. Watch and clock escapements; . to bestow,especially as they would have but very little use for such knowledgeexcept for this problem and a few others in dealing with epicycloidalcurves for the teeth of wheels. For all practical purposes it will make no difference whethersuch parallelism takes place after eight or nine degrees of angularmotion of the escape wheel subsequent to the locking action. Thegreat point, as far as practical results go, is to determine if it takesplace at or near the time the escape wheel meets the greatest 94 Watch and Clock Escapements. resistance from the hairspring
. Watch and clock escapements; . to bestow,especially as they would have but very little use for such knowledgeexcept for this problem and a few others in dealing with epicycloidalcurves for the teeth of wheels. For all practical purposes it will make no difference whethersuch parallelism takes place after eight or nine degrees of angularmotion of the escape wheel subsequent to the locking action. Thegreat point, as far as practical results go, is to determine if it takesplace at or near the time the escape wheel meets the greatest 94 Watch and Clock Escapements. resistance from the hairspring. We find by analysis of our draw-ing that parallelism takes place about the time when the tooth hasthree degrees of angular motion to make, and the pallet lacks abouttwo degrees of angular movement for the tooth to escape. It isthus evident that the relations, as shown in our drawing, are infavor of the train or mainspring power over hairspring resistance asthree is to two, while the average is only as eleven to ten ; that is,. h \ \ Fig. 92 the escape wheel in its entire effort passes through eleven degrees ofangular motion, while the pallets and fork move through ten student will thus see we have arranged to give the train-poweran advantage where it is most needed to overcome the opposinginfluence of the hairspring. As regards the exalted adhesion of the parallel surfaces, wefancy there is more harm feared than really exists, because, to takethe worst view of the situation, such parallelism only exists for thebriefest duration, in a practical sense, because theoretically thesesurfaces never slide on each other as parallel planes. Mathematically The Detached Lever Escapement. 95 considered, the theoretical plane represented by the impulse face ofthe tooth approaches parallelism with the plane represented by theimpulse face of the pallet, arrives at parallelism and instantly passesaway from such parallelism. TO DRAW A PALLET IN ANY POSITION. As delineated in Fig. 9
Size: 1497px × 1669px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, bookidwatchclockes, bookyear1904
