GB456798A - Control of power presses - Google Patents

Abstract

456,798. Machinery guards ; operating clutches. MASCHINENFABRIK WEINGARTEN VORM. H. SCHATZ AKT.-GES., and WACHTER, A., Weingarten, W³rtemberg, Germany. Feb. 5, 1936, No. 3459. [Classes 80 (ii) and 80 (iv)] Power presses are fitted with auxiliary hand controls 15 on opposite sides of the plunger which are interlocked with the main treadle control 16 so that the latter cannot function until both handles 15 are raised, the plunger 12 being declutched and braked on release of any one of the controls. A third handle 17 may be put into operation in place of the treadle 16, in which case one of the handles 15 is rendered inoperative by means of a key 19. The treadle is connected to a combined clutch and brake device, which is constructed substantially as described in Specification 448,327, by a rod 36, Fig. 4, a latch device, arms 41, 57, and shafts 28, 56. A rod 50, Fig. 6, is connected by the linkage shown with the shaft 56 and carries at one end a toothed wheel 49. When both the handles 15 are raised the wheel is held against rotation by teeth a on spring-pressed rods 48, Fig. 5. The rod 36 is connected by a bell-crank 44 with a sleeve 45, and this is normally held fast by spring - pressed pawls 46, which are disengaged, to permit use of the treadle, by shoulders 47 on the rods 48 when both the handles 15 are raised. If one of the handles is released, the wheel 49 becomes free to turn, the rod 50 is moved to the right, Fig. 6, by a spring 51, the rod 54 is raised, the rod 56 is turned clockwise, Fig. 4, the latch device is released, the connection with the treadle broken, and the brake is applied by a spring. To substitute the handle 17 for the treadle 16 a catch 18 is operated to move the handle into operative position and one of the handles 15 is then fully raised and then locked by the key 19. The clutch device referred to above provides a control whereby the machine may be worked continuously subject to the proper manipulation of the safety controls described, or intermittently, the plunger being brought to rest at top dead centre at the end of each complete reciprocation. In a modified construction, Fig. 10, the rods actuated by the handles 15 rotate shafts 77, in opposite directions against spring pressure. The shafts carry arms 76 which bear, when the handles are raised, on pivoted racks 73 to force the latter into engagement with a pinion on the end of a rod 70 connected to the clutch device. The latch device shown in Fig. 4 operates as follows. A plate 38 is pivoted at 37 in a slot in the end of the rod 36 and is slotted at s to engage a pin 39 passing through a sliding sleeve 40 into the forked end of an arm 41 fast on the shaft 28. An arm 57 fast on the shaft 56 carries a pin 58 which passes through a slot in the sleeve into a plate 60. If the shaft 56 turns clockwise the plate 60 is raised and an inclined face 61 thereon is pushed against a face 62 on the plate 38 and the latter is forced away from the pin 39 through a slot 43 in the sleeve against the pressure of a spring 42, the shaft 28 may thereupon be turned independently of the rod 36. Specification 15918/02, [Class 80], also is referred to.