Damper in particular for suspension of an engine

Claim 2

A damper in particular for suspension of an engine, comprising a plurality of armatures (1,2) one of which is for connection to an engine, while the other one being for connection to a vehicle structure; an elastic block (3) interposed between said armatures; said elastic block and said armatures defining a bore which is filled with a working fluid; a partition plate (5) to divide said bore into two chambers (A,B); means defining an orifice (4) providing a restricted flow communication between said two chambers; characterized by means defining at least one hole (14) providing an unrestricted flow communication between said two chambers; valve means (16a,16b) for closing said hole in response to a difference between a pressure in working fluid in one of said two chambers and a pressure in working fluid in the other one of said two chambers exceeding a predetermined value.

Claim 3

A damper as claimed in claim 1, characterized by that said orifice defining means (4) is in the form of an orifice tube (10) fixedly attached to said partition plate to extend therethrough.

Claim 4

A damper as claimed in claim 2, characterized by that said valve means comprises two valve seats (15a,15b), fixedly attached to the opposite surfaces of said partition plate in a manner to surround said hole means, two thin valve plates (16a,16b) cooperating with said respective valve seats axially slidably mounted on said orifice tube (10), and means for holding said valve plates at a distance spaced from the respective valve seats, said valve plates being disposed within said two chambers, respectively, to be movable against said holding means toward the respective valve seats in response to the difference in pressure.

Claim 5

A damper as claimed in claim 2, characterized by that said valve means comprises two valve seats (15a,15b) fixedly attached to the opposite surfaces of said partition plate (5) in a manner to surround said hole means (14), and two thin elastic valve plates (16a,16b) of an elastic material cooperating with said valve seats, respectively, fixed to said orifice tube (10), each at a position axially spaced a distance from the corresponding one of said valve seats, said elastic valve plates being disposed within said two chambers and being flexed toward said respective valve seats in response to the difference in pressure.

Claim 6

A damper as claimed in claim 1, characterized by that said orifice defining means (4) is in the form of said partition plate (5) formed with an orifice, and wherein said valve means comprises two valve seats (15a, 15b) fixedly attached to the opposite surfaces of said partition plate in a manner to surround said hole means (14), two thin valve plates (16a,16b) resiliently supported by elastomers (17a,17b) fixedly mounted on said partition plate in a manner to surround said orifice, said thin valve plates having a centeral aperture (16c, 16d), respectively, opening into the interior of said elastomers to communicate with said orifice formed through said partition plate, said valve seats being formed with concave grooves (15c,15d), respectively, said thin valve plates having their rim curved toward said respective valve seats and received by said respective concave grooves.

Claim 7

A damper as claimed in claim 1, characterized by that said orifice defining means is in the form of an orifice tube (10), axially slidably mounted on said partition plate (5) and movable in unitary with said valve means, and wherein said valve means comprises two valve seats (15a,15b) fixed to the opposite surfaces of said partition plate in a manner to surround said hole means and two thin valve plates (16a,16b) cooperating with said respective valve seats fixedly mounted to said orifice tube.