of the type that comprises a machine table that is substantially fixed during processing of a workpiece and that defines a reference plane said method comprising the following steps:

• (a) providing an extension table comprising:
• a beam having a lower surface which defines a beam plane, said beam comprising an inner portion and an outer portion;
• a ledge mounted to the lower surface of the outer portion of the beam to extend outwardly from at least one side of the beam, said ledge defining an upper surface substantially parallel with the beam plane;
• said beam having sufficient rigidity to ensure that the upper surface of the ledges maintained substantially coplanar with the reference plane when the beam is loaded only with the ledge;
• (b) mounting the inner portion of the beam on the machine table with the beam positioned above the reference plane such that the outer portion of the beam is cantilevered from the machine table with the beam plane substantially parallel to the reference plane thereby automatically aligning the upper surface of the ledge with the reference plane;
• (c) positioning a leg on a support surface beneath the beam;
• and then
• (d) securing the leg to the outer portion of the beam to support the beam against downward deflection when loaded with a workpiece.

In combination with a machine tool of the type that comprises a machine table having an upper surface that defines a reference plane, and a cutting element for removing material from a workpiece supported on the machine table, the improvement comprising:

• first and second beams, each having a respective lower surface which defines a respective beam plane, each beam comprising a respective inner portion and a respective outer portion;
• first and second ledges, each mounted on the lower surface of the outer portion of the respective beam to extend outwardly from at least one side of the respective beam, each ledge defining an upper surface substantially parallel with the respective beam plane;
• a beam mounted assembly secured to the machine table to rest on the upper surface, said beam mounting assembly defining first and second beam mounting surfaces oriented parallel with one another on opposed sides of the cutting element;
• means for securing the inner portion of the first beam on the first beam mounting surface with the first beam positioned on the table above the reference plane such that the outer portion of the first beam is cantilevered from the table with the first beam plane substantially parallel with the reference plane;
• means for securing the inner portion of the second beam on the second beam mounting surface with the second beam positioned on the table above the reference plane such that the outer portion of the second beam is cantilevered from the table with the second beam plane substantially parallel with the reference plane;
• said beams having sufficient rigidity to ensure that the upper surfaces of the first ad second ledges are substantially coplanner with the reference plane when the beams are loaded only with the ledges.