US2705363A - Method for erecting a sectional mast - Google Patents

Description

April 5, 1955 H. M. ANDERSON METHOD FOR ERECTING A SECTIONAL MAST 4 Shets-Sheet 1 Filed May 9, 1951 April 5, 1955 H. M. ANDERSON METHOD FOR ERECTING A SECTIONAL M ST 4 Sheets-Sheet 2 Filed May 9, 1951 April 5; 1955 H. M ANDERSON METHOD FORv ERECTING A SECTIONAL MAST 4 Sheets-Sheet 5 Filed May 9. 1951 WTmH/VEY April 5, 1955 H. M. ANDERSON 2,705,363

METHOD FOR ERECTING A SECTIONAL. MAST Filed May 9, 1951 4 Sheets-Sheet 4 Arman/m! United States Patent METHOD FOR ERECTING A SECTIONAL MAST Harry M. Anderson, Fergus, Ontario, Canada, assignor to Beatty Bros. Limited, Fergus, Ontario, Canada, a company of Canada Application May 9, 1951, Serial No. 225,416

2 Claims. (Cl. 29-467) For satisfactory television reception in some districts it is necessary to erect masts 75' or more in height. It is not practical to construct such masts on the ground and then raise them to an upright position.

This invention relates to an apparatus for erecting sectional masts, particularly that type of mast which is used for television antennae.

In my copending United States application Serial No. 211,605, I have described a sectional mast which is light and strong, and which can be erected from the ground up by successively attaching sections, one above the other until the desired height is reached. This method of erecting the mast requires the workman to climb the mast as the erection of sections progress, attaching the guy wires in place as required and finally mounting the television antennae on the top mast. The latter operation presents considerable difficulty on account of interference from the guy wires which have been securely fixed in place. Furthermore, this manner of erection has several objections: (a) It necessitates a workman who is accustomed to working at considerable heights; (b) danger of injury to the workman from falling; (c) it is slow.

The object of the present invention is to provide an apparatus and a method by which a sectional television mast, with the television antennae mounted on the top thereof, can be erected without the workman, who .is erecting the mast and antennae, leaving the ground.

The apparatus by which this is accomplished is set forth in the following description and illustrated in the accompanying drawings in which:

Figure 1 is a perspective view of the apparatus with the first section of the mast and the television antennae in position for erection.

Figure 2 is a perspective view of the apparatus with several sections of the mast in the course of erection.

Figure 3 is a fragmentary view showing a side elevation of the winch for raising and lowering the mast.

Figure 4 is a plan view of the winch.

Figure 5 is a fragmentary view to illustrate the temporary connection between the temporary guy ropes.

Figure 6 is a view showing a sectional mast being dismantled.

Referring first to Figure 1, it will be observed that the apparatus which forms the subject matter of the present invention is illustrated as raising the first section of a sectional mast identified or indicated by the numeral 10 and that Figure 2 illustrates a mast partly assembled. As will be seen from the drawings, the mast is constructed of a plurality of sections 10 constructed and connected together as described in my copending application. It is, of course, to be understood, that the apparatus hereinafter described may be usefully employed in erecting other types of sectional masts providing that the height of the individual sections do not exceed, the height, of the apparatus hereinafter described.

The apparatus for hoisting or lowering the mast includes an easel-like framework comprising a pair of leg members 11, 12 angularly disposed relative to each other so that the lower ends are a substantial distance apart to give rigidity to the structure and converge at the upper end producing a triangular shaped front member. The leg members are joined together by means of a pair of removable cross members 13 and 14 positioned between the upper and lower ends. The front member is supported in an upright position by leg 15 which has its upper end pivotally connected between the upper ends of the legs 11 and 12 by means of a removable pivot pin 17 which also serves as an axle for the pulley 16 hereinafter mentioned. The upper end of the leg 15 is formed with recess in alignment with the pin 17 in order that the pulley 16 may be rotatably mounted on the pivot 17. Mounted on the leg 15 at a position so that it can be easily operated by the party erecting the mast is a winch 18. Figures 3 and 4 illustrate the winch 18 in greater detail than is done in the other figures and it will be seen that the winch comprises a pair of spaced apart brackets 19, 20, one each to the side of the leg 15 and secured in place by bolts 21. The free ends of the brackets 19, 20 support a revolving drum 22 which carries a ratchet wheel 23 having teeth 24 adjacent one of the brackets. Pivotally mounted on the last mentioned bracket and engaging with the teeth 24 is a pawl 25 which is normally urged into engagement with the teeth 24 by a spring, the pawl having an extension 26 forming a handle whereby the pawl may be manually released from engagement with the teeth. The pawl prevents the drum from rotating in one direction except when the pawl is released for the purpose hereinafter described.

The drum 22 is provided with an operating handle 27 at one end, while the other end is extended a substantial distance beyond the bracket 19 and is provided with four channels 28, 29, 30 and 31 for the purpose hereinafter specified. The drum 22 carries a cable 45 having at its unattached end a hook 46.

Attached to the lower end of the leg 15 are four pulleys 40, 41, 42, 43, which are made use of during the dismantling of the mast as hereinafter described. A cable 45 is tied to the drum 22 and is passed over the pulley 15 and is of a length so that it will almost reach the ground. The free end of the cable 45 has a hook 46 attached thereto.

The first step in erecting the mast is to mount the top section of the television antennae shaft 32 with the antennae on the top of what will be the first section which is identified by the numeral 10a. The next lower section which is identified by the numeral 10 is attached to the lower end of the top section 10a, first inserting a guy plate 33 as set forth in my said copending application. Temporary guy ropes 34, 35, 36, 37 are then hooked to the corner posts by means of hooks 38. The temporary guy ropes 34, 35, 36 and 37 are carried through pulleys 47, 48, 49 and 50 respectively passed around a wheel 51 to a snubbing post at 52 where the four temporary guys are collectively snubbed and fed out during erection. Each of the pulleys 47, 48, 49, 50' are secured to the ground by means of a peg 54 and a hook 55 which forms part of each of the said pulley. Two operators are required to erect or dismantle the mast, one operating the hoisting device while the other holds the temporary guy ropes under suflicient stress to hold. the mast erect and prevent swaying as far as possible. In order that the temporary guy ropes may be removed when the erection has been completed, each hook is provided with an arm 38a to which is attached a releasing cord 39, as shown in Fig. 5. These two assembled units are then placed in an upright position between the legs 11 and 12 and the cable 45 attached to the lower end of the section 10 by means of the hook 46. The operator then raises the assembled parts by means of the winch 18 until the lower end of the section 10 is high enough above ground level to permit the next lower section 1% to be placed in position beneath and attached to the lower end of the section 10. Before this attachment is completed a guy plate 33a is placed in position and permanent guy wires attached thereto, these permanent guy wires are identified by the numerals 58, 59, 60 and 61.

These steps of alternately raising and attaching sections is carried out progressively until a mast of the desired height is erected. Of course during the erection additional guy wires will be attached, the total number of sets of guy wires being determined by the height of the mast. For masts of feet'in height, it is suggested that three sets are sufiicient; one set attached near the top and the other set at intervals of approximately 40 feet apart. When the desired height has been reached the base member 62 is attached and secured to its foundation. Then,

the permanent guy wires are secured to anchors 54 which are driven into the ground at equal distances apart so as to give best results for holding the mast upright and the temporary guys removed. The apparatus is then removed from its position surrounding the lower end of the post by simply removing the cross members 13 and 14 which allows the legs 11 and 12 to be folded forward beside leg 15 and the frame lowered.

The dismantling of the mast is shown in Fig. 6. To dismantle the mast, the foregoing steps described for erecting the mast are identical but carried out in the reverse order except certain specified differences which will be noted. The first step is to replace the temporary guys 34, 35, 36 and 37 and this is done by one of the workmen climbing the mast and attaching the hooks 38 carried on each guy to the corner posts above a girt. The temporary guys are then brought through the pulleys 47, 48, 49, 50 respectively which have already been attached to the anchors 54. The temporary guys are then passed through the pulleys 41, 42, 43, and 44 (a separate pulley being provided for each guy) carried on the lower end of the leg 15. It will have been observed that these pulleys are not made use of when erecting the mast. Each temporary guy rope is then given one turn through only one of the grooves or channels 28, 29, 30, 31, in the same direction as the drum will be turned to lower the mast after a section has been removed as hereinafter described. It will be seen by this method that the temporary guy ropes will be kept taut automatically as the mast is progressively lowered.

The next step is to wind the drum so as to bring the hook 46 into a position where it can be attached to the lower end of the section which is attached to the base. As the temporary guy ropes are pulled tight by one of the operators, the guys allow the Winch to be rotated without loosening the temporary guys during this operation. The cable 45 will then support the mast and permit the base to be removed. As soon as the base is removed the winch is allowed to rotate until the mast lowers a distance of one complete section. The hook 46 is then removed, the cable rewound on the winch so that when the hook is attached to the lower end of the next high section, the mast will be supported in this position by the cooperation of the winch and cable. The bottom section is then detached and removed. These steps are then repeated until the mast has been completely dismantled.

What I claim as new and desire to protect by Letters Patent of the United States is:

1. The method of erecting a sectional mast progressively from the top section to the bottom section from the ground comprising placing the top section in a position to rise centrally through a tripod hoist of the manually operated windlass type having a lift of not less than the height of one section, attaching permanent guy wires to the top section and temporary guy wires to the mast adjacent the top section arranged to be removed from ground level, maintaining temporary guy wires tight during the erection to hold the mast firmly in an upright position by passing each temporary guy wire through a pulley secured to the ground at predetermined points from the centre of the mast and then passing all the temporary wires around a central pulley, maintaining the mast in substantially a vertical position by manually pulling on the free end of said temporary guys until the permanent guy wires are secured in place, manually operating the hoist to raise the assembled sections a distance slightly greater than the height of a section, attaching the next lower section thereto to the lower end of the assembled section, successively raising the assembled sections and attaching additional sections until a mast of a predetermined height has been erected, attaching additional permanent guys to predetermined sections during the erection of the mast, attaching the base section and securing the permanent guy wires in place and removing the temporary guy wires.

2. A method of dismantling a sectional mast from the ground comprising placing a Windlass type tripod hoist having a lift of not less than the height of one section at the base of the mast with the mast rising sub" stantially centrally through the hoist, attaching temporary guy wires to the top of the mast corresponding in number to the permanent guy wires, passing each temporary guy wire through a pulley which is securely attached to the ground adjacent the point where a permanent guy wire was previously attached, passing the temporary guy wires around a drum which rotates at the same speed as the Windlass carried on the hoist to maintain said temporary guy wires tight at all times, attaching the cable of the hoist to said mast to support the mast during removal of the bottom section of the mast, disconnecting the permanent guy wires one by one from their ground connection, manually operating said windlass to lower the mast and to rotate said drum to wind the temporary guy wires in at the same rate of speed as the Windlass lowers the mast until the lower end of the mast again rests on the ground, at the same time pulling on the free ends of the temporary guy wires to prevent the wires slipping on the drum, attaching the cable to the lower end of the section immediately above the lowermost section to support the mast during the removal of the lowermost section, and repeating the foregoing steps of lowering and supporting the mast with the cable, of detaching the section adjacent the ground until the mast has been completely dismantled.

References Cited in the file of this patent UNITED STATES PATENTS 1,333,865 Mallet Mar. 16, 1920 1,839,578 Morton Jan. 5, 1932 1,941,854 Dwork Jan. 2, 1934 2,275,704 Turner, Sr. Mar. 10, 1942 2,304,354 Harvey Dec. 8, 1942 2,432,528 Lively Dec. 16, 1947 2,530,807 Campbell Nov. 21, 1950

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