US3368695A

US3368695A - Device for hoisting loads, for example antennae on towers or masts

Info

Publication number: US3368695A
Application number: US563893A
Authority: US
Inventors: Morihain Marcel
Original assignee: US Philips Corp
Current assignee: US Philips Corp; North American Philips Co Inc
Priority date: 1965-07-13
Filing date: 1966-07-08
Publication date: 1968-02-13
Anticipated expiration: 1985-02-13
Also published as: GB1157286A; DE1960827U; NL6609663A; FR1488978A

Abstract

1,157,286. Jib cranes. PHILIPS GLOEILAMPENFABBIEKEN N.V. 13 July, 1966 [13 July, 1965], No. 31503/66. Heading B8B. A derrick comprises a vertical post 1 carrying a pulley 5, a jib 2 carrying a pulley 6 and pivotally supported for luffing movement about a horizontal axis at the base of the post 1, a hoisting rope 10 passing around the pulleys and means for connecting the hoisting rope to the jib so that the rope can be used to luff the jib. The jib can be held in either its upper or lower position by either electromagnetic means or remotely controlled pawl and ratchet means. Alternatively the jib may be bolted in position. When a load 9 has been lifted into the proximity of the pulley 6, the rope is connected to the jib 2 by bolting it between a pair of clamp plates, Fig. 3 (not shown) pivoted to the jib.

Description

Feb. 13, 1968 M. MORIHAIN 3,36

DEVICE FOR HOISTING LOADS, FOR EXAMPLE ANTENNAE ON TOWERS OR MASTS Filed July 8, 1966 2 Sheets-Sheet 1 INVENTOR. MARCEL MORIHAIN AG-EN I Feb. 13,1968 M.MORIHAIN 3,368,695

DEVICE FOR HOISTING LOADS, FOR EXAMPLE ANTENNAE ON TOWERS OR MASTS Filed July 8, 1966 2 Sheets-Sheet 2 FIGS INVENTCR.

United States Patent 4,42 4 Claims. c1. 212-8) ABSTRACT OF THE DISCLOSURE A hoisting device for placing a load on a tower, such as an antenna on top of the tower having a fixed vertical arm and a swinging boom whereby one rope over the pulleys on the vertical arm and boom enables the boom to be swung to a vertical position. The latter is accomplished by a device which temporarily connects the boom to the rope.

The invention relates to a device for hoisting loads such as antennae on top of towers or masts.

For arranging an antenna of large dimensions on top of a tower or a mast it is known to hoist the antenna first along the mast up to the top thereof, after which it is arranged at its place by tilting it; the antenna being mounted previously on the ground. The final height, the weight and the dimensions of large antennae render this tilting movement dangerous, while if the antenna is too bulky then this movement is no longer possible. In a practical case the antenna had a length of 23 meters, while side rods of about 35 meters were provided; the weight of the whole load was of the order of 2 tons and it had to be hoisted to the top of a mast of 33 meters high. Such a large-size load can be rigged on a mast or tower only with great difficulty.

The invention overcomes these diificulties by providing the possibility of first hoisting the load first along the mast and of arranging it subsequently on the top by means of a combined double translatory movement.

The device according to the invention for hoisting loads such as antennae on top of masts or towers is characterized in that it comprises a substantially vertical arm, provided with a pulley and secured to the top of the mast, a boom adapted to swing in a plane bounded by the stationary arm about a shaft fastened in the proximity of the foot of the stationary arm, one of the ends of said boom being provided with a pulley, there being provided a hoisting rope passed through the grooves of said two pulleys, the device comprising furthermore a mechanism for the temporary connection of the boom with the rope in order to achieve a swinging movement of the boom solely by hoisting or running out the rope.

The device may be employed so that, when the boom is fixed in a first position, the load is lifted in a first stage with the aid of the sole rope, after which also by means of said rope, which is temporarily connected by a mechanism with said boom then released, the hoisting movement traverses a second stage like a circular translatory movement, in which each point of the load traces substantially an arc of the circle covered by the shaft of the pulley of the boom, while when the boom has reached a second fixed position, after the release of the connection between the boom and the rope, the load is deposited by the rope released in a third stage at the predetermined place.

The invention will be described more fully with reference to the drawing.

FIG. 1 shows the device according to the invention in the first stage of operation.

3,368,695 Patented Feb. 13, 1968 "ice FIG. 2 shows said device in a second stage of operation.

FIG. 3 shows a connecting piece employed between the first and the second stages.

FIG. 4 shows a variant of the part shown in FIG. 3.

FIGS. 5 to 9 show the various stages in arrangingthe load on the tower or the mast.

The device shown in FIGS. 1 and 2 is mainly formed by the combination of a stationary arm 1 and a boom 2, adapted to pivot about a shaft 3. The arm 1 is secured to the top of a mast 4 and is provided at its top with a pulley 5. The boom 2 is adapted to pivot on the top of the mast 4' about the shaft 3 and is provided at its end With a further pulley 6. The boom can be swung against the arm 1.

FIGS. 1 and 2 show the two extreme positions of the boom, which, in its lowermost position, has a supporting point 7 on the mast 4, and in the topmost position, a supporting point 11 on the arm 1. The device employs a single hoisting rope 10, which extends from a winch 8 (not shown) along the pulley 5 of the arm 1 and then along the pulley 6 of the boom 2.

In an advantageous embodiment the boom of the device according to the invention is removably secured to the mast at the supporting point 7 by means of an electro-niagnet (not shown); this connection is improved by the weight of the load 9, which urges the boom 2 against the support 7. Other structures using for example pawl mechanisms, which may be remote-controlled, or even bolts, in which case a mechanic is required to climb to the top of the mast, are also possible.

When the boom 2 is in the position shown in FIG. 1, the load 9, for example an antenna, which is arranged vertically below the pulley 6, can be lifted along the mast. When the load 9 arrives at the proximity of the pulley 6, the rope 10 is connected to the boom 2, the load remaining connected to said rope. The electric current energizing the electro-magnet is then switched off, so that the connection at the supporting point 7 between the boom 2 and the mast 4 is released or the equivalent connection is disengaged. During the hoisting operation by means of the rope 10 the boom is lifted from the lowermost position shown in FIG. 1 and is swung about the shaft 3 to arrive at the topmost position shown in FIG. 2. The load connected with the boom performs a translatory movement and is moved above the top of the mast in the axial direction of the latter or at least perpendicularly above the final position.

In the position shown in FIG. 2 the boom 2 is connected for reasons of safety by means of a pawl mechanism (not shown) with the supporting point 11 of the arm 1, but it should be noted that the prevailing forces also tend to urge the boom 2 against the arm 1. For the same purpose, the connection may be electro-magnetic or use may be made of any other equivalent connection. The rope 10 is then disengaged from the boom and the load is lowered on the mast, where it is finally positioned.

FIG. 3 shows diagrammatically a first embodiment of the fastening mechanism for the rope 10 and the boom 2. A component 12 is adapted to turn about a shaft 13, which is arranged at the side of the shaft of the pulley 6. This movable component 12 is provided with a clamping jaw 14 for rigidly connecting the rope 10 with the boom 2. Any other mechanical or electromechanical clamping means may be employed for this purpose.

FIG. 4 shows diagrammatically a variant of the connecting mechanism, the clamping jaw being omitted. A component 15 pivots at one end about a shaft 16, provided with a pawl mechanism and arranged at the side of the shaft of the pulley 6. At the other end the component 15 is provided wth a shaft 18, into which the rope 10, fastened to the load 9 can be hooked. The component 15 may be provided in place before the upward 3 or downward movement of the boom 2 and then be removed.

As shown in FIG. 3, the clamping jaw 14 holds the rope 10 and as shown in FIG. 4, the load 9 is connected with the shaft 18, which gives rise to bending forces being exerted on the component 15, the boom 2 swinging about the shaft 3.

FIGS. 5 to 9 show more clearly how the antenna 9 is arranged in its final position on top of the mast in the consecutive stages of operation; the movements are indicated by arrows.

The embodiments described above have to be considered as examples; it being understood that other variations may be possible within the scope of the invention.

What is claimed is:

1. A hoisting device for placing a load on the top portion of a tower comprising a substantially vertical arm provided with a first pulley and fixed to said top portion of said tower, a boom adapted to swing about a pivot point located in the proximate area of the foot portion of said fixed vertical arm in a plane from at least a substantially horizontal position to a substantially vertical position adjacent to said fixed vertical arm, the free end of said boom being provided with a second pulley, a hoisting rope passing through said first and second pulleys, and means for temporarily connecting the boom to the rope in a fixed manner whereby the hoisting solely of said rope results in said swinging movement of said boom.

2. A hoisting device as claimed in claim 1 wherein said means for temporarily connecting the boom to said rope in a fixed manner is a device having clamping jaws, and further means including a shaft pivotally mounting said device adjacent to said second pulley.

3. A hoisting device as claimed in claim 1 wherein said means for temporarily connecting the boom to said rope in a fixed manner is a device provided with a shaft located adjacent to said second pulley, said device being rotatable on one end on said shaft, the other end of said device being fastened to said load at a location where said load and said rope are secured.

4. A hoisting device as claimed in claim 1 wherein said boom swings in a vertical plane through approximately and the extreme positions of said boom are determined respectively by said fixed vertical arm and the tower on which said fixed vertical arm is mounted.

References Cited UNITED STATES PATENTS 456,332 7/1891 Hitchcock 2l29 1,357,150 10/1920 Curtis 21258 2,051,497 8/1936 Sasgen et al. 21258 3,049,242 8/1962 Stevens et al. 2l258 ANDRES H. NIELSEN, Primary Examiner.