Patent GB-1081933-A (GB)
Title: Hydraulic apparatus controlling one or more beams
IPC: B65H23/185
Filed: 1964-08-25
Abstract: 1,081,933. Winding and unwinding fabric webs. PEDER MORTENSEN A.S. Aug. 25, 1964 [Aug. 26, 1963], No. 34780/64. Heading B6B. [Also in Divisions D1 and F2] In an hydraulic apparatus winding and/or unwinding cloth on one or more beams (i.e. textile rollers) comprising one or more oil motors the turning moment and speed of rotation of which are substantially proportional respectively to the oil pressure difference across and oil quantity per unit time flowing through the motor, variable resistance means varies the quantity of oil per unit time flowing through the motor or motors or the difference in oil pressure between the two sides of each motor, and adjustment means sensitive to an oil pressure in the hydraulic system varies said resistance means. In the winding apparatus shown in Fig. 1, a constant speed electric motor driven pump 1 feeds a motor 2 the pressure in the supply line thereto being determined by a pressure adjustment valve 3, or a pressure adjustment valve 5 in series with an electromagnetic valve 6. When the pump drive motor is started the valve 6 is open so that the valve 5 determines a small pressure in the supply line sufficient for cloth tensioning, and when a main machine from which the cloth comes is started the valve 6 is closed and the valve 3 determines a full pressure in the supply line. Needle valves 16, 19 are respectively shunted across the motor 2 and provided in the return line so that steady pressure increase and decrease is attained before and after the motor 2 to increase the pressure difference thereacross to meet the turning moment which increases with beam diameter. With constant beam peripheral speed the speed of the motor 2 decreases with increase in beam diameter so that the quantity of oil shunted through the valve 16 increases and, with a constant flow area in this valve, the pressure in the supply line increases. Further, as the motor speed decreases the flow through the valve 19 decreases so that the pressure between the motor 2 and the valve 19 decreases. To avoid excessive pressure difference across the motor 2 with resultant high cloth tension in the event of a stoppage of the main machine, the valve 6 is arranged to open on main machine stoppage. For use behind a variable-speed main machine, first a valve 14 is closed and the valve 6 opened, and after the cloth is tensioned oil flowing through the valve 16 flows partly through a valve 15 and partly through a motor 8 and a non-return valve 11 to the return line. Rotation of the motor 8 in this direction effects through chains, opening and closing adjustment respectively of the valves 16, 19 until pressure equalizing obtains, whereupon the motor 8 stops and the valves 16, 19 are adjusted for start. The main machine is then started and the valve 6 closed, the supply line has full pressure, and a small amount of oil is passed through a valve 18 to a pilot line the pressure in which acts closingly together with a spring on a valve 7. An air enclosing pressure compensation container 9 is provided for this pilot line and excess oil is returned through a valve 17 which is adjusted to determine the maximum pressure after the motor 2. A non-return valve 10 is held closed by a relatively high pressure after the motor 2. When the pressure before the valve 19 increases it acts through a further pilot line and a three-way changeover valve 12 to open the valve 7 and allow oil from after the motor 2 to flow through the motor 8 and the valves 15, 14 the latter having been opened with main machine starting, the resultant rotation of the motor 8 opens up the valve 19 so that the pressure thereafter decreases, and the motor 8 stops, and the valve 16 is correspondingly closed. When the main machine attains its desired speed the valves 16, 19 have been automatically set correspondingly. The valve 18 is then manually closed and, the pressure in the following pilot line being retained by the container 9 until the pressure after the motor 2 drops, the pressures in the pilot lines on both sides of the valve 7 are equal so that the valve 7 is closed exclusively by its spring. If the main machine speed increases, the pressure before the valve 19 increases and opens the valve 7 to rotate the motor 8 to adjust the valves 16, 19 to suit the new peripheral speed without change in turning moments. If the main machine speed decreases, the valve 14 (main machine speed responsive) closes and oil from the valve 16 flows through the motor 8 in the opposite direction to adjust the valves 16, 19 until the valve 14 reopens. On stopping the machine the valves 14 and 6 are closed and open respectively, oil flowing through the motor 8 and the non-return valve 11 acts to keep the non-return valve 10 closed and the closing pressure retained on the valve 7, and the valve 19 is set for pressure equalizing. When the machine is started again it will adjust itself to the closing pressure on the valve 7 that corresponds to the beam diameter and main machine speed. When a new beam is to be wound the valve 18 which may be electrically actuated at starting is reopened to reset the valve 7. An additional valve 23 may be inserted to retain closing pressure on the valve 7. To compensate for water unbalance when winding wet cloth on a large diameter the three-way valve 12 is switched over so that the supply line is connected to act in the opening direction on the valve 7, a needle valve by-passing the non- return valve 10 is opened so that the pressure after the motor 2 is connected to act in the closing direction on the valve 7, a valve 13 bypassing the motor 8 is opened, and the spring on the valve 7 is so loaded that its pressure plus that after the motor 2 approximates the supply pressure. When the beam heavy-side rises the speed of the motor 2 decreases and since the pressures before and after the motor 2 respectively increase and decrease the valve 7 opens to further decrease pressure after the motor 2 so that the turning moment increases. When the heavy-side lowers the resulting increased speed of the motor 2 increases the pressure after the motor 2 so that the valve 7 is nearly closed and necessitates forcing the oil through the valve 19 for braking. When the heavy-side is at top or bottom the valve 7 is somewhat open so that oil passes partly through the valve 7 and partly through the valve 19 to provide a rather high pressure after the motor 2. In the unwinding apparatus shown in Fig. 2 (not shown), where the cloth tension is maintained constant, a constant-speed electric motor-driven pump (1) feeds a motor (2) through a pressure-reduction valve (25), the pressure in the supply line to the valve (25) being determined by a pressure-adjustment valve (27) relieving excess oil back to the tank. Oil return from the motor (2) passes through a valve (26) regulating flow regardless of pressure. A regulation motor (8) is mechanically connected to the valves (27), (26). Pressure equalizing before and after the motor (2) is attained through the motor (8) and a non-return valve (11). A valve (7) between the return line, after the motor (2), and the motor (8) is acted on by pressures in pilot lines connected between the valves (25), (27) and the motor (2) and the valve (26). The motor (2) functions as a brake. The peripheral speed is adjusted by the valve (26), and the valve (25) is set so that the pressure difference thereacross is that across the motor (2) to balance and close the valve (7). As the beam diameter decreases during unwinding the turning moment caused by the cloth tension decreases and the thereby reduced pressure after the motor (2) allows the valve (7) to open. The motor (8) rotates and opens up the valve (26) to effect increase of the speed of the motor (2) and adjusts the valve (27) to decrease the pressure between the valves (25), (27), whereupon the valve (7) closes and the motor (8) stops. Since the procedure repeats each time pressure is reduced after the motor (2), the valve (7) opens and closes continually. In the unwinding apparatus of Fig. 3 (not shown), oil return from a motor (2) passes through a needle valve (19). A motor (8) is connected by a chain to the valve (19) and to a screw loading a closure spring of a valve (7) between the return line, after the motor (2), and the motor (8). The valve (7) is also acted on by pressures in pilot lines alternatively connected by a four-way change-over valve (43) to the supply line and the return line after the motor (2). When the pump is started oil flows with small pressure to the motor (2), which starts to rotate, and through the motor (8) and a non-return valve (11) to the rear of the motor which is thereby braked. The rotation of the motor (8) adjusts the valve (19) in a closing direction and increases the spring load on the valve (7). When pressure equalization obtains the motors (2), (8) stop. When the main machine is started the cloth is tensioned and acts on a large beam diameter on the motor (2) thereby increasing the pressure after the motor (2). With the valve (43) positioned as shown, the pressure after the motor (2) opens the valve (7) to allow oil to rotate the motor (8) so that the valve (19) is opened up to reduce the pressure after the motor (2) whereupon the valve 7 closes, and so that the spring load of the valve (7) decreases. Automatic adjustment for varying main machine speeds is provided: if the main machine speed decreases, the cloth tension decreases so that the relatively greater pressure in the supply line rotates the motor (8) to adjust the valve (19) in a closing direction to brake the motor (2), and when the cloth again is tensioned, the pressure after the motor (2) increases, the valve (7) opens and the valve (19) is adjusted to the new speed; if the main machine speed increases, the valve (7) and the motor (8) regulate directly the valve (19) in relation to the new speed; and if the main machine stops, the motor (8) instantly closes