| 摘要 |
A drive and frame shaft assembly for a lawn trimming tool or the like, having a bent portion to dispose the tool end of the assembly at an angle to the head end thereof. A curved assembly of a frame shaft and sheath for a flexible drive shaft is formed by, first, assembling onto a straight rigid sheath tube an elongated thick-walled cylindrical bushing of semirigid plastic material over the length of the sheath tube which is subsequently bent, together with a plurality of annular metal spacers at fixed points along the length thereof which is to remain straight and securing the bushing and spacers in place as with tape and by flaring ends of the sheath tube; second, inserting such sheath tube assembly in a close-fitting frame-shaft tube; and third, subjecting the assembled sheath tube and frame-shaft tube to a bending operation in which the bending action is applied to the outer frame shaft tube and the semirigid plastic bushing transmits bending forces therefrom to the sheath tube contained therein so as to bend the sheath tube and maintain it substantially concentric within the frame shaft tube over the bent length of the assembly. |
