Resources Contact Us Home
Solenoid self-cleaning pressure valve for automatic vehicle transmission

Image Number 2 for United States Patent #5971889.

A system for controlling an automatic vehicle transmission, including a gear system and hydraulic clutches which hold a member of the gear system stationary to produce gear reduction or reverse, having an oil line which connects the clutches to an oil pressure source, a pressure control valve having a solenoid provided in the oil line which generates a regulated oil pressure to be supplied to the clutches in response to a current supplied to the solenoid, a switch valve provided in the oil line which switches the oil pressure to be supplied to the one of the clutches between the regulated oil pressure and a line pressure. In the system, it is discriminated whether the pressure control valve does not supply the regulated oil pressure to the clutches and if so, a dither current is supplied to the solenoid such that the valve repeatedly performs a vibrational motion to remove any grit therefrom, thereby removing grit without causing gear-shift shock or clutch vibration.

  Recently Added Patents
Conductive polymer and a solid electrolytic capacitor using the same as a solid electrolyte
Level-shift circuit, electro-optical device, and level shift method
Press nut
Light-emitting device with a spacer at bottom surface
Drug delivery system
Laboratory spatula
Electrical terminal
  Randomly Featured Patents
Image forming apparatus
Shock absorber control system
Preparation of impact-resistant thermoplastic molding
Methods of forming integrated circuits, and DRAM circuitry memory cells
Performance-based control system
Method of making silicate esters
Low temperature deposition method for high quality aluminum oxide films
Power-saving amplifying device
Palm held lotion and liquid applicator