Patent GB-163048-A (GB)
Title: Improvements in and relating to pressure-producing mechanisms for operating brakes, presses and the like
IPC: F16D65/28
Filed: 1921-05-09
Abstract: 163,048. Siemens - Schuckertwerke. May 8, 1920, [Convention date]. Embossing and stamping.-In apparatus for producing pressures for operating brakes, presses, &c. comprising a lever for moving the operative member, the lever, during the period of idle movement of the operative member preceding the actual pressure period, is operated simultaneously by two forces acting through a large mass and a small mass, respectively, so that the idle movement may be performed rapidly and the pressure applied without the development of large inertia forces. Fig. 2 shows mechanism for operating the main brake lever 1 of a winding- engine. The lever 1 is operated through a lever 2 moved by means of a heavy weight 3 and a light piston 5 which is pushed upwards by the pressure of a fluid in a cylinder 6. The fluid enters the cylinder through a pipe 7 and a threeway cock 8 which is opened by a lever 9 and rod 10 when release mechanism 4 is operated to free the weight 3. The rod 10 is slotted so that the lever 9 may be moved independently of the release mechanism 4. The movement of the light piston 5 causes the brake to be applied rapidly before the heavy weight 3 has fallen far enough to store up dangerous kinetic energy. In a modification, the cylinder 6 is in communication with a cylinder in which works a piston on the rod 50 supporting the weight 3, pressure being put on the fluid actuating the piston 5 by the movement of the other piston in its cylinder, so that the two forces acting on the lever 2 are obtained from the one weight. The cylinder 6 is then provided with a non-return valve and with a three-way cock mounted in a by-pass. The other cylinder is provided with a by-pass and spring-controlled valve so that the pressure fluid may be allowed to flow from below the piston to allow the full force of the weight to act on the lever 2. A rack on the weight supporting rod engages a pinion adapted to be turned by a crank and connected to the rod for operating the threeway cock by a lever and a friction coupling. In another modification, the end of the lever 2 may be moved by the rotor of a powerful electric motor, by means of a rack and pinion mechanism. The Specification as open to inspection under Sect. 91 (3) (a) states that the invention is applicable to stamping and printing presses. It describes a dash-pot connected to the lever 2, and other means for controlling the moving masses, for overcoming the play in the mechanism, and for regulating the pressure. In the apparatus shown in Fig. 1 (Cancelled) the piston 5 is pressed against stops 7 in its cylinder by a spring 6 which allows downward movement of the piston after the brake blocks have engaged. The piston 5 may work in liquid and be provided with a loaded valve 9 to increase the braking pressure. The pressure may be regulated by a liquid brake 13 connected to the lever 2 at 14 and provided with a circulating valve 12 which is gradually closed through a lever 10 and a rod 11 as the pivot 8 falls. In the apparatus shown in Fig. 3 (Cancelled) the weight 3 is rotatably connected to an axially movable screw passing through a nut 22 on the lever and rotated by a motor 19 through bevel gearing. Checking mechanism 20 for the motor may be connected to the catch mechanism 4 so as to be thrown into operation when the catch mechanism is moved to release the weight. The motor may be used to raise the weight. In another arrangement, an epicyclic gear is used instead of the screw. The weight is fastened by a rope to the drum of the gear, and the planet wheels are connected to a shaft on which is a pulley fastened by a rope to the lever for operating the brake lever, means being provided for driving the axle of the gear. In the apparatus shown in Fig. 5 (Cancelled) two jointly controlled electric motors are employed. The motor 25 drives a threaded spindle passing through a nut 27 on the lever 2, and the motor 28 acts directly on a toothed segment 29 on the lever 2. Regulating or braking mechanism for the motor 25 may be put into operation when the nut 27 reaches a certain position, and a slip coupling may be introduced between the motor and the spindle 26. In the arrangement shown in Fig. 7 (Cancelled) the motion of the falling weight 3 is transmitted by toothed gearing 38 to a self-locking screw spindle 39 for raising the pivot 8 of the lever 2. When a certain pressure of the brake block is obtained and consequently a certain compression of a spring 40, a coupling 43 is released by lever mechanism 41, 42. The spindle 39 may be turned by a motor 44 and then acts as a regulating brake, the coupling 43 being released by means of an electromagnet brought into action by the movement of the operating switch 47 for the motor 44. In the example shown in Fig. 8 (Cancelled), at the commencement of the falling movement of the weight 3 the lever 2 is rigidly connected by a cranked lever coupling 48 with a lever 50 pivoted at 49, so that movement is transmitted to the point 8. When the braking pressure rises, the counterpoise 51 of the cranked lever is raised and the coupling is released. Downward movement of the point 8 is prevented by a self-locking wedge 53 which is drawn forward by a lever 52. A dashpot 54 may be used instead of the counterpoise 51. In a modification, downward movement of the point 8 is prevented by the piston of a dashpot fitted with a back pressure valve closed by the movement of a particular point on the lever 2. In the arrangement shown in Fig. 10 (Cancelled), when the hand-lever 60 is operated it actuates the brake lever directly through the rod 75 and also turns a toothed segment 76 about an axis 78, the point 77 of the segment being temporarily held by a catch. The turning movement is transmitted through a bevel wheel 79 to a nut 80 which coacts with a self-locking screw spindle 81 and so effects an extra movement of the rod 75. When the brake comes into action, the segment disengages from the catch. Fig. 11 (Cancelled) shows an arrangement in which the rotor of an electric motor drives a screw spindle 83 and the " stator " also rotates and is geared with a toothed segment on the lever 2 by chain and bevel gearing. When the brake blocks are applied a spring 87 is compressed and a brake 88 becomes operative and stops the rotor 82, the " stator " continuing to rotate. In a modification, rotation of the " stator " commences when the rotor stops. In another modification, the " stator " is fixed and the motor drives a differential gear. In another example, a rotary " stator " drives a nut on a screw spindle driven by the rotor. This subject-matter does not appear in the Specification as accepted.