Patent GB-341927-A (GB)
Title: Improvements in pressing machines
IPC: D06F71/06
Filed: 1929-10-23
Abstract: 341,927. Safety devices for machinery. AMERICAN LAUNDRY MACHINERY CO., Cincinnati, Ohio, U.S.A.-(Assignees of Singiser, J. P. ; 1800, N. Spalding Avenue. Chicago, U.S.A.) Oct. 23, 1929, No. 32254. Convention date, May 17, [Class 80 (iv).] Safety devices requiring both hands of operator to be occupied in starting and stopping machinery.-In a press-type ironing- machine which is operated by a piston and cylinder mechanism, having fluid-pressure inlet and exhaust valves controlled by the operator, both valves are normally closing valves and a spring is provided to overcome the normal closing tendency of the exhaust valve so that the latter must be positively maintained closed by one hand of the operator until the press reaches safe closed position, after which the effect of the spring is counteracted by means automatically operated by the closing of the press so that the exhaust valve is subsequently maintained closed automatically. In order that the other hand of the operator may be occupied during the closing movement of the press the inlet valve must also be manually maintained open until the press is safely closed, after which it is automatically maintained open by the saw means that counteract the spring associated with the exhaust valve. The exhaust-valve operating means comprise two normally disconnected por. tions which are placed into operative connection with one another only by the actuation of the inlet-valve operating means. The inlet valve 32, Fig. 3, in the supply pipe 30 to the cylinder 23 in which the piston 22, connected to the press-operating toggles, works is opened against its spring 34 by depression of a bell-crank lever 60 pivoted at 61, Fig. 1, to the machine frame and at 68 to a rearwardly extending rod 69 having a bracket 72 to which is adjustably secured a valve-stem engaging-member 73. A rearward extension 104, Fig. 3, of the rod 69 extends loosely through the bifurcated lower end 103, Fig. 6, of a lever arm 102 secured to a rock shaft 100 to which is also secured a lever 112 which is pivoted to a rod 113, Fig. 1, having an enlarged head 115 over which a cylinder 116 pivoted to the head lever 6 is slidably mounted. As the press closes, the lever 112 is rocked counterclockwise, Fig. 1, and the limbs of the lever arm 102, Fig. 6, engage the enlarged head 105 of the rod 104 to hold it in its rear position and consequently maintain the inlet valve open. A spring 95, Fig. 3, surrounding the operating-rod 87 of the exhaust valve 52 is confined between a fixed part 83 of the machine frame and a collar 96 fixed to the rod, and the effect of the spring 95 is superior to that of the exhaust-valve closing-spring 53, so that, in order to maintain the exhaust valve closed, the exhaust-valve operating-lever 80 must be kept depressed by the operator to hold the rod 87 in its rear position against the action of the spring 95 until the press is safely closed, at which time a bifurcated lever arm 108, similar to the lever arm 102 on the shaft 100, engages the enlarged head 110 on an extension 109 of the rod 87 to counteract the spring 95 and hold the rod 87 in its rear position and the exhaust valve closed. The exhaust-valve operating-lever 80 is not connected directly to the rod 87 but, as shown in Fig. 7, the latter is slidably mounted in a clevis 86 pivoted to the vertical arm 85 of the lever 80 which is pivoted at 81. A spring 125 keeps the lever 80 normally horizontal. The free ends of a pair of rods 130, 131, Fig. 3, the inner ends of which are connected at 132, are journalled in the clevis 86 and in the clevis 68 on the inlet-valve operating-rod 69 respectively and arms 134, 137 are secured to the rods. The arm 134 is provided with an adjustable pin 135 lying in the path of the inlet-valve operating-lever 60, so that as the latter is depressed the rods 131, 130 are rocked to swing the arm 137 upwardly so that its free end 138 engages the collar 96. Upon depression of the lever 80, therefore, the clevis 86, arm 137, and rod 87 move rearwardly together ; if the lever 60 has not been depressed, however, the end 138 of the arm 137 remains beneath the collar 96 and consequently, on depressing the lever 80, the movement thereof is not transmitted to the rod 87 and the exhaust valve, therefore, remains open. The valve-operating levers are provided with upstanding pins 150, Fig. 7, 145, Fig. 1, engaged by buttons 152, 148 to provide an alternative means for operating the levers. The piston-rod 21, Fig. 1, of the piston 22 working in the cylinder 23 is pivoted to the toggle-link 11 at a point below the joint 12, and the cylinder is pivoted at 24 and is provided with spring-pressed bolts 180, Fig. 3, which cushion the closing movement of the press. The opening movement of the press is cushioned by a snubber linked to the press head lever 6. The exhaust valve is provided with a silencer 160. Specification 341,928 is referred to.