Patent ID: 7798297

Claim:
An apparatus comprising: in a mutually rotatable configuration, a first fluid shear member connectable to a first moveable body part of a handheld device and a second fluid shear member connectable to a second moveable body part of the handheld device, the first and second fluid shear members being configured to experience mutual rotation when the first and second moveable body parts are connected respectively to the first and second fluid shear members and when the moveable body parts are moved in relation to one another; the first and second fluid shear members being matched; and fluid between the first and second fluid shear members, wherein the first fluid shear member comprises a first cylindrical element, wherein the second fluid shear member comprises a second cylindrical element, wherein the first fluid shear member further comprises a third cylindrical element coaxially with and inside the first cylindrical element, and wherein the first and third cylindrical elements sandwich the second cylindrical element therebetween.