US3302345A

US3302345A - Tower

Info

Publication number: US3302345A
Application number: US367349A
Authority: US
Inventors: James S Ballantine
Original assignee: Individual
Current assignee: Individual
Priority date: 1964-05-14
Filing date: 1964-05-14
Publication date: 1967-02-07
Anticipated expiration: 1984-02-07

Description

Feb. 1967 J. 5. BALLANTINE 3,

} TOWER Filed May 14, 1964 5 Sheets-Sheet l INVE TOR ATTQRNEY 1967 J. s. BALLANTINE 3,302,345

TOWER Filed May 14, 1964 5 Sheets-Sheet 2 INVENT fiweswfiazifrw Feb? 1967 .1. s. BALLANTINE 3,302,345

TOWER Filed May 14, 1964 5 Sheets-Sheet 4 Feb. 7, 1967 J. s. BALLANTINE 7 3,302,345

' TOWER Filed May 14. 1964 5 Sheets-Sheet 5 w. We; u jzzzwzw United States Patent 3,302,345 TOWER James S. Ballantine, 121 North Shore Road, Absecon, NJ. 08201 Filed May 14, 1964, Ser. No. 367,349 19 Claims. (Cl. 52-121) The present invention relates to towers and more especially to portable towers which can be readily assembled and disassembled.

A purpose of the invention is to provide a support tower for a precisely located platform for an antenna or other working load.

A further purpose of the invention is to produce a precision telescopic support which is reliable and uncomplicated.

A further purpose of the invention is to use a mechanical operation for erecting a telescopic precision support.

A further purpose of the invention is to provide a telescopic precision support which requires no prepare-d foundation sites.

A further purpose is to provide a precision support structure which can be erected on any soil capable of supporting the weight of a man, while still maintaining specified accuracies.

A further purpose is to eliminate the need for or use of concrete foundations for a telescopic support or tower.

A further purpose is to use a tubular telescopic design in a precision support to eliminate azimuth and vertical deflection errors which are created in a fixed lattice tower due to environmental conditions.

A further purpose is to permit azimuth adjustment on the tower from a relatively lower position without restraint from supporting guy lines.

A further purpose is to provide a mast which is man portable and consists 'Olf a minimum number of subassernblies of maximum weight that can be readily transported by manpower at a rapid gait to permit ready access to sites not available to trucks.

A further purpose is to provide an antenna or precision support capable of rapid erection and compacting with no external power or special tools.

A further purpose is to color code connecting or mating parts for ease of correctly programming the assembly and erection of the tower by a crew of limited training.

A :further purpose is to permit the support when in operational status, even under icing conditions, to be brought rapidly to ground level and then returned to repeatable operational height and orientation.

A further purpose is to provide a precision support which is compact in form and can be extended and locked to any incremental height within its range.

A further purpose is to permit the mast portion of the support itself when extended to any height to be manually positioned in azimuth at the support base.

A further purpose is to construct a support of elements capable of being stowed within a transport vehicle.

A further purpose is to provide a support which can be selectively constructed in any one of a plurality of ranges of heights.

A further purpose is to provide a support which can be operational and survive in extremely high winds.

A further purpose is to provide a support which can be erected at a site with guy anchors but without prepared foundations in a minimum of time and with a minimum crew under adverse weather and terrain conditions using no special auxiliary equipment or power sources.

A further purpose is to provide a mast that can be tilted to provide ease of erection in the field and ease of inspection and maintenance of the unit at the top of the tower.

3,302,345 Patented Feb. 7, 1967 Further purposes appear in the specification and in the claims.

In the drawings I have chosen to illustrate a few only of the numerous embodiments in which my invention may appear, selecting the forms shown from the standpoints of convenience in illustration, satisfactory operation and clear demonstration of the principles involved.

FIGURE 1 is a perspective view of the tower or antenna support of the invention.

FIGURE 2 is a partial vertical section of the lower portion of the tower showing the outriggers.

FIGURE 3 is a top plan section taken through the mast of the tower.

FIGURE 4 is a fragmentary vertical elevation of the mast and triangular support plate for the outrigger.

FIGURE 5 is a top plan section showing the plate and bridle of FIGURE 4.

FIGURE 6 is an enlarged vertical section taken on the line 6-6 of FIGURE 3.

FIGURE 7 is an enlarged section taken on the line 77 of FIGURE 6.

FIGURE 8 is a section taken on the line S8 of FIGURE 7.

FIGURE 9 is a fragmentary section taken on the line 99 of FIGURE 7.

FIGURE 10 is a partial section taken on the line 10-ll0 of FIGURE 9, showing the bottom hinged plate.

FIGURE 11 is a top plan section showing the lift ring and the locking collar.

FIGURE 12 is a fragmentary vertical section taken on the line ]l212 of FIGURE 11.

FIGURE 13 is a fragmentary vertical section taken on the line 1313 of FIGURE 11.

FIGURE 14 is a fragmentary section taken on the line 14-14 of FIGURE 11.

FIGURE 15 is a top plan view of the split friction clamp and icebreaker.

FIGURE 16 is a top plan view of the split friction clamp and icebreaker attached to the locking collar.

FIGURE 17 is a top plan section of the elevating and depressing structure of the invention.

FIGURE 18 is a vertical section taken on the line 18I8 of FIGURE 17.

FIGURE 19 is a vertical section taken on the line 19-19 of FIGURE 17.

FIGURE 20 is a longitudinal sectional view of the hinge pin of the invention.

FIGURE 21 is a top plan view of the base support taken on the line 21-21 of FIGURE 6.

FIGURE 22 is a partial vertical section Olf mast showing the guy ring rotationally positioned on the mast.

FIGURE 23 is a plan view of the guy ring.

Describing in illustration but not in limitation and referring to the drawings:

Precision supports and towers of heights to feet and beyond have been widely used in the communications industry for wave transmission and receipt as well as other functions. These towers support varying loads from a few pounds up to several tons. The towers have been primarily of a semi-permanent type which use concrete foundation bases and fixed lattice work extending to the desired height. In instances wherein the tower was necessarily portable, much difficulty was encountered in assembly and reassembly.

The present invention is concerned with a tower for precision support which is highly portable and of particular value under military operational. type conditions wherein portability, rapid erection, high precision and dependability are required. The present tower is capable of being manually erected to heights of 100 feet and more. The precision telescopic support of the invention is reliable and uncomplicated and the mechanical operation and method of erection are a positive non-aging type of drive so that no loss of precision in erection is incurred with use. The tower requires no prepared foundation sites and can be erected on any soil capable of supporting the weight of a man and still maintain the specified accuracies for the support platform.

In the present tower, the minimum preparation required for site location, either in the planning or during actual field use permits a large measure of economy and flexibility.

The present structure makes use of a tubular telescopic design which has greater inherent stability than the prior art fixed lattice type of tower. Increased stability in azimuth is achieved over the fixed lattice tower because temperature differences from the sunny side to the dark side of the tower have been minimized. Furthermore, the use of a tubular concept results in less distortion from wind effects than result from a lattice tower, since a tube presents a more streamlined configuration to the wind.

Additionally, the geometry of a tubular cross section provides a more economic use of material than does a lattice work tower, so that the overall structure for a given load can be much lighter and compact in a tubular tower than in a lattice work tower.

The proposed tower is highly portable and of modular design which permits the minimum number of subassemblies. Each of the subassemblies can be of such a weight as to permit transport by manpower alone, thereby permitting ready access to sites not available to trucks, or other vehicles. Rapid set-up and erection is possible with no external power or special aids. To permit ease of correctly programming the assembling and erecting, connecting or mating parts are color coded so that even a crew of limited training can readily erect the tower. When in operational status, even under icing conditions, the antenna or any load supported by the tower can be rapidly brought to ground level and returned to repeatable operational heights and orientation. The tower can readily be repacked and relocated.

Considering the forms shown in the drawings, a tower has

telescoping portions

21, 21 21 21 21 and 21 of consecutive progressively reduced diameter in an upward direction, and a base or supporting portion 22. The tower has optionally secured thereto guy lines 23 anchored to stakes 24. Base portion 22 includes Outriggers 25 having

struts

26 and 27 and pads 28. A tiliting mechanism 30 includes a cable 31. An elevating hand wheel 32 is used to extend and retract the telescoping portions 21. An antenna 33 or other supported structure is secured to the topmost telescoping element 21 A plurality of locking structures 35' to 35 which will be explained later in greater detail, secure the adjoining telescoping sections 21 to one another. A pod 39 receives portions 21 when the mast is in a fully depressed position. The individual elements 21 are of a decreasing diameter in an upward direction and are a suitable size to fit one within another. The length of the sections 21 are substantially equal so that when fully telescoped within the pod 39 the extended length of the collapsed tower is substantially that of one of the telescoped sections 21.

Referring now to the specific details of the tower construction, the Outriggers 25 include diagonal struts 25', cross struts 26 and horizontal struts 27.

Struts

25 and 26 are of an adjustable type and struts 25' include a threaded rod portion 40 and a tubular portion 41 with a rotating lock nut 42 having suitable turning spokes 43. Rod 40 is fixed at one end by pivot 45 to a pad 28 through a ball and socket joint 36. Pad 28 is staked to the ground by suitable metal stakes 46 angularly spaced around the pad disc 47.

Horizontal strut 27 includes tube 48 fixed to the ball 36 at one end and integral with an adjusting sleeve 50 at the other end. Adjusting sleeve 50 receives tubular portion 51 having a plurality of spaced holes 52, one of which selectively engages with the hole 53 in adjusting sleeve 50. A suitable quick release pin, such as shown in FIGURE 20, is passed through 53 and matching hole 52.

Strut 26 is similar to strut 25 in that a rotating internally threaded sleeve 55 is used to adjustably connect strut 26 with threaded rod 57. Threaded sleeve 55 and rod 57 are pivotally connected to strut 25 and strut 27 respectively. Strut 27 is hingedly connected to support plate 60 at hinge 61. Tie rods 62 as best seen in FIG- URES 2 and 3 tie the pads 28 together and form a triangular truss. Suitable turn buckles 63 are used to adjust the tie rod lengths.

The support plate 60 as best seen in FIGURES 6 to 9 has secured thereto as by welding hinge blocks 65 which extend normal to the plane of the support plate 60. The hinge blocks receive and journal a toggle bolt 66 which passes through bore 67 of hinge plate 68. Additionally, hinge blocks 65 restrain hinge plate 68 from longitudinal movement at bearing surfaces 70.

The toggle bolt 66 has a weighted handle 71 which is connected to the toggle bolt 66 at one end and has at the other end a rotatable link or flipper 72.

The rotatable linke 72 is pivotally supported within a slot 73 at one end of the bolt. Slot 73 has an inclined end 75 or wall which forms a bearing surface for a corresponding inclined face on the rotatable link 72. In one angular position of bolt 66 the link extends longitudinally of the bolt and is adapted to extend within the confines of a hole substantially the size of the cross section of the toggle bolt. In another position which is 180 from the first position the link rotates into a position as shown in FIGURE 8 and acts to prevent the toggle bolt 66 from being withdrawn from hinge blocks 65. The handle 71 is so fixed on the toggle bolt as to rotate the toggle bolt to a locking position as shown in FIG- URE 8 under the influence of gravity.

Hinge plate 68 has a hinge portion and a bearing portion 81. The hinge plate 68 rests on an abutment 82 extending upwardly from the triangular support plate 60 at the position opposite the hinge blocks 65. On the upper side of hinge block 68 a circular flange 83 projects integrally from the base and has supported thereon a bearing block 85 suitably of Teflon (polytetrafluoroethylene). The bearing block 85 has radially extending grooves 86 or cut-outs for passing excess grease which is introduced at 87. A tube base 90 as best seen in FIG- URE 9 has flanges 91 which extend over the Teflon bearing block 85 and which bears against the Teflon block at 92. The lowermost tubular section 93, which does not raise or lower vertically, is secured to tube base 90 as by welding, and azimuth plate 95 is fixed on tube base 90 and rotates therewith. A vernier block 97 has suitable graduations which selectively match with graduations 98 on azimuth plate 95. A bolt 100 passes through a center opening in base 90 and through a center hole in hinge plate 68. A lock nut 101 is secured to the threaded portion 102 of bolt 100 and is suitably in the form of a split nut having a threaded locking screw engaged therein in a conventional prior art manner. The bolt 100 is pinned through its head at 103 so that the bolt rotates with the base 90 and in turn the lock nut 101 rotates with the bolt 100. The function of bolt 100 is to longitudinally lock the tube base 90 to hinge plate 68 while allowing relative angular motion between the lowermost tubular section 93 and the hinge plate 68. When the lowermost section 93 is rotated, as for instance manu ally by means of handles (not shown) the entire tower rotates with respect to the base.

Referring to FIGURES 22 and 23 showing the guy ring, a ring 23' is interposed between locking collar 158 and split friction clamp and icebreaker 180. Long cap screws 23 act to hold the ring 23' to the collar 158 and clamp 180. An annularly extending groove 23 receives an arcuately split guy ring 23 composed of sections 23

p

23 and 23 Flanges 23 extend radially outwardly and are clamped by shackles 23 secured by bolts 23 Guy lines 23 are secured to the shackles 23 The mast sections are free to rotate with respect to the guy ring 23 since ring 23 and guy ring 23 are in sliding engagement rotationally.

Base support 60 has a dependent ball 105 which has a threaded stem 106 threaded into base support 60. A flange 107 serves as an abutment shoulder for limiting motion of the ball bolt 106 into the support 60. The ball 105 itself extends into the ball socket 108 of base 110 as best seen in FIGURES 6 and 9. Surrounding the said lowermost tubular section 93 and secured as by welding to the support plate 60 is a U shaped cover portion 111. The cover portion 111 has a cover plate 112 secured thereto as by bolting. It will be seen that the cover section encloses the lowermost tubular section including the hinge plate. The enclosure 111 or cover portion 111 has fixed thereto at the top a support ring 112 to which inclined struts 36 are pivotally secured thereto at 113. The support ring 112' has a pulley 115 rotatably supported thereon. The mast is held in support plate 112' by an arrangement best seen in FIGURES 4 and 5. Plate 112 has a removable portion 112 which is keyed to plate 112 by keys 112 Flange plates 112 are fixed to removable portion 112 by bolting, for instance, and pins 66 shown in detail in FIGURE 20 secure flange plates 112 to plate 112'. An adjustment screw 112 engages a tapped hole in removable portion 112 and has jacking action against block 112 which has an arcuate bearing surface against tubular section 93. An adjustment wrench of conventional design is used to rotate screw 112 The lowermost tubular section 93 has secured thereto at its top a flange 116 as seen in FIGURES 2 and 17 to 19 inclusive.

The flange 116 comprises an upper half 117 and a lower half 118. Upper and

lower halves

117 and 118 respectively have annularly extending

grooves

120 and 121 which journal therein an internal ring gear 122. Roller bearings 123 provide a radial bearing wherein the bearings ride in matching V grooves 124. Pinion gears 125 and 126 engage ring gear 122 and rotate under the influence thereof. The

pinions

125 and 126 are internally threaded and receive therein respectively lift

screws

127 and 128. A drive pinion 130 engages the interal teeth of ring gear 122 and is keyed on shaft 131. Drive pinion 130 extends within a circular recess 132 in flange 116. Likewise driven

pinions

125 and 126 rotate within recesses 133 and 135 respectively within flange 116. Shaft 131 has keyed thereon bevel pinion 136 in engagement with bevel pinion 137 which is keyed to shaft 138 driven by hand wheel 32. A housing 140 supports

shafts

131 and 138 and is secured to lowermost tubular section 93. Pinion gears 125 and 126 respectively are supported vertically by upper thrust bearings 141 and lower thrust bearings 142. The lift screws engage at their topmost end with a lift ring 143 as best seen in FIGURE 14, by means of a shoulder 144 and cap screws 145.

Referring now to FIGURES 17 and 18, lift screws 127 and 128 threadably engage internally threaded

pinions

125 and 126. The lift ring 143 is best seen in FIG-

URES

11, 12 and 14 and comprises a circular or annular portion 153 which has a substantially circular inner surface 156 which is of sufficient size to extend in close proximity to a locking collar 158 which is secured to the upper outer portion of each of the tubular sections 21. The locking collar as seen in FIGURE 12 is secured at 160 as by bolting to the tube 21. It should be understood that each of the tubular portions 21 has a respective collar 158 at its upper end.

Each of the collars 158 has extending radially at diametrically opposite positions locking clamps 162 having a handle 164 attached to screw portion 166, which threadably engages a longitudinally slida'ble bolt 168 having a shoulder 170 which can engage stop ring 172. Stop ring 172 is integral with the bottom portion of the next inner tubular section 21. Each of the locking collars 158 will have an inner diameter which will conform to the diameter of the respective tubular portion 21 to which it is attached and these of course will be respectively and progressively decreased within the telescoped portions. The outer perimeter ofthe locking collar 158 will be of the same size for all locking collars and will conform to the inner opening of the lifting ring 143 as best seen in FIGURE 11.

Each of the tubular portions ,21 at their lower end will have a flange 174 which will have secured thereon a plurality of guide buttons 176. These buttons 176 can be of a suitable plastic such :as Teflon to provide a sliding relationship between the inner portion of the tube 21 and the lower portion of the next innermost portion 21. The buttons may be held to the flange 174 by means of countersunk rivets or screws 178.

As seen in FIGURE 12, the handles 164 have been rotated in the locking clamps to move bolt 168 inward so that shoulder engages the underside of stop ring 172 and holds the upper tubular portion 21 upward with respect to the lower tubular portion 21.

A split friction collar and icebreaker 180 as best seen in FIGURES 15 and 16 includes

halves

182 and 184. These halves are bolted by means of cap screws 186 to the locking collar 158 at locations 188 shown in FIG-

URES

11 and 16. The inner surface of the split friction collar and icebreaker 180 conforms to the diameter of the next inner tubular portion of that tubular portion to which it itself is secured and has a hexagonal head cap screw 192 extending through flange portions 194. The cap screw threadably engages one of the flange portions 194. The hexagonal head cap screw 192 is rotated by a suitable hand tool or wrench to draw the adjacent flanges 194 toward one another in one instance and in other instances to release the flanges with respect to one another. A stop on screw 192 at 192 acts to force the flanges 194 apart when the screw 192 is rotated to release the split halves.

By means of the cap screws 192, the

halves

182 and 184 of the split friction collar and icebreaker 180 can be drawn tightly into engagement with the inner telescoping section 21 as seen for instance in FIGURE 16 directly above flange 172 or in another instance the

halves

182 and 184 can be released and in fact, forced apart, so that they no longer grip the inner tubular portion but in effect provide a sloppy fit.

Keys

198 and 200 run longitudinally along each of the tubular sections and engage in

key slots

202 and 204 which extend between the flanges of the icebreaker and split collar halves 182 and 184. Key slots 202 are precisely for-med on the split friction collar 180 at a position exactly concentric with the next innermost, and lines up the vertical axis of the mast when the split friction collar is tightened. Perfect perpendicularity of each mast axis is achieved by the bearing of the stop ring 172 against the lower surface of the split collar 180.

As seen in FIGURES 11 and 13, the lifting ring 143 has a slot 208 which receives a cam 208 which rotates from a position completely within the ring to a position wherein a portion of the cam 208' extends radially inward from the inner circular surface of the ring, whereupon it engages a slot 210 in the locking collar 158. The cam 208 is keyed on a shaft 212 which extends downwardly from the lifting ring slidably through a rotatable nut 214 having a handle 216. The nut 214 is free to rotate with respect to fixed flange 117 but is restrained against vertical movement by key block 218 which engages key slot 219 on nut 214. The shaft 212 is suitably hexagonal in cross section at 220 and slidably engages nut 214 so that a rotation of the nut 214 causes rotation of shaft 212 with consequent rotation of cam 208. By means of this arrangement lifting ring 143 can be selectively locked to locking collar 158.

Considering the operation of the tower of the invention, the description will begin with the tower in a raised position as seen in FIGURE 1. In this position, each of the tubular portions 21 to 21 will be fully extended and locked to each other. The lowermost movable section 21' will be locked into the fixed tubular portion 93. Locking clamps 162 of the respective locking collars 158 will be in an engaging position whereby bolt 168 will extend into engagement with the flange 172. The guide buttons 176 will be engaging the inner surface of the next outer tube. The split friction collar and icebreaker 180 will be in tightly gripping engagement with the inner telescoping portion as a result of the hexagonal head cap screws 192 being tightened to draw flanges 194 together. The upper part of stop ring 172 will be in complete bearing engagement with the lower surface of split friction collar and icebreaker 180, thus assuring complete parallel relationship between the longitudinal axes of the respective telescoping portions.

Keys

198 and 200 will be held securely in keyways 202 and 264' respectively of split friction collar 180, thus assuring precise concentricity and in-line relationship of the longitudinal axes of the telescoping portions.

To lower the tower, the lift ring 143 will be freed of all the locking collars 158 by rotating cams 203 fully within the lifting ring. This will be done by rotating handles 216 on nuts 214 to rotate shafts 212 by means of hexagonal portion 220. The ring is now free to be elevated without interference from or connection to any of the locking collars. The lift ring is elevated by rotating hand wheel 32 through shaft 138 through

bevel gears

137 and 136 to rotate shaft 131 which has keyed thereon drive pinion 130. Drive pinion 13f) rotates ring gear 122 which engages with

pinions

125 and 126.

Pinions

125 and 126 being in threaded engagement with lifting

screws

127 and 128 force the screws upward when hand wheel 32 is rotated in a corresponding direction. The

screws

127 and 128 carry lift ring 143 upward.

The lift ring 143 is moved upwardly by turning hand wheel 32 until it reaches the level of the locking collar at 35 Cams 208 are then rotated into a position shown in FIGURE 11 so that the lift ring is now engaged with the locking collar at position 35 The locking clamps 162 on the fixed tubular portion 93 are released and the bolts 168 are withdrawn by releasing the locking handle 164. Additionally, the hexagonal head cap screws 192 are backed off from the engaging threads so that flange portions 194 are forced apart with respect to one another, to provide a clearance between the tubular wall and the inner surface of the combined split collar and icebreaker 180. Under these conditions section 21' as well as all the sections above 21 are now supported from the lifting ring 143 at 35 and free of any vertical support from the fixed tubular portion 93. Hand wheel 32 is then rotated to lower the entire structure from 21' upward. This lowering continues until the locking collar 158 at 35 rests against the locking collar 158 at 35. Cams 208' are then rotated to release the lift ring 143 from the collar at 35 and the lift ring 143 is again elevated as described above. The lift ring 143 is then engaged with the locking ring at 35 and the procedure repeated. The guy ropes or wires 23 may be kept snug during these entire operations by suitably taking up at stakes 24 or in the alternative the ropes 23 may be allowed to extend in a slack position and then removed from the collar at 35 This lowering procedure described above is repeated until the topmost collar at 35 or whatever other topmost collar exists, is lowered entirely onto the resting nests of collars. In this condition the entire telescoped portion may be then rotated into a horizontal position as suggested in FIGURE 6. To do this, the back portion 112 of the pod 111 is removed, the removable portion 112 is removed by extracting toggle bolts 66, and then the entire collapsed tubular sections are tilted about toggle bolt 66 in the base. The telescoped portion is controlled during tilting by exerting a restraining force on the lowermost locking collar through means of cable 31 which is wound on winch 30 which is rotated under the influence of a handle geared to the winch.

The entire mast is disassembled by means of the quick removal pins best seen in FIGURE 20 wherein the pin handle 71 is rotated so that the locking link 72 falls into a position where it is supported in a longitudinal extension of the pin body 66. The pin is able to be withdrawn at this time by merely pulling on the handle to slide the pin longitudinally within the opening.

In raising and lowering the tower of the invention, the pod section, including the tubular portions, are supported by the outriggers 25 which are suitably adjusted to provide a precision leveling of the base by means of angle levels 230 as best seen in FIGURE 7.

The tower of the invention can be readily dismantled in its entirety by removing pins shown in FIGURE 20, and used throughout the construction so that the entire disassembly, or erection, can take place in a short period of time, for instance, thirty minutes or less.

In view of my invention and disclosure, variations and modifications to meet individual whim or particular need will doubtless become evident to others skilled in the art, to obtain all or part of the benefits of my invention without copying the structure shown, and I, therefore, claim all such insofar as they fall within the reasonable spirit and scope of my claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In a collapsible tower for supporting a load at the top, a plurality of telescoping portions of consecutive progressively reduced diameters in an upward direction and including a lowermost portion, a base connected to and supporting the lowermost portion, individual locking means on each of the portions for selectively locking the adjoining telescoping portions to one another, including means for aligning the tubular sections concentrically and longitudinally, and elevating means for raising and lowering the telescoping portions comprising a lift ring, means for successively engaging the lift ring with the top of each of the telescoping portions other than the lowermost portion, and means for raising and lowering the lift ring.

2. A tower of claim 1, in combination with means for rotating the telescoping portions with respect to the base.

3. A tower of claim 1, wherein the elevating means for raising and lowering the telescoping portions exerts a controlled positive downward force.

4. A tower of claim 1, wherein the elevating means include screw means.

5. A tower of claim 1, in combination with guy lines conneced to and extending from a rotatable guy ring on said tower.

6. A tower of claim 1, wherein the base includes outriggers having adjustable struts.

7. A tower of claim 1, wherein the lowermost portion is hingedly connected to the base, in combination with cable means for tilting the telescoping portions with respect to the base.

8. A tower of claim 1, in which the means for raising and lowering the lift ring includes an internal ring gear, means for rotating the ring gear, driven pinion gears meshing with the ring gear and rotating under the influence thereof, said driven pinions having internal threads, vertically extending lift screws threadably engaged with the driven pinions and connected at the top thereof to the lift ring, a drive pinion meshing with the internal teeth of the ring gear, and means for driving the drive pinion.

9. A tower of claim 8, wherein the means for driving the drive pinion includes a hand wheel.

10. A tower of claim 1, wherein the locking means includes a locking collar secured to the upper outer portion of each of the tubular sections, an annular flange on the lower end of each of the telescoping portions other than the lowermost portion, and locking clamps within the collar adapted to selectively engage the respective annular flanges on the next innermost telescoping section.

11. A tower of claim 10, wherein the locking collars have an inner diameter conforming to the diameter of the respective telescoping portion to which each is attached, and an outer diameter conforming to the inner opening of the lift ring.

12. A tower of claim 1, wherein each of the telescoping portions has at their lower end a guide flange having secured thereon a plurality of guide buttons.

13. A tower of claim 1, wherein the locking means includes a plurality of split collars, each of which comprises resilient circumferential portions fixed to the upper end of a given telescoping portion and adapted to be drawn into tight engagement with the next innermost telescoping section.

14. A tower of claim 13, wherein each split collar selectively engages an annular flange on the lower end of the next innermost telescoping portion.

15. A tower of claim 13, wherein each split collar has keyways that engage keys integral with and extending longitudinally of the telescoping portions.

16. In a collapsible tower for supporting an antenna, a base, a plurality of telescoping portions of consecutive progressively reduced diameters inan upward direction and mounted on the base, means for individually raising and lowering the telescoped portions, comprising a lifting ring, lift screws extending vertically from the lifting ring, means for raising and lowering the lift screws, and means for engaging the lifting ring successively into engagement with each of the telescoping portions.

17. A tower of claim 16, wherein the lift screws exert a selective downward force on the telescoping portions.

18. A device of claim 16, wherein the means for raising and lowering the lift screws comprises a ring gear, means for rotating the ring gear, and a driven pinion gear in engagement with the ring gear and in threading engagement with the lift screws.

19. A device of claim 18, wherein the means for rotatin the ring gear comprises a hand wheel, a shaft geared to the hand wheel, and a driving pinion keyed to the shaft and in engagement with the ring gear.

References Cited by the Examiner UNITED STATES PATENTS 2,412,678 12/1946 Goldman 52-116 X 2,581,351 1/1952 Black 52116 X 2,795,303 6/1957 Muehlause et a1. 52-121 3,196,991 7/ 1965 Johnson et a1. 52-632 X HARRISON R. MOSELEY, Primary Examiner.

J. K. BELL, Assistant Examiner.