The rack-shaped framework is composed of left and right sides made of steel plates,oil tank and spacer.The working table is placed between the left and right sides at a lower position with two semicircular spacers among it. 

The sliding block is made of a whole piece of steel plate.It is connected with piston connecting rod.Oil cylinders are fixed on the upper part of the left and right sides.The slide block is moved up and down by the piston driven through hydraulic pressure.

 Mechanical block is fixed in the inner part of two oil tanks,it is of tight structure,two sides of it can be adjusted synchronismly,the figure is as followings.When the sliding block(upper die)are not identical on the left and right,stop sliding blocks at upper dead point，take apart locating stud on the coupling band ,turn any side of worm rod which in worm gear box on the upper part of left and right oil cylinder,then press the sliding to bottom dead point,measure and readjust(repeat the above operation) until left and right of the sliding block (upper die)have identical height,at last ,assemble the locating stud on coupling band .