具体实施方式：
[0024]The Detailed Description refers to the aforementioned example figures.
DETAILED DESCRIPTION
[0025]The following describes one or more example embodiments of the disclosed boom system, as shown in the accompanying figures of the drawings described briefly above.
[0026]For long articulated spray booms such as those used in agriculture, there are often three or four wings, sometimes called an inner wing (e.g. 24 in FIG. 1A), outer wing (middle wing, e.g. 30) and breakaway wing (outermost wing, e.g. 22). Spray vehicles having such spray booms apply nutrients, herbicides, paints, chemicals and other liquids such those used in agriculture or industrial applications; sprayers tend to be very heavy because they often have large physical structures (e.g. booms) to which pipes are attached, and the pipes are filled with the heavy liquids. To reduce the weight, mostly non-metallic embodiments of the boom are disclosed. The disclosed examples of the new boom system have a reduced weight relative to conventional systems, and include boom segments formed from multiple sections. For instance, the boom wings (e.g. inner and outer wings) are now themselves segmented and each segment has multiple pieces or sections. In FIG. 2, inner wing 24 is formed from horizontal segments 42, 46 and 94 on the lower portion, and horizontal segments 40, 44 and 92 on the upper portion. The vertical union members (e.g. A-A) for inner wing 24 forms about a 90 degree angle from both the lower portion and from the upper portion. The example boom segments with multiple pieces or sections are formed from relatively lightweight material, such as polymers or composites such as fiber, glass, Kevlar, flax or carbon fiber composites. The boom segments are joined together (joint sections, each of which have multiple sections), also using light weight materials so that over 80-95 percent of the entire boom system is non-metallic. Despite the light weight, due to the architecture, construction of the joint sections, the diamond orientation of the boom cross section, the suspension, etc., the disclosed example boom systems still manage to stay rigid and do not vibrate in the wind or when going over rough terrain or traveling up to 25 mph.
[0027]The modularity of the boom segments, sections and joint sections reduces manufacturing costs and aids flexibility during assembly and enables many possible variations in the design of the booms, somewhat like LEGO components. While the discussion below focuses on spray booms used in agriculture, the concepts can be applied to air booms used in dry chemical spreaders, booms used in construction machinery (e.g., cranes).
[0028]In some embodiments, multiple instances of such sections can be formed as identical (e.g., interchangeable) sections that can be joined together with suitable unions. In this way, for example, the manufacturing and assembly of the boom segments can be simplified considerably. Unions for the disclosed boom system can also allow for relatively simple joinder of consecutive sections of various boom segments, as well as allowing different boom segments to be folded relative to each other.
[0029]FIGS. 1A and 1B illustrate an example sprayer vehicle 20 for agricultural spraying operations. Various embodiments of a segmented boom system, as discussed herein, may be used with (and, accordingly, presented in the context of) the sprayer vehicle 20. It will be understood, however, that the disclosed segmented boom system (and components thereof) can be used with sprayer vehicles having different configurations than the sprayer vehicle 20, as well as with other types of work vehicles.
[0030]FIG. 1A illustrates the sprayer vehicle 20 during a spraying operation in an agricultural field. Generally, the sprayer vehicle 20 supports a boom 22, which can extend a substantial distance to either side of the body of the sprayer vehicle 20 in order to distribute material onto the field. As depicted, the boom 22 of the sprayer vehicle 20 is generally symmetric with respect to the body of the sprayer vehicle 20. Accordingly, discussion herein of the boom 22 may be presented with respect to only one side of the boom 22. It will be understood that such discussion may also apply to the other side of the boom 22, portions of a boom mounted directly behind (or elsewhere on) a vehicle, or booms (not shown) that may not be symmetrical with respect to a vehicle.
[0031]In some embodiments, an articulated boom includes multiple boomwings. In some embodiments, certain of these wings may be foldable relative to each other, such that the extension of the boom to either side of the relevant vehicle can be reduced. For example, as illustrated in particular in FIG. 2, the boom 22 can include at least three boom sections on either side of the sprayer vehicle 20, including a near-vehicle boom wing 24 (“inner wing”), an intermediate boom wing 26 (“outer wing”), and a tip boom wing 28 (“breakaway wing”). A joint 30 between the boom sections 24 and 26, and a joint 32 between the boom sections 26 and 28 can be configured to allow the various boom sections 24, 26, and 28 to pivot relative to each other, such that the boom 22 can be generally folded to a reduced extension distance from the body of the sprayer vehicle 20. For example, as illustrated in FIG. 1B, the boom 22 can be folded at the joint 30 until the boom sections 26 and 28 extend roughly in parallel with the front-to-rear axis of the sprayer vehicle 20, as may be useful for non-spraying vehicle transport (e.g., travel over public roads).
[0032]In some embodiments, boom sections of a boom can be further subdivided into boom segments. As illustrated in FIGS. 2, 3A and 3B, for example, the boom wing 24 includes multiple boom segments, including boom segments 40, 42, 44 and 46 disposed on either side of the joint 30. Generally, the boom segments 40, 42, 44, and 46 extend in parallel with each other (at least when the boom 22 is fully unfolded) and along the same general dimension as the boom 22 (i.e., generally left to right, as depicted in FIG. 2. In order to provide structural stability to the boom 22, the boom segments 40 and 44 can be generally axially aligned with each other (again, at least when the boom 22 is fully unfolded), as can the boom segments 42 and 46. The boom segments 40 and 44 are generally removed from the boom segments 42 and 46 along a different dimension (e.g., vertically, as illustrated). As depicted, the boom segments 40 and 44 are disposed in vertical alignment with the boom segments 42 and 46. In other embodiments, either of the boom segments 40 and 44 can instead be offset forward or rearward from either of the boom segments 42 and 46. When assembled in succession, the boom segments 40 and 44 (possibly with other additional boom segments) form part of an elongated upper boom member, and the boom segments 42 and 46 (possibly with other additional boom segments) form part of an elongated lower boom member. The elongated lower boom member is tubular as shown in FIG. 2. An orientation of the tube is such that a cross section of the tubular lower boom member is diamond shaped with the lowermost vertex of the diamond closest to the ground plane (see, e.g., FIG. 3C where the ground plane is the squiggly line at the bottom of the figure). In this context, “lower” refers to the extended boom member that is closest to the ground or plane of the target being sprayed.
[0033]In some embodiments, the elongated lower boom member is an extended articulated tubular boom that is over 30 meters long. The articulated tubular boom has three or four wings such as shown in FIG. 1A. The elongated upper boom member is made of cable except in the joint region, between the boom wings, where the wings fold. The joint region has pieces that are mostly perpendicular to the horizontal elongated upper and lower boom members. The joint region span between the elongated upper and elongated lower boom members. In other words, the elongated lower boom member is suspended or tethered to the spray vehicle or center rack of the vehicle by cables such as fiber cable (e.g. dyneema) or steel cable. The joint region may also be tethered to the spray vehicle or to other joint regions or to the elongated lower boom member by cables. In such an embodiment, the orientation of the tubular boom is such that a cross section of the tubular lower boom member is diamond shaped with the lowermost vertex of the diamond closest to the ground plane (see, e.g., FIG. 3C where the ground plane is the squiggly line at the bottom of the figure).
[0034]The boom segments 40, 42, 44, and 46 can be formed from one or more of a variety of materials, including polymers, graphite, non-ferrous metals such as aluminum or aluminum alloys, and composite fiber materials such as carbon fiber, flax fiber, and fiberglass. As illustrated in FIG. 3A, the boom segments 40, 42, 44, and 46 can be formed with hollow ends. In some embodiment, the entire lengths of the various boom segments 40, 42, 44, and 46 can be hollow. In some embodiments, only part of the lengths (e.g., only the ends) of the boom segments 40, 42, 44, and 46 are hollow, or the boom segments 40, 42, 44, and 46 are hollow, but with some amount of internal structure (e.g., internal ribs, struts, filling, and so on).
[0035]In some embodiments, the various boom segments 40, 42, 44, and 46 (and others) can be formed as generally identical (and, thereby, interchangeable) components. For example, each of the boom segments 40, 42, 44, and 46 can be formed as an extended hollow body of the same length and cross-section, such that the boom segments 40, 42, 44, and 46 may be indistinguishable from each other before installation on the boom 22. This may be useful, for example, in order to simplify manufacturing and assembly of the boom 22. For instance, tubular hollow boom segments can be manufactured in an automated pultrusion process for fiber materials. Alternatively, a reinforced 3-D printing may be more suitable for more granular materials. Reinforcement includes a composite fiber or carbon fiber reinforced 3-D printing.
[0036]In order to connect the various boom segments 40, 42, 44, and 46 to each other, a union 50 can be provided. In some embodiments, the union 50 can be formed from one or more of a variety of materials, including polymers, graphite, non-ferrous metals such as aluminum or aluminum alloys, and composite fiber materials such as carbon fiber, flax fiber, and fiberglass. In some embodiments, the union 50 can be formed from the same material as the various boom segments 40, 42, 44, and 46. In some embodiments, the union 50 can be formed from different materials than the various boom segments 40, 42, 44, and 46.
[0037]Generally, the union 50 can include two coupling segments such that the union 50 can connect the boom segments 40 and 44 to each other, can connect the boom segments 42 and 46 to each other, and can connect the boom segments 40 and 44 to the boom segments 42 and 46, respectively. In this way, for example, the union 50 can allow modular sections of the boom 22 (e.g., the various boom segments 40, 42, 44, and 46) to be joined together along the length dimension and height dimension of the boom 22.
[0038]In some embodiments, the coupling segments can extend generally in parallel with (i.e., generally along the same dimension as) the boom segments 40, 42, 44, and 46, with a strut extending between the two coupling segments (e.g., generally in a different dimension than the coupling segments). In the embodiment illustrated in FIGS. 3A and 3B, for example, the union 50 includes a strut 52 extending perpendicularly between upper and lower coupling segments 54 and 56. As illustrated in FIGS. 3A through 4, the strut 52 is configured with a generally I-shaped profile, with a relatively narrow (left-to-right, as illustrated in FIG. 4), but generally deep (into the page, as illustrated in FIG. 4) central support 58 extending between relatively wide, but generally shallow, end supports 60.
[0039]In other embodiments, other profiles are used for the strut 52 (or other struts). FIGS. 5A through 5H illustrate various examples, with components corresponding to the boom segments 40, 42, 44, and 46, the union 50, and components thereof indicated by an appended letter corresponding to the figure label (e.g., alternate union 50a for FIG. 5A, alternate strut 52c for FIG. 5C, and so on). Accordingly, it can be seen that a strut for a union can be configured as: a generally I-shaped strut 52a (rotated 90 degrees with respect to the orientation of the strut 52); a generally I-shaped strut 52b extending at a laterally non-perpendicular angle to boom segments 40b, 42b, 44b, and 46b and the coupling segments 54b and 56b; a generally I-shaped strut 52c extending at a depth-wise non-perpendicular angle to boom segments 40b, 42b, 44b, and 46c and the coupling segments 54c and 56c; a curved strut 52d (e.g., generally I-shaped, as illustrated), a generally X-shaped strut 52e with “legs” of the “X” oriented in parallel with, and perpendicularly to, the length dimension of boom segments 40e, 42e, 44e, and 46e; a generally T-shaped strut 52f, a generally X-shaped strut 52g with “legs” of the “X” oriented at non-perpendicular angles to the length dimension of boom segments 40g, 42g, 44g, and 46g, and a generally X-shaped strut 52h with curved “legs.” In other embodiments, various struts shown in FIGS. 3A through 5H can be disposed at other angles or rotational orientations with respect to the relevant boom segments or coupling segments. In some embodiments, struts of different kinds (e.g., as depicted in FIGS. 3A through 5H) can be combined into compound struts (e.g., struts with a combination of X-shaped and T-shaped profiles).
[0040]Coupling segments and associated ends (or other portions) of boom segments can be configured with various types of geometries. As depicted, for example, the ends of the boom segments 40, 42, 44, and 46 are configured as diamond shaped (when viewed in cross section), hollow tubes with substantially squared corners. Further, opposite ends of the coupling segments 54 and 56 are configured as similar diamond shaped members (which may also be hollow in some embodiments). Because the coupling segments 54 and 56 are similar to, but somewhat smaller than the ends of the boom segments 40, 42, 44, and 46, the ends of the coupling segments 54 and 56 can be inserted into the ends of the boom segments 40, 42, 44, and 46 in order to secure the union 50 to the boom segments 40, 42, 44, and 46 and thereby also connect the various boom segments 40, 42, 44, and 46 together. In this regard, the coupling segments 54 and 56 can be viewed as being aligned coaxially with, and inserted coaxially into, the relevant boom segments 40, 42, 44, and 46. Once inserted, the ends of the coupling segments 54 and 56 can be secured in place in various ways, including with rivets 62, adhesive 64, or a threaded fastener 66, as illustrated in FIG. 4.
[0041]In certain embodiment, two vertices (upper and lower in FIG. 3C) of each end of the boom segments 40, 42, 44 and 46 fall along a centerline axis 48, which may correspond to a dimension transverse to the direction of travel of the implement, such as vertical. In such an example, squared-corner diamond geometry illustrated for the boom segments 40, 42, 44, and 46 and the coupling segments 54 and 56 can provide relatively strong support and relatively high stiffness to the assembled boom 22 for a given amount of material or coupling segment perimeter. In other embodiments, however, other configurations are possible. As illustrated in FIGS. 6A through 6H, for example, the cross-section of an end of a coupling segment (e.g., one of the coupling segments 54 and 56) can be configured as a rectangle with same length sides (square) 68, a relatively wide rectangle 70, a relatively tall rectangle 72, a non-squared diamond 74, a circle 76, a relatively wide generally elliptical shape 78, a relatively tall generally elliptical shape 80, or a generally oval shape 82 (in each case, as depicted, or rotated to varying degrees). In some embodiments, the cross-section of a corresponding end of a boom segment (e.g., one of the boom segments 40, 42, 44 or 46) can then be configured with a similar (or different) geometry.
[0042]As illustrated in FIGS. 3A through 4, the coupling segments 54 and 56 can be inserted into the ends of the various boom segments 40, 42, 44, and 46. In some embodiments, an opposite configuration may be possible, in which the ends of the boom segments 40, 42, 44, and 46 can be inserted into the coupling segments 54 and 56. In some embodiments, an intermediary connector (not shown) can be used between the boom segments 40, 42, 44, and 46 and the relevant coupling segment 54 or 56. For example, in some embodiments, the boom segments 40, 42, 44, and 46 and the coupling segments 54 and 56 are configured with similar peripheral dimensions. Collars (not shown) can then be disposed between the relevant pairs of the boom segments 40, 42, 44, and 46 and the coupling segments 54 and 56, with opposing male connectors of each collar extending into (or opposing female connectors receiving) the relevant boom segment 40, 42, 44, or 46 and the corresponding coupling segment 54 or 56. In this regard, in some embodiments, such a collar can be viewed as forming part of a coupling segment of a union, even if the collar and the union are formed as separate pieces.
[0043]As illustrated in FIGS. 3A and 4, the coupling segments 54 and 56 can be formed as generally hollow bodies. In some embodiment, the entire lengths of the coupling segments 54 and 56 can be hollow. In some embodiments, only part of the lengths (e.g., only the ends) of the coupling segments 54 and 56 are hollow, or the coupling segments 54 and 56 are generally hollow, but with some amount of internal structure (e.g., internal ribs, struts, filling, and so on).
[0044]In some embodiments, a union can be configured to pivotally couple consecutive boom segments, such that the boom segments are pivoted relative to each other. This may be useful in folding booms, and other configurations. FIGS. 7 and 8 illustrate an example hinged union 90 for the joint 30 between the boom segments 24 and 26 of the boom 22. As depicted, the boom wing 24 (e.g., as discussed above) and the boom wing 26 can be configured with multiple boom segments, including boom segments 92, 94, 96 and 98 disposed adjacent to the joint 30.
[0045]Generally, the boom segments 92, 94, 96, and 98 extend in parallel with each other (at least when the boom 22 is fully unfolded) and along the same general dimension as the boom 22 (i.e., generally left to right, as depicted in FIGS. 7 and 8). In order to provide structural stability to the boom 22, the boom segments 92 and 96 can be generally axially aligned with each other (again, at least when the boom 22 is fully unfolded), as can the boom segments 94 and 98. Further, the boom segments 92 and 96 can be generally removed from the boom segments 94 and 98 along a different dimension (e.g., vertically, as illustrated). As depicted, the boom segments 92 and 96 are disposed in vertical alignment with the boom segments 94 and 98. In other embodiments, either of the boom segments 92 and 96 can instead be offset forward or rearward from either of the boom segments 94 and 98.
[0046]The boom segments 92, 94, 96, and 98 can be formed from one or more of a variety of materials, including polymers, graphite, non-ferrous metals such as aluminum or aluminum alloys, and composite fiber materials such as carbon fiber, flax fiber, and fiberglass. As illustrated in FIG. 8, the boom segments 92, 94, 96, and 98 can be formed with hollow ends. In some embodiment, the entire lengths of the various boom segments 92, 94, 96, and 98 can be hollow. In some embodiments, only part of the lengths (e.g., only the ends) of the boom segments 92, 94, 96, and 98 may be hollow, or the boom segments 92, 94, 96, and 98 may be generally hollow, but with some amount of internal structure (e.g., internal ribs, struts, filling, and so on).
[0047]In some embodiments, the various boom segments 92, 94, 96, and 98 (and others) can be formed as generally identical (and, thereby, interchangeable) components. For example, each of the boom segments 92, 94, 96, and 98 can be formed as an extended hollow body of the same length and cross-section, such that the boom segments 92, 94, 96, and 98 may be generally indistinguishable from each other before installation on the boom 22. In some embodiments, the boom segments 92, 94, 96 and 98 can also be formed to be generally identical to the boom segments 40, 42, 44, and 46 (see, e.g., FIGS. 3A through 4). This may be useful, for example, in order to simplify manufacturing and assembly of the boom 22. Like boom segments 40, 42, 44 and 46, when assembled in succession, the boom segments 92 and 96 (possibly with other additional boom segments) may form part of the elongated upper boom member, and the boom segments 94 and 98 (possibly with other additional boom segments) may form part of the elongated lower boom member. The upper and lower boom members may be thought of as the segmented structures of individual sections, which extend laterally side to side relative to the direction of travel of the implement when the boom is in an operational position, or the overall upper and lower laterally extending structures of combined sections, for example, with hinged connections between the sections.
[0048]In the illustrated embodiment, the union 90 can be used to pivotally connect the various boom segments 92, 94, 96, and 98 to each other. In some embodiments, the union 90 can be formed from one or more of a variety of materials, including polymers, graphite, non-ferrous metals such as aluminum or aluminum alloys, and composite fiber materials such as carbon fiber, flax fiber, and fiberglass. In some embodiments, the union 90 can be formed from the same material as the various boom segments 92, 94, 96, and 98. In some embodiments, the union 90 can be formed from different materials than the various boom segments 92, 94, 96, and 98.
[0049]In order to provide pivotal movement between the various boom segments 92, 94, 96 and 98 (and the boom segments 24 and 26, generally), the union 90 is formed with two parts 90a and 90b configured to mate to each other as well as to connect to relevant parts of the various boom segments 92, 94, 96, and 98. Each of the union parts 90a and 90b include a generally C-shaped strut 100, which together form a generally I-shaped compound member when the union 90 is fully closed (e.g., as illustrated in FIG. 7). In other embodiments, other configurations are possible, including generally T-shaped union parts that form a generally X-shaped compound member when the union is fully closed or various combinations or sub-divisions of the various strut geometries illustrated in FIGS. 5A through 5H. In some embodiments, struts for a generally X-shaped compound member can be disposed at a rotated orientation relative to the orientation of the struts 100. As illustrated in FIG. 9, for example, struts 100a of an alternate joint 30a can be generally T-shaped, but rotated 90 degrees relative to the struts 100. In some embodiments, the struts 100 (or equivalent members) include angled or arcuate portions (e.g., similar to that depicted for the strut 52d in FIG. 5D), relative to the various boom segments 92, 94, 96, and 98.
[0050]At opposite ends of the struts 100, each of the union parts 90a and 90b includes one of various coupling segments 102, 104, 106, and 108, such that the union 90 can connect the boom segments 92 and 96 to each other, can connect the boom segments 94 and 98 to each other, and can connect the boom segments 92 and 96 to the boom segments 94 and 98, respectively. In this way, for example, the union 90 can allow modular sections of the boom 22 to be joined together along the length dimension and height dimension of the boom 22.
[0051]In some embodiments, the coupling segments 102, 104, 106, and 108 can extend generally in parallel with (i.e., generally along the same dimension as) the boom segments 92, 94, 96, and 98, with the struts 100 extending between respective pairs of the coupling segments 102, 104, 106, and 108 (e.g., generally in a different dimension than the coupling segments).
[0052]Coupling segments and associated ends (or other portions) of boom segments can be configured with various types of geometries. As depicted, for example, the ends of the boom segments 92, 94, 96, and 98 are configured as diamond shaped, hollow tubes with substantially squared corners. Further, outside ends of the coupling segments 102, 104, 106, and 108 are configured as similar diamond shaped members (which may also be hollow in some embodiments). Because the coupling segments 102, 104, 106, and 108 are similar to, but somewhat smaller than the ends of the boom segments 92, 94, 96, and 98, the ends of the coupling segments 102, 104, 106, and 108 can be inserted into the ends of the boom segments 92, 94, 96, and 98 in order to secure the union 90 to the boom segments 92, 94, 96, and 98 and thereby also connect the various boom segments 92, 94, 96, and 98 together. In this regard, the coupling segments 102, 104, 106, and 108 can be viewed as being aligned coaxially with, and inserted coaxially into, the relevant boom segments 92, 94, 96, and 98. Once inserted, the ends of the coupling segments 102, 104, 106, and 108 can be secured in place in various ways, including with rivets, adhesives, or threaded fasteners (not shown for the union 90).
[0053]The example diamond geometry illustrated for the boom segments 92, 94, 96, and 98 and the coupling segments 102, 104, 106, and 108 can provide relatively strong support and relatively high stiffness to the assembled boom 22. In other embodiments, however, other configurations are possible. For example, cross-sections of the coupling segments 102, 104, 106, and 108 can be configured as a square, a rectangle, a non-squared diamond, a circle, a generally elliptical shape, or a generally oval shape (e.g., as depicted in FIGS. 5A through 5H). In some embodiments, the cross-section of a corresponding end of a boom segment (e.g., one of the boom segments 92, 94, 96, or 98) can then be configured with a similar (or different) geometry.
[0054]As depicted in FIGS. 7 and 8, the coupling segments 102, 104, 106, and 108 can be inserted into the ends of the various boom segments 92, 94, 96, and 98. In some embodiments, an opposite configuration is possible, in which the ends of the boom segments 92, 94, 96, and 98 can be inserted into the coupling segments 102, 104, 106, and 108. In some embodiments, an intermediary connector (not shown) can be used between the boom segments 92, 94, 96, and 98 and the relevant coupling segment 102, 104, 106 or 108. For example, in some embodiments, the boom segments 92, 94, 96, and 98 and the coupling segments 102, 104, 106, and 108 are configured with similar peripheral dimensions. Collars (not shown) can then be disposed between the relevant pairs of the boom segments 92, 94, 96, and 98 and the coupling segments 102, 104, 106, and 108, with opposing male connectors of each collar extending into (or opposing female connectors receiving) the relevant boom segment 92, 94, 96, or 98 and the corresponding coupling segment 102, 104, 106, or 108. In this regard, in some embodiments, such a collar can be viewed as forming part of a coupling segment of a union, even if the collar and the union are formed as separate pieces.
[0055]As illustrated in FIG. 8, the coupling segments 102, 104, 106, and 108 can be formed as generally hollow bodies. In some embodiment, the entire lengths of the coupling segments 102, 104, 106, and 108 can be hollow. In some embodiments, only part of the lengths (e.g., only the ends) of the coupling segments 102, 104, 106, and 108 are hollow, or the coupling segments 102, 104, 106, and 108 are generally hollow, but with some amount of internal structure (e.g., internal ribs, struts, filling, and so on).
[0056]In order to allow the boom segments 24 and 26 to pivot relative to each other the union parts 90a and 90b can include complementary hinge components. As illustrated in FIGS. 7 and 8, for example, the union part 90a can include hinge ears 110 and 112, which can be connected by a hinge pin extending along a hinge axis 118 (see FIG. 7) to complementary hinge tabs 114 and 116 on the union part 90b. In other embodiments, other hinged arrangements can alternatively (or additionally) be used.
[0057]In some embodiments, the union parts 90a and 90b can be mechanically fastened to one another at locations other than along the hinge axis 118. For example, detents, pins, catches, press- or snap-fit features, or other arrangements can be disposed to help hold the union parts 90a and 90b together when the union 90 is in the fully closed orientation. As illustrated in FIG. 8, generally C-shaped tabs 120 on the union part 90a can be configured for press-fit (or other) engagement with complimentary cavities 122 (depicted in dotted relief) of the union part 90b. When the union 90 is in the fully closed orientation (e.g., as depicted in FIG. 7) the tabs 120 can engage the cavities 122, in order to help resist unintended opening of the union 90 and corresponding folding of the boom 22.
[0058]Another example of a hinged union is illustrated in FIGS. 10 and 11 in the form of a union 130 for the joint 32 between the boom segments 26 and 28 of the boom 22. As depicted, the boom wing 26 (e.g., as discussed above) and the boom wing 28 can be configured with multiple boom segments, including boom segments 134, 136, 138, and 140 disposed adjacent to the joint 32.
[0059]Generally, the boom segments 136, 138, and 140 extend in parallel with each other (at least when the boom 22 is fully unfolded) and along the same general dimension as the boom 22 (i.e., generally left to right, as depicted in FIGS. 10 and 11). The section 134, in contrast, is configured as an angled strut extending from the top of the boom wing 28 towards the bottom of the boom wing 28. In order to provide structural stability to the boom 22, the boom segments 136 and 140 can be generally axially aligned with each other (again, at least when the boom 22 is fully unfolded), as can the boom segment 138 and the upper end of the boom segment 134. Further, the boom segments 134 and 138 and 96 can be generally removed from the boom segments 136 and 140 along a different dimension (e.g., vertically, as illustrated). As depicted, the boom segments 134 and 138 are disposed in vertical alignment with the boom segments 136 and 140. In other embodiments, either of the boom segments 134 and 138 can instead be offset forward or rearward from either of the boom segments 136 and 140.
[0060]The boom segments 134, 136, 138, and 140 can be formed from one or more of a variety of materials, including polymers, graphite, non-ferrous metals such as aluminum or aluminum alloys, and composite fiber materials such as carbon fiber, flax fiber, and fiberglass. In some embodiments, the boom segments 134, 136, 138, and 140 can be formed with hollow ends. In some embodiment, the entire lengths of the various boom segments 134, 136, 138, and 140 can be hollow. In some embodiments, only part of the lengths (e.g., only the ends) of the boom segments 134, 136, 138, and 140 may be hollow, or the boom segments 134, 136, 138, and 140 may be generally hollow, but with some amount of internal structure (e.g., internal ribs, struts, filling, and so on).
[0061]In some embodiments, certain of the various boom segments 134, 136, 138, and 140 (and others) can be formed as generally identical (and, thereby, interchangeable) components. For example, each of the boom segments 138 and 140 can be formed as an extended hollow body of the same length and cross-section, such that the boom segments 138 and 140 may be generally indistinguishable from each other before installation on the boom 22. In some embodiments, certain of the boom segments 134, 136, 138, and 140 can also be formed to be generally identical to the boom segments 40, 42, 44, and 46 (see, e.g., FIGS. 3A through 4) or the boom segments 92, 94, 96, and 98. This may be useful, for example, in order to simplify manufacturing and assembly of the boom 22. Like boom segments 40, 42, 44 and 46 and 92, 94, 96 and 98, when assembled in succession, the boom segments 134 and 138 (possibly with other additional boom segments) form