Patent ID: 7591636

Claim:
A negative pressure supply apparatus comprising: an ejector having a nozzle and a diffuser disposed downstream of said nozzle, said ejector having a vacuum port opening between said nozzle and said diffuser; and a vacuum pump having a suction port connected to an outlet of said diffuser, said vacuum pump including: a piston slidably fitted in a cylinder; a rod secured in said cylinder and extending along a central axis of said cylinder such that movement of said piston is guided by said rod; a plurality of coils provided on an outer peripheral portion of said cylinder; a magnetic path member and a plurality of magnets provided on an outer peripheral portion of said piston; and an annular seal disposed centrally on said magnets to divide the interior of said cylinder into two pump chambers, said vacuum pump being operable by the movement of said piston driven by electrical energization of said plurality of coils so as to produce a negative pressure, wherein a negative pressure of higher degree of vacuum than that of the suction negative pressure of said vacuum pump is produced at said vacuum port of said ejector by operation of said vacuum pump, and the negative pressure of higher degree of vacuum can be supplied to a negative pressure operated device which is operated by a negative pressure, and wherein said vacuum port of said ejector and said suction port of said vacuum pump are connected through respective check valves to a negative pressure supply port which is connected to the negative pressure operated device, so that either one of two negative pressures at said vacuum port and said suction port that is higher in degree of vacuum than the other is supplied from said negative pressure supply port to the negative pressure operated device.