Patent GB-802795-A (GB)
Title: Mobile track-packing machine
IPC: E01B27/16
Filed: 1957-05-27
Abstract: 802,795. Railway track tamping-machines. PLASSER, F., and THEURER, J. May 27, 1957 [June 26, 1956; March 28, 1957], No. 16758/57. Addition to 794,235. Class 104 (2). The track packing-machine of the parent Specification 5 is provided with a. mechanism arranged in the region of the packing tools and comprising members which travel over the upper surfaces of the sleepers and so control the brake actuating means of the machine. The carriage 1 is driven by wheels 22 through a clutch 7 by a shaft 6 and gears 21 by a motor 2 through a shaft 4 and gear-box 5 and is braked by a brake 8 operating on wheels 22<SP>1</SP>. Packing toolcarriers 3, 3<SP>1</SP> located one above each rail 20 are vertically slidable on columns 23 and carry eccentric shafts 24 which impart a vibratory movement to the packing tools 26. The machine operates in the following manner: Starting from the position shown in Fig. 2, in which a sleeper 19 has been packed, the carriers 3, 3<SP>1</SP> are moved upwards and the machine is then ready to move forwards. An abutment 10, pivotally mounted on the carrier 3, as the carrier 3 moves upwards, tilts a lever 11, pivoted on the carriage 1, upwards against the action of a spring 28 to move a piston 32 and rod 30 downwards. The hydraulic fluid below the piston 32 passes through a non-return valve 34 through a pipe 34<SP>1</SP> to the other side of the piston 32. The carrier 3<SP>1</SP> on moving upwards actuates a switch 37 to complete an electric circuit from a battery 41 through the rod 30 to energize an electromagnet 42. The electromagnet 42, on being energized moves a piston 15 against the action of a tension-spring 44 to close a pressure medium supply line 13 to a cylinder 17 which is vented at 13<SP>1</SP> so that a piston 171 is moved by a compression spring 17<SP>11</SP> to effect engagement of the clutch 7. At the same time as the energization of the electromagnet 42 an electromagnet 47 is energized to close a switch 46 to complete a circuit to an electromagnet 43. The electromagnet 43 on being energized moves a piston 161 against the action of a tension-spring 45 to close a pressure medium supply line 14 to a cylinder 18, vented at 14<SP>1</SP> so that a piston 18<SP>1</SP> is moved by a compression spring 18<SP>11</SP> to release the brake 8. The machine now moves forwards. After a time predetermined by an adjustable throttle valve allowing the hydraulic medium to pass through a pipe 35<SP>1</SP> from one side to the other of the piston 32, the piston 32 under the action of the spring 28 is returned to its initial position. When the piston 32 reaches its initial position the circuit through the switch 37 is broken by insulating-pieces 31 on the rod 30 to de-energize the electromagnet 42 to disengage the clutch 7 and to de-energize the electromagnet 47 and open switch 46. The machine continues to travel forwards owing to its inertia since the electromagnet 43 is energized and the brake 8 held off, through switches 49, 57 and 59 which are actuated by members 55, 60 and 60<SP>1</SP> and are closed since the members 55, 60, 601 are not in contact with the next sleeper 19 to be tamped and the beam 58 is not in the horizontal position. The members 60, 60<SP>1</SP> have a downwardly-curved under-surface and are mounted on rods vertically slidable in guides 61, 61<SP>1</SP> and pivotally attached at 58<SP>1</SP>, 58<SP>11</SP> to the beam 58 pivoted about an axis 62 on a rod 65 vertically slidable in a guide 66 and downwardly biased by a spring 65 normally against a stop 67. The beam 58 carries a contact arm 57 which, when the beam 58 is tilted engages a contact strip 59 but when the beam is horizontal rests between a break at the apex of the strip 59. The beam 58 is also acted on by springs 64 which tend to hold the beam 58 horizontal. The member 55 is also downwardly curved on its under surface and is mounted on a rod 53 vertically slidable in guides 54, 56 and downwardly biased by a spring 69, the end of which rod 53 bears against a member 52 to operate the switch 49. The circuit to the electromagnet 43 is broken when the member 55 is raised by the sleeper 19 and the members 60, 601 are at the same height to hold the beam 58 horizontal and brake 8 is then applied. The carriers 3, 31 are now lowered to the tamping position, the lowering of the carrier 3 does not move the lever 11 but the carrier 31 switches off the switch 37 so that current to operate the clutch 7 and release the brake 8 can only be supplied to the network when both carriers 3, 3<SP>1</SP> are raised and the operation is then repeated as described. An air compressor 12 supplies the pressure medium. The spacing between the centres of the members 60, 60<SP>1</SP> as measured in the longitudinal direction of the track, corresponds to the maximum width of sleeper occurring in practice, and spacing between the operative surfaces of such members to the minimum sleeper width.