Abstract:
A universal wall and bridge mounted aeration apparatus has a track extending between two distinct elevations that is coupled to a wall and bridge mount. An aeration unit is pivotally coupled to the track and has an aerator adapted to operatively at least partially submerge within and aerate a liquid. A selective mover or drive is adapted to operatively move the aeration unit along the track and thereby vary an elevation of the aeration unit. The universal wall and bridge mount supports the track and aeration unit. The universal wall and bridge mount has a first configuration for mounting to a structure such as a stationary bridge, and a second configuration for mounting to a wall. The universal wall and bridge mounted aeration apparatus may be adjusted to position the propeller after installation under the surface of the liquid through three axes of motion freedom.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit under 35 USC 119(e) of U.S. provisional application Ser. No. 61/891,384 filed Oct. 15, 2013, the entire contents incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention pertains generally to gas and liquid contact apparatus, and more particularly to such apparatus using a rotating impeller to deliver a gas at a submerged location. In another manifestation, the present invention pertains generally to liquid purification or separation with means to add a treating gas directly to the liquid through a submerged fluid inlet. In a further manifestation, a gas and liquid contact apparatus is combined with a machinery support providing an operator or actuator to facilitate installing, adjusting, and servicing the apparatus. 
     2. Description of the Related Art 
     Aeration apparatuses introduce air into a liquid. While most applications depend upon dissolving at least a portion of the oxygen contained in the air into the liquid, there are at least some applications where the mixing of the air is the important objective. For yet other applications, a gas other than air may be introduced to meet a particular need or desire. The liquid being treated will for exemplary purposes only, and not limiting the present invention thereto, often be contained in one or more ponds, lakes, wastewater lagoons, or various ones of other liquid holding tanks or reservoirs for sewage treatment plants or other diverse application. 
     Wastewater processing and aquaculture are illustrative of a few of the many applications for modern aeration apparatuses. Most commonly in wastewater processing, increased oxygen content of the wastewater increases the activity of aerobic bacteria, helping to clean and purify the wastewater before it is treated using other means, or released into the ecosystem such as through a river. In the case of aquaculture, increased oxygen content can support increased production of plant and animal species. 
     A common way to increase oxygen content is to provide an aeration unit mounted to a stationary or at least floating object. The aeration unit will typically include a motor driving a propeller. As the propeller turns, air is actively or passively mixed into the turbulent water and propelled into the water, normally at a downward and lateral angle. For most applications, several horsepower may be required for adequate aeration. For larger commercial applications, there may be a plurality of aeration units provided at different locations about a lagoon or reservoir. 
     While nearly any type of engine may find application in the aeration apparatus, most are electrically driven since, once connected to an electrical grid, there is a steady and continuous source of power, without the need for periodic refueling required by most gasoline or diesel engines. However, with the benefit of long-term, low maintenance aeration comes the need to keep an electrical motor safely and reliably connected to the electrical grid. This means that it is normally desirable to keep the aeration unit anchored or relatively stationary relative to a stationary or floating object, with the electrical components above the highest liquid level, to avoid unnecessary risks or hazards. 
     Aeration apparatus are a part of an industry that has been well-developed over the last four decades, with many advances made both by the present assignee and by others in the industry. Exemplary U.S. patents owned by the present assignee, the teachings and contents which are incorporated herein by reference, include: U.S. Pat. No. 4,240,990 by De Veau et al, entitled “Aeration propeller and apparatus”; U.S. Pat. No. 4,280,911 by Durda et al, entitled “Method for treating water”; U.S. Pat. No. 4,293,169 by Inhofer, entitled “Water bearing”; U.S. Pat. No. 4,308,221 by Durda, entitled “Apparatus for mixing a gas and a liquid”; U.S. Pat. No. 4,409,100 by Rajendren, entitled “Liquid aerating device”; U.S. Pat. No. 4,741,825 by Schiller, entitled “Mobile vortex shield”; U.S. Pat. No. 4,774,031 by Schurz, entitled “Aerator”; U.S. Pat. No. 4,806,251 by Durda, entitled “Oscillating propeller type aerator apparatus and method”; U.S. Pat. No. 4,882,099 by Durda et al, entitled “Aeration apparatus having a deicing mechanism and control circuit therefor”; U.S. Pat. No. 4,954,295 by Durda, entitled “Propeller aerator with peripheral injection of fluid and method of using the aerator”; U.S. Pat. No. 5,078,923 by Durda et al, entitled “Aeration apparatus having a deicing mechanism and control circuit therefor”; U.S. Pat. No. 5,707,562 by Karliner, entitled “Turbo aerator”; U.S. Pat. No. 5,744,072 by Karliner, entitled “Method of treating waste water”; U.S. Pat. No. 7,172,177 by Durda, entitled “Aerator”; U.S. Pat. No. 7,465,394 by Durda et al, entitled “Wastewater treatment system”; U.S. Pat. No. 7,678,274 by Durda et al, entitled “Wastewater treatment system”; U.S. Pat. No. 7,892,433 by Durda et al, entitled “Wastewater treatment system”; U.S. Pat. No. 8,110,108 by Durda et al, entitled “Wastewater treatment system”; U.S. Pat. No. 8,236,174 by Durda et al, entitled “Wastewater treatment system”; and Des 401,547 by Karliner, entitled “Aerator float”. 
     Other exemplary patents of varying relevance to aeration, the teachings and contents of each which are incorporated herein by reference, include: U.S. Pat. No. 1,343,797 by Stott et al, entitled “Aeration of sewage and other impure liquids”; U.S. Pat. No. 1,450,326 by Maitland, entitled “Apparatus for treating oils”; U.S. Pat. No. 1,505,479 by Maitland, entitled “Apparatus for treating oils”; U.S. Pat. No. 1,632,758 by Fulweiler et al, entitled “Process of purifying gas”; U.S. Pat. No. 1,639,828 by Wheeler et al, entitled “Process for treating cheese”; U.S. Pat. No. 1,745,412 by Fletcher, entitled “Aerator”; U.S. Pat. No. 1,765,338 by Jones et al, entitled “Agitator, aerator, and mixer”; U.S. Pat. No. 2,061,564 by Drake et al, entitled “Diffusion impeller deflector”; U.S. Pat. No. 2,063,301 by Durdin, Jr., entitled “Aerator”; U.S. Pat. No. 2,082,759 by Walker, entitled “Method and apparatus for treatment of sewage”; U.S. Pat. No. 2,116,023 by Gwidt, entitled “Aerator”; U.S. Pat. No. 2,194,037 by Thuma, entitled “Aerating device for liquids”; U.S. Pat. No. 2,232,388 by Ingalls et al, entitled “Froth flotation apparatus”; U.S. Pat. No. 2,243,301 by Weinig, entitled “Aeration apparatus”; U.S. Pat. No. 2,313,654 by MacLean, entitled “Apparatus for treating liquids with gases”; U.S. Pat. No. 2,410,429 by Daman, entitled “Agitation and aeration apparatus”; U.S. Pat. No. 2,433,592 by Booth, entitled “Aeration method and machine”; U.S. Pat. No. 2,515,538 by Wall, entitled “Water aerator, filter, and heater”; U.S. Pat. No. 2,590,581 by Shirley, entitled “Device for aerating water”; U.S. Pat. No. 2,609,097 by Dering, entitled “Flotation machine”; U.S. Pat. No. 2,641,455 by Poirot, entitled “Device which aerates water”; U.S. Pat. No. 2,767,965 by Daman, entitled “Dual pumping agitation”; U.S. Pat. No. 2,928,665 by Epprecht, entitled “Gas-liquid mixing apparatus”; U.S. Pat. No. 2,944,802 by Daman, entitled “Froth flotation and aeration apparatus”; U.S. Pat. No. 2,966,345 by Burgoon et al, entitled “Mixing apparatus”; U.S. Pat. No. 3,053,390 by Wood, entitled “Sewage treating apparatus”; U.S. Pat. No. 3,092,678 by Braun, entitled “Apparatus for gasifying liquids”; U.S. Pat. No. 3,108,146 by Gross, entitled “Fluid handling device”; U.S. Pat. No. 3,191,394 by Avery et al, entitled “Conservation arrangement and method”; U.S. Pat. No. 3,193,260 by Lamb, entitled “Apparatus for aerating and eliminating ice on water”; U.S. Pat. No. 3,202,281 by Weston, entitled “Method for the flotation of finely divided minerals”; U.S. Pat. No. 3,210,053 by Boester, entitled “Aerator structure”; U.S. Pat. No. 3,235,234 by Beaudoin, entitled “Apparatus for aerating water”; U.S. Pat. No. 3,278,170 by Moritz, entitled “Apparatus for placing gases and liquids into intimate contact”; U.S. Pat. No. 3,342,331 by Maxwell, entitled “Flotation machine”; U.S. Pat. No. 3,365,178 by Bood, entitled “Apparatus for agitating and aerating exposed bodies of water”; U.S. Pat. No. 3,400,918 by MacLaren, entitled “Sewage aerator”; U.S. Pat. No. 3,411,706 by Woollenweber, Jr. et al, entitled “Bearing durability enhancement device for turbocharger”; U.S. Pat. No. 3,497,185 by Dively, entitled “Aerating and cooling apparatus”; U.S. Pat. No. 3,512,762 by Umbricht, entitled “Apparatus for liquid aeration”; U.S. Pat. No. 3,572,658 by Ravitts, entitled “Floating aerator”; U.S. Pat. No. 3,576,316 by Kaelin, entitled “Apparatus for surface aeration and circulation of liquid”; U.S. Pat. No. 3,584,840 by Fuchs, entitled “Mixing device for introducing additives into a liquid”; U.S. Pat. No. 3,591,149 by Auler, entitled “Aeration apparatus”; U.S. Pat. No. 3,614,072 by Brodie, entitled “Hydraulic flow inducer”; U.S. Pat. No. 3,620,512 by Muskat et al, entitled “Aerating apparatus”; U.S. Pat. No. 3,640,514 by Albritton, entitled “Aeration”; U.S. Pat. No. 3,650,513 by Werner, entitled “Aeration device”; U.S. Pat. No. 3,669,422 by Nogaj, entitled “Aeration apparatus”; U.S. Pat. No. 3,680,845 by Carlsmith et al, entitled “Aerating apparatus and method”; U.S. Pat. No. 3,739,912 by Miller, entitled “Screening and aerating concentrator”; U.S. Pat. No. 3,755,142 by Whipple, entitled “Process and apparatus for the purification of a natural body of water”; U.S. Pat. No. 3,768,788 by Candel, entitled “Liquid aeration method and apparatus”; U.S. Pat. No. 3,775,307 by McWhirter et al, entitled “System for gas sparging into liquid”; U.S. Pat. No. 3,776,531 by Ebner et al, entitled “Apparatus and propeller for entraining fluids in liquids”; U.S. Pat. No. 3,778,233 by Blough et al, entitled “Apparatus for liquid composting”; U.S. Pat. No. 3,782,702 by King, entitled “Apparatus for mixing and treating fluids”; U.S. Pat. No. 3,794,303 by Hirshon, entitled “Method and apparatus for aerating bodies of water”; U.S. Pat. No. 3,797,809 by Sydnor, entitled “Aerator apparatus”; U.S. Pat. No. 3,829,070 by Imants et al, entitled “Gasification system”; U.S. Pat. No. 3,836,130 by Johnson et al, entitled “Liquid aerating apparatus”; U.S. Pat. No. 3,840,457 by Wilson, entitled “Method and apparatus for treating animal waste”; U.S. Pat. No. 3,846,292 by Le Compte, Jr., entitled “Ejector aerated oxidation ditch for waste treatment”; U.S. Pat. No. 3,893,924 by Le Compte, Jr. et al, entitled “Aerobic lagoon waste treatment system and method”; U.S. Pat. No. 3,975,469 by Fuchs, entitled “Device for revolving liquids and supplying gas thereto”; U.S. Pat. No. 3,984,323 by Evens, entitled “Apparatus for purifying polluted water”; U.S. Pat. No. 4,045,522 by Nafziger, entitled “Animal waste treatment system”; U.S. Pat. No. 4,051,035 by Boschen et al, entitled “Apparatus for the aerobic treatment of liquid waste”; U.S. Pat. No. 4,066,722 by Pietruszewski et al, entitled “Apparatus for sparging gas into liquid”; U.S. Pat. No. 4,070,279 by Armstrong, entitled “Eductor for dissolving gases in liquids”; U.S. Pat. No. 4,145,383 by Randall, entitled “Slurry aeration method and apparatus”; U.S. Pat. No. 4,169,047 by Wilson, entitled “Flotation machine with mixing and aeration impeller and method”; U.S. Pat. No. 4,190,619 by Cherne, entitled “Liquid aerating rotor assembly”; U.S. Pat. No. 4,193,951 by Stanley, entitled “Water aerating device”; U.S. Pat. No. 4,207,180 by Chang, entitled “Gas-liquid reaction method and apparatus”; U.S. Pat. No. 4,216,091 by Mineau, entitled “Water aerator”; U.S. Pat. No. 4,242,199 by Kelley, entitled “Aerator apparatus”; U.S. Pat. No. 4,268,398 by Shuck et al, entitled “Sludge agitating method”; U.S. Pat. No. 4,279,753 by Nielson et al, entitled “Wastewater treatment system including multiple stages of alternate aerobic-anerobic bioreactors in series”; U.S. Pat. No. 4,288,394 by Ewing et al, entitled “Sewage aeration system”; U.S. Pat. No. 4,290,979 by Sugiura, entitled “Aeration apparatus”; U.S. Pat. No. 4,308,137 by Freeman, entitled “Water aeration and circulation apparatus”; U.S. Pat. No. 4,308,138 by Woltman, entitled “Treating means for bodies of water”; U.S. Pat. No. 4,318,871 by Mentz, entitled “Mounting ring construction for surface aerator apparatus”; U.S. Pat. No. 4,334,826 by Connolly et al, entitled “Surface aerator impeller”; U.S. Pat. No. 4,350,589 by Stog, entitled “Floating jet aerator”; U.S. Pat. No. 4,350,648 by Watkins III et al, entitled “Floating aerator”; U.S. Pat. No. 4,431,597 by Cramer et al, entitled “Horizontal mixing aerator”; U.S. Pat. No. 4,443,338 by Reid, entitled “Conversion of plug flow and complete mix aeration basins to barrier oxidation ditches”; U.S. Pat. No. 4,468,358 by Haegeman, entitled “Apparatus for mixing air and liquid”; U.S. Pat. No. 4,540,528 by Haegeman, entitled “Apparatus for mixing gas and liquid”; U.S. Pat. No. 4,587,064 by Blum, entitled “Aeration apparatus for large waters”; U.S. Pat. No. 4,676,654 by Fleckner, entitled “Agitator device”; U.S. Pat. No. 4,732,682 by Rymal, entitled “Aeration apparatus and method”; U.S. Pat. No. 4,734,235 by Holyoak, entitled “Aerator”; U.S. Pat. No. 4,741,870 by Gross, entitled “Apparatus for treatment of liquids”; U.S. Pat. No. 4,818,391 by Love, entitled “Integral Clarifier”; U.S. Pat. No. 4,842,732 by Tharp, entitled “Apparatus for aerating and mixing waste water”; U.S. Pat. No. 4,844,816 by Fuchs et al, entitled “Method of aeration at specific depth and pressure conditions”; U.S. Pat. No. 4,844,843 by Rajendren, entitled “Waste water aerator having rotating compression blades”; U.S. Pat. No. 4,909,936 by Arbisi et al, entitled “Water aerating system”; U.S. Pat. No. 4,975,197 by Wittmann et al, entitled “Orbal wastewater treatment process”; U.S. Pat. No. 4,997,557 by Andersen, entitled “Floating, mixing, aerating and decanting unit”; U.S. Pat. No. 5,011,631 by Hwang, entitled “Turbo-jet aerator”; U.S. Pat. No. 5,021,154 by Haegeman, entitled “Mixer/aerator for waste water”; U.S. Pat. No. 5,076,929 by Fuchs et al, entitled “Sewage lagoon system”; U.S. Pat. No. 5,110,510 by Norcross, entitled “Aeration and mixing apparatus”; U.S. Pat. No. 5,116,501 by House, entitled “Paddlewheel aerator drive mechanism”; U.S. Pat. No. 5,122,266 by Kent, entitled “Apparatus for advanced aquaculture life support”; U.S. Pat. No. 5,160,620 by Lygren, entitled “Method and apparatus for treating water”; U.S. Pat. No. 5,160,667 by Gross et al, entitled “Bearing protection device for liquid aerators”; U.S. Pat. No. 5,185,080 by Boyle, entitled “Process for the on-site removal of nitrates from wastewater”; U.S. Pat. No. 5,211,847 by Kanow, entitled “Denitrification methods”; U.S. Pat. No. 5,213,718 by Burgess, entitled “Aerator and conversion methods”; U.S. Pat. No. 5,223,130 by Valfrido, entitled “Device for organic neutralization and removal of phosphorus compounds present in water basins”; U.S. Pat. No. 5,275,722 by Beard, entitled “Oxidation ditch wastewater treatment and denitrification system”; U.S. Pat. No. 5,275,762 by Burgess, entitled “Aerator”; U.S. Pat. No. 5,300,261 by Von Berg, entitled “Liquid aerating apparatus”; U.S. Pat. No. 5,312,567 by Kozma et al, entitled “Complex mixer for dispersion of gases in liquid”; U.S. Pat. No. 5,316,671 by Murphy, entitled “Submersible aeration train and aeration apparatus for biological purification of sewage”; U.S. Pat. No. 5,326,459 by Hlavach et al, entitled “Wastewater treatment apparatus”; U.S. Pat. No. 5,344,557 by Scanzillo, entitled “Incubator for biological cleaning of fluids”; U.S. Pat. No. 5,354,457 by Becchi, entitled “Water treatment equipment”; U.S. Pat. No. 5,356,569 by Von Berg, entitled “Liquid aerating apparatus”; U.S. Pat. No. 5,389,247 by Woodside, entitled “Waste water treatment process”; U.S. Pat. No. 5,421,999 by Poole et al, entitled “Floating nitrification reactor in a treatment pond”; U.S. Pat. No. 5,531,894 by Ball et al, entitled “Method of treating wastewater”; U.S. Pat. No. 5,545,327 by Volland, entitled “Wastewater treatment method and apparatus”; U.S. Pat. No. 5,554,291 by Scanzillo et al, entitled “Methods and apparatus for biodegradation of polluted fluids”; U.S. Pat. No. 5,582,734 by Coleman et al, entitled “Oxidation ditch modification and automated control system for nitrogen removal and sludge settling improvements”; U.S. Pat. No. 5,741,443 by Gemza, entitled “Oxygenation of stratified water”; U.S. Pat. No. 5,795,504 by Berchotteau, entitled “Apparatus for feeding and diffusing air or another gas into a liquid”; U.S. Pat. No. 5,846,425 by Whiteman, entitled “Methods for treatment of waste streams”; U.S. Pat. No. 5,851,443 by Raj endren, entitled “Aerator with dual path discharge”; U.S. Pat. No. 5,861,095 by Vogel et al, entitled “Method and device for treating wastewater”; U.S. Pat. No. 5,863,435 by Heijnen et al, entitled “Biological treatment of wastewater”; U.S. Pat. No. 5,868,091 by Gross et al, entitled “Float mounted aerator having a work deck”; U.S. Pat. No. 5,972,212 by Hongo, entitled “Apparatus for treating organic waste water utilizing microorganisms”; U.S. Pat. No. 5,988,604 by McWhirter, entitled “Mixing impellers especially adapted for use in surface aeration”; U.S. Pat. No. 5,996,977 by Burgess, entitled “Temperature adjusted water aerator and circulation system”; U.S. Pat. No. 6,022,476 by Hausin, entitled “Water treatment process”; U.S. Pat. No. 6,050,550 by Burgess, entitled “Apparatus for aeration and bottom agitation for aqua-culture systems”; U.S. Pat. No. 6,103,123 by Gantzer, entitled “Aeration device and method for creating and maintaining facultative lagoon”; U.S. Pat. No. 6,276,670 by Jacobs, entitled “Combined mixer-aerator”; U.S. Pat. No. 6,325,842 by Caldwell et al, entitled “Method and apparatus for aerating”; U.S. Pat. No. 6,328,289 by Becchi, entitled “Device for treating water in a basin”; U.S. Pat. No. 6,348,147 by Long, entitled “Fluid flow system for floating biological contactor”; U.S. Pat. No. 6,514,410 by Gantzer, entitled “Odor control apparatus for facultative lagoon”; U.S. Pat. No. 6,821,426 by Hausin et al, entitled “Process for treating a body of water”; and U.S. Pat. No. 7,008,538 by Kasparian et al, entitled “Single vessel multi-zone wastewater bio-treatment system”. 
     A variety of support anchors and floats are illustrated in the aforementioned patents, and these support anchors and floats have generally performed quite well over the years. Nevertheless, historically these mounts for aeration units were custom-created for each application. This is costly and time-consuming, and the aeration apparatus, anchors and floats cannot readily be adjusted after installation. Where the liquid body to be treated is irregular, large, or complex, even the best of planning and design may yield less than optimal results. This in turn then requires that the aeration apparatus most preferably be adjustable, to allow the system to be fine tuned to achieve desired optimal results. 
     In addition to system adjustment and tuning, installation can also be challenging for some of the existing support anchor and float designs. An aeration support will preferably be mounted out of the liquid, thereby permitting the support to be installed dry. Dry installation is safer not only due to the hazards of electrical machinery and water, but also due to the increased risk of personnel slipping and falling on a wet and therefore more slippery surface. Similarly, machinery will from time to time require maintenance or servicing. Such maintenance is, of course, preferably also achieved out of the liquid. Consequently, there has been and still remains a need for a much more universally mounted aeration system that may be coupled to very diverse anchors and floats, that preferably permits dry installation and servicing. 
     In addition to the more relevant aeration-related patents, several additional patents showing less relevant and otherwise unrelated machine supports and the like have also been identified by the present applicants, the teachings and contents which are nevertheless incorporated by reference, including: U.S. Pat. No. 565,346 by Goodyear, entitled “Optical lantern”; U.S. Pat. No. 1,511,336 by Hoey, entitled “Adjustable mounting device”; U.S. Pat. No. 2,346,217 by Heybourne, entitled “Light support for document photographing cameras”; U.S. Pat. No. 3,164,353 by Rene, entitled “Variable pitch roof bracket”; U.S. Pat. No. 7,159,262 by Jackson, entitled “Bridge overhang bracket”; U.S. Pat. No. 7,354,323 by Mayers, entitled “Motor mount for watercraft”; U.S. Pat. No. 7,407,419 by Douglas, entitled “Outboard engine mounting assembly”; and U.S. Pat. No. 7,522,213 by Chapman, entitled “Shock and vibration isolator for a camera”. 
     In addition to the foregoing patents, Webster&#39;s New Universal Unabridged Dictionary, Second Edition copyright 1983, is incorporated herein by reference in entirety for the definitions of words and terms used herein. 
     SUMMARY OF THE INVENTION 
     In a first manifestation, the invention is a mounted aeration unit. The aeration unit has a motor and an aerator at least partially submerged within a liquid and driven by the motor. The mount has a track; at least one horizontal wall brace; and at least one vertical wall brace rigidly affixed to the at least one horizontal wall brace and extending down therefrom. At least one lower track support bar extends horizontally from adjacent a lower end of the at least one vertical wall brace. A pedestal rests on the track. A selective mover is operative longitudinally co-extensive with the track and is adapted to operatively move the pedestal relative to the track. A first bracket is affixed to the pedestal and rotatable about a vertical axis with respect thereto. A second bracket is rotatably affixed to the first bracket about a horizontal axis and supports the aeration unit thereupon. 
     In a second manifestation, the invention is, in combination, a wall and bridge mount, a track extending between two distinct elevations and coupled to the wall and bridge mount, an aeration unit pivotally coupled to the track and having an aerator adapted to operatively at least partially submerge within and aerate a liquid, and a drive adapted to operatively move the aeration unit along the track and thereby vary an elevation of the aeration unit. 
     In a third manifestation, the invention is a universal bridge and wall mounted aeration unit having a first configuration adapted to couple with a bridge defining a generally horizontal plane and a second configuration adapted to couple with a wall defining a generally vertical plane. The aeration unit has a motor, and an aerator at least partially submerged within a liquid and driven by the motor. A mount has a track; at least one horizontal wall brace; at least one vertical wall brace rigidly affixed to the at least one horizontal wall brace and that extends down therefrom; at least one lower track support bar extending horizontally from adjacent a lower end of the at least one vertical wall brace; a pedestal resting on the track; and a selective mover operative longitudinally co-extensive with the track and adapted to operatively move the pedestal relative to the track. A first bracket is affixed to the pedestal and rotatable about a vertical axis with respect thereto. A second bracket is rotatably affixed to the first bracket about a horizontal axis and supports the aeration unit thereupon. At least one detachable diagonal wall brace in the first configuration is rigidly affixed to the at least one vertical wall brace and extends at an angle relative to the at least one horizontal wall brace and extends vertically to reach a lesser vertical height than the at least one horizontal wall brace. A vertical gap is defined between the at least one diagonal wall brace and at least one horizontal wall brace which is operative to span two opposed major surfaces of a bridge in the first configuration, and in the second configuration the at least one diagonal wall brace is detached from the at least one vertical wall brace. 
     OBJECTS OF THE INVENTION 
     Exemplary embodiments of the present invention solve inadequacies of the prior art by providing an aeration unit having a motor, a propeller, and a shaft that couples the motor to the propeller. A universal mount supports the aeration unit and operatively may be affixed to a structure such as a stationary bridge or wall, and may be adjusted to position the propeller after installation under the surface of the liquid. In one embodiment, the shaft may include an opening above the liquid surface that allows for the intake of air. Under the liquid surface, another opening allows for the expelling of air. In one embodiment, suction is preferably created behind the propeller blades when the propeller begins to spin, and this suction draws air either into the shaft to then be mixed into the liquid, or in a yet further alternative embodiment draws air from the surface directly into the liquid. In another embodiment, a blower may be provided to force air into the shaft of the propeller and out through an expeller opening, with the blower thereby actively forcing air through the shaft and into the liquid. 
     The present invention and the preferred and alternative embodiments have been developed with a number of objectives in mind. While not all of these objectives are found in every embodiment, these objectives nevertheless provide a sense of the general intent and the many possible benefits that are available from embodiments of the present invention. 
     A first object of the invention is to provide an aeration apparatus and support that may be mass produced to reduce variability and cost, and which may be used in many diverse applications by mounting to a variety of structures such as bridges, walls and the like. A second object of the invention is for the support to accommodate a variety of diverse aeration units, further enabling the benefits of mass produced apparatus while also enabling precise configuration to a single particular application. Another object of the present invention is to provide a means to adjust shaft horizontal and vertical angles and propeller depth of a mounted aeration unit through a wide range, allowing for coupling to different structures; different containment area depths and geometries and contents; and different treatment designs and objectives. In a preferred embodiment, this adjustment may be made through three axes of motion. A further object of the invention is to improve the safety and convenience of installing, adjusting, servicing, and otherwise maintaining the aeration apparatus. In consideration thereof and in at least some embodiments an aeration mount is provided that may be installed above the liquid and without any submersion, and that permits a supported aeration unit to be retracted fully from a liquid basin. Yet another object of the present invention is to achieve the foregoing objectives while consuming a minimal footprint upon the surface of a wall or bridge or similar structure, thereby preserving surface area for a person to access the aeration apparatus and support. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing and other objects, advantages, and novel features of the present invention can be understood and appreciated by reference to the following detailed description of the invention, taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  illustrates a first preferred embodiment universal bridge and wall mounted aeration apparatus designed in accord with the teachings of the present invention from a perspective view and coupled to a bridge structure. 
         FIG. 2  illustrates the first preferred embodiment universal bridge and wall mounted aeration apparatus of  FIG. 1  from a side elevational view coupled to a bridge structure. 
         FIG. 3  illustrates a preferred embodiment track stop, optionally used in the first preferred embodiment universal bridge and wall mounted aeration apparatus of  FIG. 1 , from a perspective view. 
         FIG. 4  illustrates the first preferred embodiment universal bridge and wall mounted aeration apparatus of  FIG. 1  from a side elevational view and coupled to a wall structure. 
         FIG. 5  illustrates a second preferred embodiment universal bridge and wall mounted aeration apparatus from a side elevational view and coupled to a bridge structure. 
         FIG. 6  illustrates a third preferred embodiment universal bridge and wall mounted aeration apparatus from a side elevational view and coupled to a bridge structure. 
         FIG. 7  illustrates the second preferred embodiment universal bridge and wall mounted aeration apparatus of  FIG. 5  from a lower perspective view. 
         FIG. 8  illustrates the second preferred embodiment universal bridge and wall mounted aeration apparatus from a top perspective view, showing the pedestal and track in greater detail. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Manifested in the preferred embodiments, the present invention provides a universal bridge and wall mounted aeration unit  100  having an aeration unit  160  including a motor  162 , a motor electrical access panel  164 , an air or other gas inlet  168 , a propeller  170 , and a shaft  166  that couples motor  162  to propeller  170 . The universal bridge and wall mounted aeration unit  100  may operatively be affixed to a structure such as a stationary bridge  10  or wall  11 , and may be adjusted to position propeller  170  after installation under the surface of the liquid. 
     In a first preferred embodiment of the invention illustrated in  FIGS. 1-4 , universal bridge and wall mounted aeration unit  100  is comprised of: 
     a track  110  formed from two parallel long bars connected for exemplary purposes by one or more bars and in the preferred embodiment by two perpendicular bars adjacent the distal ends of the parallel long bars; 
     horizontal wall braces  112  consisting of two parallel horizontal bars and a perpendicular horizontal bar connecting the horizontal bars on one end, herein referred to as the back end; 
     two vertical bars that define vertical wall braces  114  rigidly affixed to two parallel horizontal wall braces  112  and that extend down therefrom; 
     two diagonal wall braces  116  rigidly affixed to vertical wall braces  114  comprising bars that extend upwards and backwards for exemplary purposes at an approximately 45-degree angle relative to horizontal wall braces  112  and to approximately the same horizontal distance as horizontal wall braces  112 , but which do not extend vertically to reach the same height as horizontal wall braces  112 , and thereby define a gap therebetween which spans two surfaces of a bridge  10  or other generally horizontal supporting structure, such that horizontal wall braces  112  for exemplary purposes will rest upon the top surface of bridge  10  while diagonal wall braces  116  will for exemplary purposes engage with the bottom surface of bridge  10 ; 
     lower track support bars  122  comprising for exemplary purposes two or more bars extending horizontally forward from adjacent the lower ends each of vertical wall braces  114 ; 
     additional track support bars  118  comprising for exemplary purposes two or more bars extending upwards and forward from parallel horizontal wall braces  112  and arranged so that the angle between bars  118  and vertical wall braces  114  forms for exemplary purposes an approximately 45-degree angle; 
     track  110  preferably rotatably affixed to lowest track support bars  122  and topmost track support bars  118 ; 
     diagonal track support bars  124  rigidly affixed to track support bars  122  and vertical wall braces  114 , comprising for exemplary purposes one bar on each side placed at an approximately 45-degree angle from horizontal, extending downward and forward and connecting adjacent to track support bar  122  ends; 
     optional additional track support bars  120  comprising for exemplary purposes two or more bars extending approximately horizontally forward from adjacent vertical wall braces  114  and terminating at diagonal track support bar  124 ; 
     a selective mover, which in the preferred embodiment universal bridge and wall mounted aeration unit  100  comprises a jackscrew  126  preferably longitudinally co-extensive with and longitudinally bisecting track  110 ; 
     a plate and pedestal  130  affixed to jackscrew  126  and resting on the top of track  110  and carried thereupon by one or more friction reducing members such as rollers  132  as illustrated in the preferred embodiment; and 
     two U-brackets  134 ,  136 , one U-bracket  134  preferably affixed to pedestal  130  and rotatable about a vertical axis with respect thereto, and second U-bracket  136  preferably rotatably affixed with first U-bracket  134  about a horizontal axis, U-brackets  134 ,  136  operative to further support an aeration unit  160  thereupon. 
     It is important to note that track  110  is not directly affixed to or anchored by diagonal track support bars  124 . Instead, diagonal track support bars  124  are fixed in position and anchored relative to bridge  10  or wall  11 , while track  110  may be pivoted about pintle  125  to change the slope or angle of shaft  166  into the tank, pool, water, treatment receptacle or other fluid body intended to be aerated. 
     As can be seen in  FIGS. 1-4 , preferred embodiment universal bridge and wall mounted aeration unit  100  is attached to a surface, preferably a metal or concrete bridge  10  or wall  11 ; however, another stable surface would suffice, such as an anchored floating platform.  FIG. 1  illustrates mounting bolts  117  that are preferably installed through one or more of reinforcement beams  113  to provide secure coupling to a bridge  10  or wall  11 . Reinforcement beams  113  preferably provide both a suitable site for installing mounting bolts  117  and also add strength and stability to horizontal and vertical wall braces  112 ,  114  shown in  FIG. 2 . Horizontal and vertical wall braces  112 ,  114  are preferably installed adjacent to the top and side of the attachment surface, minimizing torque forces, and are preferably rigidly affixed to each other and to the mounting surface. 
     An optional diagonal wall brace  116  best visible in  FIG. 2  provides additional stability to installation sites in which vertical wall brace  114  continues below the attachment surface, such as below a bridge  10  illustrated in  FIG. 2  or other similar more horizontal structures. In the case of a vertical wall  11  illustrated in  FIG. 4 , diagonal wall brace  116  may be unnecessary and so may be removed or not provided. Alternatively, where horizontal wall brace  112  is longer than the width of vertical wall  11  upon which brace  112  rests, then diagonal wall brace  116  may be switched from extending from vertical wall brace  114  as illustrated in  FIG. 2  to alternatively couple adjacent first alternative coupling point  127  and extend from horizontal wall brace  112  downward and forward towards and terminating against the face of vertical wall  11  spaced from vertical wall brace  114 . In this position, a gap is defined between diagonal wall brace  116  and vertical wall brace  114 , the width of the gap which would desirably match or be similar to the width of vertical wall  11 . 
     Lower track support bars  122  illustrated in  FIG. 2  are in the preferred embodiment rigidly affixed to vertical wall braces  114 . Diagonal track support bar  124  is also rigidly affixed to lowermost track support bar  122  and vertical wall brace  114 , and extends diagonally there between. This ensures that preferred embodiment universal bridge and wall mounted aeration unit  100  is stable and secure, and the arrangement allows the forces applied from mounted track  110  and aeration unit  160  to be distributed in such a way that minimizes stress to universal bridge and wall mounted aeration unit  100 . For example, the vertical forces applied to the front end of lower two track support bars  122  generates torque that could weaken the connection between track support bars  122  and vertical wall brace  114 . However, diagonal track support bars  124  provide support to counteract these torque forces. Additionally, the lateral forces applied to vertical wall brace  114  by track support bars  122  is mitigated either by diagonal wall brace  116  or by bridge  10 , wall  11  or other mounting surface. 
     As visible in  FIG. 1 , ladder supports  115  preferably further reinforce the preferred embodiment, helping to mitigate lateral forces. Additionally, these ladder supports  115  may optionally facilitate maintenance by providing surfaces for a person to step and move around upon. 
     As illustrated in  FIGS. 1-4 , track  110  is preferably pivotally secured to track support bars  122  through a pintle  125 . Movement of pedestal  130 , U-brackets  134 ,  136  and aeration unit  160  relative to track  110  is preferably controlled by a drive. The drive illustrated in the preferred embodiment is a jackscrew  126 , though other suitable apparatus are contemplated herein. For exemplary purposes only, and not solely limiting the present invention thereto, a fluid drive such as a pneumatic or hydraulic drive, a cable drive, or any other known equivalents in the mechanical arts may be used. Jackscrew  126  in the preferred embodiment begins above the top end of track  110  and terminates at a point near the bottom of track  110 . Jackscrew actuation point  128  allows jackscrew  126  to be rotated with an actuating mechanism. For exemplary purposes only, and not solely limiting the present invention thereto, this actuating mechanism may be a drill, other motor or hand crank, or any other known equivalents. When jackscrew  126  is rotated, attached pedestal  130  is moved along track  110 , the direction of movement depending on the direction of rotation of jackscrew  126 . This changes the height of attached aeration unit  160 . 
       FIGS. 1-4  also illustrate optional track stop  121 . Stop  121  preferably prevents pedestal  130  from going too low on track  110  for a particular application, either due to differing aeration or mixing effects at specific heights, as a safety feature to prevent propeller  170  from contacting the bottom of a containment area, or to otherwise limit or control the extent of travel of pedestal  130  for a particular installation. 
     Stop  121 , which is illustrated in greater detail in  FIG. 3 , comprises a generally rectangular stop body  142  with two projecting pegs  144  on the underside. These two pegs  144  preferably insert into stop holes  119  that are spaced along track  110 . The particular number or geometry of pegs  144  is not critical to the present invention, and so might for exemplary and non-limiting purposes comprise a single triangular or square peg, wherein the use of a polygonal cross-section prevents such a peg from rotating about the longitudinal axis of peg  144 . The use of more than one peg, such as two illustrated herein, also prevents rotation of stop  121 . As may be appreciated, more than two pegs  144  may be used. Furthermore, and also for exemplary purposes, any other known apparatus operative to affix and release stop  121  from track  110  may be used instead of or in addition to one or more pegs  144 . 
     A receiver  146  in stop  121  may be provided that has a coupling  148  such as internal threading as illustrated that is accessible from the top of stop  121 , as illustrated in  FIG. 3 . This receiver  146  having threading  148  allows a user to stand at the top of track  110  on bridge  10  and insert a stick, similar to a broom handle, into threading  148 , rotate the stick to secure with threading  148 , lift stop  121  out, and change which stop holes  119  stop pegs  144  are inserted into. As may be appreciated, the use of pegs  144  facilitates this, since pegs  144  will both securely hold stops  121  when pedestal  130  impinges, and pegs  144  are easily removed by a person holding the broom-handle like stick. 
     Preferably, a stop  121  is located on each side of track  110 , to provide balanced forces when pedestal  130  encounters stops  121 . While this is the preferred embodiment stop  121 , alternative stopping mechanisms may be used to prevent pedestal  130  from being lowered too far, such as a clamp, an actuating stop, or travel limits built into or controlled through features in jackscrew  126 . 
     Pedestal  130  is preferably held onto track  110  by a supporting plate to which jackscrew  126  and a plurality of rollers  132 , such as four rollers  132  illustrated for exemplary purposes in the preferred embodiment shown in  FIG. 1 , are coupled. Jackscrew  126  preferably prevents pedestal  130  from rotating or lifting off track  110 , while also positioning pedestal  130  along track  110 . Rollers  132  or other known equivalents are preferably provided to reduce friction between track  110  and pedestal  130  when jackscrew  126  is being turned. The use of an anti-friction device such as rollers  132  or other known equivalent is preferred, since the weight of aeration unit  160  can be quite substantial, and the friction that could be generated between pedestal  130  and track  110  without such an anti-friction device might otherwise lead to undesirable binding, wear, and eventual destruction. 
     As illustrated in  FIGS. 1-4 , pedestal  130  preferably provides support for an aeration unit  160 .  FIG. 2  illustrates the connection between aeration unit  160  and pedestal  130 . Preferably, an inner U-bracket  136  is rigidly affixed to aeration unit  160  on the underside of motor housing  162 , thereby desirably locating the center of mass as close to bracket  136  as is possible. Inner U-bracket  136  is preferably rotatably affixed to an outer U-bracket  134  by a connection pivotal about a horizontal axis. The pivotal connection may be any suitable pivoting connection  135  such as a ball-bearing and clamp combination, but in the preferred embodiment a simple pintle or bushing and bolts are used. Around pivoting connection  135  are preferably several bracket lock holes  137  through which bolts  138  can be inserted. Bracket lock holes  137  on inner U-bracket  136  can preferably be aligned to bracket lock holes  137  on outer U-bracket  134  in multiple ways, such that motor housing  162  can be positioned at multiple angles relative to track  110 . For exemplary purposes only, and not solely limiting thereto, in the preferred embodiment bracket lock holes  137  are positioned so that aeration unit  160  may be placed at a 38-, 45-, 50-, 55-, or 60-degree angle from vertical; however, in alternate embodiments, bracket lock holes  137  could be placed closer or farther apart in order to change the incremental difference between bracket lock holes  137 , as desired for manufacturing or installation specifications. As also noted herein above, where desired other adjustable couplings may alternatively be provided. Nevertheless, the simplicity and positive locking provided by the preferred pivoting connection  135 , bracket lock holes  137  and bolts  138  is preferred for many applications. 
     Pedestal  130  preferably contains a pedestal column  131  terminating at a pedestal top coupler  133  having lock holes that form a circle around the top of pedestal top coupler  133 . The base of outer U-bracket  134  preferably contains four pedestal lock holes, though the exact number is not critical to the present invention. This arrangement allows the base of outer U-bracket  134  to be attached to a pedestal top coupler  133  by bolts  138  inserted through holes in pedestal  130  in multiple positions, so that the horizontal orientation of aeration unit  160  about a vertical axis is adjustable by rotation about that vertical axis. The number of holes and the hole spacing is adjustable based on design, manufacturing or installation specifications. This rotatable connection secures pedestal  130  to the base of outer U-bracket  134  in order to aid in the adjustment of the horizontal angle of aeration unit  160  without allowing aeration unit  160  to accidently become disconnected from pedestal  130 . 
     The combination of horizontal and vertical angle versatility of aeration unit  160  from pedestal  130 , including bracket locking mechanisms and adjustable height through jackscrew  126  actuation allows for reduced variation between different installations, reduced design and manufacturing expenses, decreased installation costs, versatility in vertical depth operation, increased versatility in placement and orientation of an aeration unit  160 , and easier access for installation and maintenance. Different containment areas and different units have different needs in terms of propeller depth and propeller angle. The preferred embodiment can be customized at the time of installation and after installation in order to accommodate the different needs of the containment area, as may be determined to be ideal for efficacy and running costs based on the site. 
     Track  110  is preferably rotatably attached to lowest track support bar  122  by bolts or a suitable alternative pivoting connection at pintle  125 , and attached to topmost track support bar  118  by bolts or other suitable pivotal connection. This arrangement allows the bolts or other fasteners to be loosened or removed and track  110  rotated. Track  110  in the preferred embodiment illustrated in  FIG. 2  is additionally adjustable by separating topmost track support bar  118  from horizontal wall brace  112  at first alternative coupling point  127 , such as by unbolting. Next, topmost track support bar  118  is moved to a second alternative coupling point  129  at the right hand side of horizontal wall brace  112 , near to the connection between horizontal wall brace  112  and vertical wall brace  114 . By attaching track support bar  118  at this second alternative connection point, track  110  is tilted to a greater angle of inclination. 
     As may be apparent, while two alternative coupling points  127 ,  129  are illustrated for topmost track support bar  118  to horizontal wall brace  112 , one or many such connection points may be provided, depending upon the degree of adjustability of this track support angle of inclination. In an alternative embodiment further contemplated herein, top track support bars  118  may be comprised of extendible or rotatable members. For exemplary purposes only, and not solely limiting thereto, two pivotally connected bars may be used as an alternative to the illustrated single track support bar  118 . In this alternative embodiment, the two bars may hinge with respect to each other, thereby pivoting track  110  to varying angles with respect to horizontal. 
     In accord with a preferred method of use, a user can raise pedestal  130  all the way to the top by rotation of jackscrew  126  and perform maintenance from bridge  10 .  FIG. 1  also illustrates optional ladder supports  115  upon which a person can optionally stand and move around upon while performing maintenance or during installation. This accessibility and adjustability allows a user to perform installation or maintenance on universal bridge and wall mounted aeration unit  100  or on aeration unit  160  primarily from wall or bridge  10  without the use of a separate service platform and without necessitating draining of a basin or other body of liquid, saving costs and improving the safety of the maintenance and installation personnel. 
     The particular technique used to couple the various horizontal wall braces  112 , beams  113 , vertical wall braces  114 , ladder supports  115 , diagonal wall braces  116 , track support bars  118 , optional track support bars  120 , track support bars  122 , and diagonal track support bars  124  will vary depending upon the intent at the time of design. As may be appreciated, these components may be welded or otherwise permanently and rigidly coupled. However, for some applications it may be desirable to enable universal bridge and wall mounted aeration unit  100  to be shipped from manufacturing location to installation site in an only partially assembled configuration. In such instances, some of the various components may be shipped unattached, and then affixed at the installation site. In these instances, known fasteners may be used to couple the components together. For exemplary and non-limiting purposes, in one embodiment beams  113  and ladder supports  115  may be left unattached at the manufacturing location, and then coupled into the remainder of universal bridge and wall mounted aeration unit  100  using bolts or other equivalent fastener at the installation site. In a second embodiment, horizontal wall braces  112  and diagonal wall braces  116  may be left unattached at the manufacturing location, and then coupled into the remainder of universal bridge and wall mounted aeration unit  100  using bolts or other equivalent fastener at the installation site. In a third embodiment, capable of providing very compact shipping from the manufacturing location, beams  113  and ladder supports  115  may be left unattached at the manufacturing location. Horizontal wall braces  112 , vertical wall braces  114 , and track support bars  122  will preferably interconnected with each adjacent component using pintles, such as pins or other suitable equivalent. In addition, diagonal wall braces  116  and diagonal track support bars  124  may be provided with pins, allowing the entire side-wall structure to be unfolded to form a straight and linked assembled. In such instance, other potentially interfering components such as optional track support bars  120  will either be similarly pintle-attached or fastener-removable. These three shipping embodiments are presented as exemplary and illustrative, but are not limiting to the many possible configurations that may be used for packaging and shipping of the present invention. 
     While aeration units are the focus of the present invention, preferred embodiment universal bridge and wall mounted aeration unit  100  may also be used with other units that operate in the same conditions as aeration units, such as mixers and related apparatus. 
     From the foregoing figures and description, several additional features and options become more apparent. Many aeration units may be arranged in a single holding space to work concurrently and possibly compound the effect of each aeration unit  160 . Furthermore, the angles and orientations of each aeration unit  160  may readily be adjusted for optimum flow within a containment tank or pond. The preferred universal bridge and wall mounted aeration unit  100  may be manufactured from a variety of materials, including metals, resins and plastics, ceramics or cementitious materials, or even laminations, combinations or composites of the above. Nevertheless, for most applications metals may be preferable given the high forces, and the metals will preferably be either intrinsically corrosion resistant, such as is the case with aluminum and stainless steel, or may be galvanized or otherwise coated or plated to obtain necessary corrosion resistance. 
     Various additional preferred embodiments of apparatus designed in accord with the present invention have been illustrated in  FIGS. 5-8 . These second and third preferred embodiments are distinguished by the hundreds digit, and various components within each embodiment designated by the ones and tens digits. However, many of the components are alike or similar between embodiments, so numbering of the ones and tens digits have been maintained wherever possible, such that identical, like or similar functions may more readily be identified between the embodiments. Where no numbering has been provided, it will be understood that these components are identical or have like or similar function. If not otherwise expressed, those skilled in the art will readily recognize the similarities and understand that in many cases like numbered ones and tens digit components may be substituted from one embodiment to another in accord with the present teachings, except where such substitution would otherwise destroy operation of the embodiment. Consequently, those skilled in the art will readily determine the function and operation of many of the components illustrated herein without unnecessary additional description. 
     Second preferred embodiment universal bridge and wall mounted aeration apparatus  200  is illustrated in  FIG. 5  from a side elevational view coupled to a bridge structure, similar to and easily contrasted with the view of  FIG. 1 .  FIG. 7  illustrates the second preferred embodiment universal bridge and wall mounted aeration apparatus  200  of  FIG. 5  from a lower perspective view, and  FIG. 8  illustrates the second preferred embodiment universal bridge and wall mounted aeration apparatus  200  from a top perspective view, showing the pedestal and track in greater detail. In this second preferred embodiment universal bridge and wall mounted aeration apparatus  200 , pedestal  230  has a compound pedestal column  231  that extends both horizontally and vertically. In addition, outer U-bracket  234  has a slightly different geometry to accommodate slightly different aeration unit  260 . While similar to the pedestal top coupler  133 , pedestal top coupler  233  visible in  FIG. 8  also clearly shows one preferred implementation of this coupler using available locating holes  239  through which fasteners such as bolts, pins or other equivalent structures may pass to set and hold the orientation of outer U-brackets  234  and aeration unit  260  about a vertical axis of rotation. 
     A third preferred embodiment universal bridge and wall mounted aeration apparatus  300  is illustrated in  FIG. 6  from a side elevational view coupled to a bridge structure, similar to and easily contrasted with the views of  FIGS. 1 and 5 . In this second preferred embodiment universal bridge and wall mounted aeration apparatus  300 , the selective mover comprises a cable actuation point  328 , which may be used to wind and unwind a cable that may be used to raise and lower platform and pedestal  130  along track  110 , as an alternative to jackscrew  126  and jackscrew actuation point  128 . In a yet further alternative embodiment, a cable from a separate or free-standing selective mover, such as a davit, other crane or other equivalent device, may be guided by cable actuation point  328  and coupled with platform  330 . An optional safety catch  350  may be provided, which acts as a pawl or ratchet mechanism similar to that found in jacks and roller coasters to prevent platform  330  from dropping suddenly if the cable breaks or becomes unintentionally disconnected. Safety catch  350  may for exemplary and non-limiting purposes couple to any beam or ladder support or other structure extending across or within the center of track  110 , or any other structure or apparatus that may be provided therefor. 
     While the foregoing details what is felt to be the preferred embodiment of the invention, no material limitations to the scope of the claimed invention are intended. Further, features and design alternatives that would be obvious to one of ordinary skill in the art are considered to be incorporated herein. The scope of the invention is set forth and particularly described in the claims herein below.