Patent GB-686458-A (GB)
Title: Work-table driving and locating means for power presses having rotatable work-tables
IPC: D06F71/10
Filed: 1949-11-10
Abstract: 686,458. Ironing-presses. TAYLOR, J. A. M. Feb. 9, 1951. [Nov. 10, 1949; Dec. 8, 1950] Nos. 28836/49 and 30107/50. Class 138 (ii). In a pneumatic or hydraulic power press of the kind having a work table structure rotated intermittently through part of a revolution into a position where one of the tables is raised against a pressing head, and the rotation is effected by a device energized or operated by the fluid pressure used to raise the table and is controlled by a manually operated valve which also controls the table raising device, and arranged so that the table structure is powerrotated after each pressing operation, the power rotation device is a cylinder and piston mounted to oscillate about a fixed vertical column of the machine. As shown in Figs. 1 and 2, two tables 2 and associated trays 2a are mounted on the structure 1 rotatable about axis x-x. Under the fixed pressing head 3 is a hydraulic ram 4 which raises one of the tables 2 against the head. Pressure fluid enters the pipe 6, through valve 6a which is opened automatically by a tappet 6c when one of the tables has been rotated into operative position, to operate the hydraulic ram 4, to raise its associated table 2. Depression of pedal 9 closes the valve 6a and exhausts the ram cylinder. When the valve 6a is opened pressure is also admitted through flexible pipe 29 to cylinder 13, see also Fig. 3, which is pivotally mounted on the vertical post 11. The pivotal mounting and the collar 15 on which it rests may each be formed in two parts as shown whereby the device may be applied to existing machines. The piston 16 and rod 17 move to the right and arm 19, which is connected to vertical spindle 25 by a ratchet, rotates freely about spindle 25. When the pressure is cut off and the cylinder connected to exhaust by depression of pedal 9, the piston returns under the action of spring 20, which rotates the arm 19 to swing the tables round. Fig. 8 shows a stop device for arresting the swinging movement of the tables at the desired position. The pivoted arm 31 normally rests on stop 35 under the influence of tension spring 34. Each table has depending therefrom an arm 32 with a cranked end carrying a roller 33. The table and arm 32 travelling from right to left are arrested in the position shown. The ram then automatically raises the table and with it arm 32, which then abuts against member 37 and permits the pivoted arm 31 to return to its inclined position against stop 35, so that when the table and arm 32 again descend they are free to move to the left. In the modification shown in Figs. 10 and 11, the table structure is rotated when fluid pressure is admitted to the cylinder 13. In this arrangement rotation of the table structure to its operative position opens valve 6a and admits pressure from pipe 6 to the ram cylinder 4 which raises the table. Attached to the ram 4a is a plate 46 which can actuate two valves 45, 47. When pedal 9 is depressed valve 40 is closed to cut off pressure to the ram cylinder and valve 41 is opened to exhaust the cylinder ; valve 42 is opened to admit pressure from supply pipe 6 to valve 45, which is opened when the ram and table have descended, whereby cylinder 13 is pressurised to rotate the table structure. Descent of the ram also closes the exhaust valve 47 for the cylinder 13. An automatic stop to arrest the rotation of the table structure similar to that shown in Fig. 8 may be provided with the modification shown in Figs. 10 and 11.