Patent GB-564111-A (GB)
Title: An improved dividing engine
IPC: B25H7/04
Filed: 1943-03-09
Abstract: 564,111. Dividing-engines. BARFORD, F. C. March 9, 1943, No. 3816. [Class 97 (iii)] A dividing-engine comprises a bed for supporting a scale to be calibrated, a carriage movable along the bed, a marking device mounted on the carriage and a standard scale or the equivalent mounted on the bed for controlling the marking of the scale to be calibrated. The marking device includes an arm for actuating the marking tool and is movable over a quadrant to a fixed stop in one direction and to one of a number of stops in the other direction according to the length of graduation to be marked, a plunger normally preventing the arm from passing the stops in one direction, but can be moved to do so while the stops are so formed that the plunger can ride over them in the other or marking direction. Both manual and automatic arrangements are described. The bed comprises two rigid bars 1, 2, the rear bar 1 carrying stops 3 for the scale to be calibrated. The bar 2 carries the standard scale 201 from which the calibrations are to be made and is provided with a lead screw 10 for operating a slider 12 having two pairs of pointers 13, 14, each pair being spaced apart such that if the scale, say, is to be marked at every .025", the pointers 13 are spaced .025" apart while the pointers 14 are spaced .024" apart to calibrate a vernier for co-operation with the scale. A lead screw 4 operable by handles 7 is also provided for operating the carriage which slides on the bed 1, 2. The carriage comprises a base 15, adapted to slide on the bed 1, 2, and provided with a lug 23 tapped to engage the lead screw 4 and a second lug having a vertical slot for adjustably carrying the marking device which includes a frame 30. A slider 31 is movableon the frame 30 in the fore-and-aft direction, being urged to its forward direction by a spring 32. The slider 31 carries an arm 33, pivoted at 34 and urged downwards by the spring 35, and carrying the tool holder 36 and cutting tool 37. For moving the slider 31 in making the graduations, a rack 38 fixed to its upper edge is engaged by a pinion 39 fast on the arm 40 which has a finger piece 41 at its end. The frame 30 is provided with a quadrant 42 carrying an arcuate bar 44 upon which the stops 45 ... 48 are adjusted and fixed. A plunger is carried by the arm 40 so that the arm 40 is arrested by any of the stops 46 ... 48 on the upward stroke, but can be moved to allow the arm to pass any of the stops desired. In operation, the arm is brought to, say, the stop 46, the tool 37 is released by the bell-crank lever 51 allowing the tool to bear on the scale to be marked and the arm 40 is depressed to the stop 45 causing the tool 37 to make the length of mark desired. When it is desired to make longer marks, say, at 0.1" and at every inch, the arm is brought to bear against the stops 47, 48 respectively and the arm 40 depressed to the stop 45, the plunger on the arm 40 passing freely over any intermediate stops on the downward stroke. The Specification also includes a modification which is operated automatically by power and includes means for selecting the appropriate stop for the desired length of graduation, the raising and lowering of the marking tool and the operation of its working stroke.