Writing instrument compressing device

A writing instrument compressing device, comprising:

• a base, which has an underside on which a plurality of raiser pieces are mounted and adapted to separate the base from a carrying surface by a distance in a vertical direction, the base being formed with an elongate hole, the elongate hole being defined by two opposite sidewalls, which are provided, in a manner of corresponding to and opposite to each other, tooth ridges and tooth troughs arranged alternate with each other;
• a handle rod, which is pivotally coupled to an end of the base to drive a pusher to reciprocally move;
• a retainer, which is reciprocally movable along the elongate hole of the base, the retainer at least comprising an upper seat and a lower seat, the upper seat and the lower seat being spaced from each other by a distance by two support posts that are coupled to the upper seat and the lower seat, a holding plate being arranged between the upper seat and the lower seat, the holding plate receiving the two support posts to extend therethrough, the holding plate being movable along the two support posts in the vertical direction, each of the support posts being provided with a spring encompassing an outer circumference thereof, each of the springs being located between the holding plate and the lower seat, the lower seat having a bottom surface on which a screw rod is provided to extend through the elongate hole of the base;
• a fastening member, which is screwed into the upper seat, the fastening member having an upper end forming rotary knob, a bolt extending downward from a bottom of the rotary knob, the bolt having a lower end contacting and engageable with the holding plate, such that screwing the fastening member downward drives the holding plate to move downward;
• and
• a tightening assembly, which comprises a nut and a rotation bar that penetrates through the nut and is rotatable, the nut being screwed to the screw rod on the bottom surface of the lower seat of the retainer, the rotation bar having two ends, wherein one of the two ends is movable close to the nut, while the other one of the two ends is moved away from the nut, the nuts being driven by the rotation bar to tighten the retainer and the base or to be loosened to allow the retainer to reciprocally move on and along the base.