GB677066A - Improvements in or relating to the forming of curved surfaces - Google Patents

Abstract

677,066. Copy-milling. FAIREY AVIATION CO., Ltd. Jan. 9, 1950 [Feb. 11, 1949], No. 3828/49. Class 83 (iii). [Also in Group XXIII] A milling, grinding or like machine for forming a curved surface such as that of an aerofoil rib 19 or 20, comprises a work-holder 16 supported at its ends on profile cams 17, 18 in rolling contact with plates 14, 15, a tool 10 traversable along the length of the work-holder between the contact plates, means to maintain the work-holder in any desired position relatively to the tool, and adjusting-means for presenting different faces of the work to the tool while the profile cams are maintained against the contact plates. The work-holder is balanced by counterweights 25 connected to it, at the level of its centre of gravity, by cables 21 which pass over a beam 23 pivoted on a vertical axis to allow for cross-traversing movements. The work-pieces are dependently mounted between the profile cams and, if the aerofoil is of sweptback formation, they are mounted in an inclined position as shown at 20; if the aerofoil is of tapered form, one cam is of larger crosssection than the other. A spindle 33 connected by a universal joint to the work-holder is splined to a worm-wheel on a carriage 35 which is slidable vertically on a bracket 28 transversely adjustable on the machine frame. In operation, with the cam bearing on the profile plates 14, 15, under the pressure of adjustable springs 36 acting on the carriage, an end-mill cutter 10 is traversed past the work-pieces to produce a facet of the required form and after each traverse, the work-holder is rotated slightly by a hand wheel 42 and the worm-wheel to present another part to be cut, the cams being maintained in contact with the plates 14, 15. Subsequently, the facets may be removed by exchanging the milling cutter for a grinding or sanding wheel.