阅读说明：本技术 基于航天试验用高压气体储罐加工用切割机构及其方法 (Cutting mechanism and method for machining high-pressure gas storage tank based on aerospace test ) 是由 郭东伟 陈林 侯永柱 王文民 刘华锁 于 2019-10-30 设计创作，主要内容包括：本发明公开了基于航天试验用高压气体储罐加工用切割机构及其方法,涉及航天试验技术领域,航天试验用高压气体储罐加工用切割机构包括压力罐承载基座,所述压力罐承载基座的两侧端面均通过焊接方式固定设置有槽钢板,两个所述槽钢板的上、下端面均固定开设有拓位槽孔,且两个所述槽钢板的上方共同连接有压力罐切割机构,该压力罐切割机构可以借助槽钢板以及拓位槽孔在压力罐承载基座的上方移动,当操作员做出切割标记后,通过移动压力罐切割机构,让切割头准确定位被标记的切割点,该机构在移动后,不仅可以截断压力罐,还可以在压力罐的表面开孔,从而可以根据实际的需求,实现多个方式的切割处理,提高实用性。(The invention discloses a cutting mechanism for processing a high-pressure gas storage tank for an aerospace test and a method thereof, and relates to the technical field of the aerospace test, the cutting mechanism for processing the high-pressure gas storage tank for the aerospace test comprises a pressure tank bearing base, the end surfaces of the two sides of the pressure tank bearing base are respectively and fixedly provided with a slotted steel plate in a welding mode, the upper end surface and the lower end surface of the two slotted steel plates are respectively and fixedly provided with an expansion slotted hole, a pressure tank cutting mechanism is jointly connected above the two slotted steel plates, the pressure tank cutting mechanism can move above the pressure tank bearing base by means of the slotted steel plates and the expansion slotted holes, when an operator makes a cutting mark, a cutting head is enabled to accurately position the marked cutting point by moving the pressure tank cutting mechanism, after the mechanism moves, the pressure tank can be cut off, holes can also be formed on the surface of the pressure tank, so that the actual requirements can, realize the cutting of a plurality of modes and handle, improve the practicality.)

1. Based on a cutting mechanism for processing a high-pressure gas storage tank for an aerospace test, the cutting mechanism comprises a pressure tank bearing base (1), it is characterized in that two pressure tank brackets (4) are symmetrically and fixedly arranged on the top end surface of the pressure tank bearing base (1), the top end surfaces of the two pressure tank brackets (4) bear and place the pressure tank (5) together, the top surface of the pressure tank (5) is symmetrically welded and fixedly connected with two lug plates (6), the two side end faces of the pressure tank bearing base (1) are both fixedly provided with slotted steel plates (7) in a welding mode, the upper end face and the lower end face of each of the two slotted steel plates (7) are both fixedly provided with extended slot holes (8), and the upper parts of the two groove steel plates (7) are connected with a pressure tank cutting mechanism (9) together, the two side end faces in the pressure tank bearing base (1) are connected with a buffering protection mechanism (10) in a sliding mode.

2. The cutting mechanism for processing the high-pressure gas storage tank for the aerospace test according to claim 1, wherein the pressure tank cutting mechanism (9) comprises two sliding bases (91) correspondingly installed above the two channel steel plates (7), the top end surfaces of the two sliding bases (91) are welded together to form a section of cambered plate (92), hinge shafts (97) are embedded in the two ends of the section of cambered plate (92), and the two ends of the section of cambered plate (92) are correspondingly connected with a two-section cambered plate (93) and a three-section cambered plate (94) through the two hinge shafts (97).

3. The cutting mechanism for machining the high-pressure gas storage tank for the aerospace test as claimed in claim 2, wherein the first-section arc panel (92), the second-section arc panel (93) and the third-section arc panel (94) are jointly spliced to form a limiting frame with a circular structure, guide slots (95) are fixedly formed in the first-section arc panel (92), the second-section arc panel (93) and the third-section arc panel (94), and the laser cutting head (96) is slidably mounted in the guide slots (95).

4. The cutting mechanism for machining the high-pressure gas storage tank for the aerospace test according to claim 3, wherein the ends, contacting with the tops, of the two-section arc-shaped panel (93) and the three-section arc-shaped panel (94) are complementary structures, and the complementary structures are fixedly connected through bolts.

5. The cutting mechanism for machining the high-pressure gas storage tank for the aerospace test according to claim 2, wherein the sliding base (91) comprises a base bearing frame (911) arranged above the channel steel plate (7), a vertical plate (912) is fixedly connected to the upper surface of the base bearing frame (911), roller shafts (913) are fixedly mounted on two sides of the bottom of the base bearing frame (911), the roller shafts (913) are arranged inside the channel steel plate (7), and the bottom ends of the roller shafts (913) extend to the lower side of the channel steel plate (7) and are fixedly connected with limiting plates (914).

6. The cutting mechanism for machining the high-pressure gas storage tank for the aerospace test is characterized in that the buffering protection mechanism (10) comprises two slide rails (101) which are respectively connected with two inner side walls of the pressure tank bearing base (1) in a sliding manner, a base plate (102) is connected to top ends of the two slide rails (101) together, two telescopic rods (103) are symmetrically installed on a top end face of the base plate (102), a transverse rod (104) is connected between the two telescopic rods (103) together, two sliding sleeves (105) are movably sleeved on an outer section of the transverse rod (104), and a first buffer spring (106) is sleeved on the outer section of the transverse rod (104) and located between the telescopic rods (103) and the sliding sleeves (105).

7. The cutting mechanism for machining the high-pressure gas storage tank for the aerospace test according to claim 6, wherein the two telescopic rods (103) are sleeved with a second buffer spring (107), and the telescopic ends of the two telescopic rods (103) are connected with a stress plate (109) together.

8. The cutting mechanism for machining the high-pressure gas storage tank for the aerospace test according to claim 7, wherein a buffering force connecting piece (108) is fixedly installed on the bottom end face of the stress plate (109) and located between the two second buffering springs (107), the buffering force connecting piece (108) is a triangular hinge, and two ends of the bottom of the buffering force connecting piece (108) are respectively connected with the two sliding sleeves (105) through pin shafts.

9. The cutting mechanism for machining the high-pressure gas storage tank for the aerospace test is characterized in that a plurality of reinforcing plates (3) are fixedly welded to two sides of the interior of the pressure tank bearing base (1), and a plurality of universal rollers (2) are correspondingly mounted at the bottoms of the two sides of the pressure tank bearing base (1) respectively.

10. The cutting mechanism for the high-pressure gas storage tank processing based on the aerospace test as recited in any of claims 1-9, wherein the operation method comprises the following steps:

s1, preparation: before the pressure tank is placed, an operator unscrews bolts connecting complementary structures at the tops of the two-section cambered panel (93) and the three-section cambered panel (94), and can respectively outwards unfold the two-section cambered panel (93) and the three-section cambered panel (94) under the action of the hinge shaft (97) to enable the limiting frame which is originally in a sealed state to open a gap;

s2, placing the pressure tank to be processed: hanging a suspension rope inside the two lug plates (6) by using a crane, starting the crane, placing the pressure tank (5) on the tops of the two pressure tank brackets (4) by using the gap opened in the step S1, and then reconnecting the two-section arc panel (93) and the three-section arc panel (94) to reconstruct a limit frame of which the one-section arc panel (92), the two-section arc panel (93) and the three-section arc panel (94) jointly form a circle;

s3, cutting point positioning adjustment: an operator correspondingly marks a position to be cut on the surface of the pressure tank (5) according to the processing requirement, and the pressure tank cutting mechanism (9) can integrally move outside the pressure tank (5) by virtue of the groove steel plate (7) and the rubbing groove hole (8) until the tail end of the laser cutting head (96) is positioned at the marked position;

s4, cutting: starting the laser cutting head (96), holding the holding end of the laser cutting head (96) by an operator, and making the laser cutting head (96) perform circular motion in a circular limiting frame formed by a first section of arc panel (92), a second section of arc panel (93) and a third section of arc panel (94) under the action of the guide slot hole (95) to realize cutting treatment on the pressure tank (5);

s5, cutting and buffering: when the pressure tank (5) is cut into two sections, the cutting end falls into the inner part of the arc panel (92) of one section, at the moment, the pressure tank cutting mechanism (9) is integrally moved again, the cutting end is separated from the arc panel (92) of one section, then the arc panel (92) of one section falls above the buffer protection mechanism (10), and the buffer effect is realized by virtue of the first buffer spring (106), the second buffer spring (107) and the telescopic rod (103);

s6, collecting and tidying: and (3) hoisting the two sections of pressure tanks (5) formed after cutting off the whole cutting mechanism by using a crane respectively, and finishing the cutting treatment.

Technical Field

The invention relates to the technical field of aerospace tests, in particular to a cutting mechanism and a cutting method for machining a high-pressure gas storage tank based on the aerospace test.

Background

And (3) carrying out comprehensive detection tests for verifying the performance, service life and reliability of the spacecraft. The spacecraft test inherits the procedure and technology of the rocket test, and develops the space environment test on the basis, and generally comprises a development test, an identification test, an acceptance test, a life test, a reliability test and the like. The test object is a part, a component, a subsystem and the whole spacecraft. The environmental stress screening test of parts, the test of a recovery system, the test of an attitude control system, the thermal vacuum test of a temperature control system, the modal test of a structural system and the like are the basis of the overall test of the spacecraft. The environmental test is the main content of the overall test of the spacecraft, and the environmental test technology and equipment are very complex.

In the aerospace test project, the high-pressure gas storage tank needs to be cut and processed, and the cutting mechanism needs to be used for completing the process, but the cutting mechanism used by the existing pressure storage tank is not only complicated in structure, but also single in function, and cannot realize accurate positioning treatment, so that a cutting port is damaged due to large error after the pressure storage tank is cut, in addition, the pressure storage tank is changed into two sections after being cut, and the cutting mechanism can deform and damage in the falling process, so that economic loss is caused, and therefore technical personnel in the field provide the cutting mechanism and the method for processing the high-pressure gas storage tank based on the aerospace test.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a cutting mechanism for processing a high-pressure gas storage tank based on an aerospace test and a method thereof, and solves the problems that the cutting mechanism used by the conventional pressure storage tank is complex in structure, single in function and incapable of realizing accurate positioning treatment, so that a cutting port of the pressure storage tank is damaged due to large error after cutting, and in addition, the pressure storage tank is changed into two sections after cutting, so that the pressure storage tank is deformed and damaged in the falling process, and further economic loss is caused.

In order to achieve the purpose, the invention is realized by the following technical scheme: cutting mechanism is used in processing of high-pressure gas storage tank for aerospace test, including overhead tank bearing base, the symmetrical formula fixed mounting of top end surface of overhead tank bearing base has two overhead tank supports, the top end surface of two overhead tank supports bears jointly and has placed the overhead tank, two lug plates of the symmetrical formula welding fixedly connected with of top surface of overhead tank, the both sides terminal surface that the overhead tank bears the base all sets up slotted steel sheet, two through welding mode is fixed the upper and lower terminal surface of slot steel sheet is all fixed has been seted up and has been opened up a position slot hole, and two the top of slot steel sheet is connected with overhead tank cutting mechanism jointly, the common sliding connection of both sides terminal surface of overhead tank bearing base inside has buffering protection machanism.

Preferably, pressure tank cutting mechanism is including corresponding two sliding base who installs in two channel-section steel board tops respectively, two sliding base's the common welding of top end face is provided with a district section cambered plate, the embedded articulated shaft of installing in both ends of a district section cambered plate, and the both ends of a district section cambered plate are through two the articulated shaft corresponds respectively and is connected with two district section cambered plates and three district section cambered plates.

Preferably, the first section of arc panel, the second section of arc panel and the third section of arc panel are spliced together to form a limiting frame with a circular structure, guide slotted holes are fixedly formed in the first section of arc panel, the second section of arc panel and the third section of arc panel, and the laser cutting head is slidably mounted in the guide slotted holes.

Preferably, the ends of the two-segment arc panels, which are contacted with the tops of the three-segment arc panels, are complementary structures, and the complementary structures are fixedly connected through bolts.

Preferably, the sliding base comprises a basic bearing frame arranged above the groove steel plate, the upper surface of the basic bearing frame is fixedly connected with a vertical plate, two sides of the bottom of the basic bearing frame are fixedly provided with roller shafts, the roller shafts are arranged inside the groove steel plate, and the bottom ends of the roller shafts extend to the lower side of the groove steel plate and are fixedly connected with limiting plates.

Preferably, the buffering protection mechanism comprises two slide rails which are respectively connected with two side walls of the pressure tank in a sliding manner, the top ends of the two slide rails are jointly connected with a base plate, two telescopic rods are symmetrically installed on the top end face of the base plate, a transverse shaft rod is jointly connected between the two telescopic rods, two sliding sleeves are movably sleeved on the external section of the transverse shaft rod, and a first buffering spring is sleeved between the telescopic rod and the sliding sleeves and located on the external section of the transverse shaft rod.

Preferably, the outside of the flexible end of two telescopic links all cup joints and is provided with second buffer spring, and the flexible end of two telescopic links is connected with the atress board jointly.

Preferably, the bottom terminal surface of atress board just is located fixed mounting between two second buffer spring and has buffering power link up piece, buffering power link up piece is the articulated elements of triangle-shaped, the bottom both ends of buffering power link up piece correspond respectively and pass through the round pin hub connection with two sliding sleeves.

Preferably, the inside both sides of overhead tank bearing base are all fixed welding and are provided with a plurality of reinforcing plate, and the bottom that overhead tank bearing base both sides corresponds respectively installs a plurality of universal gyro wheel.

Preferably, the operation method of the cutting mechanism for processing the high-pressure gas storage tank for the aerospace test comprises the following steps:

s1, preparation: before the pressure tank is placed, an operator unscrews the bolts connecting the complementary structures at the tops of the two-section cambered panel and the three-section cambered panel, and can respectively outwards unfold the two-section cambered panel and the three-section cambered panel under the action of the articulated shaft, so that the limiting frame which is originally in a sealing state is provided with a notch;

s2, placing the pressure tank to be processed: hanging the suspension rope inside the two lug plates by a crane, starting the crane, placing the pressure tank on the tops of the two pressure tank brackets by the aid of the notches opened in the step S1, and then reconnecting the two-section arc panel and the three-section arc panel to reconstruct a circular limiting frame formed by the first-section arc panel, the two-section arc panel and the three-section arc panel;

s3, cutting point positioning adjustment: an operator correspondingly marks a position to be cut on the surface of the pressure tank according to the processing requirement, and the pressure tank cutting mechanism can integrally move outside the pressure tank by means of the groove steel plate and the position-expanding groove hole until the tail end of the laser cutting head is positioned at the marked position;

s4, cutting: starting the laser cutting head, wherein an operator holds the holding end of the laser cutting head, and under the action of the guide slot hole, the laser cutting head can do circular motion in a circular limiting frame formed by the arc panels of the first section, the arc panels of the second section and the arc panels of the third section, so that the cutting treatment of the pressure tank is realized;

s5, cutting and buffering: when the pressure tank is cut into two sections, the cutting end falls into the inner part of the arc panel of one section, at the moment, the pressure tank cutting mechanism is integrally moved again, the cutting end is separated from the arc panel of one section, then the arc panel of one section falls above the buffer protection mechanism, and the buffer effect is realized by virtue of the first buffer spring, the second buffer spring and the telescopic rod;

s6, collecting and tidying: and (4) respectively hoisting the two sections of pressure tanks formed after cutting off the whole cutting mechanism by using a crane, thus finishing the cutting treatment.

Advantageous effects

The invention provides a cutting mechanism and a method for machining a high-pressure gas storage tank based on an aerospace test. Compared with the prior art, the method has the following beneficial effects:

1. this cutting mechanism is used in processing of high-pressure gas storage tank based on space flight test, including overhead tank bearing base, overhead tank bearing base's both sides terminal surface all sets up slotted steel sheet through welding mode is fixed, on two slot steel sheets, lower terminal surface is all fixed has been seted up and has been opened up a slot hole, and the top of two slot steel sheets is connected with overhead tank cutting mechanism jointly, this overhead tank cutting mechanism can remove in overhead tank bearing base's top with the help of groove steel sheet and open up a slot hole, after the operator makes the cutting mark, through removing overhead tank cutting mechanism, let the cutting head pinpoint by the cutting point of mark, this mechanism is after removing, not only can cut the overhead tank, can also be at the surperficial trompil of overhead tank, thereby can be according to actual demand, realize the cutting of a plurality of modes and handle, and the practicality is improved.

2. This cutting mechanism is used in processing of high-pressure gas storage tank for space test, there is buffering protection machanism through the common sliding connection of both sides terminal surface that bears the weight of the base inside at the overhead tank, be sliding connection between this buffering protection machanism and the overhead tank bearing base, thereby buffering protection machanism can move on the overhead tank bearing base according to the cutting point of reality, be applicable to different cutting positions, in addition, buffer spring through self and the cooperation of telescopic link are used, can realize carrying out good buffering processing to the overhead tank section that drops, prevent to appear damaging the problem of warping, structure scientific and reasonable, high safety and convenience in utilization.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a schematic structural view of a pressure tank cutting mechanism according to the present invention;

FIG. 3 is a front view of the pressure tank cutting mechanism of the present invention;

FIG. 4 is a schematic view of the deployed configuration of the pressure canister cutting mechanism of the present invention;

FIG. 5 is a schematic view of a basic carrier of the present invention;

fig. 6 is a schematic structural diagram of the buffering protection mechanism of the present invention.

In the figure: 1. a pressure tank carrying base; 2. a universal roller; 3. a reinforcing plate; 4. a pressure tank support; 5. a pressure tank; 6. a lug plate; 7. a channel steel plate; 8. expanding slot holes; 9. a pressure tank cutting mechanism; 91. a slide base; 911. a base carrier; 912. a vertical plate; 913. a drum shaft; 914. a limiting plate; 92. a segment arc panel; 93. two segment arc panels; 94. a three-segment cambered plate; 95. a guide slot hole; 96. a laser cutting head; 97. hinging a shaft; 10. a buffer protection mechanism; 101. a slide rail; 102. a substrate; 103. a telescopic rod; 104. a transverse shaft rod; 105. a sliding sleeve; 106. a first buffer spring; 107. a second buffer spring; 108. a force-absorbing engagement member; 109. a stress plate.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1, the present invention provides a technical solution: based on the cutting mechanism for processing the high-pressure gas storage tank for the aerospace test, the cutting mechanism comprises a pressure tank bearing base 1, wherein a plurality of reinforcing plates 3 are fixedly welded on two sides of the interior of the pressure tank bearing base 1, the bottom parts of the two sides of the pressure tank bearing base 1 are respectively and correspondingly provided with a plurality of universal idler wheels 2, the top end surface of the pressure tank bearing base 1 is symmetrically and fixedly provided with two pressure tank brackets 4, the top end surfaces of the two pressure tank brackets 4 jointly bear and place a pressure tank 5, the top surface of the pressure tank 5 is symmetrically and fixedly welded and connected with two lug plates 6, the two side end surfaces of the pressure tank bearing base 1 are both fixedly provided with slotted steel plates 7 by welding, the upper end surface and the lower end surface of each slotted steel plate 7 are both fixedly provided with position-expanding slotted holes 8, and the upper parts of the two groove steel plates 7 are jointly connected with a pressure tank cutting mechanism 9, and the end surfaces of the two sides in the pressure tank bearing base 1 are jointly connected with a buffer protection mechanism 10 in a sliding manner.

Referring to fig. 2-4, the pressure tank cutting mechanism 9 includes two sliding bases 91 respectively and correspondingly installed above the two channel steel plates 7, a section arc panel 92 is welded together on the top end surface of the two sliding bases 91, hinge shafts 97 are installed in embedded manner on both ends of the section arc panel 92, both ends of the section arc panel 92 are respectively and correspondingly connected with a two-section arc panel 93 and a three-section arc panel 94 through the two hinge shafts 97, the first section arc panel 92, the two-section arc panel 93 and the three-section arc panel 94 are jointly spliced to form a limiting frame with a circular structure, guide slots 95 are fixedly installed inside the section arc panel 92, the two-section arc panel 93 and the three-section arc panel 94, a laser cutting head 96 is installed inside the guide slots 95 in a sliding manner, and one end of the two-section arc panel 93 and the top of the three-section arc panel 94 are of a complementary structure, the complementary structures are fixedly connected through bolts.

Referring to fig. 5, the sliding base 91 includes a base carrier 911 disposed above the channel steel plate 7, a vertical plate 912 is fixedly connected to the upper surface of the base carrier 911, roller shafts 913 are fixedly mounted on both sides of the bottom of the base carrier 911, the roller shafts 913 are disposed inside the channel steel plate 7, and the bottom ends of the roller shafts 913 extend to the lower side of the channel steel plate 7 and are fixedly connected to a limiting plate 914.

Referring to fig. 6, the buffering protection mechanism 10 includes two sliding rails 101 slidably connected to two inner side walls of the pressure tank supporting base 1, a base plate 102 is connected to top ends of the two sliding rails 101, two telescopic rods 103 are symmetrically installed on a top end surface of the base plate 102, a horizontal shaft 104 is connected between the two telescopic rods 103, two sliding sleeves 105 are movably sleeved on an outer section of the horizontal shaft 104, and the external section of the cross shaft rod 104 and between the telescopic rod 103 and the sliding sleeve 105 is sleeved with a first buffer spring 106, the outsides of the telescopic ends of the two telescopic rods 103 are sleeved with a second buffer spring 107, and the flexible end of two telescopic links 103 is connected with atress board 109 jointly, and the bottom terminal surface of atress board 109 just is located and fixedly installs buffering power link member 108 between two second buffer spring 107, and buffering power link member 108 is the articulated elements of triangle-shaped, and buffering power link member 108's bottom both ends correspond respectively and pass through the round pin hub connection with two sliding sleeves 105.

In the invention, the operation method of the cutting mechanism for processing the high-pressure gas storage tank for the aerospace test comprises the following steps:

s1, preparation: before the pressure tank is placed, an operator unscrews the bolts connecting the complementary structures at the tops of the two-section cambered panel 93 and the three-section cambered panel 94, and can respectively expand the two-section cambered panel 93 and the three-section cambered panel 94 outwards under the action of the hinge shaft 97 so as to open a gap on the limiting frame which is originally in a sealing state;

s2, placing the pressure tank to be processed: hanging the suspension rope inside the two lug plates 6 by a crane, starting the crane, placing the pressure tank 5 on the top of the two pressure tank brackets 4 by the gap opened in step S1, and then reconnecting the two-section arc panel 93 and the three-section arc panel 94 to reconstruct a circular limiting frame formed by the one-section arc panel 92, the two-section arc panel 93 and the three-section arc panel 94;

s3, cutting point positioning adjustment: an operator correspondingly marks a position to be cut on the surface of the pressure tank 5 according to the processing requirement, and the pressure tank cutting mechanism 9 can integrally move outside the pressure tank 5 by virtue of the groove steel plate 7 and the position-widening groove hole 8 until the tail end of the laser cutting head 96 is positioned at the marked position;

s4, cutting: starting the laser cutting head 96, wherein an operator holds the holding end of the laser cutting head 96, and under the action of the guide slot hole 95, the laser cutting head 96 can do circular motion in a circular limiting frame formed by the first-section arc panel 92, the second-section arc panel 93 and the third-section arc panel 94, so that the cutting treatment of the pressure tank 5 is realized;

s5, cutting and buffering: when the pressure tank 5 is cut into two sections, the cutting end falls into the inner part of the section arc panel 92, at this time, the pressure tank cutting mechanism 9 is moved integrally again, the cutting end is separated from the section arc panel 92, then the section arc panel 92 falls above the buffer protection mechanism 10, and the buffer effect is realized by virtue of the first buffer spring 106, the second buffer spring 107 and the telescopic rod 103;

s6, collecting and tidying: and (3) respectively hoisting the two sections of pressure tanks 5 formed after cutting off the whole cutting mechanism by using a crane, and finishing the cutting treatment.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.