The present invention relates generally to the field of supports for low friction bearings. More particularly, the present invention relates to a leveling shoe assembly and method, for incorporating a gas or liquid bearing.
During the manufacture and assembly of large pieces of machinery, it is often necessary to accurately position or hold a work piece in an aligned position for proper mating. This is particularly true when assembling very large scale equipment or parts, such as an airplane engine to a wing frame. For such heavy equipment it is sometimes very difficult to make adjustments in the horizontal and vertical positioning without engaging very sophisticated and often imprecise and cumbersome positioning machinery such as, for example, cranes, hydraulic lifts, or wheel castering system. Therefore, the simple procedure, for example, of moving the bolt hole of a large piece of equipment into alignment with the mating bolt hole can sometimes involve tedious, time consuming, and/or very expensive adjustment procedures.
One approach to addressing this difficulty has been the use of air bearings which use a principle of lift similar to that of a hovercraft. Air bearings utilize an inflatable “donut-shaped” air bag which creates an air pocket with a “leaking” film of air between the assembly floor and a platform above the air bearing, which platform operates to support the object being moved. The suspending force of the air flow from the air pocket eliminates the need for any direct physical contact between the floor and supported object. Since the leaking film of air acts as a fluid with a very low coefficient of friction, the frictional forces are very low and the supported object can be moved along its lateral axes with very little physical force. Accordingly, by virtue of air bearings, heavy objects can be conveniently moved over an assembly floor by hand.
The operation and requirements of air bearings are well known in the art and descriptions regarding such can be found for example, in literature associated with the products of AeroGo, Inc. of Seattle, Wash. (see www.aerogo.com) the text of which is incorporated herein in its entirety, or Air Film Corp., also of Seattle, Wash. AeroGo has also demonstrated a water bearing for moving ship structures. Therefore, alternate forms of bearings using a non-ambient gas film or liquid film are available in the industry as substitutes for an air bearing. Likewise, polytetrafluoroethylene, Teflon®, or Delrin AF, with or without a fluid interface, are commonly used in the industry as low friction bearings.
It is well known, however, that the successful operation of an air bearing such as described above benefits from a floor surface that is both level and smooth. Otherwise, the air bearing can sometimes leak in an unsymmetrical manner around the non-level area of the floor, which can cause the air bearing to tilt or fail. Unfortunately, achieving a suitably level, smooth floor can involve the smoothing and leveling of the floor surface with fillers and/or the process of terrazzo grinding, which can entail of substantial sum of money, as well as the attendant maintenance costs. The added cost of obtaining a level and smooth floor has been a deterrent to the wide-spread use of air bearings in the industry.
Accordingly, there exists a need for systems and methods for a mechanism that has the advantages of an air or low friction bearing, but does not necessarily require a perfectly level and smooth floor.
The foregoing needs are met, to a great extent, by the present invention, wherein in one aspect an apparatus and method is provided that in some embodiments facilitates the support for movement of objects using low friction bearing assembly which is able to accommodate at least to some extent non-level floor surfaces.
In accordance with one aspect of the present invention, a leveling bearing support device is provided that has a platform with a first surface area adapted to support a low friction bearing. At least one adjustable leveler that at least partially supports the platform and is adjustable to adjust a level condition of the platform, and at least one level measurement device that measures a level condition of the platform is provided.
In accordance with another aspect of the present invention, a support system for supporting an item is provided having platform with a first surface area. At least one adjustable leveler that at least partially supports the platform and is adjustable to adjust a level condition of the platform is provided. At least one level measurement device that measures a level condition of the platform, and a low friction bearing disposed on said platform and resting on the first surface area is provided.
There has thus been outlined, rather broadly, certain embodiments of the invention in order that the detailed description herein may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional embodiments of the invention that will be described below and which will form the subject matter of the claims appended hereto.
In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of embodiments in addition to those described and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein, as well as the abstract, are for the purpose of description and should not be regarded as limiting.
As such, those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.
The invention provides in some embodiments apparatus and methods that facilitate the support and movement of objects using an air bearing assembly. Preferred embodiments of the invention will now be described with reference to the drawing figures, in which like reference numerals refer to like parts throughout. The following figures provide illustrations of embodiments in accordance with the present invention which demonstrate systems and methods for facilitating the movement and alignment of objects for example over non-level or unsmooth floor surfaces using air bearings with a leveling shoe assembly.
An exemplary embodiment of the present inventive low friction bearing having a leveling shoe assembly 100 is illustrated in
The substructure 110 shown in
The top of the landing pad 120 is preferably but not necessarily smooth and may be integrally formed from the metal stock or may be attached to the center of the substructure 110. For example, the landing pad 120 may be attached to the substructure 110 via a welding procedure. The landing pad 120 operates as a resting surface for the low friction bearing mechanism, which may be a conventionally available air bearing. Air bearing mechanisms such as those available from AeroGo with flow rates of 40 PSI @ 22 SCFM, for example, may be placed over the landing pad 120. Other flow-rated air bearing mechanisms may be used according to design preference. Additionally, other low friction bearing mechanisms may be used, as deemed suitable, such as, non-ambient gas bearings, polytetrafluoroethylene, Delrin AF, Teflon® surfaced bearings, or liquid bearings, etc., for example.
The restraining ring 130 operates to restrict the range of lateral movement of the bearing mechanism to prevent out-of-domain operation and to protect the bearing from damage from collateral objects. Additionally, the restraining ring 130 may be of sufficient height to operate as a secondary or primary landing pad. That is, the restraining ring 130, if desired, may be fabricated to provide structural support to the bearing mechanism in addition to or, alternatively, instead of the landing pad 120. The restraining ring 130 may also be removeably attached to the substructure 110. For example, a circular channel (not shown) may be “cut” into the upper surface of the substructure 110 to enable the restraining ring 130 to be removably secured therein.
The wheel assemblies 170 are of a lockable load/no load type and are commonly available in the industry. The wheel assemblies 170 may be attached to the substructure 110 in any number of ways, such as, for example, by being bolted, screwed, or welded. An adjustable spring 173 is provided in the wheel assemblies 170 and moderated by an adjustable screw 175 to determine the amount of suspension afforded by the spring 173. Swivelable wheels 177 are bolted or attached to the wheel assembly 170 to provide mobility for the air bearing assembly 100. The swivelable wheels 177 may be retracted or locked upward by appropriate adjustment of the adjustable screw 175 or by sufficient downward pressure placed upon the substructure 110 such as when sufficient weight is applied.
In operation, if the leveling shoe assembly 100 is placed over a non-level floor surface, the bubble levels 160 will indicate a level condition or the degree of non-levelness. To accommodate an out-of-level condition, an operator may adjust the appropriate leveling feet 150 to adjust the assembly 100 to place an upper surface of the substructure 110 within a substantially level plane as assisted by monitoring of the bubble levels 160. Adjustment of the leveling feet 150 may occur manually, for example by rotating threadably engaged leveling feet 150. Alternatively other level indicators besides visual bubble levels 160 can be implemented such as electronic level measurement devices, and the leveling feature may be implemented automatically, for example by motor driven leveling feet controlled by a controller that receives feedback from leveling indicators. Upon proper leveling of the leveling shoe assembly 110, the operator may inflate or activate the bearing mechanism and manually maneuver an object placed onto the bearing mechanism.
It should be appreciated that the elements described in this embodiment may be modified, as desired, by one of ordinary skill in the art without departing from the spirit and scope of this invention. For example, the elastic bumpers 140 in
Moreover, while the above description provides for the leveling feet 150 and the bubble levels 160 as being housed in the elastic bumper 140, other locations may be used as desired. For example, the leveling feet 150 and the bubble levels 160 may be positioned interior to the elastic bumpers 140 or, alternatively, at the median between pairs of the elastic bumpers 140.
Additionally, the landing pad 120 and restraining ring 130 are illustrated as being circular in nature. Other shapes, such as, for example, square or rectangular forms may be used. Further, the restraining ring 130 is shown as having one contiguous form, but may not necessarily be contiguous. In such case, the separate portions of the non-contiguous restraining ring 130 may be replaced or removed as desired.
The exemplary embodiment 200 of
The manifold support plate 220 is shown in
Drain holes 480 are provided to enable the draining of accumulated water or to assist in diffusing the air or effluent escaping from the bearing mechanism 430. The jack assembly 401 supports an outboard leg weldment 410. As the jack assembly 401 is operated to raise or lower the outboard leg weldment 410, the guide pin 405, which is illustrated as being inside a guide tube 415 of the outboard leg weldment 410, is constrained from movement. Since the guide pin 405 is attached to the manifold support plate 420, movement and rotation of the attached air hose 450 can be minimized, thus protecting the air hose 450 from damage.
In this embodiment, the leveling shoe substructure 520 has semi-trapezoidal shaped bumpers 530 arranged in a “points-of-a-compass-like” configuration. Circular levels 540 are positioned in the bumpers 530, which are preferably made of metal or of a similarly stiff material. Leveling feet 550 are positioned interior to the bumpers 530. The outer edge of the bumpers are provided with an access channel 535 to enable easy mounting of the levels 540. An elastic barrier may be inserted into the channels 535 to provide additional cushioning. Underneath the substructure 520 are rolling ball transfers (such as shown and described herein with reference to
At four opposing symmetric positions on the outer periphery of the aluminum tube 730, individual leveling feet 740, levels 750 and bumpers 760 are attached. In this exemplary embodiment, the leveling feet 740 are of a Carr-Lane (No. CL-8-L) type and are positioned exterior to the aluminum tube 730. The leveling feet 740 can be raised or lowered by rotating a removable crank handle 760. The upper portion of the leveling feet 740 passes through and threadably engages an annular ring 775 in the bumper 760. The annular ring 775 is secured to the bumper 760 via external Truarc snap rings 777. Alternately, the annular ring 775 may be affixed to the bumper 760 by inserting a key between the annular ring 775 and the snap rings 777 to prevent the annular ring 775 from turning.
In close proximity to the leveling feet 740 is a level 750 of a disk or dome like shape. The exemplary embodiment utilizes an Edmund scientific circular level which is recessed into the bumper 760. The exemplary embodiment of
It should be very apparent that the materials, dimensions, and configuration of the various elements shown for example in the cross sectional view of
In view of the above descriptions, it should be readily apparent to one of ordinary skill that while some of the above-described embodiments illustrate the implementation of the low friction bearing leveling shoe assembly in the context of an aircraft assembly plant, other implementations and uses of this invention, not necessarily related to the aircraft industry, are suitable for various embodiments of the invention.
The many features and advantages of the invention are apparent from the detailed specification, and thus, it is intended by the appended claims to cover all such features and advantages of the invention which fall within the true spirit and scope of the invention. Further, since numerous modifications and variations will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation illustrated and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.