Point of sales openable by casing opening device

A point of sales openable by a casing opening device, the point of sales having a casing, the casing having a front casing and a rear casing, four border frames of the front casing covering around four border frames of the rear casing, the casing opening device comprising:

• two hinges respectively disposed inside one of the four border frames of the front casing and inside a corresponding one of the four border frames of the rear casing at a same side, each of the two hinges comprising:
• a rotary arm having a rotary end and a driving end opposite to the rotary end;
• a rotary arm spring disposed at the rotary arm and configured to drive the rotary arm to rotate from inwardly lying down to outwardly standing up;
• a base being of a strip shape and fixed at the rear casing, a front end of the base pointing to the corresponding one of the four border frames of the rear casing and pivotally connecting to the rotary end of the rotary arm, a rear end of the base being opposite to the front end of the base and being disposed with a sliding path, a middle portion of the base being disposed with a positioning hole;
• a front casing pivoting shaft pivotally connected to the front casing;
• a sliding plate, a front end of the sliding plate pointing to the corresponding one of the four border frames of the rear casing and being disposed with the front casing pivoting shaft, a rear end of the sliding plate being opposite to the front end of the sliding plate and sliding at the sliding path of the base, a middle portion of the sliding plate being pivotally connected to the driving end of the rotary arm;
• and
• a positioning rod, a front end of the positioning rod pointing to the corresponding one of the four border frames of the rear casing and being pivotally connected to the driving end of the rotary arm, the positioning rod following the sliding plate to slide, a rear end of the positioning rod being opposite to the front end of the positioning rod and being disposed with a positioning hook.