Method for raising a multi-element mast and apparatus for performing the method and masts provided with these means

A method for raising a multi-element mast wherein successive elements are added to a bottom of said mast, comprising the steps of:

• (a) assembling a first and a second upper element, said first upper element having an antenna attached thereto;
• (b) mounting said first and second upper elements within a vertical guide shaft, said guide shaft having a bore therethrough, said guide shaft being spaced at a predetermined distance from a ground surface and supported by a base framework;
• (c) securing said second upper element within said vertical shaft to prevent said first and second elements from moving vertically downwardly;
• (d) disposing, in said space between said guide shaft and said ground surface, a support plate and a tieline, said support plate being operable, by means comprising said tieline, to move vertically between a position near the ground surface and a bottom of said guide shaft;
• (e) defining a direction of traction wherein movement of said tieline in said direction will cause said support plate to be raised toward said guide shaft, and movement opposite said direction will cause said support plate to be lowered;
• (f) lowering said support plate to a lowered position near the ground surface;
• (g) engaging said tieline to at least one takeup device, said takeup device including locking means for permitting movement of said tieline in said direction of traction upon application of a traction force, said means being further operable to prevent movement of said tieline in said direction opposite the direction of traction substantially upon release of said traction force;
• (h) placing a first additional mast element in a vertical orientation on said support plate, when said support plate is in a lowered position with respect to said vertical shaft;
• (i) grasping said tieline with a traction assist device at a free end thereof extending from said locking means;
• (j) locking, by application of a traction force, said traction assist device onto said tieline to prevent relative movement between said traction assist device and said tieline when said tieline is moved in the direction of traction;
• (k) applying a force on said tieline in the direction of traction sufficient to move said tieline in said direction, thereby causing said support plate carrying said first additional mast element to be raised toward and into an opening in said bottom of said guide shaft;
• and causing said first additional element to engage a lower end of said second upper element;
• (1) ceasing the application of force on the tieline;
• (m) unlocking said traction assist device from said tieline;
• (n) sliding said traction device along said tieline in a direction opposite the direction of traction;
• and
• (o) repeating steps (j)-(n) above, as necessary to raise said support plate carrying said first additional mast element substantially to the level of the bottom of said guide shaft.

A device for raising a lightweight multi-element mast by adding successive elements to a bottom of said mast, comprising:

• a vertical guide shaft having a bore therethrough, said vertical guide shaft being spaced apart from a ground surface at a predetermined distance;
• a base framework connected to said guide shaft, said base framework supporting said guide shaft at said predetermined distance from said ground surface, wherein said successive mast elements are introduced through a bottom opening in said shaft and raised into engagement with a lowermost mast element to thereby progressively raise the top of the mast;
• raising means for raising said mast elements and said mast, said means comprising:
• a support plate adapted to receive a bottom portion of each of said successive elements,
• at least a first pulley connected to said support plate;
• at least a second pulley supported from said guide shaft;
• a tieline having a first end and a second end, said first end being affixed to said guide shaft, said second end being a free end, said tieline further being wound about and engaging said first and said second pulleys;
• takeup means, intermediate said second free end of said tieline and a portion of said tieline emerging from said pulleys, for enabling said mast elements to be raised in response to an application of a traction force in a predetermined direction of traction, such that when said force is exerted by at least one opeator at said free end of said tieline, a translation of said tieline in said predetermined direction causes said pulleys to raise said support plate vertically upward toward said guide shaft, said takeup means incuding:
• locking means for locking said tieline, said locking means fixed in position with respect to said guide shaft, said locking means so constructed and arranged to allow, on the one hand, a translation of said free end of said tieline when said traction force is applied in said predetermined direction of traction and, on the other hand, to lock said free end of said tieline thereby prohibiting translation of said tieline in a direction opposite said predetermined direction of traction when said traction force is substantially ceased,
• means for grasping said free end of said tieline including at least one handle means adapted to be grasped by at least one operator, and
• at least one means for locking said grasping means to said tieline when said traction force is applied in said predetermined direction of traction, and for allowing said grasping means to freely slide along said tieline in the direction opposite the predetermined direction of traction.