초록 ▼

A pressure control apparatus, which can be used for a braking force magnification apparatus for a vehicle or a door closing and opening apparatus includes a sensor for sensing a pressure within a vacuum booster. The sensor is of a transfer-contact-type including a medial movable contact and two stat

A pressure control apparatus, which can be used for a braking force magnification apparatus for a vehicle or a door closing and opening apparatus includes a sensor for sensing a pressure within a vacuum booster. The sensor is of a transfer-contact-type including a medial movable contact and two stationary contacts. The movable contact makes contact with one of the stationary contacts connected to an alarm lamp but breaks contact with the other connected through a control circuit to a DC motor connected to a vacuum pump or a compressor when the absolute gauge pressure produced by the vacuum pump or compressor is below a first predetermined threshold value. The movable contact breaks contact with the one stationary contact to energize the DC motor when the absolute gauge pressure is below a second predetermined threshold value but is above the first one. When the absolute gauge pressure is above the second predetermined threshold value, the movable contact makes contact with the other contact to deenergize the DC motor.

대표청구항 ▼

A pressure control apparatus comprising: a pump means for generating a pressure different from atmosphere pressure when energized; a pressure sensing means comprises a single pole, double throw electrical switch for providing both alarm and pressurizing signals when the absolute value of the gauge p

A pressure control apparatus comprising: a pump means for generating a pressure different from atmosphere pressure when energized; a pressure sensing means comprises a single pole, double throw electrical switch for providing both alarm and pressurizing signals when the absolute value of the gauge pressure generated by said pump means is below a first predetermined threshold value, and for providing a pressurizing signal when the absolute gauge pressure is below a second predetermined threshold value but is above said first threshold value, and for providing a stop signal when the absolute gauge pressure is above said second predetermined threshold value; and a control circuit connected to said pump means and said pressure sensing means for respectively energizing or deenergizing said pump means in response to said pressurizing or stop signal from said pressure sensing means.