Patent Publication Number: US-10774533-B2

Title: Cross-strut

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application claims priority from and is a non-provisional of U.S. Provisional Application No. 62/475,711, entitled “MULTI-DIRECTION STRUCTURAL CHANNEL,” filed on Mar. 23, 2017, the entire contents of which is herein incorporated by reference for all purposes. 
    
    
     TECHNICAL FIELD 
     This technology relates to structural channels which provide functional capability in multiple directions, for example providing platforms for component attachments in multiple directions and physical protection to system integrated components inside the structural channel. More particularly, the disclosed structural channels are configured to provide platforms for permitting multiple carriers to slide and/or roll in linear motion independently in multiple directions. 
     BACKGROUND 
     Unistruts are a standardized formed structural system used in the construction and electrical industries for light structural support, often for supporting wiring, plumbing, or mechanical components such as air conditioning or ventilation systems. 
       FIG. 1  shows Unistrut channels in various configurations. Unistrut channels are formed from sheet metal folded over into an open channel shape with inwards curving lips to provide additional stiffness and as a location to mount interconnecting components. Unistrut channels have holes in the base to facilitate interconnection or fastening the Unistrut to underlying building structures.  FIG. 2  shows an example application of a Unistrut. 
     Unistrut channels can be used in connecting lengths of Unistrut together and other hardware to the Unistrut, for example using various specialized Unistrut specific fasteners and bolts. A disadvantage of the Unistrut occurs when components need to be attached facing different directions. In order to accomplish this with Unistrut time consuming modification is needed, such as welding, drilling more holes or bolting these additional items with additional fasteners. The resulting structure either lacks structural integrity or has a low ratio of structural integrity over weight, i.e. the assembly is very heavy relative to how strong it is. Examples of undesirable assemblies are shown in  FIGS. 3A and 3B . Further, Unistruts have the disadvantage of lacking surfaces which provide platforms to allow smooth rolling and sliding for linear movement assemblies. 
     BRIEF SUMMARY 
     The present technology relates to beams having a cross section defining a plurality of channels and assemblies comprising the beams. In embodiments the cross section may define four channels, facing in four directions. The cross section has the advantages of providing structural channels that provide strength, platforms for attaching sliding and fastening components, and conduits for protecting internal components. The interior and exterior surfaces of the channels are configured to permit multiple carriers to slide/roll in linear motion independently in multiple directions, with smooth action and stability due to one or more guiding features to distribute load. These and other embodiments are discussed in greater detail in the detailed description and drawing figures. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Illustrative aspects of the present disclosure are described in detail below with reference to the following drawing figures. It is intended that that embodiments and figures disclosed herein are to be considered illustrative rather than restrictive 
         FIG. 1  shows a plurality of Unistrut channels. 
         FIG. 2  shows an assembly of two Unistrut channels. 
         FIG. 3A  shows a cross section of a Unistrut channel assembly. 
         FIG. 3B  shows a cross section of a Unistrut channel assembly. 
         FIG. 4A  shows a channel according to the present technology. 
         FIG. 4B  shows detail of a flange of  FIG. 2A . 
         FIG. 5  shows a beam according to the present technology, with the middle section omitted for clarity purposes. 
         FIG. 6  shows a cross section of the beam of  FIG. 5 . 
         FIGS. 7A and 7B  show a perspective view and cross section of an embodiment including an electrical actuator embedded in a beam. 
         FIGS. 8A and 8B  show a perspective and cross section view of an embodiment including guides within a beam. 
         FIGS. 9A and 9B  show a perspective and cross section view an embodiment including a guide within a beam. 
         FIGS. 10A and 10B  show a perspective and cross section view an embodiment including a guide within a beam. 
         FIGS. 11A and 11B  show a perspective and cross section view of exemplary embodiments of rollers which may be used with a beam according to the present technology. 
         FIGS. 12A and 12B  show a perspective and cross section view of exemplary embodiments of roller assemblies, each comprising multiple rollers which may be used with a beam according to the present technology. 
         FIGS. 13A and 13B  show a perspective and cross section view of an embodiment of a roller/guide assembly which may be used with a beam according to the present technology. 
         FIGS. 14A and 14B  show a perspective and cross section view of an embodiment of a roller/guide assembly with an actuator which may be used with a beam according to the present technology. 
         FIG. 15  shows cross section views and close up views of an end flange of a beam according to the present technology. 
         FIG. 16A  shows a cross section view of an embodiment of a beam  510  according to the present technology in a “T” shape. 
         FIG. 16B  shows a cross section view of an embodiment of a beam  511  according to the present technology in a “T” shape. 
         FIG. 16C  shows a cross section view of an embodiment of a beam  500   a  according to the present technology with variable thickness walls. 
         FIG. 16D  shows a cross section view of an embodiment of a beam  512  according to the present technology with variable thickness walls in a “T” shape. 
         FIG. 16E  shows a cross section view of an embodiment of a beam  513  according to the present technology in a “T” shape and thicker inner walls. 
         FIG. 16F  shows a cross section view of an embodiment of a beam  514  according to the present technology with tubular flanges. 
         FIG. 16G  shows a cross section view of an embodiment of a beam  515  according to the present technology with a single channel. 
         FIG. 16H  shows a cross section view of an embodiment of a beam  516  according to the present technology with two opposing channels. 
         FIGS. 16I-P  show cross section views of embodiments of beams  517 ,  518 ,  519 ,  520 ,  521 ,  522 ,  523  and  524  according to the present technology with hollow central portions, with a circular truss  530  provided inside each of the beams  521 ,  522 ,  523  and  524 . 
         FIG. 17  shows a schematic of a lifting beam assembly according to the present technology. 
         FIG. 18A  shows a pulley lifting beam assembly according to the present technology. 
         FIG. 18B  shows a mechanically synchronized beam assembly according to the present technology. 
         FIG. 19  shows a beam assembly for a utility truck according to the present technology. 
         FIGS. 20A-20D  show the beam assembly of  FIG. 19  installed in a utility truck in various configurations. 
         FIGS. 21A and 21B  show an elevator assembly according to the present technology. 
     
    
    
     DETAILED DESCRIPTION 
     The present disclosure describes embodiments of channels, beams, and apparatuses and systems composed of embodiment of the beams. Certain details are set forth in the following description and in the figures to provide a thorough understanding of various embodiments of the present technology. 
     Many of the details, dimensions, angles and other features shown in the figures are merely illustrative of particular embodiments. Accordingly, other embodiments can include other details, dimensions, angles and features without departing from the spirit or scope of the present invention. Various embodiments of the present technology can also include structures other than those shown in the figures and are expressly not limited to the structures shown in the figures. Moreover, the various elements and features shown in the figures may not be drawn to scale. In the figures, identical reference numbers identify identical or at least generally similar elements. 
     As used herein, the term “substantially” refers to the complete or nearly complete extent or degree of an action, characteristic, property, state, structure, item, or result. For example, an object that is “substantially” uniform in height to another object would mean that the objects are either completely or nearly completely uniform in height. The exact allowable degree of deviation from absolute completeness may in some cases depend on the specific context, however, generally speaking, the nearness of completion will be so as to have the same overall result as if absolute and total completion were obtained. 
     As used herein, the term “about” is used to provide flexibility to a numerical range endpoint by providing that a given value may be “above” or “below” the value. For example, the given value modified by about may be, for example, by ±5%, ±10%, ±15%, ±20%. 
     Wherever used throughout the disclosure and claims, the term “generally” has the meaning of “approximately” or “closely” or “within the vicinity or range of”. The term “generally” as used herein is not intended as a vague or imprecise expansion on the term it is selected to modify, but rather as a clarification and potential stop gap directed at those who wish to otherwise practice the appended claims, but seek to avoid them by insignificant, or immaterial or small variations. All such insignificant, or immaterial or small variations should be covered as part of the appended claims by use of the term “generally”. 
     As used herein, the terms “back”, “side”, “front”, “inner” and “outer” are used to provide orientation, direction, position, or a reference point other component. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, a term such as “below” can encompass both an orientation of above and below, depending on the context of its use. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein are interpreted accordingly. 
     As used herein, the singular forms “a”, “an”, and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “includes” and/or “including”, when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. 
     Although the terms “first”, “second”, etc. may be used herein to describe various elements, components, regions, layers and/or sections, it should be understood that the terms do not connote the number or order of the elements. These terms are used to distinguish one element, component, region, layer, or section from another. Thus, a first element, component, region, layer, or section discussed below could be termed a second element, component, region, layer, or section without departing from the teachings of the present invention. 
     As used herein, the terms “and/or” and “at least one of” include any and all combinations of one or more of the associated listed items. 
       FIG. 4A  shows a cross section of a channel  400 . As will be discussed below the channel  400  may be one of a plurality of channels of a beam and channels of the beam may share walls with various portions of other channels of the beam. For clarity,  FIG. 4A  omits the portions of the beam beyond the surfaces that define the channel  400 , as indicated by the dashed line  402  around the surface. Channel  400  includes a back inner surface  404 , two side inner surfaces  406 , and two flanges  408  at the front  410  of the channel  400 . The surfaces described herein with relation to the channel  400  are substantially planar and extend the length of the beam which the channel is defined by. As shown, side inner surfaces  406  extend from and are substantially perpendicular to the back inner surface  404 , and further are substantially parallel to each other. Side inner surfaces  406  and back inner surface  404  define three sides of the channel  400 , wherein the fourth side completing the rectangle is referred to as the front  410  of the channel  400 . A centerline  412  extends between the middle of the back inner surface  404  and the front  410 . Flanges  408  extend from the front of the side inner surfaces  406  toward the center  412  of the channel  400 . As shown the opening  414  to the channel is defined by the space between the opposing flanges  408 . 
       FIG. 4B  shows a detailed cross section of a flange  408  of the channel  400  of  FIG. 4A . As shown, flanges include a first portion  421  extending from side inner surface  406  toward centerline  412  of the channel  400 . First portion  421  includes a first inner surface  424  facing toward and substantially parallel to the back inner surface  404  and a first outer surface  426  facing away from and a substantially parallel to the back inner surface  404 . First outer surface  426  provides a planar external surface for rollers to roll against and guides to slide against. In embodiments, first outer surface  426  may have a width of between 0.25″ and 0.5″. Flange  408  further includes a second portion  422  extending from the end of the first portion  421  opposite the side inner surface  406  toward the back inner surface  404 . Second portion  422  includes second inner surfaces  428  substantially parallel to the side inner surface  406  and facing the side inner surface  406  opposite from the side inner surface  406  from which the flange  408  extends from. The second inner surface  428  may provide rolling and sliding surfaces that prevent motion of rollers and guides in a direction transverse to the direction of movement. Second inner surfaces may also be referred to as side rolling surfaces. In embodiments, second inner surface  428  may have a width of between 0.25″ and 0.5″. The distance between second inner surfaces  428  define the opening  414  of the channel  400 . In embodiments, the opening is between 0.75″ and 1.0″. Flange  408  further includes a third portion  423  extending from the end of the second portion  422  opposite the first portion  421  toward the side inner surface  406  from which the flange  406  that the third portion  423  comprises extends. Third portion  423  includes third inner surfaces  432  substantially parallel to and facing the back inner surface  404 . Third inner surface  432  provides a rolling or sliding surface that may retain rollers and guides within the channel from being pulled out of the channel. In embodiments, third inner surface  432  may have a width of between 0.16″ and 0.20″. As shown, a gap  430  is formed between the side inner surface  406  and the third portion  423  of the flange  408  since the third portion is shorter than the first portion. The gap provides an opening to a passage defined by a portion of the side inner wall  406 , the first portion  421 , the second portion  422  and the third portion  423 . The passage may be configured to receive and protect electrical or hydraulic cabling or tubing. For example, as shown in  FIG. 15 , the passage  1502  may protect wiring  1504  or tubing  1506 . 
     As shown in  FIG. 4A , channel  400  further includes a side outer surfaces  434  opposite and sharing a portion of a wall with side inner surfaces  406 . In embodiments, side outer surface  434  may have a width substantially the same as the depth of the channel  400  or may only extend a fraction of the depth of the channel, for example  ˜ 50%. In embodiments, side outer surfaces  434  of adjacent channels of a beam may be coplanar or may form inward (i.e. concave) corners. 
     As shown, channel  400  is substantially rectangular. In embodiments, the channel may be substantially square. In embodiments the channel may be rectangular with the depth  436  greater than the width  438  or the width greater than the depth. Deeper channels are beneficial four housing actuators, tubing and cables. Further, shallower channels are beneficial in reducing material costs and size while also providing the beneficial rolling and sliding surfaces as noted above. 
       FIG. 5  shows an embodiment of a beam including a plurality of channels as shown in  FIGS. 4A and 4B . Specially, the beam includes four channels. The beams disclosed herein may be any length. For clarity purposes the middle portion is omitted in  FIG. 5 .  FIG. 6  shows a cross section of the beam  500  of  FIG. 5 . As used herein, directions (e.g. front, back, left, right, up, down, side, outer, central etc.) are used to convey positions and orientations of components relative to each other and are not intended to limit the position and orientation of the present technology relative to its surrounding environment. 
     As shown in  FIG. 6 , the cross section defines four channels. A first channel  501  (Top) and a second channel  502  (Bottom) opposite each other. In embodiments, for example as shown in  FIG. 6 , the back inner surfaces of the first and second channels share a common wall of webbing  550 . In embodiments, opposing channels may have the same depth, or may have different depths. As shown in  FIG. 6 , the depths of the first and second channels are the same, however in embodiments webbing  550  may not be in the middle of the cross section and the channels may have different depths. The first and second channels define a central H frame. 
     The cross section further defines a third channel  503  (Left) and a fourth channel  505  (Right) which oppose each other and are separated by the H frame of the first and second channels. The back inner surfaces of the third and fourth channels share walls with the side inner surfaces of the first and second channels. In the configuration shown in  FIG. 6 , the third and fourth channels  503  and  504  have a smaller depth than the first and second channels  501  and  502 . In embodiments, for example as shown in  FIG. 6 , the first and second channels have a depth of 1.625″ and the third and fourth channels have a depth of 0.875″. In the embodiment shown, the first and second channels are generally square and the third and fourth channels are rectangular with a greater width than depth. In embodiments, the first and second channels may be rectangular with a greater depth than width, and the third and fourth channels may be substantially square or rectangular. 
     In embodiments, a rectangular bounding box of a four channel beam is defined by the first outer surfaces of the first, second, third and fourth channels is generally square. A square bounding box is advantageous in that the beam is versatile by being able to be oriented in any of the four directions around the longitudinal axis of the beam while providing channels in the same directions. 
     As shown, side outer surfaces of the four channels define four inward corners. As will be discussed below, the surfaces of the inward corners may be used in various rolling and sliding applications. 
     In embodiments, the surfaces of the channels of a beam provide smooth planar sliding and rolling surfaces for guides and rollers attached to a carrier bracket to slide and/or roll on in linear motion. Multiple channels may allow for independent linear motion in multiple directions within the channels of a beam. The sliding/rolling surfaces may be planar and smooth to reduce friction, for example the beam may be manufactured of extruded aluminum. The corners and edges may be rounded and free from sharp edges to prevent wear on guides and rollers, which may be constructed of softer materials than the beam, such as polymers. The wall thickness of the cross section may be uniform or may be different at different sections to provide additional structural support for portions of one or more of the channels. 
     In embodiments, a linear actuator  702  may be disposed within a channel of a beam, for example as shown in  FIGS. 7A and 7B . In embodiments, any number of the channels of a beam may have a linear actuator disposed within them. Linear actuators disposed within a channel may be for example a mechanical, electrical, hydraulic, pneumatic, or combinations therefore. The linear actuators include a translatable piston or slider which may be attached to a carrier bracket external to the beam. 
     As shown in  FIGS. 7A and 7B , the piston or slider may be positioned within the second channel of the beam. The linear actuator  702  is coupled to a carrier bracket  704  located externally of the channels of the beam  100 . Carrier bracket  704  is L-shaped and is coupled to a first guide  706  and a second guide  708  disposed within different channels of the beam. The first guide  706  is received in the second channel and the second guide  708  is received in the fourth channel. Carrier bracket  704  provides mounting surfaces to attach components to be lifted, for example toolboxes, ladder racks, or elevators, as will be discussed below. As shown, the first and second guides have complementary shapes to the channels including notches that the flanges of the channels are received within to secure the guides within the channels. Guides secured within channels in this manner may be referred to as trapped guides. Trapped guides provide the advantage of maintaining the linear path of motion of the guide regardless of a direction of force pulling the guide away from the channel. 
     In embodiments, guides include surfaces configured to slide against the back inner surface, the side inner surfaces and the third inner surfaces. The guides may be dimensioned to be slightly smaller than the dimensions of the channel to prevent excess friction. The complementary surfaces of the guides and channels are configured so that the bracket remains coupled to the beam regardless of the direction of the load on the bracket relative to the beam. The guides may be constructed of a material with low friction with the beam, for example synthetic material such as nylon or fiberglass. 
     In embodiments, guides attached to a carrier bracket may not be trapped within channels of the beam, and will be referred to as free guides. For example,  FIGS. 8A and 8B  show an embodiment including guide  802 , which is a free guide. Guide  802  comprises surfaces configured to glide along first and second portions of the flange. With this configuration, guide  802  is not trapped within the channel. This configuration has the advantage of being easy to install as it can be installed anywhere on the beam, whereas trapped guides can be installed by inserting a portion of the trapped guide at an end of a channel or by assembling the trapped guide with multiple components sized to be able to enter through the opening of the channel within the channel. The free guide configuration is advantageously used when the carrier bracket is attached to other guide features in other channels which constrain the movement of the device to a linear path or when the free guide will not experience forces pulling the guide away from the channel. 
     In embodiments trapped guides may not occupy the entire channel. For example,  FIGS. 9A and 9B  show an embodiment with a guide  902 . Guide  902  has a depth less than the depth of the channel which it is received in. The space in the channel not occupied by the trapped guide may be used to house actuators, wires, tubes, or sensors. This configuration of a trapped guide reduces weight and material which is beneficial for manufacturing and movement of the guide. 
       FIGS. 10A and 10B  show an embodiment with a guide  1002 . Guide  1002  occupies the portion of the channel between the flanges and does not occupy the remaining portion of the channel. In embodiments, this unoccupied space is occupied by a translatable piston or slider of a linear actuator. As shown, linear actuator  1004  occupies the channel and is coupled to guide  1002 . The linear actuator is secured to the guide and moves the guide to positions along the length of the beam. 
     In embodiments, in addition to sliding guides as discussed above carrier brackets may be attached to rollers. Rollers may be shaped and dimensioned to contact and roll against one or more surfaces of a channel or multiple channels.  FIGS. 11A and 11B  show a beam with exemplary embodiments of rollers which may be used with channels as disclosed herein. Roller  1102  is positioned within the third channel, which in this figure is oriented at the top. Roller  1102  has an axle which rotates along an axis of rotation which is parallel to first outer surface and perpendicular to the longitudinal axis of the beam. Roller  1102  includes outer cylindrical roller surfaces configured to roll along the outer first surfaces. Roller  1102  further comprises a central cylindrical roller surface with a larger diameter than the outer cylindrical roller surfaces. The central cylindrical roller surface is dimensioned to span the opening of the channel and be aligned and retained between the second inner surfaces in order to prevent transverse movement of the roller as it rolls along the length of the channel. 
     Further shown in  FIGS. 11A and 11B , roller  1104  is received in the first channel, in  FIG. 11B  on the right. Roller  1104  includes outer cylindrical roller portions and a smaller central roller portion. The central roller portion is positioned between the second inner surfaces of the flanges of the channel. The central roller portion includes a roller surface configured to roll against either one of the second inner surfaces of the channel. The distal outer cylindrical portion of roller  1104  is positioned within the channel may be configured to roll along either one of the side inner surfaces of the channel. The proximal and distal outer cylindrical portions capture the flanges and prevent the roller from moving in and out of the channel. Further, as shown, roller  1104  is sized to occupy a portion of the channel leaving a portion of the channel available for other components, as discussed above. 
     Roller  1106  occupies the second channel, in this figure on the left. Roller  1106  comprises a single cylindrical section. The single cylindrical section is received within the second channel. The single cylindrical section is configured to roll against either side inner surface of the channel. The diameter of the single cylindrical section may be at least 0.005″ smaller than the distance between the side inner surfaces, and at least 0.75″ greater than the distance between the second inner surfaces of the flanges. This is advantageous in preventing the roller from being pulled out of the channel. 
     In embodiments, rollers with portions captured within the channel may be installed at the end of a beam, or may be formed of multiple pieces which may be inserted through the opening between the end flanges and assembled within the channel. 
       FIGS. 12A and 12B  show exemplary roller assemblies, each comprising multiple rollers. Roller assemblies  1202  and  1204  in the first and second channels comprise two roller wheels  1206  which attach to an attachment stem  1208  which extends through the opening and is configured to attach to external devices, for example the arm of a car lift, an elevator cabin, or a sliding door. The roller wheels are positioned between the third portions of the flanges and the back inner surfaces of the channel, and depending on the orientation of the beam and/or load on the attachment stem, will roll on either the third portion or the back inner surface. 
     Roller assembly  1210  is positioned in the third channel and comprises a guide  1212  similar to the free guide shown in  FIG. 8A  and further comprises rollers  1214  positioned on either side of the second channel in the inward corners defined by the outer side surfaces of adjacent channels. The rollers are configured to roll against the outer side surfaces. 
     Roller assembly  1216  is positioned in the fourth channel and comprises a guide  1218  similar to the trapped guide shown in  FIG. 9A , which is captured within the channel. The roller assembly  1216  further comprises rollers  1220  positioned on either side of the second channel in the inward corners. The rollers are configured to roll against the outer side surfaces. 
     In embodiments, carrier brackets may be coupled to a plurality of guides and a plurality of rollers engaging a plurality of surfaces of a plurality of channels. For example,  FIGS. 13A and 13B  show a roller assembly  1302  including rollers  1304  and guides  1306  configured to be received in a plurality of the channels of a beam. As shown the roller assembly  1302  comprises a u-shaped bracket  1308 . The guides  1306  are received in three of the four channels. The rollers  1304  include a first pair configured to roll against the outer side surface of the third and fourth channels in the inward corners adjacent to the first channel and a second pair configured to roll against the outer side surfaces of the second channel. As shown, the pairs of rollers have perpendicular axes of rotation which is beneficial in providing alignment and load support in various loading conditions from various directions. Similarly, the guides of the roller assembly  1302  provide a plurality of surfaces facing different directions and contacting complementary surfaces of the beam to also provide alignment and load support in various loading conditions from various directions. 
       FIGS. 14A and 14B  show a roller assembly  1402  including rollers  1404  and guides  1406  configured to be received in a plurality of the channels of a beam. As shown the roller assembly  1402  comprises a u-shaped bracket  1408 . The guides  1406  are received in three of the four channels. The rollers  1404  are configured to roll against the outer side surfaces of the second channel. The guide  1406  in the third channel is attached to a linear actuator  1410 . 
     The guides, rollers, and assemblies shown herein are exemplary embodiments, and in other embodiments, any combination of the rollers, guides, brackets and actuators may be used with any of the beams including the channels as disclosed herein. 
     In embodiments beams may include any number of channels. For example, a beam may have one, two, three or more channels. As disclosed above, in embodiments each of the plurality of channels of a beam may each have the same depth or a different depth than other channels of the same beam.  FIGS. 16A-16H  show cross sections of embodiments of beams.  FIG. 16A  shows a beam with three channels including two deep channels opposing each other with one shallower channel on the side to form a T-shaped cross section. This configuration may be used with two linear actuators in the deeper channels.  FIG. 16B  shows a beam with three channels including one deep central channel and two shallower channels on either side of the central channel to form a T-shape cross section. This configuration may be used with a single linear actuator in the deeper channel coupled to a carrier bracket with guides and/or rollers engaging surfaces of the shallower channels.  FIGS. 16C, 16D and 16E  show a four channel and a three channel cross section with varying wall thickness. In embodiments, flanges may be tubular and provide circular cross sectioned rolling surfaces, for example as shown in  FIG. 16F . 
     In embodiments a beam may include a single channel, for example as shown in  FIG. 16G , which provides the benefits of the rolling and gliding surfaces as discussed above. The single channel may be of any depth and may be sized to accommodate a linear actuator.  FIG. 16H  shows a beam with two opposing channels. The channels as shown are the same depth but in embodiments may be different depths. 
     In embodiments, in addition to the channels the cross sections of beam may include a hollow cavity, for example as shown in  FIGS. 16I-16L . The structures surrounding the hollow cavities give the beam additional strength to resist bending a buckling without adding excess additional weight. In embodiments, the hollow cavity may include a circular truss to provide additional strength, for example as shown in  FIGS. 16M-P . 
     While the channels shown in the figures are generally oriented at 90 and 180 degrees relative to adjacent channels, in embodiments adjacent channels may be positioned at any orientation from 0-180 degrees. 
     In embodiments, the beams as disclosed herein may be used in systems for sliding equipment, such as a toolbox or work table in and out of a truck bed in an utility truck, loading and unloading ladders and racks on top of work trucks, home or commercial elevators, guides for linear rolling movement in any direction (e.g. vertical, horizontal, diagonal), structural framing, automatic sliding doors (e.g. for gated communities or commercial buildings), guiding devices for window blinds, and garage door opening systems. 
       FIG. 17  shows a schematic view of a system  1700  comprising a plurality of beams  1710 - 1 ,  1710 - 2 ,  1710 - 3 , and  1710 - 4 . The beams may be any of the cross-sections described above. For clarity purposes the beams are depicted as rectangular prisms, however the beams may be any of the configurations described above. 
     Between the vertical beams  1710  are horizontal lifting shafts  1720 . The horizontal lifting shafts may be beams as disclosed herein, as wells as other type of beams, tubing and structures capable of being suspended by the ends. The horizontal lift shafts may be parts of components that are lifted, for example toolboxes, ladder racks, elevator cabins, forklifts, car lifts, stage risers, adjustable beds, desks, or chairs. The horizontal lifting shafts  1720  may be coupled to the vertical beams  1710  with carrier brackets as described in various embodiments above. For clarity purposes the carrier brackets are not shown in  FIG. 17 . One or more of the channels of any of the vertical beams  1710  may include a linear actuator coupled to the carrier brackets in order to raise and lower the carrier brackets and horizontal lift shafts, as indicated by the arrows  1730 . The vertical beams may be coupled to each other with support braces (not shown) and in embodiments the support braces may couple to the vertical beams with couplings engaging the channels. 
     In embodiments linear actuators in a plurality of beams may be mechanically synchronized to a single powered motor or multiple powered motors. For example a single motor may be coupled to acme screws in two or more of the beams. Rotating the motor causes a mechanical linkage to simultaneously rotate each acme screw causing carrier brackets coupled to the acme screws to raise or lower in unison. In embodiments, for example as shown in  FIG. 18A  a linear actuator may be directly coupled to a carrier bracket of one of the beams and the carrier bracket may be linked with pulleys  1810  to carrier brackets in other beams so that each carrier bracket raises and lowers in unison. 
     In embodiments, for example as shown  FIG. 18B , a component to be lifted, for example a toolbox  1820 , may be coupled to two vertical beams  1830  with carrier brackets  1840  as described above. Each beam  1830  may include a linear actuator with a motor  1850 . The motors may be mechanically coupled with a shaft  1860  in order to synchronize the raising and lowering of the carrier brackets so that the toolbox is always horizontal while being vertically translated. 
       FIGS. 19 and 20A -D show an embodiment including four beams that are in a utility trucked bed configuration.  FIG. 19  shows the assembly without the utility truck for clarity. As shown, the assembly  1900  includes four vertical beams  1910  in a rectangular configuration corresponding to the four corners of the truck bed. The tops of the four beams may be connected with two running rails  1912  extending in the direction of the length of the utility truck. Further, stationary cross bars  1914  may extend between the running bars.  FIGS. 20A-D  shows the assembly  1900  installed in a utility truck  2000 . The bottoms of the beams may be fastened to the truck bed with mounting brackets. 
     In embodiments, the assembly may include one or two toolboxes  1940  extending along the sides of the truck bed between two of the vertical beams  1910 - 2   1910 - 3 . The toolboxes  1940  are coupled to carrier brackets on either end of the toolbox. The carrier brackets are slidably coupled to one or more channels of the beams  1910 - 2   1910 - 3 , for example as discussed above regarding guides and rollers. One or both of the carrier brackets is coupled to a linear actuator disposed in one of the channels of the beams  1910 , as shown for example in  FIGS. 7A, 7B, 10A, 10B, 14A and 14B . A controller is connected to the linear actuators allowing a user to selectively cause toolboxes  1940  to be raised and lowered.  FIG. 20A  shows a lowered position of the toolboxes  1940 . As shown, the toolboxes  1940  are stowed so at least a lower portion is below the rim of the truck bed. The door of the toolbox  1940  may be on the side that faces the side of the truck bed so that when in the lowered position tampering of the door is prevented because it is blocked by the side of the truck bed, as shown in  FIG. 20A . This is gives additional security compared to a lock alone of preventing theft of tools from the toolbox.  FIG. 20B  shows a raised position of the toolboxes  1940 . In the raised position the bottom portions of the toolboxes are raised above the rim of the truck bed so that the door of the tool box is accessible. 
     In embodiments, assemblies may include ladder racks with ladder lifts. The ladder racks and lifts allow a user to lean a ladder  2010  against the stationary middle crossbar  1914  of the ladder rack and the assembly automatically lifts the ladder  2010  to a stowed horizontal position. As shown in  FIG. 19 , the assembly may include an aft crossbar  1916  coupled to the aft vertical beams  1910 - 1   1910 - 2 . The aft crossbar  1916  is coupled to one of more linear actuators in channels of the vertical beams  1910 - 1   1910 - 2  with carrier brackets for example as disclosed above and shown in  FIGS. 7A, 7B, 10A, 10B, 14A and 14B . The linear actuators can raise and lower the aft crossbar  1916 . As shown in  FIG. 20C , the aft crossbar  1916  may be in a lowered position. In the lowered position a user is able to place a ladder  2010  at an angle onto the aft crossbar  1916  and the mid crossbar  1914 . The aft crossbar  1916  may be raised as shown in  FIGS. 20A and 20B  so that the ladder  2010  is in a raised horizontal position. This is beneficial to conventional methods of raising a ladder onto a stationary rack of a truck wherein a user would manually lift the ladder onto a stationary rack. 
     In embodiments, the ladder rack and toolboxes may each be independently controlled to be raised and lowered with the controller actuating dedicated linear actuators for each component. In embodiments two of more the components may be synchronized either mechanically or electrically. For example, the linear actuators and controller may be configured to raise and lower the toolboxes simultaneously, and may also be configured to raise and lower the ladder rack independently of the toolboxes. In embodiments the linear actuators and controller may be configured to raise the toolboxes  1940  to an accessible position while simultaneously lowering the aft crossbar  1916  of the ladder rack to a position where the ladder  2010  is accessible, for example as shown in  FIG. 20C . In this configuration the synchronization translates different components of the system in opposite directions. This is beneficial because the ladder is accessible in the lowered position while the toolboxes are accessible in the raised position. In embodiments a single powered linear actuator is mechanically linked to raise and lower all of the components in the same or opposite directions simultaneously. 
     In embodiments, assemblies may be configured for the vertical beams to be in non-rectangular configurations. For example,  FIGS. 21A and 21B  show an elevator assembly including four vertical beams  2110  in a triangular configuration.  FIG. 21B  shows a top view of the elevator assembly. A shown, the beams  2110  may have four channels, for example as shown in  FIGS. 5 and 6 . However, in embodiments, the beams  2110  may have other numbers of channels. Horizontal lifting beams  2120 , for example as discussed above, may form triangular lifting platforms. The horizontal lifting beams  2120  are coupled to channels of the beams  2110  with carrier brackets, as disclosed above. An elevator cabin  2130  is coupled to each of the horizontal lifting beams  2120 . Linear actuators may be disposed within channels of one or more of the beams  2110 , for example as shown in  FIGS. 7A, 7B, 10A, 10B, 14A and 14B . The linear actuators may be synchronized to a single motor  2140 . Actuating the linear actuators causes the elevator cabin  2130  to translate vertically along the channel of the beams. In embodiments, three vertical beams may be used in place of four vertical beams in a triangular configuration. For example in place of read vertical beams  2110 - 3  and  2110 - 5  a single rear vertical beam may be used. The rear vertical beam may include linear actuators in multiple channels of the rear vertical beam that are each coupled to a different horizontal lifting beam  2120  and are mechanically synchronized with linear actuators in channels of the forward beams  2110 - 1  and  2110 - 2 . 
     From the foregoing, it will be appreciated that specific embodiments of the invention have been described herein for purposes of illustration, but that various modifications may be made without deviating from the spirit and scope of the various embodiments of the invention. Further, while various advantages associated with certain embodiments of the invention have been described above in the context of those embodiments, other embodiments may also exhibit such advantages, and not all embodiments need necessarily exhibit such advantages to fall within the scope of the invention. Accordingly, the invention is not limited, except as by the appended claims. 
     While the above description describes various embodiments of the invention and the best mode contemplated, regardless how detailed the above text, the invention can be practiced in many ways. Details of the system may vary considerably in its specific implementation, while still being encompassed by the present disclosure. As noted above, particular terminology used when describing certain features or aspects of the invention should not be taken to imply that the terminology is being redefined herein to be restricted to any specific characteristics, features, or aspects of the invention with which that terminology is associated. In general, the terms used in the following claims should not be construed to limit the invention to the specific examples disclosed in the specification, unless the above Detailed Description section explicitly defines such terms. Accordingly, the actual scope of the invention encompasses not only the disclosed examples, but also all equivalent ways of practicing or implementing the invention under the claims. 
     The teachings of the invention provided herein can be applied to other systems, not necessarily the system described above. The elements and acts of the various examples described above can be combined to provide further implementations of the invention. Some alternative implementations of the invention may include not only additional elements to those implementations noted above, but also may include fewer elements. Further any specific numbers noted herein are only examples; alternative implementations may employ differing values or ranges, and can accommodate various increments and gradients of values within and at the boundaries of such ranges. 
     References throughout the foregoing description to features, advantages, or similar language do not imply that all of the features and advantages that may be realized with the present technology should be or are in any single embodiment of the invention. Rather, language referring to the features and advantages is understood to mean that a specific feature, advantage, or characteristic described in connection with an embodiment is included in at least one embodiment of the present technology. Thus, discussion of the features and advantages, and similar language, throughout this specification may, but do not necessarily, refer to the same embodiment. 
     Furthermore, the described features, advantages, and characteristics of the present technology may be combined in any suitable manner in one or more embodiments. One skilled in the relevant art will recognize that the present technology can be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments of the present technology. 
     Any patents and applications and other references noted above, including any that may be listed in accompanying filing papers, are incorporated herein by reference. Aspects of the invention can be modified, if necessary, to employ the systems, functions, and concepts of the various references described above to provide yet further implementations of the invention. 
     Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise,” “comprising,” and the like are to be construed in an inclusive sense, as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to.” As used herein, the terms “connected,” “coupled,” or any variant thereof means any connection or coupling, either direct or indirect, between two or more elements; the coupling or connection between the elements can be physical, logical, or a combination thereof. Additionally, the words “herein,” “above,” “below,” and words of similar import, when used in this application, refer to this application as a whole and not to any particular portions of this application. Where the context permits, words in the above Detailed Description using the singular or plural number may also include the plural or singular number respectively. The word “or,” in reference to a list of two or more items, covers all of the following interpretations of the word: any of the items in the list, all of the items in the list, and any combination of the items in the list. 
     Although certain aspects of the invention are presented below in certain claim forms, the applicant contemplates the various aspects of the invention in any number of claim forms. Accordingly, the applicant reserves the right to pursue additional claims after filing this application to pursue such additional claim forms, in either this application or in a continuing application.