705,069. Folding piece goods. AMERICAN LAUNDRY MACHINERY CO. March 9, 1951, No. 5781/51. Class 42 (2) Control means adapted to time the execution of an operation on each of a series of spaced articles moving on a conveyer, and whereby an operating member is energized to perform such operation responsive to rotation of a timing member past a point of registry, comprise first and second driving members, with means for rotating the first driving member and for rotating the second driving member at a proportional lower rate, means for producing planar frictional engagement between the first driving member, and the timing member, which is prevented from rotation by stop means, means for producing positive driving engagement between the timing member and the second driving member while simultaneously rendering the stop means ineffective, so that the timing member rotates with the second driving member and means for terminating this positive driving engagement while the stop means remains ineffective, permitting the timing member to be driven by its frictional engagement with the first driving member until it reaches the point of registry. The apparatus is described as applied to a folding machine which includes a conveyer 13, Fig. 6, with which is associated a trip switch 14 which is operated by .the leading and trailing edges of an article, a solenoid-operated folding blade 10, and a pair of folding rolls 11. The folding impulses are supplied to the solenoid 12 by a controller comprising two alternately operating timing units A and B (Fig. 2), for controlling the folding of successive articles, each unit comprising two sections for timing two successive folds on a given article. The controller has a main shaft 19, driven by a chain 29, sprocket 28 and bevel gearing 25, 26 at a speed proportional to that of the conveyer; a shaft 31 is driven through gearing 33, at one quarter and a shaft 30 at three quarters, of the speed of the shaft 19, and two timing sections are associated with each of the shafts 30, 31, all four sections being of similar construction. In that shown in Fig. 4, one half 42 of a positive clutch is pinned to the shaft 30, the other half 44 being secured to one side of a disc 45 which is free to rotate on a sleeve 46 which is freely rotatable on the shaft 30. On the other side of the disc 45 is a slip clutch comprising a compressible friction ring 47 and a flanged sleeve 48 secured to a gear 36 which is driven by a gear 34 on the shaft 19, the corresponding gears for the othei three sections having the same number of teeth. The ring 47 is compressed between the flange on the sleeve 48 and the disc 45 by a spring 50, and thus the disc 45 rotates at the speed of the gear 36 unless either (a) restrained by a finger 59 on a yoke lever 55 contacting a stop 60 on the disc 45, or (b) driven at the speed of the shaft 30 when the clutch parts 42, 44 are engaged by movement of the sleeve 46 along the shaft 30, against the bias of a spring 53, by a spool 57 which is operated by fingers 56 on the lever 55, movement of which simultaneously releases the stop 60. The yoke lever 55 is common to both units of section A and has a forked leg 62 straddling a rod 63 and engaging a nut 65 on its end. The rod 63 is operated by a solenoid 64, as the leading edge of an article closes the switch 14 when the disc 45 and the similar disc 45a of the other section of timing unit A are released and clutched to the shafts 30 and 31 respectively until the solenoid ceases to act on the trailing edge of the article leaving the switch 14, when the slip clutches cause them to rotate at the speed of the shaft 19 until the stop 60 is arrested by the finger 59. The peripheries of the discs 45 and 45a have projections for operating switches 16 and 15 at fixed points in their paths. A separate solenoid 66 is provided for independently operating timing unit B through a rod and yoke lever. For using the units A and B alternately for timing successive articles, a cam disc 73 is loosely mounted on shaft 19 and is pressed by a spring 75 against a friction disc 74 supported by a collar 77 pinned to the shaft 19. The disc 73 has stop pins 78 and 79 extending alternately to front and rear thereof, and cooperating with arms 91, 92 of a rocker 90 to form an escapement. The rocker is operated by a spring-urged rod 95, when either of the solenoids 64 or 66 is energized, the rod 95 having a collar 99 for engaging a plate 100 on yoke 55, the end of the rod engaging a similar plate on the yoke 68 of unit B. Rises on the edge of cam disc 73 are adapted to operate a double throw switch 72, which alternately connects the solenoids 64 and 66 in the effective circuit. The leading edge of an article, e.g. a sheet on the conveyer 13 closes trip switch 14 (Fig. 6), completing a circuit from L1 through switch 72 and solenoid 64 to L2, releasing the discs 45 and 45a of timing unit A, and engaging clutch parts 42, 44, so that the discs rotate at three-quarters and one-quarter, respectively, of the speed of shaft 19. On the trailing edge of the article passing switch 14, solenoid 64 is de-energized, and the clutch parts 42, 44 separate, the discs then being driven at full speed through the slip clutch 45, 47. When the cam rise 45c on disc 45 operates switch 16, it completes a circuit from L1, through switch 16, a switch 112 operated by a cam 113 on the folder shaft 14, and solenoid 12 to L2. This operates a half-revolution clutch mechanism 94, causing the arm 10 to move to its rear position contacting the dropping sheet, which drapes over the horizontal portion of the arm, and opening switch 112 and closing a switch 118. Operation of switch 15 by the cam rise 45d on disc 45a completes circuit from L1 through switches 15 and 118 and solenoid 12 to L2, causing a second operation of folder arm 10, and a half-revolution of shaft 114, closing switch 112 and opening switch 118. Energization and de-energization of the solenoid 64 permits the cam disc 73 to undergo two increments of rotation, throwing over the switch 72, so that the arrival of the next article at the trip switch 14 causes a circuit to be completed through the solenoid 66 timing operations are then carried out by unit B.