Abstract:
Conveying systems and methods in which a series of inflatable bladders are inflated and deflated in such a way as to convey objects in given directions.

Description:
REFERENCE TO RELATED APPLICATION 
     The present application is the subject of provisional application Serial No. 60/180,122 filed Feb. 3, 2000 entitled BLADDER CONVEYOR. 
    
    
     BACKGROUND AND BRIEF DESCRIPTION OF THE INVENTION 
     The present invention relates to conveying systems and methods in which a series of inflatable bladders are inflated and deflated in such a way as to convey objects in given directions. 
     There is a need for multi-celled air pads/mattresses (mat) which can be configured to be capable of conveying themselves relative to the supporting surface or alternatively conveying resting objects to move relative to the mat. 
     In this invention, there are two general conveying principles that apply, one to convey objects smaller than a wave length of a bladder array and the other for larger-than-wave-length objects. However, both involve the sequential inflation and deflation of adjacent air cells in a wave pattern. 
     In a first embodiment of the invention a conveyor or transporter is provided for moving an object smaller than a predetermined dimension in a given direction. A plurality of elongated, inflatable bladder elements in parallel array, each bladder element has an elongated axis which is transverse to the given direction, there being an X group of the bladder elements connected to a first source of air, a Y group of the bladder elements to a second source of air, and a Z group of the bladder elements connected to a third source of air. A control unit for pulsing the first, second and third sources of air to thereby sequentially and rhythmically inflate and deflate the X, Y and Z groups of bladder elements to thereby move the object in the given direction. 
     In a second embodiment of the invention a conveyor or transporter is provided for moving an object larger than a predetermined dimension in a given direction. A plurality of elongated, inflatable bladder elements in parallel array, each bladder element has an elongated axis which is transverse to the given direction, there being an X group of the bladder elements connected to a first source of air, a Y group of the bladder elements connected to a second source of air, and a Z group of the bladder elements connected to a third source of air. A flexible member joined to each of the bladder forms an object conveying surface, and a control unit for pulsing the first, second and third sources of air to thereby sequentially and rhythmically inflate the X, Y and Z groups of bladder elements to epitroichardly raise and lower points on the object conveying surface and move the object in the given direction. 
     Thus, the object of the invention is to provide bladder conveyor systems and methods for moving objects smaller and/or larger than predetermined dimensions related to the wavelength of the spacing between the bladder elements. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above and other objections, advantages and features of the invention will become more apparent when considered with the following specification and accompanying drawings wherein: 
     FIGS. 1A shows the movement of a locus of a single point on a bladder, and FIGS. 1B and 1C show the wave at two different times and is progressive to the left, 
     FIG. 2 is a visualization of the path described by a point on the circumference of a circle as it rolls along a line, 
     FIG. 3 shows the wave can be generated by the sequential inflating and deflating of an array of fluid air bladders comprising a mat if the bladders are properly interconnected, and 
     FIG. 4 is a schematic illustration of a fluidic circuit used for inflating the bladders in a given sequence. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Conveying Smaller-Than-Wavelength Objects 
     Referring to FIGS. 1A,  1 B and  1 C, the first embodiment involves stand-alone bladders  10 - 1 ,  10 - 2 ,  10 - 3  . . .  10 -N which are not physically interconnected. As they are caused to sequentially inflate and deflate, a point on the bladder  10  will rise and fall in a vertical straight line as shown in FIG.  1 A. 
     In FIGS. 1B and 1C, the wave is shown at two different times and is progressing to the left. During the time between FIG.  1 B and FIG. 1C, the wave has progressed one bladder width. The peaks P and troughs T have moved and therefore could convey objects smaller than a wave length, say liquid or small objects, i.e. stones, sand, balls, etc. But it would not convey a plank, for instance, that was greater in length than a wave length and placed lengthwise across two peaks P. The reason the plank would not convey is that the points of the bladder touching the plank rise and fall in a vertical line, i.e., no motion is imparted to the plank in a lengthwise (horizontal) direction. 
     Conveying Larger-Than-Wavelength Objects 
     Perhaps the most familiar but the more complicated principle is the epitrochoidal wave commonly seen as ocean waves. This familiar wave form can be more technically visualized as the path inscribed by a point A on the circumference of a circle as it rolls along a line as shown in FIG.  2 . 
     This circular motion of any given point A on the line can be observed if one carefully watches a floating object&#39;s path as the ocean wave passes. 
     As shown in FIG. 3, this epitrochoidal wave can be generated by the sequential inflating and deflating of an array of air bladders B 1 , B 2 , B 3 , B 4 , B 5  . . . BN comprising a mat  15  if the bladders are properly interconnected by a flexible member FM preferably connected to the bladders and having an object conveying surface OCS. 
     Consider a segment of the mat  15  having a wavelength&#39;s worth of bladders N (eight in the illustrated example of FIG. 3) proportionally inflated to create the wave shape shown in FIG. 3. A cover (conveying surface OCS) is attached to the tops of the bladders B 1 , B 2 , B 3  . . . BN. Then, as indicated by the arrows, consider the individual bladders to be inflating or deflating so as to cause the wave to progress to the right. Each of the individual points to which the top cover OCS is attached courses through a circular (or elliptical) path as the wave goes through. This approximately circular motion will impart, through friction, motion to an object situated on top of the mat FM (shown as a locus of points at the center bladder). 
     A fluidic method may be used to provide the control and appropriate switching of the air to the bladders to provide the wave motion. Such a fluidic circuit is shown in FIG.  4 . 
     The fluidic switches  15 ,  16 ,  17  are NOR elements to minimize the required plumbing. The preferential side is accomplished by skewing the power nozzle PN, which are supplied with fluidic under pressure from a pump P. The switching sequence is numbered 1 through 6 (e.g. the circled number in the output lines) at the elements and correspond to the hookup to the bladders. The sequencing is caused by the output of switch  15  being connected to a control port on switch  16 ; an output of switch  16  is connected to a control port of switch  17 ; and, an output of switch  17  is connected to a control port on switch  15 . 
     The fluidic switch elements  15 ,  16 ,  17  have vented output receivers (not shown). Other fluidic circuits could be used but this one is preferred because of the minimal connections required. 
     It will be appreciated that a system of mechanical valves can be used to sequentially inflate and deflate the bladders in place of the fluidic elements. 
     More on the uses of the conveying bladder of the epitrochoidal type: Since the orbital motion of surface points is present with this type of conveyor, there are many possible modes of usage. In addition to conveying objects smaller than one wavelength, the mat is capable of conveying itself with respect to its supporting surface, a feature that could be used to position the mat into hard-to-reach places such as to move under a refrigerator, for instance. Then the mat could be further inflated so as to lift the refrigerator, and a second mode activated to convey the refrigerator relative to the mat if the mat were secured to the floor—or convey the mat and refrigerator relative to the floor if the mat were attached to the refrigerator. 
     In a patient-care situation, the new capability could be used to move that mat onto a bed. If the mat is secured to the bed it can be used to transport the patient without any other help. Or if the patient were held and the mat secured to the bed, the bed clothing could be conveyed from under the patient without resorting to the normal double roll of the patient. 
     While the invention has been described in relation to preferred embodiments of the invention, it will be appreciated that other embodiments, adaptations and modifications of the invention will be apparent to those skilled in the art.