The American watchmaker and jeweler; an encyclopedia for the horologist, jeweler, gold and silversmith .. . ce that 30° is one-fourth of the distancebetween two arms. With a compensation balance a third of the dis-tance between two of the quarter screws is 30°. A round ruby pin, although it is sometimes used in common watches,gives a bad action and necessitates a very large balance arc. Fig. 200 is appended as a guide to students in setting out the escape-ment. A circle representing the extreme diameter of the escape wheelis taken as a basis, and on the left of the center line is set off, byme
The American watchmaker and jeweler; an encyclopedia for the horologist, jeweler, gold and silversmith .. . ce that 30° is one-fourth of the distancebetween two arms. With a compensation balance a third of the dis-tance between two of the quarter screws is 30°. A round ruby pin, although it is sometimes used in common watches,gives a bad action and necessitates a very large balance arc. Fig. 200 is appended as a guide to students in setting out the escape-ment. A circle representing the extreme diameter of the escape wheelis taken as a basis, and on the left of the center line is set off, bymeans of a protractor, the middle of one pallet (30°) and its width(10°). The chord of this arc of 10° is then produced till it cuts thecenter line, and this intersection is taken as the center of the palletstaff. From the pallet-staff center curves, A and B, (representing thepaths of the pallet corners,) are drawn. The amount of locking C(say 2°) and impulse D (say 9°) are set off from the chord of the left-hand pallet. The impulse plane is traced through the intersection of 223 Lever -^^• Lever Escapement. 224 the angular lines with the curves A and B, and the line of the planeproduced toward the center of the staff as shown. From the centerof the staff is described a circle just touching the line so impulse plane of the other pallet forms a tangent to this this position of the pallets, a line drawn from the locking cornerof the left-hand pallet to form an angle of 12° with the radial linefrom the center of the wheel, will be required to show the lockingface of the pallet, and a similar line forming 3° will answer for thelocking face of the right-hand pallet. Mark off the center of the roller(E), and take, say, one-fourth of the distance between this center andthe center of the pallet staff for the position of the center of the im-pulse pin, and describe the arc F to represent its path. The line G,forming with the center line runni
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Keywords: ., bookcentury1800, bookdecade1890, bookidamericanwatc, bookyear1892
