Rotary telescopeable shaft with resilient insert

A rotary telescopeable shaft comprising:

• a tubular shaft having a pair of diametrically opposite parallel flat sides and a pair of diametrically opposite cylindrical segments,
• a solid shaft slidably telescoped in said tubular shaft having a pair of diametrically opposite parallel flat sides facing said parallel flat sides of said tubular shaft and engageable thereon to effect a rotary driving connection and a pair of diametrically opposite cylindrical segments facing said cylindrical segments of said tubular shaft with running clearance between said solid shaft and said tubular shaft parallel to and perpendicular to said flat sides,
• a notch in one of said pair of flat sides of said solid shaft overlapped by a corresponding one of said flat sides of said tubular shaft,
• a pair of lateral ramps on a bottom of said notch converging with said one flat side of said tubular shaft,
• a longitudinal ramp on said bottom of said notch converging with one of said pair of cylindrical segments of said tubular shaft,
• a first slider,
• a second slider,
• a third slider,
• a spring urging relative separation between said third slider and each of said first and said second sliders, and
• means operative to prevent said spring from ejecting said third slider from each of said first and said second sliders,
• said first slider, said second slider, said third slider, and said spring being disposed in said notch with said spring wedging said first and said second sliders between said pair of lateral ramps and said one flat side of said tubular shaft to eliminate running clearance perpendicular to said flat sides by spreading apart said solid and said tubular shafts perpendicular to said flat sides and to eliminate running clearance parallel to said flat sides by wedging said third slider between said longitudinal ramp and said one cylindrical segment of said tubular shaft to spread apart said solid shaft and said tubular shaft parallel to said flat sides.