Forms for casting cement tanks

Claim 1

AN INNER FORM FOR CASTING A CONCRETE TANK HAVING BULGING SIDES AND GENERALLY FLAT ENDS, SAID FORM BEING ADHERED TO THE TANK AND COMPRISING: (A) A BASE, (B) OPPOSITE SECTIONAL ENDS, EACH COMPRISING A CENTRAL TRAPEZOIDAL SECTION AND OPPOSITELY FORMED END SECTIONSO THAT HAVE CONVEX EDGES RESIDING IN THE BULGES OF A TANK CAST AROUND SAID FORM, (C) OPPOSITE CONVEX SIDES CONFORMING TO THE INNER CONCAVE FACES OF THE TANK SIDES, (D) MEANS LOOSELY CONNECTING THE CONVEX EDGES OF THE OPPOSITELY FORMED END SECTIONS WITH THE EDGES OF THE CONVEX SIDES, (E) HINGE MEANS CONNECTING THE TRAPEZOIDAL END SECTIONS TO THE BASE TO DRAW SAID SECTIONS INWARDLY TO RELEASE THE SAME FROM ENGAGEMENT WITH THE INNER FACES OF THE FLAT ENDS OF THE TANK UPON RAISING OF THE TANK AWAY FROM THE BASE, (F) MEANS INTERCONNECTING THE TRAPEZOIDAL SECTION, AT EACH END, WITH ONE OF THE OPPOSITELY FORMED END SECTIONS TO INWARDLY MOVE AND RELEASE THE LATTER ALSO, (G) CONVERGING SLIDE MEANS CONNECTING EACH SLOPING EDGE OF THE TWO TRAPEZOIDAL SECTION WITH THE ADJACENT EDGES OF THE OPPOSITELY FORMED END SECTIONS, (H) THE SLIDE MEANS THAT CONNECT THE NON-RELEASED OPPOSITELY FORMED SECTIONS BEING SLOPED IN A DIRECTION TO MOVE THE CONVEX SIDE CONNECTED TO SAID NONRELEASED SECTIONS AND THE TANK ADHERED THERETO LATERALLY TO FREE THE RELEASED OPPOSITELY FORMED SECTIONS AND THE CONNECTED CONVEX SIDE FROM THE BULGE OF THE TANK SO THE SAME MAY GRAVITATIONALLY SLIDE ON THE SLIDE MEANS TO INITIAL POSITION DURIANG CONTINUED UPWARD MOVEMENT OF THE TANK, AND (I) MEANS TO ARREST THE UPWARDLY SLIDING MOVEMENT OF THE NON-RELEASED SECTIONS TO RELEASE THE SAME AND THE CONNECTED CONVEX SIDE DURING CONTINUED UPWARD MOVEMENT OF THE TANK, THE LATTER SECTIONS AND SIDE GRAVITATIONALLY RETURNING TO INITIAL POSITION.