Clamshell mounted pipe nozzle weld milling machine with centering apparatus

Apparatus for removing the overlay weld material from an arcuate surface of a pipe fitting, comprising:

• (a) clamshell means adapted to be concentrically mounted on a pipe whose fitting is to be treated, said clamshell means including an annular stationary member, an annular rotatable member and means for driving said rotatable member relative to said stationary member around said pipe as a center;
• (b) stationary guide block means affixed to said rotatable member for rotation therewith, said stationary guide block means projecting normally from a side surface of said rotatable member and including a guide groove extending in the radial direction relative to said pipe on which said clamshell means is mounted and a first lead screw journaled for rotation in said stationary guide block means with a longitudinal axis oriented in said radial direction;
• (c) a moveable guide block having a projection for extending into said guide groove in said stationary guide block and operatively coupled to said first lead screw for reciprocal movement in the direction of said guide groove as said first lead screw is rotated, said movable guide block further including a cam track having an arcuate shape corresponding to said arcuate surface of said pipe fitting to be treated;
• (d) tool block translating means joined to said rotatable member of said clamshell means and including an axial extending guide groove and a second lead screw journaled for rotation therein and extending parallel to said axial extending guide groove;
• (e) tool block slide means having a projection slidably received in said axial extending guide groove and operatively coupled to said second lead screw whereby rotation of said second lead screw translates said tool block slide means, said tool block slide means further including a radial guide groove;
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• (f) tool bit clamping means for clamping a cutting bit therein, said tool bit clamping means having a projection insertable into said radial guide groove of said tool block slide means and a cam follower joined thereto and engaging said cam track whereby axial movement of said tool block slide means causes said cutting bit to follow said arcuate surface and rotation of said first lead screw determines the depth of cut.

Apparatus for removing the overlay weld material from an arcuate surface of a pipe fitting, comprising:

• (a) clamshell means adapted to be concentrically mounted on a pipe whose fitting is to be treated, said clamshell means including an annular stationary member, an annular rotatable member and means for driving said rotatable member relative to said stationary member around said pipe as a center;
• (b) stationary guide block means affixed to said rotatable member for rotation therewith, said stationary guide block means projecting normally from a side surface of said rotatable member and including a guide projection extending in the radial direction relative to said pipe on which said clamshell means is mounted and a first lead screw journaled for rotation in said stationary guide block means with a longitudinal axis oriented in said radial direction;
• (c) a moveable guide block having a guide groove for receiving said guide projection therein and operatively coupled to said first lead screw for reciprocal movement in the direction of said guide projection as said first lead screw is rotated, said movable guide block further including a cam track having an arcuate shape corresponding to said arcuate surface of said pipe fitting to be treated;
• (d) tool block translating means affixed to said rotatable member of said clamshell means and including an axial extending projection and a second lead screw journaled for rotation therein and extending parallel to said axial extending projection;
• (e) tool block slide means having a guide groove for slidably receiving said axial extending guide projection and operatively coupled to said second lead screw whereby rotation of said second lead screw translates said tool block slide means, said tool block slide means further including a radial guide projection;
• and
• (f) tool bit clamping means for clamping a cutting bit therein, said tool bit clamping means having a guide groove formed therein in which said guide projection of said tool block slide means is received and a cam follower joined thereto and engaging said cam track whereby axial movement of said tool block slide means causes said cutting bit to follow said arcuate surface and rotation of said first lead screw determines the depth of cut.