Patent GB-431820-A (GB)
Title: Improvements in or relating to cam mechanism
IPC: D03D49/60
Filed: 1934-08-28
Abstract: 431,820. Cam mechanism; loom beat-up motions. HEWTON, W. R., 1433, North 62nd Street, Philadelphia, U.S.A. Aug. 28, 1934, No. 24806. [Class 80 (iii)] [See also Group IX] Cam mechanism for converting rotary into reciprocating motion with a period of rest during alternate revolutions of the cam, and particularly applicable for actuating the lays of weaving looms, comprises a rotary cam having a track with mergent circular grooves, one within the other, and respectively concentric with and eccentric to the axis of rotation, a follower engaging the track and means to cause the follower to traverse alternately the concentric and eccentric grooves. In one form, Figs. I, III, VI, the cam consists of two discs 13, 13a mounted on a shaft 15 and formed with concentric grooves 16, 16a and eccentric grooves 17, 17a. Each groove has an inclined plane 19, 19a and 21, 21a respectively whereby it vanishes into the side face of the cam disc at 18, 18a and 20, 20a. When the discs are assembled, the vanishing surfaces such as 18, 20 on one disc are opposed to the deep portions of the corresponding grooves on the other. The follower, in the form of a roller 24, engages the grooves at its ends and imparts motion to a slotted link 26 connected to the lay 10 and constrained to slide over the shaft 15. During rotation of the cam, the roller is shifted laterally and is obliged to follow alternately the concentric and eccentric grooves. In a modification, Fig. VIII, the cam consists of only a single disc 13b with concentric and eccentric grooves 16b, 17b, and the follower is caused to follow the grooves alternately by means of an additional cam 31 mounted on a shaft 32 geared to shaft 15b to rotate at one quarter of the speed thereof. A roller 36 engaging groove 35 of cam 31 is carried by a lever 37 pivoted at 38, the other end of the lever being slotted at 40 to engage the follower 24b connected to the lay 10b. In a further modification, Figs. X, XII, there is a single disc 13<c> with concentric and eccentric grooves 16c, 17c and the engagement of a follower 24c in one or other of these grooves is determined by a pair of switch tongues 42, 43 rockable about studs 44, 45 on the cam disc. These tongues have arms 46, Fig. XV, provided with lateral studs 48 which pass through openings 50, 51 in the cam disc for connection by a link 52. One of the studs 48, extends beyond the link 52, Fig. XII, to engage either of concentric grooves 54, 55 of another coaxial and fixed disc alongside the cam disc 13c. The fixed disc is provided with a pivoted semicircular switch segment 59 the pin 61 of which has an arm 65, Fig. XII, adapted to be actuated by an elliptic cam 67 to which is secured the star wheel 69 of a Geneva stop motion whereof the pin disc 70 is secured to the shaft 15c. During rotation of the cam disc, the elliptic cam 67 is actuated to move the switch segment 59 to cause the stud. 48 to travel in one or other of the grooves 54, 55 and this moves the switch tongues 42, 43 to cause the follower 24c to move in the appropriate concentric or eccentric groove.