Patent GB-190110131-A (GB)
Title: Improvements in or connected with Hydraulic Presses and Machines
Inventor: FLETCHER JOSEPH ERNST
Filed: 1901-05-16
Granted: 1902-05-15
Abstract: 10,131. Fletcher, J. E. May 16. Hydraulic machines and presses.-Relates to valves for controlling the supply of water to hydraulic presses or other machines. Fig. 2 shows a simple form of valve suitable for an ordinary vertical press. The valve block H is provided with suitable passages to which are coupled the supply pipe J<10>, the exhaust pipe K, and a pipe G leading to the press cylinder. The exhaust and supply passages are fitted with hard Muntz-metal bushes N, N<5> forming seats for the valve spindles N<1>, N<6>, which are provided with right-handed doublepitched screws engaging gland nuts N<2>, N'. The spindles are geared together by means of toothed pinions N<4>, N<9> mounted in the cross-plate I, and the spindle N' is fitted with a hand-wheel L. When the hand-wheel is operated to open or close the exhaust passage, the supply passage is simultaneously closed or opened. In the arrangement shown in Fig. 4, means are provided for supplying water under two different pressures. The supply passage is connected by pipes J<3>, J<10> to two sources of supply. The low-pressure supply orifice is fitted with a back-pressure valve J<1> provided with a guide and stop J'. When low-pressure fluid is admitted by the pipe J<10>, the valve J<1> is lifted. When highpressure fluid is required, it is admitted by the pipe J<3>, aud the pressure of the water closes the valve J<1>. By an arrangement of three supply pipes and corresponding back-pressure valves, fluid under three different pressures may be admitted to the press as required. Fig. 9 shows an arrangement of the valve suitable for a horizontal press &c. in which water has to be admitted on both sides of the piston. A simple valve H, such as above described by reference to Fig. 2, is coupled to a cylinder H<3> in which slides a piston valve N<20>. A three-way block J" has passages coupled to the main supply pine J<14> and pipes J<12>, J<13> leading to the valve H and cylinder H<3> respectively. The cylinder H<3> is connected by a pipe J<10> to the controlling-valve for the press &c. This valve consists of a combination of two simple valves, and comprises threaded spindles N', N<6>, N<10>, N<15> adapted to engage seatings N, N<5>, N", N<16> formed on hand metal bushes. The pairs of spindles N', N<6> and N<10>, N<15> are each geared together by pinions. The pipes G lead to the ends of the cylinder, and the pipe K<1> leads to the exhaust. The spindles N', N<10> control the supply, and the spindles N<6>, N<15> control the exhaust. Pinions on the spindles are in gear with wheels L<3>, L<4> mounted on a shaft L' carrying an operating-lever L<5>. Owing to the difference in area on the two sides of the piston valve N<20>, the supply of water to the controlling-valve is cut off when the supply spindle N<6> of the simple valve H is raised so as to admit pressure to the back of the valve N<20>. When the spindle N<6> is down to close the supply to the valve H, water can pass by way of the pipes J<13>, J<14> to the controlling-valve. By operating the lever L<5>, the pressure water can be admitted to either side of the press piston, the opposite side of the piston being simultaneously opened to the exhaust. Upon opening the supply passage of the valve H, water can be admitted to the back of the valve N<20> to close the same and so serve to stop the operation of the press. In a modification, one pair of valve spindles are screwed, and the other pair are plain and have volute springs interposed between crossheads arranged on the ends of the spindles and the valve block. Each crosshead is coupled up to the corresponding screwed spindle by rods provided with adjusting-nuts, or a shank on the screwed spindle may pass through the plain spindle and be secured thereto by a nut. When a screwed spindle is raised from its seat, the opposite plain spindle is brought down upon its seat, and, when the screwed spindle is forced down on its seat, the plain spindle is raised from its seat by the action of the spring. The spindles are screwed with opposite-handed threads, the pinions thereon being in gear with a wheel mounted on the shaft of the operating-lever.