Abstract: The present invention is directed to a wobble piston and seal assembly for an oil free compressor. An upwardly directed curvature is provided on a piston surface which supports the seal. The curvature is located adjacent the perimeter of the surface to impart a slight dish shape to the surface. Preferably, the curvature has the same radius as the bend radius of the seal when the piston head is inserted into a cylinder. When the seal is initially clamped to the support surface, the seal is formed to take on the curvature of the support surface. Consequently, the seal is preformed into a shallow cup shape prior to final forming when the piston and seal assembly are inserted into a cylinder.

Abstract: An improved wobble piston and seal assembly for an oil free air compressor. The piston has a seal support surface which is provided with an upwardly directed curve adjacent its perimeter. A flat annular seal is secured to the piston to be supported by the support surface. The curve imparts a limited bend to the seal adjacent the perimeter of the piston. The piston and seal are then inserted into a cylinder which increases the bend to substantially 90°. The region of the bend in the seal adjacent the top of the piston is supported by the curved top to reduce flexing during operation at high air pressures. By preventing a reduction in the bend radius at high air pressures, stress in the seal at the bend is reduced, permitting use of a harder more durable seal material.

Abstract: A two stage reciprocating piston oil free air compressor having an improved service interval. In a first stage, a first wobble piston is reciprocated in a first cylinder to compress ambient air to an intermediate pressure. In a second stage a second wobble piston is reciprocated in a second cylinder to compress the intermediate pressure air to a desired high pressure. Each wobble piston is provided with a seal which seals to the adjacent cylinder walls as the piston reciprocates and rocks. The stroke of the higher pressure second stage piston is less than the stroke of the lower pressure first stage piston to increase the operating life of the second seal, preferably to substantially the same operating life as the first seal.

Abstract: A pump for a pressure washer. The pump includes a cam housing, a piston assembly disposed within the cam housing, a rotary shaft assembly disposed within the cam housing, a journal plate attached to the cam housing, a head assembly attached to journal plate and valve assembly operatively connected to the head assembly. The rotary shaft assembly includes a cam shaft, a vertically-extending oil tube partially disposed within a central portion of the cam shaft, a cam threaded onto the cam shaft and a thrust washer positioned adjacent the threaded cam. The piston assembly includes a plurality of pistons, preferably three, in mating contact with the thrust washer. Each piston includes a piston spring cap at one end, a spring disposed over the piston and engaging the piston spring cap, and a seal retainer having a low pressure seal at one end and a high pressure seal at the other end.

Abstract: An air compressor driven by a permanent split capacitor electric motor of the type having substantially the same value capacitance for starting as for operating and which has insufficient starting torque for starting when the air compressor is loaded with pressurized air. The pressurized air output from the air compressor is delivered through an air line to a compressed air storage tank. A check valve between the air line and the tank permits air flow from the air line to the tank while preventing a reverse air flow. A vent valve is connected to vent air pressure from the air line when the motor is stopped to unload the air compressor. When the motor is restarted, closure of the vent valve is delayed until the output torque from the motor exceeds the torque requirements of the compressor when loaded. Vent valve closure may be delayed for a predetermined me or until the motor reaches a predetermined high operating speed or until the air flow from the unloaded air compressor reaches a predetermined level.

Abstract: An air compressor cylinder sleeve is formed from an extrusion having a central passage surrounded by a plurality of closed sided passages. Preferably, grooves are formed between adjacent ones of the closed sided passages. The extrusion is cut into individual cylinder sleeves which are mounted on compressor housings. The central passage receives a piston which is reciprocated by an eccentric on a motor shaft. The ends of the closed sided passages adjacent the housing open into the interior of the housing and the opposite ends of the passages open to atmosphere. A fan on the motor shaft causes air to flow through the compressor housing and through the closed sided passages to cool the cylinder sleeve.

Abstract: This invention is directed to an improved eccentric crank assembly for a reciprocating piston type air compressor. The eccentric crank assembly includes an eccentric plate, a compressor shaft, and an eccentric shaft. The eccentric plate is provided with a pair of parallel overlapping openings formed therethrough. The compressor shaft includes one end provided with a flat angled surface, and the eccentric shaft includes one end provided with a corresponding flat angled surface. The angled surface ends of the shafts are disposed within the openings of the plate. When the eccentric shaft is moved away from the compressor shaft, the angled flat surfaces force the shafts radially apart and into engagement with the openings of the eccentric plate, thereby locking the shafts and the eccentric plate together.

Abstract: An improved wobble piston for an air compressor. The piston has a head integrally connected to a connecting rod. The connecting rod has a free end for connection to a rotating eccentric. The piston head has an internal chamber. Openings are formed through the piston head into the chamber on opposite sides of the connecting rod in a plane perpendicular to the eccentric axis. The location of the chamber openings establishes a flow of cooling air through the chamber as the piston is reciprocated in a cylinder.

Abstract: An anti-corrosion plug for closing a threaded condensate drain opening in a compressor air tank. The plug is formed from a material having a lower potential in the electrochemical series than said air tank to prevent electrolytic corrosion of the tank. The plug has a central cavity open to receive any condensate in the tank. An acid neutralizing insert, for example, of limestone, is located in the cavity to neutralize any acidity in the tank condensate.

Abstract: An improved paint cup lid assembly of the type having a paint feed tube which is attached by a nut to a hand held paint spray gun. The paint feed tube is secured to a lid. The lid assembly includes a yolk which releasably secures the lid to a paint cup. When the paint cup is detached from the lid assembly, the yolk may be moved to a position wherein a socket formed in the yolk engages the nut and the yolk is used as a wrench for loosening or tightening the nut.

Abstract: An improved oilless air compressor which is driven by a high speed universal motor. A sprocket and belt driven pulley are arranged to reduce the compressor speed. A motor driven fan and baffles are provided to direct cooling air in predetermined sequences over the motor and compressor components to increase the operating life of the compressor components, to optimize the compressor efficiency and to reduce the temperature of the compressed air output. The compressor is provided with improved intake and exhaust valves.