Patent GB-1356559-A (GB)
Title: System for controlling the hydraulic ram of a refuse compactor
IPC: B30B9/28
Filed: 1973-03-01
Abstract: 1356559 Apparatus for compacting refuse &c INTERNATIONAL DYNETICS CORP 1 March 1973 [2 March 1972] 10040/73 Heading B8C Apparatus, for controlling the operation of a compactor formed of a longitudinal compression chamber 10 having an inlet 24 for delivery of material, e.g. refuse, to be compacted, a compression zone 26, and an hydraulic ram 18, adapted to move against the material to compact the latter in the zone 24, comprises means 16 for actuating the ram 18 to move the material into the compaction zone, a timer T for limiting the movement of the ram 18 to a first predetermined interval means for sensing the pressure of the material on the ram 18, and means S, responsive to the sensing of a predetermined level of said pressure, for determining a second predetermined time interval for the movement of the ram less than the first predetermined interval, and means for arresting the movement of the ram 18 within the first predetermined interval and on expiration of said second time interval. When a photo-eye 32, in a feed hopper 30 senses refuse in the inlet section 24 a valve VR, in a flow line 38, is opened to cause fluid to flow from a pump P, driven by a motor M, to an hydraulic cylinder 22 to retract the ram 18 from a forward position, where it closes the inlet 24, to its trailing end position whereat the rise in pressure in the line 38 closes a switch HPS1 so that the valve VR is shut and a valve VF, in a flow line 38, is opened. The ram 18 then moves forward, a timer TM, previously set to said first predetermined interval, simultaneously being switched on. If, during its forward stroke, the pressure of the refuse on the ram 18 does not reach said predetermined level of pressure then, at the end of the time period set by the timer TM, the hydraulic system is switched off the ram 18 stopping at the forward end of its refusecompacting stroke. In order to regulate the density, volume, and weight of the compacted refuse when the pressure in the line 36 rises to the predetermined level, due to the reaction of the ram 18 pushing refuse against a door 28, a switch HPS2 is actuated to operate a time delay relay T3 which, after the elapse of said second predetermined time interval sufficient to provide the desired compaction of refuse, causes the motor M to be stopped and a lamp A to be illuminated to indicate the completion of a compacted load, the switch HPS2 being bridged, at the same time, to ensure the operation of the relay T3. In order to set the predetermined pressure on the switch HPS2 a relief valve 40R is set to blow at a predetermined level above that of the high pressure which actuates the switch HPS2. The relief valve 40R is preferably set so that its pressure setting is reached just an instant before the period of the time delay T3 expires. The interval of the time delay relay T3 must fall within the total predetermined period set by the timer T otherwise the ram stops when only a partial load has been made. When the refuse is fully compressed the door 28 is opened, and a manual switch S2 is depressed, so that the ram 18 is advanced to eject the load.