Centrifugal injection timing control device for fuel injection pumps

Claim 1

In a centrifugal injection timing control device for a fuel injection pump, including a driving rotary member, a driven rotary member, a housing arranged concentrically with said driven rotary member and rotatable in unison therewith, centrifugal weight means accommodated within said housing and displaceable diametrically thereof in response to rotation of said driven rotary member, said centrifugal weight means defining a radially inner chamber in cooperation with said driven rotary member and at least one radially outer chamber in cooperation with said housing, and double eccentric cam means interposed between said driving rotary member and said centrifugal weight means and engaging with said driving rotary member and said centrifugal weight means, wherein diametrical displacement of said centrifugal weight means causes corresponding circumferential displacement of said driven rotary member relative to said driving rotary member through said double eccentric cam means; the improvement comprising: passage means formed in said centrifugal weight means and communicating said radially inner chamber with said radially outer chamber; said centrifugal weight means includes a pair of centrifugal weight members arranged diametrically oppositely with respect to said driven rotary member, said centrifugal weight member each having a radially inner face disposed opposite said driven rotary member and defining said radially inner chamber, and a radially outer face disposed opposite said housing and defining said radially outer chamber; and said passage means including a first groove formed in said radially inner face of each of said centrifugal weight members, and a second groove formed in said radially outer face of each of said centrifugal weight members and continuous with said first groove.