Patent Application
20080083490
The concepts presented herein will be further explained with reference to the attached figures, wherein like structure or system elements can be referred to by like reference numerals throughout the several views.
While the above-identified figures set forth several embodiments of the present invention, other embodiments are also contemplated, as noted herein. In all cases, concepts presented herein describe the invention by way of representation and not by limitation. It should be understood that numerous other modifications and embodiments can be devised by those skilled in the art which fall within the scope and spirit of the principles of this invention.
The sensing elements 20 incorporated in the weight sensor 9 can utilize any suitable technology. For example, sensing elements 20 that approximate capacitive plates may be located on either side of the bladder 8 and as a weight is applied to the bladder 8, subsequent compression of the material within the bladder can cause a change the distance between the sensing elements 20 and a corresponding change in an output signal from the sensing elements 20. Other examples of suitable technologies for sensing elements 20 include strain gauges and inductive sensing devices. These examples are not meant to be limiting but rather are meant to be illustrative. Bladder 8, while shown in
The second sheet 12 of bladder material is positioned above the first sheet 10 of bladder material when the first and second sheets 10 and 12 are extended across the top surface 40 of bed 32. In one embodiment, the second sheet 12 is dispensed from second dispensing roll 36 across the first sheet 10. As seen in
A receiving roll 38 is disposed on the opposite side of the top surface 40 of table 32 from the first and second dispensing rolls 34 and 36. The receiving roll 38 is positioned to accept a processed portion 46 of the first and second sheets 10 and 12 (that is, portions of the first and second sheets 10 and 12 that have been processed on the bed 32 so that bladders 8 have been at least partially formed). The processed portion 46 is then rolled up onto the receiving roll 38. Receiving roll 38 includes a pair of trunnions 52 extending from opposite ends of the receiving roll. Receiving roll 38 is configured to be attached to a fixture (not shown), which can engage the trunnions 52 to pull the processed portion 46 toward the receiving roll 38 and correspondingly, pull the first and second sheets 10 and 12 from the first and second dispensing rolls 34 and 36 across the top surface 40 of bed 32.
First and second receiving rolls 34 and 36 and receiving roll 38 are shown as being positioned so as to properly position the first and second sheets 10 and 12 onto the top surface 40 of bed 32. However, the first and second dispensing rolls 34 and 36 and receiving roll 38 may not be positioned thusly, nor may positioning of the first and second dispensing rolls 34 and 36 and receiving roll 38 alone be enough to properly align first and second sheets 10 and 12 along the top surface 40. Thus, one or more positioning and or tensioning devices such as rollers (not shown) maybe positioned on either the side of the bed 32 where the dispensing rolls 34 and 36 are positioned or the side of the bed 32 where the receiving roll 38 is positioned, or both.
Once the first and second sheets 10 and 12 have been positioned onto the top surface 40 of bed 32, it is advantageous to properly secure the sheets 10 and 12 prior to processing the sheets 11 and 12 with the laser member 42. In one embodiment, bed 32 can include or be attached to a vacuum generator 45 capable of drawing a vacuum between the top surface 40 and the first sheet 10 through a series of small apertures (not shown) disposed along the top surface 40. For example, the top surface 40 can include a one inch by one inch grid of apertures having a diameter of about 1/16 of an inch disposed across the top surface 40. Other patterns and sizes of apertures can be implemented. For example, when the top surface 40 includes a honeycomb pattern as discussed above, small apertures may be formed into the walls 41. By employing a vacuum to draw the first sheet 10 to the top surface 42, the first sheet can be smoothed to reduce the likelihood of wrinkles forming into bladders 8 causing them to be improperly or inadequately sealed. In addition, the first sheet 10 can include a series of apertures (not shown) extending through it in strategic positions, that is, in areas of the first sheet 10 that will not be a part of any bladder 8, to provide a vacuum to draw the second sheet 12 onto the first sheet 10.
As mentioned above, system 30 includes a laser member 42, which is positioned above the top surface 40 of bed 32. Laser member 42 is employed to provide sufficient energy to melt the first and second sheets 10 and 12 together along a predetermined path to form at least a portion of the bond pattern 14 of each bladder 8. In addition, laser member 42 is also employed to provide sufficient energy to cut the first and second sheets 10 and 12 along at least a portion of the perimeter 17 (shown in
Referring to
Laser member 42 also includes a programmable control unit 66, which is capable of receiving programming information to control the laser member 42. For example, programmable control unit, in one embodiment, can cause the laser beam generator 60 to vary the output power of the laser beam 44 as it becomes advantageous to do so. Laser member 42 also includes a laser member positioning actuator 62, which is capable of moving the laser member 42. In one embodiment, the positioning actuator 62 is capable of moving the laser member 42 along at least a portion of the length L and the width W (as defined in
Laser member 42 also includes, in one embodiment, a vision member 64 that is capable of creating and detecting visual indicators on the first and/or second sheets 10 and 12. For example,
Laser member 42 further includes, in one embodiment, an assist gas supply/actuator 68. Assist gas can be applied during the process of generating a laser beam 44 to advantageously diffuse smoke or particles that may accrue during the process of providing a laser beam 44 to cut or melt the first and second sheets 10 and 12. By diffusing the smoke and/or particles, the welding and cutting processes can become more predictable by allowing the vision member 64, for example, to provide a more precise location of the laser member 42 as it traverses the top surface 40 of bed 32. In addition, the assist gas can apply pressure onto the second sheet 12 to assist in holding it in proper position so as to minimize wrinkles or other imperfections from being formed into the bladder 8. Programmable control unit 66, in one embodiment, is capable of controlling whether the assist gas supply 68 is to be activated as well as varying the amount and pressure of the assist gas that is supplied. Referring briefly to
As described above, in one embodiment, the top surface 40 has a length of about four feet and a width of about four feet. By contrast, one embodiment of the bladder 8 has an area of about 256 square inches. While it should be appreciated that these dimensions can vary even substantially, it should also be appreciated that a plurality of bladders 8 can fit on the top surface 40 of the bed 32 simultaneously. Accordingly, more than one bladder 8 can be formed from a portion of the first and second sheets 10 and 12 positioned on the top surface 40. Referring to
A certain amount of spoil 54 can be advantageous. For example, as can be seen, when the laser member 42 (not shown in
Once the step 102 of loading the program into the programmable control unit 66 of laser member 42 is completed, the first and second sheets 10 and 12 are applied and secured to the bed 32, as shown in block 104. As discussed above, bed 32, in one embodiment, provides a vacuum to secure the first sheet 10 and possibly second sheet 12 to the top surface 40 of the bed 32. As is shown in
Once the first and second sheets 10 and 12 have been applied and secured to the top surface 40 of the bed 32, laser member 42 is aligned to begin to traverse a path defined by melt pattern 70 for one of the plurality of bladder sites 86 as is represented by block 106. If none of the bladder sites 86 have been previously traversed, the vision member 64 of laser member 42 finds fiducial marks 50 previously placed on second sheet 12 to orient the laser member 42 with respect to the first and second sheets 10 and 12 and the bed 32. Referring additionally to
Once laser member 42 is properly positioned at the beginning 74 of the melt pattern 70, it travels the melt pattern 70 from the beginning 74 to an end 76. While the positioning actuator 62 is moving the laser member 42 along the melt pattern 70, the laser beam generator 60 generates a laser beam 44 to melt or fuse the first and second sheets 10 and 12 together to form a portion of the bond pattern 14 as is represented by block 108. Assist gas supply 68 can supply a gas to diffuse smoke and/or particles that may collect around the laser beam 44 during the melting process. In addition, the gas supplied by the assist gas supply can apply pressure to the second sheet 12 to hold the second sheet 12 in the proper position. Due to variations in the melt pattern 70 such as corners or curves, it may be necessary to vary the speed at which the positioning actuator 62 moves the laser member 42 and/or the amount of power supplied by the laser beam generator 60 to ensure that the first and second sheets 10 and 12 are properly fused together without being cut. As can be seen in
At block 110, the laser member 42 moves to beginning 78 of cut pattern 72 of the particular bladder site 86. The laser beam generator 60 is refocused and positioning actuator 62 then moves the laser member 42 from the beginning 78 to and end 80 of cut pattern 72. While travelling along the cut pattern 72, laser beam generator 60 applies a laser beam 44 of sufficient energy to cut through both the first and second sheets 10 and 12. Similar to the process described above in relation to block 108, the assist gas supply 68 can apply gas. In addition, the speed that the positioning actuator 62 moves the laser member 42 and the amount of power applied by the laser beam generator 60 can vary at various locations along the cut pattern 72. As has been described above, when the laser member 42 has traversed the entire cut pattern 72, a partially formed bladder 87 remains. The partially formed bladder 87 is not completely detached from the first and second sheets 10 and 12.
Once the laser member has melted and cut the first and second layers 10 and 12 to create a partially formed bladder 87 at the current bladder site 86, the programmable control unit 66 of laser member 42 checks to see if an additional bladder sites 86 remain on the top surface 40 had have not yet been traversed to create a partially formed bladder 87, as is represented at block 112. If it is determined that there are additional bladder sites 86 remaining to be traversed by the laser member 42 to create partially formed bladders 87 out of the first and second sheets 10 and 12 as they are currently positioned on bed 32, the laser member 42 is aligned to the beginning 74 of the melt pattern 70 at the next bladder site 85, as is represented at block 114. Then method 100 returns to block 108 to repeat the process at the next bladder site 86. If it is determined that there are no further bladder sites 86 remaining on top surface 40, the first and second sheets 10 and 12 are removed from the bed 32 as represented by block 116. It should be appreciated that although the method 100 describes a method of forming a portion of the bond pattern 14 and then cutting around a portion of the bladder at a single site 86 before moving to another bladder site, an alternative method would include forming the bond pattern 14 for a plurality of or all of the bladder sites 86 before performing the step of cutting the first and second sheets 10 and 12 at any of the bladder sites 86.
In one embodiment, removal of the first and second sheets 10 and 12 from the top surface 40 of bed 32 is accomplished by engaging receiving roll 38 to roll up the now processed material 46 from the top surface 40. Prior to rolling the first and second sheets 10 and 12 onto the receiving roll 38, however, laser member 42 moves to an edge of the bed 32 closest to the distribution rolls 34 and 36. The vision member 64 forms fiducial marks onto the second sheet 12. Once the first and second sheets 10 and 12 are rolled onto the receiving roll 38, the fiducial marks 50 shall be positioned in a location similar to that shown in
Subsequently, the partially formed bladder 87 is cut out of the first and second sheets 10 and 12 and the inner volume 16 can be filled with filler material. Once the partially formed bladder 87 has been properly filled, the gap 84 can be closed through the application of heat from any suitable source such as RF heating to finish the process of forming a bladder 8. Sensing elements 20 can then be attached to the bladder 8 if they have not already be previously attached, as described above.
The embodiments described herein provides several advantages. For example, different shapes and sizes of bladders can be manufactured without requiring the fabrication of a tooling fixture. Simply creating a different path for the laser to travel as it emits its beam, will create a different shape or size of bladder. This allows for rapid development of different sizes and shapes of bladders, as well as the ability to quickly manufacture different sizes and shapes of bladders without changing a tooling fixture. Further, as described above, multiple bladders can be simultaneously formed on the bed.
Although the present invention has been described with reference to several alternative embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and the scope of the invention.
