GB641886A - Improvements in or relating to cam devices - Google Patents

Abstract

641,886. Cam mechanism. NAAMLOOZE VENNOOTSCHAP PHILIPS' GLOEILAMPENFABRIEKEN. Nov. 4,. 1946, No. 32755. Convention date, March 3, 1943. [Class 80(iii)] [Also in Group XXXVII] A cam mechanism for giving a member,. such as the contact of an electric switch, a rapid movement in both directions comprises a cam 1, Fig. 2, movable in the direction A and having a profiled edge 2 cooperating with a follower member 4 loaded by a spring 5. On movement of the cam 1 the spring 5 is gradually loaded until the follower 4 drops rapidly into the re-entrant portion 6 of the cam which may move a switch contact into an " on " position. Movement of an auxiliary cam member 9 in a direction B gradually loads the spring 12 of an auxiliary follower 7 until this follower drops into a re-entrant portion 10 of the cam 9. During this movement the end 13 of this member 7 engages a hooklike portion 14 on the follower 4 to move the latter quickly to its original " off " position. The auxiliary member 9 may be coupled to the member 1 or may be operated independently. In the arrangement of Fig. 4 rotary main and auxiliary cam discs 20, 21 are provided for actuating a lever arm 23. On rotation of the discs in the direction of arrow C the end 29 of lever 23 is adapted to fall rapidly into a reentrant 27 of the disc 20 under the tension of a spring 30 connected between lever 23 and an auxiliary lever 24. The spring 32 of this auxiliary lever is gradually loaded by the cam 21 until the re-entrant portion 33 passes the end 31 of this lever when it moves rapidly and engages an abutment 26 of lever 23 to move the latter back to its original position. In a modification of this last arrangement the cam discs are driven by a pin engagement with an arm on the driving shaft and the re-entrant portion 27 is provided with a bevelled edge co-operating with a bevel on the follower. The action in this case when the follower drops into the re-entrant is to advance the discs in front of the driving means and speed-up the operation of the return movement. Applications of the mechanism mentioned are for the intermittent operation of a stylus on to a registering strip in an automatic registering device and for an electric device for checking the rotation of a shaft in which the cam operated member effects a make and break of an electric circuit to maintain a condenser charged and a relay energized.