Automatic packing system for refuse vehicle

Claim 1

An automatic packing mechanism for refuse compaction bodies including: a compaction head inside the compaction body and extending across the compaction body, an hydraulic cylinder connected to said compaction head and to the front of the compaction body, hydraulic fluid circuit means connected to the hydraulic cylinder so that pressurized hydraulic fluid can flow to and from the hydraulic cylinder to extend and retract the hydraulic cylinder to thereby move the compaction head longitudinally back and forth within the compaction body, hydraulic cylinder control means including: (a) a control valve in the fluid circuit means having a first position to direct fluid to the hydraulic cylinder to cause the cylinder to extend and advance the compaction head rearwardly through the compaction body and a second position to direct fluid to the hydraulic cylinder to cause the cylinder to retract and to return the compaction head back to the front of the compaction body. (b) an advance solenoid and a return solenoid operatively associated with the control valve to move the valve to the first position and second position respectively upon energization of each solenoid, electrical circuitry connected to the advance and return solenoids including: (a) means to energize the advance solenoid (b) a first pressure sensitive switch positioned in the hydraulic fluid circuit means to sense hydraulic fluid pressure and to close electrical contacts when the fluid directed to the hydraulic cylinder to extend the cylinder reaches a preset pressure, (c) a first electrical timer positioned electrically in series with the first pressure switch whereby said timer is activated when fluid to the hydraulic cylinder reaches the preset pressure, (d) electrical contact means associated with the first electric timer to de-energize the advance solenoid and to energize the return solenoid to thereby return the compaction head to the front of the compaction body after the first electric timer has been activated for a preset, relatively short length of time, (e) a second pressure sensitive switch positioned in the hydraulic fluid circuit means to sense hydraulic fluid pressure and to de-energize the return solenoid when the pressure of fluid from the hydraulic cylinder as the cylinder retracts drops below a preset low pressure level.