US3439467A

US3439467A - Portable collapsible tower

Info

Publication number: US3439467A
Application number: US611861A
Authority: US
Inventors: Jackson A Partlow
Original assignee: ZIP UP LIGHTING TOWER CO Inc
Current assignee: ZIP UP LIGHTING TOWER CO Inc
Priority date: 1967-01-26
Filing date: 1967-01-26
Publication date: 1969-04-22
Anticipated expiration: 1986-04-22

Description

April 22, 1969 J. A. PARTLOW PORTABLE COLLAPSIBLE TOWER Filed Jan. 26, 1967 INVENTOR JACKSON A. PART LOW 1 Ask/ im n n ATTORNEYS A ril 22, 1969 J. A. PARTLOw 7 PORTABLE COLLAPSYIBLEV TOVWER Filed Jan. 26, 1967 Sheet 8 of6 lNVENTbR.

AcKsoN A. Man LOW ATTORNEYS p 1959 J. A. PARTLOW PORTABLE COLLAPS IBLE TOWER Filed Jan. 26, 1967- Sheef 5 of s f I l I l JACKSON A. Pmanow F 4/ MKJZ, J, ,MM

ATTORNEYS l 5 INVENTOR:

A ril 22, 1969 J. A. pAR-rmw 3,439,467

PORTABLECOHLLAPSIBL'E TOWER Filed Jan. 26, 1967 Sheet 4 of6 INVENTOR:

JACKSON A. AQTLOW BYM Z 4%, %W V ATTORNEYS.

April 22, 1969 J. A. PARTLOW PORTABLE COLLAPSIBLE TOWER Filed Jan. 26. 1967 Sheet 5 are s V M w mm H W m w w W MN mwq vN mm) @M V r g U M m j m w M Kw k J- T; An Km $w J W u i 5 J K I M T: .6 M M mm W 3 g K m @m, m E Q. @w "and La. 2%? Q $3 Q Q? Nm M M m k mu WWW mm m1 m N mm n Q 1 u F B m F u u 1.|L 1&5 8N NM mm fl April 22, 1969 J. A.PARTLOW 3,439,467

PORTABLE COLLAP S IBLE TOWER Filed Jan. 26, I967 Sheet 6 of 6 INVENTOR.

JACK sou A.PAETLOW ATTORNEY 5 United States Patent Oflice 3,439,467 Patented Apr. 22, 1969 3,439,467 PORTABLE COLLAPSIBLE TOWER Jackson A. Partlow, Rock Hill, S.C., assignor to Zip-Up Lighting Tower Co., Inc., Rock Hill, S.C., a corpora. tion of South Carolina Filed Jan. 26, 1967, Ser. No. 611,861 Int. Cl. E04h 12/18; E04g 25/00 US. Cl. 52-632 9 Claims ABSTRACT OF THE DISCLOSURE This invention relates to portable elevating apparatus and more particularly to an improved collapsible tower for supporting accessory equipment.

Portable towers are often used to support equipment at rather extreme heights under circumstances of a temporary nature which do not warrant the construction of permanent support scaffolding. For example, support of lighting equipment and display signs at traveling carnivals, amusement parks and the like is often accomplished by the use of such towers. Portable towers also are frequently used in military operations to provide elevated support for communication and detection equipment, such as radio and radar antennas, particularly when speed in relocation of the equipment is essential.

One general form of construction of such portable towers utilizes a plurality of telescoping box-shaped sections which are vertically movable by suitable lifting means between a nested position and an extended position of predetermined height. Generally, the sections are mounted on a movable base, such as a truck or other wheeled vehicle, and various accessory equipment is attached to the uppermost one of the sections. Proper relative movement of the sections during extension and retraction of the tower is accomplished by the provision of guide means, generally consisting of cooperating tongue and groove elements having large contact surfaces, which are located in the corners of the sections.

Although towers of the type described function in an acceptable manner to support various accessories thereon, it is generally necessary to exercise extreme care when extending and retracting the sections due to the tendency of the guide elements to become misaligned and stop relative movement of the sections when non-uniform lifting forces are exerted across a horizontal sectional profile of the sections or when there is unequal weight distribution of the equipment on the tower.

Another problem which sometimes develops in using such towers occurs when certain types of accessory equipment are mounted on the towers. For example, when lighting equipment is mounted on the towers to illuminate a defined area, proper coverage can be best effected by providing a spacial array of the lights. Also, communication and electronic equipment, such as antennas, etc., are best arranged in a spaced configuration to provide maximum reception and transmission. In such cases, it can be appreciated that compactness of the collapsed tower will be sacrificed unless provision is made for disassembly or relocation of the accessories when the support sections are nested.

It is therefore an object of the present invention to provide an improved portable collapsible tower having a plurality of telescoping sections which are freely movable between a retracted position, wherein the sections and accessories thereon are disposed in compact, nested relationship, and a dimensionally stable, extended condition for the use of the accessory equipment at elevated heights.

It is a more specific object to provide an accessory support section for such towers which. has means to independently position the accessory equipment at widely spaced locations atop the tower and to relocate the same to achieve compactness of the accessory section and tower when the same are placed in a collapsed condition of portability.

Another related and more specific object is to provide improved guide means for the telescoping sections of a collapsible tower which are of simple and economical construction, and which are so located as to permit utilization of minimum power for extension of the tower, and as to prevent jamming of the sections during extension and retraction of the same.

Some of the objects of the invention having been stated, other objects will appear as the description proceeds, when taken in connection with the accompanying drawings, in which- FIGURE 1 is a perspective view of the portable tower of the present invention shown in an extended, upright position of use;

FIGURE 2 is an enlarged perspective view, with parts broken away, of the upper portion of the tower of FIG URE 1, showing in detail the accessory support portion of the tower;

FIGURE 3 is an enlarged, front elevational view of the support tower of FIGURE 1 shown in its collapsed condition of portability, the lighting accessories of FIGURE 1 having been removed to more readily show the interior arrangement of the nested sections of the tower;

FIGURE 4 is a side elevational view of the collapsed tower looking in the direction of arrow 4 in FIGURE 3 and including a showing of a portion of the lighting accessories of the tower;

FIGURE 5 is a vertical sectional view taken generally along line 55 through the collapsed tower of FIGURE 4 and looking in the direction of the arrows;

FIGURE 6 is a horizontal sectional view on a further enlarged scale, taken generally along line 6-6 through the collapsed tower of FIGURE 3 and looking in the direction of the arrows;

FIGURE 7 is an enlarged perspective view of an intermediate, telescopic section of the tower; and

FIGURE 8 is an enlarged perspective view of the outer lowermost telescopic section of the tower, and showing the relation of the section to a portion of the portable base of the tower.

Referring more specifically to the drawings, FIGURE 1 shows a collapsible, portable tower 10 incorporating the novel features of the present invention and generally com-prising a base portion 11, an intermediate support portion 12, andan upper accessory portion 13. A power supply unit 20 is located on the base portion 11 and provides power for extension and retraction of the tower, as will be explained. The tower may be constructed of suitable weather-resistant, rigid material, such as steel or aluminum, with the component parts of each section thereof being conected in a conventional manner. In the embodiment shown in the drawings, the parts are joined by welding.

The base portion 11 of the tower includes an open, rectangular frame 14 having ground-engaging casters 15 located in each of its corners to provide for mobility of the overall tower unit. A plurality of leveling devices in the form of manually-operated jacks 16 are mounted about the sides of frame 14 to permit proper vertical alignment of the tower at geographic locations in which it is to be used.

The intermediate support portion 12 of the tower includes a plurality of telescoping box-shaped sections 21 through 26, which, in that order, are of progressively decreasing horizontal dimensions. Since the sections are otherwise of substantially identical construction, with the exception of certain lift and guide features which will be explained, the following detailed description of section 23 (FIGURE 7) will also apply to the remain ing sections except where indcated.

Sectou 23 is hollow throughout its vertical dimension and is formed of vertical corner post members 23a joined by horizontal cross members 23b adjacent the top and bottom ends of the posts. Additional horizontal and diagonal members, 230 and 2311, may connect posts 23a along the sides of the section to increase the stability and strength of the tower. In the embodiment shown in the drawings, the horizontal and vertical members are formed of angle iron and the diagonal members of thin metal rods, all of which are suitably joined by welding.

To maintain proper alignment of the sections during the extension and retraction of the tower, the sections are provided with vertically-extending primary guide means which are located on the approximate horizontal midlines of a pair of corresponding oposing sides of each of the sections. As seen in FIGURE 7, each of a pair of opposing sides of section 23 are provided with a first pair of vertically-extending, parallel

angle iron elements

46, 47 which are welded to the inner surface of the

horizontal members

23b, 23c of the sides so that their inwardly-extending legs are horizontally spaced to form an inwardly-facing, vertically-extending groove. In like manner each side of the section also is provided with a second pair of vertically-extending, parallel angle iron elements 48, 49 which are welded to the outer surface of the horizontal cross members 23b, 230 of the sides in alignment with the first pair of elements and positioned so that their outwardly-extending legs are juxtaposed to form protecting tongues.

Also performing a highly important guide function in the present invention are auxiliary guide means located in each of the corners of the sections 22-26. As best seen in FIGURE 7, extending horizontally outwardly from a lower portion of the corners of the opposing sides of section 23, and in planes parallel to the planes of the projecting tongues and grooves of the primary guide means, are thin elongate plates 51, the outer ends of which serve to engage the inner surfaces of the corner posts of the immediately adjacent lower section thereto, as will be explained.

Section 26, due to its uppermost location when the tower is in extended position, is provided only with the outwardly-extending tongue elements of the primary guide means, and the lowermost section 21, which is fixed to the base frame 14 and forms the outermost section of the tower in nested condition, is provided only with the inwardly-extending groves of the primary guide means.

The lowermost section 21 is secured to base frame 14 by welding. As best seen in FIGURE 8, its lower end protrudes slightly below the frame and it is further stabilized on the frame by the provision of additional horizontal members, 54, 55, which are welded to opposing sides of section 21 and also to respective

verticallyexteuding corner posts

56, 57, the lower ends of which are welded to the corners of base frame 14. The lowermost section 21 also has a pair of spaced, horizontal cross members 58, 59 (FIGURE 6) which are secured to the bottom cross-members of the section and serve to support the intermediate sections 22-25 in nested condition within section 21. A ladder 17 is provided at the end of the frame 14 and provides ready access to the accessory portion 13 of the tower when the telescopic 4 sections are in nested condition, as shown in FIGURE 3.

The power supply unit 20 (FIGURE 3) is located on the base frame 14 alongside the lowermost section 21 and includes an electrically-driven motor 43 and a winding drum 44 which is connected to the motor by suitable reduction gearing means (not shown). The winding drum is driven at low speed in a clockwise direction.

Lifting force is transmitted from the power supply unit 20 to the sections to telescopically move the same by a series of pulleys which are mounted on the sections and a pair of

cables

31, 32 which operatively connect the winding drum of the unit to the pulleys. In this respect, base section 21 is provided with four pulleys, 33-36, (FIGURES 3 and 6) which are respectively positioned outside the upper and lower ends of opposing sides of the section. Each of the intermediate, movable sections 22 through 25, is provided with four smaller pulleys which, as indicated on section 23 (FIGURE 7), include cooperating pairs of substantially vertically-aligned

pulleys

37, 38 and 39, 40 located on the respective upper and lower ends of opposing sides of section 23. The uppermost section 26 is provided with a single pair of pulleys, one of which is shown in FIGURES 5 and 6 and indicated by the numeral 41, which are located on the lower end of the corresponding opposing sides of the section.

Cables

31 and 32, which are respectively entrained about the pulleys on left and right-hand sides of the tower sections (FIGURES 5 and 6), have their inner ends secured to the surface of the winding drum 44 and their outer ends fastened by eye-bolts, one of which 45 is seen in FIGURE 6, to the respective upper left and right-hand ends of the innermost section 26. As seen in FIGURES 5 and 6, the

cables

31 and 32 pass upwardly and downwardly through the respective left and righthand pulleys on the intermediate sections, and are directed by the pulleys 33-36 on the lowermost section 21 to the surface of the winding drum 44. Clockwise rotation of the winding drum uniformly retracts the cables to sequentially raise the sections from a nested position to a fully extended position, as seen in FIGURE 1. The sections may be similarly lowered from extended position to nested position on the base of the tower by reversing the rotation of the winding drum, which may be accomplished by suitable means, such as reversing rotation of motor 43 or providing a clutch and brake arrangement whereby gravitational force may be used to nest the sections.

During movement of the sections between their nested and extended positions, the sections are guided by the primary and auxiliary guide means. As seen in FIGURE 6, the tongue-forming elements of the primary guide means on each section cooperate with the groove-forming elements on the outer section adjacent thereto and are vertically slidable therein to maintain proper movement of the sections in a vertical direction. The outer ends of the projecting plates which form the auxiliary guide means of the sections contact the inner surfaces of the angle irons forming the corner posts of the adjacent outer sections thereto and are vertically slidable therealong to maintain alignment of the corners during extension and retraction of the tower. The upper edges of the projecting plates contact the lower surfaces of the upper horizontal cross members of the section therebelow when the tower is in fully extended position to stop upward movement of the sections and also to provide both a horizontally and vertically-directed stabilizing force at the corners of the sections.

It can be appreciated from the view seen in FIGURE 6 that the projecting plates of the auxiliary guide means are of sufiicient length to prevent engagement of the outer ends of the tongues with the bottoms of the grooves of the primary guide means and thus eliminate binding of the primary guide means and jamming of the telescopic sections during movement of the sections. Further, by 10- cating the primary guides means along the vertical midplane of the tower, with a minimum of areal contact by the auxiliary guides in the corners of the sections, the tower may be raised and lowered uniformly with a minimum of force exerted by the pulley groups located on opposite sides of the vertical midplane of the tower.

As is best shown in FIGURE 2, the accessory support portion 13 of tower includes three vertically-spaced platforms. The platforms consist of two

circular discs

64 and 65 and a rectangular frame 66 which are supported in spaced relation on a pair of vertically-extending members or

tubes

67, 68, the upper, smaller one 67 of which -is telescopically received within the upper end of the larger lower tube 68.

The lower tube 68 is operatively secured to the upper telescopic section 26 by means of a horizontal plate 69 which is suitably welded to a pair of

angle irons

70, 71 which are in turn secured to the upper horizontal members of opposing sides of the section. The plate 69 has a central opening therethrough in which is disposed a short tubular member or cylindrical sleeve 72 which slidably receives the lower tube 68 for free vertical movement therein. The ends of the

angle irons

70, 71 extend outwardly beyond the corners of the upper section 26 and support, in a horizontally-extending position, a second rectangular frame 73 which has a guide cylinder 74 located in each of its corners.

The rectangular frame 66 forming the lowermost platform is suitably constructed of angle iron and is provided with a pair of cross members 75a, 75b to which is welded a horizontally-disposed guide plate 76. Tube 68 extends through a central aperture in the plate and is free to slide therein during initial movement of the upper two platforms. The frame 66 is stabilized and guided during its own vertical movement by the plate 76 and by downwardly-extending rigid rods 77 which are suitably fixed to the corners of the frame with their lower ends slidably received within the guide cylinders 74 located on the lower support frame 73.

The circular disc '65 forming the intermediate platform is horizontally disposed upon the upper end of the tube 68 and has a central opening to permit the reception of the upper tube 67 into the tube 68. Suitably attached to the lower face of the disc 65 and extending downwardly therefrom are our flexible members, or wires 78, which have their lower ends suitably attached to the corners of the frame 66 forming the lowermost platform.

The circular disc 64 forming the uppermost platform is of smaller diameter than disc 65 and is horizontally disposed on the upper end of the smaller tube 67. A handle 79 is provided on the upper face of the disc to manually raise and lower the upper platform with respect to the intermediate platform. The upper platform is spaced a predetermined distance above the intermediate platform by a stop pin 81 which may be inserted through a pair of aligned apertures a in the tube to rest upon the upper face of the intermediate disc 65 To raise and lower the three platforms from a collapsed or nested position (FIGURE 5) to a fully extended position (FIGURE 2), a manually operated winch 82 is provided and secured to one side of the support frame 73. Attached to the lower end of the tubular member 68 by an eye-bolt 84 (FIGURE 5) is a cable 85 which extends upwardly through an opening in the horizontal support plate 69, over a guide pulley 86 mounted thereon, and around the Winch 83.

Takeup of the cable 85 on the winch causes upward movement of the support tube 68 through the cylindrical sleeve 72 and simultaneously raises the intermediate platform and the upper platform, which has been previously manually spaced from the upper platform, as described. When the two upper platforms have been raised through a distance which is determined by the length of the flexible wires 78 connecting the intermediate and lower platforms, further upward movement of the tube 68 causes the lower platform frame 66 to be simultaneously lifted with the other two platforms until it reaches its fully extended position (FIGURE 2). Upward movement of the three patforms is limited by the engagement of the eye-bolt 84 in the lower end of the tube 68 with the bottom edge of the cylindrical sleeve 72.

The accessory support portion 13 of the tower also includes auxiliary equipment support means which includes a box-shaped cage 91 suitably formed of angle iron. The upper end of the cage is secured to the upper end of the uppermost section 26 by means of four outwardlyprojecting angle iron members 92 (FIGURE 2) which are suitably welded to the frame member73 and space the cage 91 outwardly from section 26 to dispose the section centrally therein. Horizontally spaced about the sides of the cage 91 area plurality of fluorescent lights 93 which overlie Vertical support members 94 of the cage and provide both a decorative effect and lighting in immediate area of the tower. Although the size of cage 91 may be varied, it can be appreciated that it should be sufficiently large as to encompass the lowermost support section 21 when the tower 10 is in retracted condition.

When necessary, to permit full retraction of the sections and thus provide a more compact unit for portability, a portion 95 of one side of the cage may be pivotably connected to the top horizontal members of the cage by hinges 96 (FIGURES 3 and 5) so as to be free to move outwardly and avoid obstructions, such as power unit 20 (FIGURES 3-5), in the downward path of travel of the cage.

Although the platforms of the accessory support section 13, as shown in the drawings, support and position a plurality of light fixtures L which are connected by suitable wires (not shown) to a power source, it is to be understood that other types of accessory equipment may be readily mounted on the platforms without departing from the scope of the invention.

In operation, the tower is transported, in a nested, collapsed condition, to a desired geographic location and leveled by means of jacks 16. The accessory support platforms are then manually elevated as previously described, while the telescoping intermediate support sections are still in nested position.

Power is then supplied to energize motor 43 and rotate winding drum 44 in a clockwise direction. As

cables

31 and 32 are uniformly wound onto the drum, the telescoping sections 22-26 sequentially rise from their nested position until the auxiliary guide plates on each section engage the upper horizontal members of the immediately lower section to stop upward movement of the sections and maintain the tower in a dimensionally-stable, erect condition. In the embodiment of the tower shown in the drawings the telescopic sections are retained in extended position by maintaining the tension on the lifting cables. If desired, suitable safety locking means for the sections may be provided to insure that they are retained in extended condition in the event of cable breakage. After use, the tower, with the accessories thereon, is easily retracted into compact nested condition by reversing the procedure just described.

From the foregoing description of the invention, it can be appreciated that provision of primary guide means along a vertical midplane of the telescopic sections of the tower together with auxiliary guide means of reduced areal contact in the corners of the sections, permits extension and retraction of the tower of the present invention with a minimum of force and without binding or jamming of the sections due to unequal forces being applied at the corners of the sections. Additionally, by providing the separate extensible and retractable accessory support section of the present invention, accessory equipment may be spacially-arranged on the tower in extended position, while ensuring compactness of the tower in collapsed condition of portability.

In the drawings and specification there has been set forth a preferred embodiment of the invention and, although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being defined in the claims:

That which is claimed is:

1. In a portable tower including a movable base, a plurality of generally box-shaped sections telescopic one within another and supported on said base, the outermost one of said sections being fixed to said base and the remaining sections being relatively movable between a retracted, nested position inside said outermost one of said sections and a vertically extended position to form an upright supporting portion of said tower, accessory support means attached to the uppermost one of said sections in said extended position, and means for extending and retracting said remaining sections; the improvement therewith comprising vertically-disposed guide means located at an intermediate point along the horizontal length of a corresponding pair of opposing, verticallyextending sides of each of said sections, said guide means including means on each of said pair of opposing, vertically-extending sides of one of said sections defining a groove extending for at least substantially the entire vertical extent of said sections, and means on each of said opposing sides of a section disposed immediately adjacent said one of said sections defining a tongue extending for at least substantially the entire vertical extent of said section, said tongue means extending into said groove means in mating relationship and being slidably movable therein during extension and retraction of said sections, said tongue and groove means of adjacent sections cooperating by area contact therebetween to facilitate proper track and alignment of the sections during extension and retraction of said remaining sections and providing dimensional stability to the tower when said sections are in said vertically-extended position of use.

2. A portable tower as defined in claim 1 wherein said tongues and grooves are positioned at the substantial midpoint of the horizontal length of said opposing sides.

3. In a portable tower including a movable base, a plurality of generally box-shaped sections telescopic one within another and supported on said base, the outermost one of said sections being fixed to said base and the remaining sections being relatively movable between a retracted-nested position inside said outermost one of said sections and a vertically extended position to form an upright supporting portion of said tower, and means for extending and retracting said remaining sections; the improvement therewith comprising guide means located at an intermediate point along the horizontal length of a corresponding pair of opposing, vertically-extending sides of each of said sections, said guide means of adjacent sections cooperating to facilitate proper track and alignment of the sections during extension and retraction of said remaining sections and providing dimensional stability to the tower when said sections are in said vertically-extended position of use, a plurality of verti- Cally-movable, generally horizontally-disposed accessory platforms attached to the uppermost one of said sections, and means independent of said means for extending and retracting said remaining sections for raising and supporting said platforms at predetermined, vertically-spaced positions above said uppermost section.

4. A portable tower as defined in claim 3 wherein said raising and supporting means includes first manuallyoperated means for raising and supporting a first of said platforms a fixed distance above a second of said platforms, and second manually-operated means for raising said first and second platforms fixed distances above a third of said platforms and thereafter simultaneously raising said first, second, and third platforms to said predetermined vertically-spaced positions above said uppermost section.

5. A portable tower as defined in claim 3 wherein said raising and supporting means includes a plurality of telescoping elongate tubular members generally vertically disposed, a first of said members fixedly attached to said uppermost section, a second of said members telescopically received in the open upper end of said first member and a third of said members telescopically received in the open upper end of said second member, one of said platforms attached to an upper end portion of said second member and a second of said platforms attached to an upper end portion of said third member.

6. A portable tower as defined in claim 3 including a third of said platforms having a centrally-disposed aperture slidably receiving said second tubular member in contiguous relation therewith; and wherein said raising and supporting means further includes at least one flexible element of fixed length connecting said second and third platforms.

7. In a portable tower including a movable base, a plurality of generally box-shaped sections telescopic one within another and supported on said base, the outermost one of said sections being fixed to said base and the remaining sections being relatively movable between a retracted, nested position inside said outermost one of said sections and a vertically extended position to form an upright supporting portion of said tower, and means for extending and retracting said remaining sections; the improvement therewith comprising vertically-disposed guide means located at an intermediate point along the horizontal length of a corresponding pair of opposing, vertically extending sides of each of said sections, said guide means of adjacent sections cooperating to facilitate proper track and alignment of the sections during extension and retraction of said remaining sections and providing dimensional stability to the tower when said sections are in said vertically-extended position of use, and a box-shaped support cage attached to and extending downwardly from an upper portion of the uppermost one of said sections to encompass generally centrally therein a portion of said uppermost section when in extended position, said cage being of sufficient horizontal dimensions to enclose said outermost section when said sections are in retracted-nested position.

8. A portable tower as defined in claim 7 wherein a vertically-extending side of said cage is secured adjacent its upper edge for outward pivotal movement of said side during retraction of said sections to avoid obstructions in the downward path of travel of said cage.

9. A portable tower as defined in claim 7 including a plurality of lights mounted on said accessory support means and means on said support cage for receiving and supporting a plurality of elongate lights in substantially parallel, spaced relation about the vertical sides of said cage.

References Cited UNITED STATES PATENTS 294,860 3/1884 Dye 182-63 483,001 9/1892 Hughes 182-141 815,594 3/1906 Kouacevic 182-141 1,715,200 5/1929 Lambert 182-141 2,948,363 8/1960 Hopfeld 182-141 REINALDO P. MACHADO, Primary Examiner.

US. Cl. X.R. 182-141