Patent GB-190519711-A (GB)
Title: Improvements in or relating to Ratchet Mechanism.
Inventor: JOHN HUGO
Filed: 1905-09-29
Granted: 1906-08-09
Abstract: 19,711. John, H. Sept. 29. Gearing, driving; punching ; shearing ; welding. -Relates to mechanism for releasing the pawl of a ratchet gear, such as is described in Specification No. 14,366, A.D. 1900, [Abridgment Class Mechanism &c.]. Beneath the pawl k, Figs. 2 and 6, is arranged a finger 2 carried on a spindle 3 on which is mounted an arm 6. This finger is actuated to lift the pawl out of engagement with the ratcbet-wheel 1 by a toggle arrangement, operated by band or foot or by the machine, such as a punch, shears, or press, to which the gear is applied. This toggle arrangement comprises an adjustable and yielding member 7 connected to the arm 6 and to an arm 16 on a rocking shaft 18. The member 7 is made up of end portions 9, 12, Fig. 8, connected by a rod 8, one end of which is adjustably screwed into the part 9, and the other end slides in the part 12 ; a spring 13, encircling the rod 8, keeps the portions 9, 12 pressedapart. This yielding member enables the arm 16 to be . turned, even when the pawl is in actual engagement with the ratchet, the pawl being lifted immediately it becomes disengaged, and also serves to allow the levers to be retained in the position to which they are moved, and to allow for the elight oscillation of the arm 6. The arm 16 is operated by a lever 19, fixed to the shaft 18 movable by hand, or through a connexion 52 by a treadle, stops being provided on the hub of the lever to engage stops on the hub of the arm 16 ; other stops on the arm 16 engage stops on the bearing of the shaft 18 to limit the motion. By the arrangement of the mechanism shown in Figs. 2, 4, 9, and 11, the motion of the ratchet-wheel is employed to rock the shift 18, and thereby release the pawl. A cam 38 on the shaft of the eccentric 37 actuates one end of a pivoted lever 41, the other end of which is adapted to engage a spring pin 42 mounted on one member of a bell-crank lever 33 fixed to the shaft 18. The other member of the lever 33 is connected to the machine frame by a spring 35 so arranged that, when the lever is pushed over the dead centre, the spring carries the lever to the end of the travel and retains it in that position. By pulling the spring pin 42 within the boss of the lever 33, so as to remove it out of the path of the lever 41, the releasing-mechanism is put out of operation. The cam 38 is not directly secured to the shaft, but is driven by a bowl on a pin 44, which is fixed in a groove 45 in a ratchet-wheel 46 and engages a slot 43 in the cam. After the cam has released the pawl, it falls by gravity into such a position that the swell is clear of the lever 41, thereby enabling the pawl to be put into engagement again. By adjusting the position of the pin 44 in the groove 45, the pawl may be released at any point of travel of the tool. In order to set the tool, such as a punch, a lever 54, pivoted on the end of the shaft 37, has a projection 62, Fig. 11, adapted to engage notches in a setting-disk 59 secured to the shaft. By bringing the projection into engagement with the disk and turning, the lever, the shaft may be rotated to set the tool. Normally, the lever is held out of engagement with the disk by a spring 63 on the lever engaging the disk. The pawl may be brought into engagement automatically by operating the controlling-lever by an element on the main driving-shaft.