Lens stop-down mechanism

Claim 2

A stop-down mechanism for a lens having adjustable aperture means urged by biasing means toward a maximum open position, comprising: stopper means being manually adjustable to engage with the aperture means and limit movement thereof away from the maximum open position to a position corresponding to the desired aperture setting; actuating means arranged to move the aperture means from the maximum open position to the position corresponding to the desired aperture setting when manually actuated; and inertial mass means arranged to be accelerated by movement of said actuating means and transfer kinetic energy to the aperture means in substantial simultaneity with the engagement thereof with said stopper means in a direction to cancel the force of rebound of the aperture means from the stopper means.

Claim 3

A stop-down mechanism according to claim 1, in which said inertial mass means comprises an inertial mass movable from a first to a second position when accelerated by movement of said actuating means, and biasing means to urge said inertial mass toward the first position.

Claim 4

A stop-down mechanism according to claim 2, in which said actuating means comprises: a generally arcuate lever having an intermediate pivot point with one end thereof being engageable with the aperture means and the other end being manually actuable; and biasing means urging said arcuate lever away from engagement with the aperture means; said actuating lever having a generally arcuate slot formed therethrough with said inertial mass being arranged to slide within the slot; the first position being the end of the slot farthest from the aperture means and the second position being the end of the slot closest tO the aperture means, said biasing means of said inertial mass means being carried on said actuating lever.

Claim 5

A stop-down mechanism according to claim 3, in which the aperture means includes a diaphragm of variable diameter, a diaphragm ring arranged to vary the diameter of the diaphragm when rotated, and a diaphragm lever having one end fixed to the diaphragm ring and the other end engageable with said one end of said actuating lever so that the diaphragm ring is rotated in a direction to stop-down the lens when said actuating lever is manually actuated.

Claim 6

A stop-down mechanism according to claim 4, in which the lens is for a camera.

Claim 7

A stop-down mechanism according to claim 5, in which the camera is a single-lens reflex camera.

Claim 8

a stop-down mechanism according to claim 6, in which the lens is an interchangeable lens.

Claim 9

A stop-down mechanism according to claim 6, in which said actuating lever is connected through a linkage to a shutter mechanism of the camera, whereby said actuating lever is actuated to stop-down the lens when the shutter release member of the shutter mechanism is manually actuated.

Claim 10

In a stop-down mechanism for a lens having adjustable aperture means urged by biasing means toward a maximum open position, stopper means being manually adjustable to engage with the aperture means and limit movement therof away from the maximum open position to a position corresponding to the desired aperture setting, and actuating means arranged to move the aperture means from the maximum open position to the position corresponding to the desired aperture setting when manually actuated, the improvement comprising: an inertial mass arranged to be accelerated from a first position by movement of the actuating means to a second position to transfer kinetic energy to the aperture means in a direction to cancel the force of rebound of the aperture means from the stopper means; and a biasing member to urge said inertial mass toward the first position.

Claim 11

In a stop-down mechanism for a lens having adjustable aperture means urged by biasing means toward a maximum open position, stopper means being manually adjustable to engage with the aperture means and limit movement therof away from the maximum open position to a position corresponding to the desired aperture setting, and actuating means arranged to move the aperture means from the maximum open position to the position corresponding to the desired aperture setting when manually actuated, the improvement comprising: an inertial mass arranged to be accelerated from a first position by movement of the actuating means to a second position to transfer kinetic energy to the aperture means in a direction to cancel the force of rebound of the aperture means from the stopper means; and a biasing member to urge said inertial mass toward the first position.

Claim 12

A stop-down mechanism according to claim 9, in which the actuating means includes a generally arcuate lever having an intermediate pivot point with one end thereof being engageable with the aperture means and the other end being manually actuable, and biasing means urging the actuating lever away from engagement with the aperture means; and in which the actuating lever is formed with a generally arcuate slot, said inertial mass being arranged to slide within the slot; whereby the first position is the end of the slot farthest from the aperture means and the second position is the end of the slot closest to the aperture means, said biasing member being carried on the actuating lever.

Claim 13

A stop-down mechanism according to claim 10, in which the lens is for a single lens reflex camera.

Claim 14

A stop-down mechanism according to claim 11, in which the aperture means includes a diaphragm of variable diameter, a diaphragm ring arranged to vary the diameter of the diaphragm when rotated, and a diaphragm lever having one end fixed to the diaphragm ring and the other end engageable with the one end of the actuating lever so that the diaphragm ring is rotated in a direction to stop-down the lens when the actuating lever is manually actuated.

Claim 15

A stop-down mechanism according to claim 12, in which the actuating lever is connected through a linkage to a shutter mechanism of the camera, whereby the actuating lever is actuated to stop-down the lens when the shutter release member of the shutter mechanism is manually actuated.