# US 2012/0073456 A1 · Solar-powered waste compactor and method of operation thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2012/0073456 A1 - Document ID: US20120073456A1 - Status: Published application - Kind: A1 - Application number: 12/892,296 - Filed: 2010-09-28 - Published: 2012-03-29 - Earliest claimed: 2010-09-28 - Assignees: Marathon Equipment Company - Inventors: Bradley L. Lyle; James K. Robbins - Web page: https://patentgrep.com/patent/US20120073456A1 ## CPC - B30B 15/166: {Electrical control arrangements} - B30B 9/3007: {Control arrangements} - B30B 9/305: {Drive arrangements for the press ram} - B30B 9/3057: {Fluid-driven presses} - B30B 13/00: Methods of pressing not special to the use of presses of any one of the preceding main groups - B30B 15/161: {controlling the ram speed and ram pressure, e.g. fast approach speed at low pressure, low pressing speed at high pressure} - B30B: PRESSES IN GENERAL (producing ultra-high pressure or ultra-high pressure and high temperature to effect modifications of a substance, e.g. for making artificial diamonds B01J3/00 ){(compressing means for refuse receptacles B65F1/1405)} ## Abstract A solar-powered waste compactor comprises a waste container for housing waste, a compactor ram actuated by a hydraulic cylinder and piston assembly for compacting the waste in the waste container, and a hydraulic power unit operably associated with the hydraulic cylinder and piston assembly for powering the compactor ram. The hydraulic power unit comprises a motor/pump assembly including a pump unit, a single-phase electric motor driving the pump unit and a flow control valve operating the motor/pump assembly at first or second flow rate depending on an operating pressure. The hydraulic power unit further comprises a battery unit, a solar panel to charge the battery unit, a DC-to-AC inverter, a single-phase AC power inlet connectable to a source of a single-phase electrical power grid, and a reversing contactor providing the electric current only from the inverter or the power inlet at any given time. ## Claims ### Claim 1 A waste compactor, comprising: a waste container for housing waste; a compactor ram actuated by a hydraulic cylinder and piston assembly for compacting the waste in said waste container; and a hydraulic power unit operably associated with said hydraulic cylinder and piston assembly for powering said compactor ram, said hydraulic power unit comprising: a motor/pump assembly including a pump unit, a single-phase electric motor driving said pump unit for selectively providing hydraulic fluid to said hydraulic cylinder and piston assembly and a flow control valve operating said motor/pump assembly at a first flow rate of the hydraulic fluid when an operating pressure of said pump unit is less than a predetermined threshold value and operating said motor/pump assembly at a second flow rate of the hydraulic fluid when the operating pressure of said pump unit is greater than the predetermined threshold value; a battery unit for storing electrical energy and for providing the electrical energy to said single-phase electric motor; a solar panel for converting solar energy to electrical energy to charge said battery unit; a DC-to-AC inverter converting a direct current from said battery unit into a single-phase alternating current; a single-phase AC power inlet connectable to a source of a single-phase electrical power grid; and a reversing contactor including first contactor provided between said DC-to-AC inverter and said single-phase electric motor and a second contactor provided between said single-phase AC power inlet and said single-phase electric motor, said reversing contactor preventing said first and second contactors from closing connections thereof at the same time so as to provide the electric current only from one of said DC-to-AC inverter and said single-phase AC power inlet at any given time and to prevent backflow of electrical current to either said DC-to-AC inverter or to the electrical power grid. ### Claim 2 (depends on 1) The waste compactor as defined in claim 1, wherein said first flow rate of the hydraulic fluid is bigger than said second flow rate thereof. ### Claim 3 (depends on 2) The waste compactor as defined in claim 2, wherein said pump unit includes a first pump section and a second pump section both driven by said single-phase electric motor. ### Claim 4 (depends on 3) The waste compactor as defined in claim 3, wherein said pump unit further includes a first output line providing an output from said first pump section, a second output line providing an output from said second pump section, a node at which flows of the hydraulic fluid from said first and second output lines are combined and a check valve disposed between said second output line and said node for preventing backflow of the hydraulic fluid to said second pump section; and wherein said hydraulic power unit further comprises a reservoir containing a supply of the hydraulic fluid, a supply line provided for conveying the hydraulic fluid combined from said first and second output lines to said hydraulic cylinder and piston assembly and a return line delivering the hydraulic fluid from said hydraulic cylinder and piston assembly back to said fluid reservoir. ### Claim 5 (depends on 4) The waste compactor as defined in claim 4, wherein said flow control valve is a normally closed pressure relief valve; said pressure relief valve is disposed between said second output line and said fluid reservoir. ### Claim 6 (depends on 5) The waste compactor as defined in claim 5, wherein said pressure relief valve is closed when the operating pressure is less than the predetermined threshold value so as to provide said first flow rate of the hydraulic fluid of said motor/pump assembly by delivering to said supply line the pressurized hydraulic fluid generated by both said first and second pump sections; and wherein said pressure relief valve is open when the operating pressure is greater than the predetermined threshold value so as to provide said second flow rate of the hydraulic fluid of said motor/pump assembly by delivering to said supply line the pressurized hydraulic fluid generated only said first pump section. ### Claim 7 (depends on 5) The waste compactor as defined in claim 5, further comprising a directional control valve in fluid communication with both said pump unit and said hydraulic cylinder and piston assembly for selectively controlling the hydraulic fluid flow to/from said hydraulic cylinder and piston assembly for extending and retracting said compactor ram; said directional control valve is provided to selectively operate said hydraulic cylinder and piston assembly in an extending mode of operation and a retracting mode of operation. ### Claim 8 (depends on 7) The waste compactor as defined in claim 7, wherein said hydraulic cylinder and piston assembly includes a hydraulic power cylinder and a power piston provided to reciprocate within said hydraulic power cylinder; said power piston defines a first chamber and a second chamber both disposed within said hydraulic power cylinder on opposite sides of said power piston; said power piston provided with a power rod extending from said power piston through said second chamber and drivingly connecting said power piston to said compactor ram so that the reciprocating sliding movement of said power piston within said hydraulic power cylinder is translated into the reciprocating movement of said compactor ram for compacting the waste in said waste container. ### Claim 9 (depends on 8) The waste compactor as defined in claim 8, wherein when said hydraulic power unit is initially turned on, said motor/pump assembly operates at said second flow rate of the hydraulic fluid and said directional control valve switches to an extending position so as to operate said hydraulic cylinder and piston assembly in said extending mode of operation to extend said compactor ram until a predetermined operation time of said hydraulic power unit is reached. ### Claim 10 (depends on 9) The waste compactor as defined in claim 9, wherein when said predetermined operation time is reached, said directional control valve switches to a retracting position so as to operate said hydraulic cylinder and piston assembly in said retracting mode of operation to retract said compactor ram. ### Claim 11 (depends on 10) The waste compactor as defined in claim 10, further comprising a logic controller including a timer provided for timing an operation of said hydraulic power unit and detecting said predetermined operation time, and a pressure sensor for detecting the operating pressure at said pump unit; and wherein said directional control valve is a solenoid operated valve automatically controlled by said logic controller based on the operation time detected by said timer. ### Claim 12 (depends on 9) The waste compactor as defined in claim 9, wherein when said predetermined threshold value is reached, said motor/pump assembly operates at said second flow rate of the hydraulic fluid and said directional control valve switches to an extending position so as to operate said hydraulic cylinder and piston assembly in said extending mode of operation to continue to increase the operating pressure until said waste container is full, at which point said hydraulic power unit shuts down. ### Claim 13 (depends on 12) The waste compactor as defined in claim 12, wherein said waste container is determined to be full when the operating pressure reaches a predetermined maximum value, at which point said motor/pump assembly shuts down. ### Claim 14 (depends on 1) The waste compactor as defined in claim 1, further comprising a voltage control relay controlling said first and second contactors based on battery charge of said battery unit so that ### Claim 15 (depends on 14) The waste compactor as defined in claim 14, wherein when said battery charge is bigger than a predetermined threshold value, said voltage control relay closes said first contactor and opens said second contactor to connect said battery unit to said single-phase electric motor and disconnect said single-phase AC power inlet therefrom; and wherein when said battery charge is smaller than said predetermined threshold value, said voltage control relay opens said first contactor and closes said second contactor to connect said single-phase AC power inlet to said single-phase electric motor and disconnect said battery unit therefrom. ### Claim 16 A method of powering a compactor ram of a waste compactor, comprising the steps of: providing a motor/pump assembly including first and second pump sections for providing pressurized hydraulic fluid to a hydraulic cylinder and piston assembly associated with the compactor ram, and a directional control valve in fluid communication with both said motor/pump assembly and said hydraulic cylinder and piston assembly for selectively controlling the hydraulic fluid flow to/from said hydraulic cylinder and piston assembly for extending and retracting said compactor ram; providing said hydraulic cylinder and piston assembly with hydraulic fluid generated by both first and second pumps when an operating pressure of the pump assembly is less than a predetermined threshold; and providing said hydraulic cylinder and piston assembly with hydraulic fluid generated only the first pump when the operating pressure of the pump assembly is greater than the predetermined threshold; controlling said directional control valve to selectively operate said hydraulic cylinder and piston assembly in extending and retracting modes of operation. ### Claim 17 (depends on 16) The method as defined in claim 16, wherein when said waste compactor is initially turned on, said motor/pump assembly provides said hydraulic cylinder and piston assembly with hydraulic fluid generated by both first and second pumps when an operating pressure of the pump assembly is less than a predetermined threshold and said directional control valve is in an extending position so as to operate said hydraulic cylinder and piston assembly in said extending mode of operation to extend said compactor ram and to increase the operating pressure until a predetermined operation time of said hydraulic power unit is reached, at which point said motor/pump assembly is operated in said retracting mode of operation to retract said compactor ram. ### Claim 18 (depends on 17) The method as defined in claim 17, wherein when said predetermined threshold value is reached, said motor/pump assembly provides said hydraulic cylinder and piston assembly with hydraulic fluid generated only by said first pump and said directional control valve is in an extending position so as to operate said hydraulic cylinder and piston assembly in said extending mode of operation to continue to increase the operating pressure until said waste container is full, at which point said hydraulic power unit shuts down.