Tham khảo tài liệu 'five hundred and seven mechanical movements part 3', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Ị Mechanical Movements. 21 64. Another arrangement of jumping motion. Motion is communicated to worm-gear B by worm or endless screw at the bottom which is fixed upon the driving-shaft. Upon the shaft carrying the worm-gear works another hollow shaft on which is fixed cam A. A short piece of this hollow shaft is half cut away. A pin fixed in wonn-gcar shaft turns hollow- shaft and cam the spring which presses on cam holding hollow shaft back against the pin until it arrives a little further than shown in the figure when the direction of the pressure being changed by the peculiar shape of cam the latter falls down suddenly independently of worm-wheel and remains at rest till the pin overtakes it when the same action is repeated. 65. The left-hand disk or wheel c is the driving-wheel upon which is fixed the tappet A. . The other disk or wheel D has a series of equidistant studs projecting from its face. Every rotation of the tappet acting upon one of the studs in the wheel D causes the latter wheel to move the distance of one stud. In order that this may not be exceeded a lever-like stop is arranged on a fixed center. This stop operates in a notch cut in wheel c and at the instant tappet A strikes a stud said notch faces the lever. As W heel D rotates the end between studs is thrust out and the other extremity enters the notch but immediately on the tappet leaving stud the lever is again forced up in front of next stud and is there held by periphery of c pressing on its I other end. 66. A modification of 64 a weight D attached to an arm secured in the shaft of the worm-gear being used instead of spring and cam. 67. Another modification of 64 a weight or tumbler E secured on the hollow shaft being I used instead of spring and cam and operating in combination with pin c in the shaft of I W orm-gear. 68. The single tooth A of the driving-wheel J B acts in the notches of the wheel c and turns 1 the latter the distance of one notch in every revolution of c. No stop is .
