US 3320703 A
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Description (OCR text may contain errors)
y 1967 R. HAWTHORN ETAL 3,320,703
DEVICE FOR RAISING OR LOWERING ANTENNA MAST 2 Sheets-Sheet 1 Filed Aug. 26, 1964 INVENTORS ROBERT HAWTHORN BY JOHN E H/ATT PEG 2 ATTORNEY y 1967 R. HAWTHORN ETAL 3,320,703
DEVICE FOR RAISING OR LOWERING ANTENNA MAST Filed Aug. 26, 1964 2 Sheets-Sheet 2 IN VEN'IORS 7 ROBERT HAWTHORN JOHN E HIATT United States Patent Ofiice 3,320,703 Patented May 23, 1967 tion of Iowa Filed Aug. 26, 1964, Ser. No. 392,113 3 Claims. (Cl. 52-123) This invention relates in general to a mast structure and in particular to a quickly and easily erectable mast.
Rad-i communications oftentimes require a mast structure to support the antenna. It is an object of this invention therefore, to provide a quickly erectable mast structure for an antenna or other device.
Another object is to provide an antenna mast which may be simply and easily erected or taken down.
Yet another object of the invention is to provide an antenna mast structure of simple design.
A feature of this invention is found in the provision for a mast having locking collars and an erecting lever so as to provide a simple and easy to install mast.
Further features, objects, and advantages of this invention will become apparent from the following description and claims when read in view of the drawings in which:
FIGURE 1 illustrates the mast of this invention;
FIGURE 2 is a sectional view through the locking collars of this invention;
FIGURE 3 is a sectional view of the locking collars during disassembly; and
FIGURE 4 is an exploded view of a locking collar of this invention.
FIGURE 1 illustrates an antenna supporting structure comprising a base plate 10. Vertical supporting mem bers 11 and 12 are attached to the base plate and cross brace members 13 and 14 are connected between the vertical members 11 and 12. It is to be realized that there are at least three vertical members similar to 11 and 12 but that one of these cannot be seen in FIGURE 1. A top structure of the antenna support comprises in clined brace members 16, 17, and 18 which terminate in a locking collar 19. Shorter inclined support members 21 and 22 support a second locking collar 23.
A lever 24 is attached to the antenna supporting structure by pivot pin 26 and is formed with a bifurcated end 27. The end 27 is formed with slots 28 which receive therein pivot pins 29 and 29 of a third friction collar 31.
An antenna mast 32 extends through the friction collars 19, 23, and 31 and terminates in a tapered point 33 upon which is mounted a suitable antenna 34. A guy wire collar 36 is formed in two semicircular portions which can be joined together about the mast 32 above friction collar 19 by suitable holding bolts. The guy collar 36 is formed with suitable guy wire openings to which guy wires 37 and 38 may be attached. A second split ring guy wire collar 39 is attached to the mast 32 and carries guy wires 40 and 45'. It is to be realized that the other end of guy wires 37, 38, 40, 45 are attached to anchors in the ground plane on which the base 10 rests so as to give mechanical rigidity to the structure. Although only a pair of guy wires is shown attached to each guy collar, it is to be realized that at least three guy wires would be attached to each collar to give suitable bracing.
FIGURE 2 illustrates the mast 32 extending through the three friction collars 19, 23 and 31. The mast 32 is formed of metal or plastic material and comprises a number of sections of interlocking tubes which are joined by spigot joints. These joints allow a lower section to be inserted into an upper section such that a rigid joint is produced and the outer walls of the two adjacent sections are smooth so that they may easily pass through the friction collars 19, 23 and 31. The friction collars 19, 23 and 31 are capable of applying locking friction action to the mast in one direction but will allow the mast to freely move therethrough in the opposite direction.
For example, in FIGURE 2 the locking collars 19 and 23 will completely support the weight of the mast 32 and transfer it to the antenna supporting structure. During the erection process, however, the lifting collar 31 grips the mast to lift it upward through the collars 19 and 23. Movement of lever 24 lifts collars 31 toward the collars 23 and 19 for this purpose. This is possible because the collars 23 and 19 will allow the mast to move upwardly therethrough, however, when the collar 31 reaches its upper position and the lever 24 is moved to move collar 3-1 downwardly, the collar 31 will slide on the outer surface of the mast 32 and the holding collars 19 and 23 will not allow the mast to move downwardly due to their locking action. Thus, by actuating the lever 24- upwardly and downwardly, the mast structure 32 may be erected upwardly through the collars 19 and 23 and held in the raised position.
Thus, the mast may be raised until a particular section is almost through the three collars and then a new lower section 33 may be attached and the process continued. As more and more of the mast extends from the upper collar 19 periodically split guy rings such as 36 and 39 are attached and guy wires are fastened to them to give mechanical support to the mast.
As shown in FIGURE 2 and exploded view 4, the collars 19 and 23 comprise an outer support collar 41 which has attached to its outer surface the supporting lugs 42, 43 and 44 to which the mechanical supports such as 16 and 18 are attached by suitable pins. The hollow internal structure of col-lar 41 is formed with a ledge 46 into which a number of openings 47 have been drilled. A sleeve insert 48 is receivable within the collar 41 and has a rim 49 which rests on the shoulder 46. Semicircular openings 51 are formed in the rim 49 and provide an index locking means for locking the sleeve 48 relatively to the collar 41. This is accomplished by a locking pin 52 which may be inserted in one of the semicircular openings 51 in the sleeve 48 and into one of the drilled openings 47 formed in the collar 41 to prevent rotation between the collar and sleeve. The lower end 53 of sleeve 48 is threaded, and a ring nut 54 is receivable on the lower end to lock sleeve 48 and the collar 41 together.
Three tapered friction collets 57, 58 and 59 are received within sleeve 48 and are formed with their lower rims 61, 62 and 63 extending beneath the ends of the collar 41 and sleeve 48. The internal surfaces 64, 65 and 66 of tapered collets are adapted to receive the mast 32 therethrough and are covered by a suitable friction material. Grooves 67, 68 and 69 are formed in the upper ends of the collets 57, 5'8 and 59 for receiving a retainer ring 71 therein. Keyways 72, 73 and 74 are formed in the collets 57, 58 and 59 and keyways 76, 77 and 78 are formed in the sleeve 48 to receive keys 79, 81 and 82 therein. Keys 79, 81 and 82 hold the retaining ring 71 in place and also prevent rotational motion between sleeve 48 and collets 57, 58 and 59.
The internal surface of sleeve 48 is tapered to mate with the outer tapered surface of the collets 57, 58 and 59. This is best shown in the sectional view of FIG- URE 2.
The frictional sleeve assembly collar 23 is identical to collar 19. Likewise the lifting collar 31 is similar except the tabs 42, 43 and 44 have been eliminated from the 3 collar 41 as shown in FIGURE 4 and the pivot pins 29 and 29' have been substituted to receive the lifting lever 24.
As best shown in FIGURE 2, a sleeve 83 is mounted between the collars 23 and 19 and is. formed with a rim 84 which bears on the upper surface of the tapered collets of collar 23 and has an upper rim 86 which at times engages the lower ends of the tapered collets of the sleeve 19.
In operation, the mast sections are fed upwardly through the collars 23, 19 and collar 31 and the lifting handle 24 is actuated to raise the mast. As collar 31 is moved upwardly the friction surfaces on the tapered collets will lock to the mast and force it upwardly through the collars 19 and 23. Due to the tapered collets in collars 19 and 23 they will slide upwardly thus releasing their grip on the mast to allow it to slide therethrough. However, as the lever 24 is moved to lower the collar 31 the tapered collets within sleeves 19 and 23 will move downwardly to grip the mast to hold it and prevent it from moving downwardly. Collar 31 will be released due to the tapered shape of the collets to allow the sleeve 31 to be lowered for a new grip on the mast and another stroke. As the end of a mast section approaches the lifting'collar 31, a new section 33 is joined to the lower end of the mast sect-ion and lifted through the collars. Thus, means are provided for simply andeasily raising the mast.
To lower the mast, the pin 26 is removed and the collar 31 is lowered off the end of the mast and turned over so that the position shown in FIGURE 3 is assumed. Then the pin 26 is reinserted in the pivot bracket of the antenna support and the lever 24 moved to push the collar 31 against the collar 23. The rims 89 of the collets of sleeve 31 will push upwardly against the rims 91 of collets of sleeve 23 to release the collar 23 from its locking relation with the mast. Simultaneously, the sleeve 83 will push upwardly on the rims 61, 62 and 63 of the collets 57, 58 and 59 of sleeve 19. This will release collars 19 and 23 to allow the mast to slide downwardly through the antenna supporting structure. Since the lifting collar 31 his been inverted, the mast may freely slide downwardly through it and thus the mast may be lowered in a controlled manner by applying pressure to the lever 24. The mast will be periodically stopped to remove a section from the lower end of the mast below collar 31.
It is seen that this invention discloses a mast structure which may be easily raised or lowered. Although it has been described with respect to a particular embodiment thereof, it is not to be solimited, as change and modifications may be made therein which are within the spirit and scope of the invention as defined by the appended claims.
1. A mast structure comprising a supporting member, a pair of locking sleeves supported above each other by the supporting structure; said locking sleeves each comprising an annular member formed with a tapered bore, a plurality of collet members receivable within said tapered bore and formed with outlettapered surfaces and inner gripping surfaces, a sleeve between the collets of the first and second sleeve, a mast received through the locking sleeves and the sleeve between the collets and in engagement with the inner surfaces of said collets, and means for moving said mast through said locking sleeves wherein the tapered collets are carnrned upwardly due to the lifting action to release their hold upon the mast but wherein they are cammed downwardly and inwardly due to the weight of the mast to lock the mast to the sleeve when the lifting force on the mast is removed.
2. An antenna mast structure comprising a base member, a pair of locking collars attached to the base member and formed with a central bore through which a mast extends, said locking collars locking to the mast to prevent downward movement of the mast but releasable from the surface of the mast when the mast is moved upwardly to allow it to move upwardly therethrough, a sleeve mounted between said locking collars, a lifting collar receivable on the mast and movable relative to the base member to lift the mast through the pair of locking collars, means for moving said lifting collar, and said lifting collar being locked to the mast when lifting sa-id shaft through the locking collars but slidable relative to the mast when the locking collars are supporting the mast, said means for moving the lifting collar comprising a lever pivotally supported by the base member and formed with a bifurcated end which is engageable with the lifting collar to move it relative to the locking collars.
3. In apparatus according to claim 2 wherein said lifting collar may beinverted to move upwardly against one of the locking collars to release it by force applied upwardly and wherein the sleeve mounted between the two locking collars is moved by the first locking collar to release the second locking collar.
References Cited by the Examiner UNITED STATES PATENTS 1,024,860 4/1912 Kline 254106 2,703,691 3/1955 Minnis 28758. 2,739,673 3/1956 Foster 52-423 X FOREIGN PATENTS 1,009,906 3/1952 France.
JOHN E. MURTAGH, Primary Examiner.
RICHARD W. COOKE, JR., Examiner.