Split mould for making tapered concrete poles

A mould structure for use in making tapered concrete poles, comprising:

• a tapered outer frame essentially consisting of a plurality of longitudinal guide members (11-14) radially arranged about a common axis and each inclined to the axis at an angle corresponding to the taper of concrete poles to be formed, the mould structure having a longitudinally extending mould axis, a plurality of annular connecting members (10) axially spaced from each other and each secured to said guide members in their respective angular positions spaced apart from each other, and at least one annular drive wheel (3) secured to said guide members in encircling relation thereto;
• and a frustoconical tubular casing (2) of resilient steel sheet material formed with the same taper as that of said outer frame so as to be inserted in said outer frame substantially coaxially therewith and having a gap (20) formed in the wall of said tubular casing along a longitudinal line on its periphery and extending the entire length thereof, said tubular casing (2) having a pair of longitudinally extending stiffening members (21--21) secured to the outer peripheral surface thereof on the opposite sides of said gap (20) and a number of additional longitudinally extending stiffening members (22-24) secured to said outer peripheral surface in spaced relation to each other and to said pair of stiffening members (21--21), all of said stiffening members (21-24) being placed in contact with the respective guide members (11-14) of said outer frame for sliding movement therealong so that said gap (20) is opened and closed as said tubular casing (2) is moved axially in opposite directions relative to said outer frame.