US3789415A

US3789415A - Apparatus for wrapping cables or the like and a rotatable antenna utilizing the same

Info

Publication number: US3789415A
Application number: US00318265A
Authority: US
Inventors: J Vickland
Original assignee: Philco Ford Corp
Current assignee: Space Systems Loral LLC; Lockheed Martin Tactical Systems Inc
Priority date: 1972-12-26
Filing date: 1972-12-26
Publication date: 1974-01-29
Anticipated expiration: 1991-01-29
Also published as: JPS4996277A; BR7308677D0; CA996911A; AU6201273A; AU476970B2; JPS5425622B2

Abstract

Apparatus for wrapping cables, hoses or the like, leading from fixed structure to a rotatable element such as a mechanical scanning antenna, said apparatus accommodating multiturn rotation of the antenna without subjection of the cables or hoses to substantial torsional forces. A planetary cable winding and guiding carrier is used, in association with a main cablereceiving drum which comprises the sun element of a planetary cable take-up system.

Description

United States Patent [191 Vickland APPARATUS FOR WRAPPING CABLES OR THE LIKE AND A ROTATABLE ANTENNA UTILIZING THE SAME [75] Inventor: Jack M. Vickland, Palo Alto, Calif.

[73] Assignee: Philco-Ford Corporation, Blue Bell,

22 Filed: Dec. 26, 1972 211 App]. No.: 318,265

[52] US. Cl 343/763, 254/l75.5, 254/175.7 [51] Int. Cl. H01q 3/04 [58] Field of Search 343/757, 763, 764, 766;

[56] References Cited UNITED STATES PATENTS 3,044,723 7/1962 Blue 254/1757 X Jan. 29, 1974 4/1966 Benson et al. 254/175.7 UX 12/1967 Walsh et al. 254/1757 X Primary Examiner--Paul L. Gensler Attorney, Agent, or FirmRobert D. Sanborn; Carl H. Synnestvedt 7 1 ABSTRACT Apparatus for wrapping cables, hoses or the like, leading from fixed structure to a rotatable element such as a mechanical scanning antenna, said apparatus accommodating multiturn rotation of the antenna without subjection of the cables or hoses to substantial torsional forces. A planetary cable winding and guiding carrier is used, in association with a main cablereceiving drum which comprises the sun element of a planetary cable take-up system.

12 Claims, 9 Drawing Figures PAIENIED 3.789. 11 5 sum 2 or 3 APPARATUS FOR WRAPPING CABLES OR THE LIKE AND A ROTATABLE ANTENNA UTILIZING THE SAME BACKGROUND OF THE INVENTION In certain apparatus, particularly mechanically rotatable electrical apparatus such as scanning antennas, it is necessary to establish and maintain connections between stationary and rotatable members. These connections may comprise electrical conduits, mechanical actuating cables, and hydraulic or pneumatic hoses. The term cable, or cable means, as used in this disclosure, contemplates all such connections.

Antennas of the kind which may to advantage embody this invention, are frequently used on board ships, or in other installations where space, particularly space along the antennas axis of rotation, must be maintainedat a minimum. Rotation of the antenna tends to twist or wrap the cables with respect to the fixed structure with which they are associated. Such wrapping not only limits the revolutions of the antenna, or other rotatable element, about its axis, but also may damage or break the cables.

Attempts have been made to meet these problems by use of slip rings, which are space consuming and tend to be unreliable, or by hanging the cables for example in Maypole" fashion. The latter expedient is very space consuming and subjects the cables or conduits to torsional forces. Another approach to the problem has been to provide sufficient slack between the rotating element and the points at which the cables are anchored. This expedient is wasteful of space and has been, if anything, less successful than the other prior art arrangements.

SUMMARY OF THE INVENTION It is the broad objective of my invention to provide improved apparatus for accommodating electrical cables, hoses and the like, which extend to a rotating structure from fixed machinery in order to control, or provide electricity or fluids to said structure. This objective is accomplished by provision of means for wrapping a portion of the cable, intermediate the rotating system and the stationary structure to which the cable is fixed, the wrapping apparatus including a main cablereceiving drum, a planetary. carrier having a portion mounted for rotation about the axis of the main drum and carrying planetary drum means. During angular traverse of the rotatable element with which the apparatus of the invention is utilized, the planetary carrier and its drum means are constrained, by the cable and by apparatus for applying certain biasing force, to operate as a planetary system, with respect to the main drum means, and thereby to wrap the cable without twisting thereof during several complete turns of the rotatable element. In a representative embodiment of the invention, it has been possible to provide about 3 /2 turns of rotary movement at a scanning antenna, with freedom for corresponding reverse travel, and without subjecting the cable to any substantial torsional forces. It is a feature of the invention that this type of operation can be achieved while yet maintaining the overall dimensions of the cable wrapping apparatus at a minimum.

BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawing:

FIG. I is a simplified perspective showing of a rotating element, specifically a dish-like scanning antenna incorporating cable wrapping apparatus in accordance with this invention;

FIG. 2 is an enlarged sectional view of the cable wrapping apparatus;

FIG. 3 is a plan view of the apparatus shown in FIG. 2; and

FIGS. 4 to 9, inclusive, are diagrammatic views illustrative of the operation of the cable wrapping unit.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT Making initial reference to FIG. 1, cable wrapping apparatus 10 incorporating the features of this invention is shown in cooperative association with a scanning antenna 11 rotatable, in azimuth, about an axis defined by a vertically extending shaft or kingpost" 12. The post 12 is rotated through the agency of any suitable apparatus (not shown) and it will be understood that elevational adjustments of the antenna may also be made. Suitable support and control devices of known type would be used, and these are shown diagrammatically as contained within a housing 13. It should be understood that the antenna would be connected to and controlled from a suitable control signal and power source, as illustrated diagrammatically at 14 in FIG. 3. The nature of these inputs will be well understood to those skilled in the art and require no description herein, other than to mention that they may take the form of electrical signals and power inputs as might be furnished through electrical cables and by means of pneumatic or hydraulic fluids contained within hoses.

In an antenna installation of the kind with which the apparatus of this invention is particularly useful, it is desired to provide rotation of the antenna for several revolutions in one given direction, and then to complete the scanning by reversing the rotation and returning the antenna through a similar travel in the opposite direction. In the present instance the antenna is capable of rotating in azimuth, in either direction, through approximately 3% revolutions about its main axis. As noted earlier in this disclosure, this extended rotational capability taken together with the fact that it is necessary to maintain connections between a plurality of hoses or cables (all contemplated by the term cable), and stationary signal and power sources, results in problems when it is desired to provide a compact installation. Such an installation would, for example, be desired on shipboard. However, regardless of the use to which the apparatus is to be put, multiturn rotation of the antenna must be accomplished without subjecting the cables to substantial torsional forces.

In particular accordance with the present invention, a compact, effective, cable wrapping apparatus is provided within the generally cylindrical housing 10' from which the antenna kingpost extends. In a shipboard installation the cylindrical housing could be fabricated of steel while, for certain land based equipment, it could be made of concrete. Within the housing 10' is a pedestal 15 (FIG. 2) which supports a suitable thrust bearing 16 disposed beneath the lower end of the kingpost l2 and effective to support the weight of the antenna and its cable wrapping apparatus.

The cables, five of which are shown in side view by way of example in FIG. 2, and seen from above in FIG. 3, enter the housing through a funnel-like entry spout 17 having smoothly curved walls which minimize the possibility of damage to the cables. Cables are clamped at the point of entry as indicated at 18 in FIG. 3, and extend from the region of clamping to such control and power sources (14) as may be required. In the position illustrated in FIGS. 2 and 3, the cables, for example the representative cable shown at C, extend through the housing 10 toward and around a cable winding and guiding drum 19. From this drum the cable extends to and around a similar drum 20 and thence to a main wrapping drum 21, integral with the post 12, being secured in the latter drum, as at 22, in any convenient fashion.

The

drums

19, 20 and 21 comprise a planetary system including the planetary carrier 23 mounted by means of bearings 24 (FIG. 2) for rotation about the axis 25 of kingpost l2 and main drum 21. As will become clear as the description proceeds, the carrier 23 carries the drums l9 and 20 and provides for rotation thereof about the main drum 21, which latter comprises the sun element in the system. Shafts 26 and 27 mount the planet drums l9 and 20 respectively so that said drums may rotate with low friction with respect to the planet carrier 23. Although it is not essential to the operation of the system, it may be desirable, in the interest of minimizing the possibility of fouling of the cables, that either or both of the planet drums be biased to maintain tension in the cable at certain positions of cable wrap.

In accordance with the invention, the planetary carrier is biased, in this instance in the counterclockwise direction, as shown by the arrow 30. If bias of the planetary drums is provided, this may readily be achieved through the use of negator springs, one of'which is shown at 31 in FIG. 2. The illustrated spring would have its ends suitably secured within the planet drum 20 in such manner as to result in sufficient bias.

In the illustrated embodiment, the counterclockwise bias at the planetary carrier 23 is applied through counterweight 32 connected with a rope or cable 33 wrapped around a pulley 34 which is secured to the lower surface of the planetary carrier 23. The system is designed to provide sufficient freedom of movement at the counterweight 32 to accommodate about 3% turns of the kingpost, and of the antenna, in a given direction, followed by return through the same angular traverse. In the arrangement illustrated this given direction is clockwise, as shown by the arrow on main drum 21 (FIG. 3).

While the concepts of the present invention are applicable to systems utilizing a single cable, or a number of cables, if several cables are employed it is desirable that means be provided to prevent interference between the cables during wrapping thereof. This may be accomplished in novel and effective fashion by providing a belt or band, shown at 35 in FIGS. 2 and 3. This band provides a flexible backing for the cables and encircles the main and planetary drums in the manner shown in FIG. 3. Any suitable means is employed to maintain the several cables in the desired spacing in the direction of the rotational axis of the wrapping system. The U-shaped elements 36 are intended only as a diagrammatic indication of the said suitable means for spacing the cables on the belt. Maintenance ofa helical wrap may be desirable. It will be noted from FIG. 2 that the band 35 may also interact with the flanges provided at the two planetary drums, see the flanges 19a and 2011, thereby preventing excessive deflection or movement of the belt in directions parallel to the main, central, axis.

In operation of a system of the kind illustrated it must be understood that the antenna is rotated or scanned in a given direction, in this case in a clockwise direction, through any suitable motor drive means (not shown) and that this motion, and the retrograde return motion, has a tendency to snarl the cables and subject them to severe torsional stresses. The cable wrapping system of this invention completely eliminates these difficulties, and utilizes only a small amount of space in accomplishing these purposes. Since the main sun drum 21 is formed integrally with the lower portion of the kingpost 12 to which the antenna is attached, there is no relative rotation between the main drum 21 and the antenna. Accordingly, the cables may be extended directly from the point 22, where they are secured within the main drum, upward into suitable association with the antenna. Exteriorly of this rotating system, however, it is necessary that proper dress of the cables be maintained and that the cables be wrapped precisely and rapidly during both forward and reverse scanning of the antenna.

FIGS. 4 through 9 show the operation of the wrapping system in various positions, from a time at the start of the multiturn clockwise rotation of the antenna to and through the final position (about 3% turns later), when substantially all of the cable disposed within the housing 10, between the entry spout 17 and the clamping point 22 in the main drum, is wrapped about said main drum. During this entire movement the planetary carrier 23 is subjected to the mentioned bias tending to rotate it counterclockwise, that is in the direction shown by the arrow 30 in FIG. 3. It should be understood that, for the sake of simplicity of illustration, the planetary carrier has been omitted from FIGS. 4 to 9. Also, it is to be recognized that, as appears in FIGS. 2 and 3, the main drum 21 and the

planetary drums

19 and 20 need not be of the same size. It is convenient that the main drum 21, as shown in FIGS. 2 and 3, be somewhat smaller to prevent interference between the side of said drum and the cable as it encircles the planetary drums. In any event, however, a variety of drum sizes may be used without departing from the principles of this invention. Variations in drum size would change the angular travel of the planetary carrier and hence would vary the distribution of the cable as between the sun and planet drums. In the diagrammatic form of the apparatus, shown in FIGS. 4 to 9, the sun and planet drums are shown, for the sake of simplicity as being of the same size and as being closely spaced.

The values of azimuth angle (6, being rotation of the antenna and of the main drum 21, given in the following description, should be understood as applying to a system of the kind shown in FIGS. 4 through 9. This is also the case with regard to the extent of cable wrapped about the main drum (0. and the angular travel of the planetary carrier (t9..,,,,,,.,).

FIG. 4 shows the cable wrapping apparatus when the antenna, or'other rotatable machine with which the cable wrapper is employed, has been rotated to its extreme allowable counterclockwise position when 0, 0. In certain subsequent views the original position of drums l9 and is shown in phantom lines, in the interest of ready comparison.

As the antenna begins its clockwise rotation, it produces corresponding rotation of the main drum 21 and the cable, (or cables, as the case may be) starts to wrap around the primary drum, since it is fixed thereto at 22. This wrapping foreshortens the amount of free cable, and applies a counterclockwise torque to the axis of drum 19. This torque is resisted by tension in the righthand run of cable between

drums

19 and 20 thus resisting, but not preventing, independent counterclockwise rotation of drum 19, and thereby transmitting a clockwise torque to the planet carrier. This torque causes the carrier 23 to rotate clockwise against the bias of the counterweight 32 (FIG. 2). In this manner, as the main drum and the antenna continue clockwise rotation about the center axis, the planet carrier and its

drums

19 and 20 are forced to precess around the main axis 25.

This movement continues (FIGS. 5 and 6) until planet drum 19 has precessed 180, as shown in FIG. 6, and drum 20 is just beginning to go out of contact with cable C. The conditions of wrap obtaining at this stage will be understood from inspection of the heavy line representation of the cable. The 180 precession of the planetary drum 19 has been accompanied by movement of the main drum 21 until 0 about 413 and 0,, the sum of the previous angles, or about 593.

As the process continues, drum 20 is no longer in the cable wrapping circuit through the positionshown in FIG. 7 (0, about 862, 0 about 270, and 6,,,,,,,, about 592), and until the final position, shown in FIG. 9, in which the cable C is taut between the fixed cable entry spout 17 and the point 22 on the periphery of the main drum 21. At this point, the cable is tangent to the periphery of the main drum 21 and 0, about l,277 (3.54 revolutions), while 6, about 857. This is, of course, the extreme clockwise position, and when this point is reached 0 about 420.

In considering the operation of the apparatus, it should of course be kept in mind that 0 represents the degree of cable wrap around the main drum and not the complete angular travel of the main drum 21. This latter travel is equal to 1,277", since the maindrum and the antenna rotate together. The difference between this complete rotation, and the 857 through which the cable has been wrapped on the main drum, is accounted for by the fact that precessing of the planetary carrier has tended to lessen the wrap of the cable on the main drum. It will be noted that the sum of the angular travel of the drum wrap and of the carrier equals the travel of the antenna in azimuth, that is, it amounts to about 3 /2 revolutions. Rotating in the opposite direction, the action is exactly the reverse and need not be described in detail herein. In making the reverse scan the constant take-up torque on the planet carrier 23 causes the carrier to rotate counterclockwise, and thus keeps the slack out of the cable as it is paid off the main drum.

In the broader aspect of my invention, it is contemplated that only one planetary drum might be used and that the apparatus would still operate in essentially the same way, although the total scan of the system would be reduced to something over two turns.

I claim:

1. Apparatus for guiding and wrapping cables connected between fixed structure and a rotatable element, comprising: a main drum to which such a cable is connectable in a region intermediate points of connection to said fixed structure and said rotatable element, to provide for wrapping of such cable thereon, means for driving said main drum in a given direction during rotation of such an element in said given direction and for driving said main drum in the reverse direction during rotation of such an element in the reverse direction; a planetary carrier mounted for rotation about the axis of said main drum and carrying planetary drum means for guding and receiving cable during at least a major portion of a wrapping operation; and means biasing said planttary carrier for rotation in a direction opposite to said given direction, said planetary carrier and said planetary drum means being constrained by a cable being wrapped, against the bias of said biasing means, to operate as a planetary system, with respect to the main drum means, during cable wrapping.

2. Apparatus in accordance with claim 1, and further characterized in that gravitationally responsive means is utilized to bias said planetary carrier.

3. Apparatus in accordance with claim 1, and further including means biasing said planetary drum means toward rotation in a direction opposite to the direction of bias of said planetary carrier.

4. Apparatus in accordance with claim 3, and in which said means for biasing said planetary drum means includes a negator spring.

5. Apparatus in accordance with claim 1, and in which an intermediate portion of said planetary carrier is mounted for rotation about said axis, and said planetary drum means includes a pair of planet drums rotatably mounted on said carrier and straddling said axis.

6. Apparatus in accordance with claim 5, and further characterized in that: when said element begins rotation in said given direction the cable extends from its point of connection to fixed structure, traverses said two planet drums, and extends therefrom into connection with said main drum; and when said element completes rotation in said given direction the cable extends directly from its point of connection to fixed structure to said main drum, without traversing said planet drums.

7. Apparatus in accordance with claim 1, and in which a plurality of cables is connectable in the system, provision being made to secure each such cable to the main drum.

8. Apparatus in accordance with claim 7, and further including belt means to which cables may be secured, the construction and arrangement being such that said belt means serves to space such cables in the direction of the axis of rotation of said main drum means during cable wrapping.

9. Apparatus for connecting cable means or the like between base structure and a rotatable antenna, in such manner as to allow multiturn rotation of said antenna in a given direction with respect to said base structure and with freedom for return of said antenna in the reverse direction, without subjecting said cable means to substantial torsional forces, said apparatus including, at least one cable having a first portion fixed to said base structure, a second portion associated with the rotatable antenna in such manner as to be rotated with respect to the first portion in response to rotation of said antenna, and means for wrapping a portion of said cable, intermediate said first and second portions, during such multiturn rotation of said antenna, said last means comprising: main cable-receiving drum means coaxial and rotatable with said antenna, said cable being secured to said main drum means and extending therefrom to said antenna for association therewith; a plane tary carrier having a center portion mounted for rotation about the axis of said main drum means and carrying adjacent each opposite end thereof, a planetary drum for guiding and receiving cable during at least a major portion of the wrapping operation; and means biasing said planetary carrier for rotation in a direction opposite to said given direction, said planetary carrier and said planetary drums being constrained by said cable, against the bias of said biasing means, to operate as a planetary system, with respect to the main drum means, during wrapping of the cable.

10. Apparatus in accordance with claim 9, and further including means biasing each said planetary drum toward rotation in a direction opposite to the direction of bias of said planetary carrier 11. Apparatus in accordance with claim 9, and in which a plurality of cables are employed, each fixed to said base structure and each associated with the rotatable element and secured to the main drum means.

12. Apparatus in accordance with claim 11, and further including flexible belt means to which the plurality of cables are secured, and which serves to space said cables in the direction of the axis of rotation of said main drum means during cable wrapping.

Claims

9. Apparatus for connecting cable means or the like between base structure and a rotatable antenna, in such manner as to allow multiturn rotation of said antenna in a given direction with respect to said base structure and with freedom for return of said antenna in the reverse direction, without subjecting said cable means to substantial torsional forces, said apparatus including, at least one cable having a first portion fixed to said base structure, a second portion associated with the rotatable antenna in such manner as to be rotated with respect to the first portion in response to rotation of said antenna, and means for wrapping a portion of said cable, intermediate said first and second portions, during such multiturn rotation of said antenna, said last means comprising: main cable-receiving drum means coaxial and rotatable with said antenna, said cable being secured to said main drum means and extending therefrom to said antenna for association therewith; a planetary carrier having a center portion mounted for rotation about the axis of said main drum means and carrying adjacent each opposite end thereof, a planetary drum for guiding and receiving cable during at least a major portion of the wrapping operation; and means biasing said planetary carrier for rotation in a direction opposite to said given direction, said planetary carrier and said planetary drums being constrained by said cable, against the bias of said biasing means, to operate as a planetary system, with respect to the main drum means, during wrapping of the cable.

10. Apparatus in accordance with claim 9, and further including means biasing each said planetary drum toward rotation in a direction opposite to the direction of bias of said planetary carrier.

11. Apparatus in accordance with claim 9, and in which a plurality of cables are employed, each fixed to said base structure and each associated with the rotatable element and secured to the main drum means.