US 3175650 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
March 1965 c. E. HARTFORD ETAL 3,175,559
'IRUS SED S TRUC TURE 3 Sheets-Sheet 2 Filed Aug. 2, 1962 INVENTOR. CIIAEMS .6. HARTFORD BY Roux) J h/OHLRQRT ATTORNEYS March 30, 1965 Filed Aug. '2, 1962 C. E. HARTFORD ETAL TRUSSED STRUCTURE 3 Sheets-Sheet 5 INVENTOR-S' CHARLES E. HARTFORD RONALD .I WOHLFORT States This invention relates to trussed supports and, more particularly, to an improved structure which provides for compact folding of a prefabricated extensible load supporting truss.
A need has long existed for many types of high strength support structure having a high degree of mobility or portability. Heretofore, such features have been exceedingly diiiicult if not impossible to achieve because the provision of suficient strength has resulted in heavy structures which are lacking in mobility, and provision of a structure having a high degree of mobility or portability has resulted in a structure which lacks adequate strength.
Accordingly, an object of the present invention is to provide an improved structure for obviating the abovementioned difiiculties.
Another object of the invention is the provision of a fully fabricated extensible high-strength load supporting truss structure that is foldable into a compact unit for storage or portage purposes.
Another object is in the provision of a light weight foldable trusscd support structure which is capable of being erected in a very short time with a minimum of manpower, erection tools or other facilities.
Still another object is in the provision of an improved truss structure which can be fully fabricated in a factory and produced with relatively simple and inexpensive tooling.
A further object is in the provision of a fully fabricated modular extensible light weight truss structure which is easily portable and which, when erected, provides a strong and sturdy load supporting structure.
Other objects and advantages will be apparent to those skilled in the art from a consideration of the following description taken in connection with the accompanying drawings in which:
FIGURE 1 is a perspective view of a foldable trussed structure in accordance with the invention, this view illustrating the extended position and including two and a half bays of the structure, the remainder being broken y;
FIGURE 2 is an exploded view illustrating the way in which the various members (broken) are connected in FIGURE 1;
FIGURE 3 is a partial diagrammatic view of left side of FIGURE 1, illustrating the manner of folding the trussed structure;
FIGURE 4 is a view illustrating an alternative modification of a bracing and locking member;
FIGURE 5 is a fragmentary view showing portions of the FIGURE 1 embodiment, partially folded; and
FIGURE 6 is a diagrammatic view showing the details of a junction point per FIGURE 2 in their relationships to three truss sections and two sets of spannners, each comprising two paris of spanners;
FIGURE 7 is a diagrammatic showing of five truss sections in partially collapsed conditions; and
FIGURE 8 is a perspective review of the junction point when the elements of FXGURE 2 are assembled.
Throughout the drawings, like numerals designate like parts and, while the various features of the invention are hereinafter illustrated and described as preferred embodiments, it is to be understood that such embodiments are intended to be illustrative only and not limiting, since various changes and modifications can be made Without departing from the invention.
The concept of the present invention is applicable to a wide variety of trussed supports of either a portable or permanent type and which include but are not necessarily limited to bridges, floors, roofs, towers, scaffolds, beams, posts. For purposes of illustration and not of limitation, the invention will be described herein in connection with a microwave reflector or antenna structure, which is an embodiment particularly illustrative of a type of use wherein both a high degree of strength and mobility or portabilityare required.
Tactical military equipment requirements include a high degree of mobility as well as operation in extremely remote areas. Hence, it is extremely desirable that all components of such equipment should be readily transported, quickly and easily erected for operation, and be collapsible or compressible into compact units for rapid movement from one tactical location to another. For example, the mobility of high power radar units has heretofore remained a limiting factor largely due to the cumbersome nature of the antenna structure. The con cept of the present invention employs modular mechanical support construction to provide the required strength in light weight folding sections which are combined to form large special shaped structures which can be erected or disassembled very quickly, in some instances by a single Workman. The folding sections compress into a compact package which is easily handled, and a relatively large section of compressed structure in accordance with the invention can be carried by four men.
Referring now to the drawings, FIGURE 1 illustrates a portion of a microwave reflector or antenna structure in the extended or erect state. The structure comprises a plurality of spaced truss sections three of which are shown and designated 1, 1A, 1B. Trusses 1, etc. may be constructed of any suitable material, and, in the interest of light weight and portability without undue sacrifice of strength, it may be desirable to utilize hollow tubular members in the construction of the trusses. When set up, the several truss sections are disposed in spaced parallel planes. Each of the truss sections comprises upper and lower horizontal chord members 2 and 3, respectively, vertical members 4, 5, 6 and diagonally upwardly extending members 7, 8, 9, and 19. Each of the truss sections is hingedly connected to two spanner sections each comprising end members such as 11, 12 connected together by a diagonal brace 13. In certain instances the spanner section comprises end members 11', 12' and a diagonal brace 13' which extends in the opposite diagonal direction, so that a spanner section employing members designated with primes is in a sense a mirror image of the other sections.
As illustrated in FIGURE 1, the upper horizontal chord member 2 of the first truss section 1 is hingedly connected to a spanner (ll, 12, 13) which in turn hingedly connected to the upper chord member 2 of the second truss section 1A, whereas the upper chord member of the second truss section 1A is hingedly connected to a spanner (ll', l2, 13) which is in turn hingedly connected to the upper chord member 21B, of the third truss section so that the diagonal bracing 13 or 13' is oppositely disposed between adjacent pairs of spanners.
Similarly, the lower chord member 3 of the first truss section 1 is hingedly connected to a spanner (11 l2, 13') which is in turn hingedly connected to the lower chord member 3 of the second truss section 1A. Again, the diagonal bracing 13 or 13 is oppositely disposed in the upper and lower spanners between adjacent truss sections. The lower chord member 3 of the second truss section 1A is hingedly connected to a spanner (11 l In) l3) which is in turn hingedly connected to the lower chord member 3 of the third truss section 1B.
In the foregoing material, the spanner sections have been described as mirror images in order to illustrate how the oppositely disposed diagonal members 13, 13' are utilized to brace the various spanners. As a practical matter and considering function only, each of the spanners is structurally identical to all other spanners, and each of the spaced truss sections is structurally identical to all other truss sections. This not only facilitates the construction, but it also effects substantial savings in materials, assembly, and labor. In addition, fabrication and erection are accomplished through the use of only simple tools, and only one set of fixtures is required for the fabrication of the truss section and only one additional set of fixtures is required for the fabrication of the spanners.
As noted heretofore and as illustrated in the drawings, the various truss sections are parallel to each other; like wise, the spanners connecting any two adjacent truss sections are parallel to each other, each pair of adjacent truss sections and their associated upper and lower spanners at all times forming a parallelepiped (in section), irrespective of whether the assembly is fully extended or folded. Of course, each truss section is per se rigid, and each spanner is per se rigid.
The expression hingedly connected is now further discussed. Let attention be directed to the first, second, and third truss sections 1, 1A, 1B, respectively, specifically the left end thereof as illustrated in FIG. 1. The two elements 4 of the first and second truss sections and the elements 11 and 11 of the upper and lower spanners between the first and second truss sections are substantially coplanar and articulated in the manner of a pantograph, being foldable in such a way that the elements 11 and 11 are always parallel and the elements 4-4 are always parallel, the hinged connections (see FIGURE 8) providing for turning of the various elements effectively about horizontal axes. Similarly, the elements 44 of the second and third truss sections and the elements 11' and 11 of the upper and lower spanners between the second and third truss sections are coplanar and foldable as a pantograph, and are likewise provided with appropriate pivotal or hinged connections directed to such folding capability. The element 4- of the section truss section 1 A is common to the two pantographs just described. As will be seen from an inspection of FIGURE 7, each element 4 with the exception of those on the ends of the structure is common to two pantographs.
In accordance with the invention, means are provided which perform the dual function of providing cross bracing for the parallelepiped sections and for locking the structure in extended or folded position. This is accomplished by the provision of a locking rod 14 having an upper end portion adapted to be pivotally connected to member 2 (FIGURES 2 and 8), and a lower end consisting of a pivotally secured transverse sleeve. This sleeve is adapted to be positioned in translation horizontally slidingly to engage lower spanner member 11, as is best illustrated in FIGURE 3. For example, as is illustrated in FIGURE 2, rod 14 may terminate in a pivotally secured or ball-joint secured sleeve 15 having an internal diameter sufliciently large to receive member 11 in sliding engagement. A set screw 16 is provided for locking rod 14 in any desired positions relative to member 11. Member 14' is similar to member 14 in that it is pivotally connected at its upper end to member 2 and disposed so that vertical truss member 4 is slidably received and positioned in translation vertically in sleeve 15'. As illustrated in FIGURE 3, the lower end portion of member 14 (i.e., transverse sleeve 15) is slidably disposed relative to member 11, and the corresponding lower end portion of member 14' (i.e., transverse sleeve 15') is slidably disposed relative to member 4; but it will be understood that either or both such connections can be made without departing from the invention.
An alternative embodiment of locking rod is illustrated in FIGURE 4. in accordance with this embodiment, either member 14 or 14' may be replaced by a telescopically extensible link 17, 18 having one end portion adapted to be pivotally connected to a truss section member 2 and having its opposite end connected to an opposed member such as 3, for example. A locking means, such as set screw 19, is provided for locking members 17 and 13 in any desired relative disposition.
In the practice of the invention, truss sections 1 may be fully fabricated in a factory in accordance with known manufacturing methods and procedures. It is to be understood that, while a particular type of truss section configuration has been illustrated in the drawings, the invention is not so limited, and any desired type of truss configuration may be employed. Similarly, the spanners may be fully fabricated, if desired, in the factory.
Upon completion of the fabrication of diagonal locking members 14, 14', or the alternative embodiment comprising telescoping members 17, 18, the various truss sections l and the spanners are assembled and connected together in the manner indicated above. It will be understood by those skilled in the art that through the proper choice of appropriate length of diagonal locking members l4, M, or telescoping members 1'7, 18, or through the use of any well-known type of stop to limit the folding action, the upper chord members 2 of each of the trusses will be caused to lie, in extended position, either in a single plane, or to be disposed along any desired type of curved surface such as, for example, a parabola. Of course, the foregoing discussion in reference to the disposition of chord members 2 is equally applicable to chord members 3.
After the various truss members 1 and connecting spanners and'locking rods have been connected together in the manner indicated above, the entire structure is folded in the manner illustrated in FIGURES 3, 5 and 7. When completely folded, the trussed structure compresses to a relatively small package which is easily carried with a minimum of manpower. When it is desired to erect the trussed structure, it is simply extended by any convenient means, either manually or by means of a hydraulic cylinder or jack, to extended position, and the locking rods or links are locked by locking means 16, 16', or 19, as the case may be.
Thus it will be seen that the invention provides a missed type of structure having a high degree of strength which is easily portable and can be quickly erected for use.
While particular embodiments of the invention have been illustrated and described, it will be obvious to those skilled in the art that various changes and modifications can be made without departing from the invention, and it is intended in the appended claims to cover all such changes and modifications that fall Within the true spirit and scope of the invention.
What is claimed is:
1. A collapsible load-bearing structure for supporting an antenna, comprising, in combination:
at least three vertically extending frame-like rigid truss sections which are normally disposed in spaced parallel planes, each section comprising at least upper and lower horizontal members rigidly inter-- connected by vertical members;
a plurality of means between each pair of adjacent truss sections for maintaining the sections in parallelism and for collapsing the structure into more closely spaced parallel planes, said means comprising:
a first pair of spanners normal to and hingedly con nected to the upper horizontal members of said adjacent truss sections,
and a second pair of spanners normal to and hingedly connected to the lower horizontal members of said adjacent truss sections,
5 6 whereby each subcombination of adjacent truss secand a set screw projecting through said sleeve and tions and the spanners therebetween defines a boxbearing against said spanner or truss member to lock like configuration when fully extended and comsaid sleeve in position, prises a unitary but normally non-rigid pantograp'nthe pivotal connection between each brace member like collapsible structure; 5 and transverse sleeve comprising a ball and socket and locking means for rigidifying said structure when j int,
fully extended, said locking means comprising at least one pair of diagonal brace members, both mem- References Cited by the Examiner bers of said pair being hingedly connected at one UNITED STATES PATENTS end to a common horlzontal member of a truss 10 section intermediate two other truss sections, one of 1,471,223 10/23 Tqmlmson said brace members being slidably locked at its other 2,693,195 11/ 54 Frledel' et end to a spanner and the other of said brace mem- 2,917,129 12/ 59 Grover t bers being slidably locked at its other end to a 11,586 12/61 Harvey 189l2 X vertical truss member. 15 3,062,340 11/62 I-Iunnebeck 5 05 6 2. The combination in accordance with claim 1 in which the means for slidably locking each of said brace FOREIGN PATENTS members comprises: 941336 6/36 Italya transverse sleeve pivotally connected to said other end and having an internal diameter suflicient to 20 RICHARD COOKE Pnmary Examme" receive its associated spanner or truss member in HENRY C. SUTHERLAND, JACOB I. NACKENOFF, sliding engagement, Examiners.