Patent attributes
A focal device for a telescope includes an eyepiece tube, a main body, a fixing washer, a direction restricting member, a focus adjusting ring, a focus adjusting tube, an eyepiece, an eyepiece clamping member and a tightening ring. The eyepiece-clamping member is fixed with the eyepiece and with the focus adjusting tube, having male threads at the other end. The focus adjusting tube and the eyepiece have the same axial line and are able to shift axially only for restricted by the direction-restricting member. The focus adjusting ring engages with the focus adjusting tube, having the same axial line as the focus adjusting tube does, limited to rotate at its site for activating the focus adjusting tube to shift axially. All the axial lines of the eyepiece and the telescope overlap with each other, enabling focusing absolutely precise.
