Actuator for device for delivery of ophthalmic lenses
AssigneeDuckworth & Kent Limited
InventorStephen Paul Woods
Life of this patent
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Abstract
The actuator comprises a barrel and a plunger received within the barrel. A clutch mechanism is operable between the plunger and the barrel. The clutch mechanism includes a driven member and a fixed member having respective castellations. The driven member carries pins which engage a three-start thread on the plunger. The castellations are urged into engagement by three annular springs. In the engaged condition of the clutch, the plunger is advanced by rotation relative to the barrel. An axial load on the plunger disengages the clutch mechanism, allowing the plunger to be advanced axially whilst rotating the driven member. Two-handed or one-handed operation according to a user's choice is therefore possible. The actuator can be used in combination with a lens delivery device.
Claims23
An actuator for a device for delivery of ophthalmic lenses, the actuator comprising a barrel, a plunger receivable within the barrel and movable between a first, withdrawn position and a second, more advanced position, and a coupling means operable between the plunger and the barrel and operable selectively in a first condition to allow the plunger to move axially relative to the barrel from the first to the second position and in a second condition in which rotation of the plunger relative to the barrel produces axial movement of the plunger from the first position to the second position, the coupling means being responsive to an axial load on the plunger to change from the second to the first condition and from the first to the second condition on release of the load.
Dependencies are inferred from the claim text.