Patent GB-383895-A (GB)
Title: Improvements relating to the feed-mechanism of slicing machines
IPC: F16H31/00
Filed: 1932-05-14
Abstract: 383,895. Slicing-machines. NAAMLOOZE VENNOOTSCHAP MAATSCHAPPIJ TOT VERVAARDIGING VAN SNIJMACHINES VOLGENS VAN BERKEL'S PATENT EN VAN ANDERE WERKTUIGEN and BERKEL, W. A. VAN, 33, Boezemsingel, Rotterdam, Holland. May 14, 1932, No. 13945. [Class 28 (ii).] Ratchet and pawl feed-mechanism for slicing- machines is characterized by the provision of a movable auxiliary member having an operative connection with the pawl, the said connection being such that the said member moves with the pawl in its working movement and in its idle movement, and that the pawl is maintained clear of the ratchet teeth during the idle movement. As shown in Figs. 1, 3, and 4, the feed pawl 11 is pivoted at 11a to a swinging double-armed member 15, 17 actuated in known manner by a tubular member 19 universally jointed at 18 to the arm 17 and universally jointed at 20 to a rocking arm 21 actuated from some part of the machine. A roller 30 on the pawl engages a slice-thickness regulating cam 31 journalled on the feed screw 12 and having an extension 32 adjustably connected by a pin-and-slot arrangement 33 with an arm 34 journalled on the feed screw and extended in arcuate form 36 to lie close to an arcuate fixture 37 secured to the reciprocating carriage 14. The extension 36 carries a member 39 having a pin or plunger 40 engageable with any one of a series of holes 41 in the fixture 37, the corresponding slice thickness being readable on a scale through an aperture 42. Adjustment of the substance holder, irrespective of the feed movements, may be effected by a handle 50 on a boss 51 having a pin 55 projecting inwardly into a helical groove 56 in the end of the feed screw. The boss 51 is normally pressed by a spring 54 against a retaining washer 53 so that, when the handle is rotated counterclockwise, Fig. 1, the boss jams against the washer and the handle, boss and shaft rotate as a solid unit to advance the material towards the knife. For the reverse movement, it is essential that the pawl should be disengaged, this being effected on the clockwise rotation of the handle 50 by the boss 51 being moved in against the spring by the pin 55 and groove 56. The bevelled edge 51a of the boss then engages a finger 59, Fig. 1, connected to the pawl, and by a wedge-like action raises the pawl from the feed ratchet. When the pin 55 reaches the end of the groove 56, or when the boss 51 contacts with the nave 10a of the ratchet 10, the handle, boss and feed screw rotate as a solid unit to withdraw the substance from the knife. The mechanism for lifting the pawl during the idle strokes of the automatic feed comprises a ring 62 revoluble on the nave 10a and spring-pressed by the sleeve 64 against the side of the ratchet 10 so that a frictional drag is imposed on the ring's movements. The ring has a recess 61 into which projects, with play, a finger 60 connected with the pawl. When the pawl swings back on its idle stroke, it first rides up the first ratchet tooth and the finger 60 rises in, and contacts with the righthand side of, the recess. As the arm 15, 17 swings back further, the finger 60 again rises slightly in the recess, and is retained in this position by the frictional engagement of the finger with the side of the recess. The pawl thus travels back out of contact with the ratchet teeth. When the arm 15, 17 reverses for the feed stroke, the left-hand side of the recess contacts with the finger 60 and when the pawl is freed from the slice-feed regulating cam 31, the pawl is forced, by the interaction of the finger 60 and recess, into engagement with the ratchet. In a modification, the pawl is overbalanced so as normally to tilt out of engagement with the ratchet. The pawl is held in engagement with the ratchet during the feed stroke by the interaction of the finger on the pawl and the recess in the auxiliary ring. The pin and helical groove construction associated with the feed screw handle is dispensed with. A spring-pressed plunger may be used instead of a solid finger 60, and the auxiliary ring may be arranged externally of the ratchet wheel, the pawl then having an extension which projects radially outwards into a recess in the interior of the ring.