阅读说明：本技术 一种复合悬式绝缘子芯棒加工系统 (Composite suspension insulator mandrel machining system ) 是由 吴信任 沈方园 于 2020-05-13 设计创作，主要内容包括：本发明涉及一种复合悬式绝缘子芯棒加工系统,包括烘干箱、置料机构与辅助机构,所述烘干箱内安装有置料机构,置料机构中部布置有辅助机构,辅助机构安装在烘干箱中部,且烘干箱下端开设有出料口,出料口数量为四,四个出料口两两一组左右对称布置,烘干箱内设置有风管。本发明通过在置料机构从上往下堆叠放置待清洗的芯棒,再通过辅助机构带动芯棒在烘干过程中进行上下移动,以增大芯棒与热风的接触面积,保证烘干的全面性,烘干结束后,芯棒能够自动从置料机构上落下,方便进入下一加工流程。(The invention relates to a composite suspension insulator mandrel processing system which comprises a drying box, a material placing mechanism and an auxiliary mechanism, wherein the material placing mechanism is installed in the drying box, the auxiliary mechanism is arranged in the middle of the material placing mechanism, the auxiliary mechanism is installed in the middle of the drying box, discharge ports are formed in the lower end of the drying box, the number of the discharge ports is four, the four discharge ports are arranged in a bilaterally symmetrical mode in a mode of being two by two, and air pipes are arranged in the drying box. According to the invention, the core rods to be cleaned are stacked and placed on the material placing mechanism from top to bottom, and then the auxiliary mechanism drives the core rods to move up and down in the drying process, so that the contact area of the core rods and hot air is increased, the drying comprehensiveness is ensured, and after the drying is finished, the core rods can automatically fall off the material placing mechanism, so that the next processing flow can be conveniently carried out.)

1. The utility model provides a compound suspension insulator plug system of processing, includes stoving case (1), puts material mechanism (2) and complementary unit (3), its characterized in that: the drying box (1) is internally provided with a material placing mechanism (2), the middle part of the material placing mechanism (2) is provided with an auxiliary mechanism (3), the auxiliary mechanism (3) is arranged in the middle part of the drying box (1), the lower end of the drying box (1) is provided with four discharge ports, the four discharge ports are arranged in a left-right symmetrical mode in a mode of being pairwise and in a group, and air pipes are arranged in the drying box (1);

the material placing mechanism (2) comprises material placing frames (21), bearing plates (22), sliding plates (23), connecting plates (24), moving frames (25) and a translation frame (26), the material placing frames (21) are installed in the drying box (1), the number of the material placing frames (21) is four, four material placing frames (21) are distributed in a group in bilateral symmetry mode, the material placing frames (21) are located right above a discharge port, the bearing plates (22) are installed at the lower ends of the material placing frames (21), the bearing plates (22) are of a frame structure, sliding grooves are symmetrically formed in the front side and the rear side of each bearing plate (22), the sliding plates (23) are installed in the sliding grooves in a sliding fit mode, the sliding plates (23) which are located on the same side of the drying box (1) and are adjacent to each other in the left side and the right side, the connecting plates (24) are connected, the moving frames (25) are installed on the side walls of the sliding plates (23) connected with the inner sides of the connecting plates (24), the moving frames (25) are of L type structures, the upper ends of the moving frames (25) are closely attached to the auxiliary mechanisms (3), and the upper ends of the sliding;

the auxiliary mechanism (3) comprises a driving branched chain (31), a rotating shaft (32), a rotating lug (33), a lifting rod (34), a guide rod (35), a fixing plate (36), a lifting plate (37) and an extrusion block (38), wherein the driving branched chain (31) is installed at the bottom end of the drying box (1), the upper end of the driving branched chain (31) is connected with the lower end of the rotating shaft (32), the rotating shaft (32) is of a hollow structure with an open upper end, the rotating lug (33) is installed on the outer side of the upper end of the rotating shaft (32), the lower end of the rotating lug (33) is tightly attached to the upper end of the moving frame (25), the inner side of the rotating shaft (32) is connected with the side wall of the lifting rod (34) in a threaded fit mode, the upper end of the lifting rod (34) is connected with the lower end of the guide rod (35) in a, the fixed plate (36) is installed in the drying box (1), the left side and the right side of the lifting rod (34) are symmetrically provided with lifting plates (37), the lower end of each lifting plate (37) is provided with an extrusion block (38), each extrusion block (38) is of an isosceles trapezoid structure, and the front side wall and the rear side wall of each extrusion block (38) are closely attached to the side wall of the translation frame (26) in a sliding fit mode;

the driving branched chain (31) comprises a driving motor (311), a rotating frame (312), a guide frame (313), a driving rack (314), a connecting gear (315) and a driven rack (316), the driving motor (311) is installed at the bottom end of the drying box (1) through a motor base, the upper end of an output shaft of the driving motor (311) is connected with the rear end of the rotating frame (312), a convex column is arranged at the front end of the rotating frame (312) and is tightly attached to a guide groove formed in the guide frame (313), the guide frame (313) is installed at the lower end of the driving rack (314), the rear end of the driving rack (314) is meshed with the front end of the connecting gear (315), the front end of the connecting gear (315) is meshed with the front end of the driven rack (316), the upper end of the connecting gear (315) is connected with the lower end of the rotating shaft (32), and the driving rack (314) and the driven rack (316) are both installed at the bottom end of the, the guide groove is in a structure that the front end and the rear end are semicircular and the middle part is rectangular.

2. The composite suspension insulator mandrel machining system of claim 1, wherein: put work or material rest (21) and include curb plate (211), limiting plate (212) and rubber strip (213), curb plate (211) quantity is two, two curb plate (211) bilateral symmetry install in stoving case (1), limiting plate (212) are installed to the symmetry around between two curb plate (211), vertical spout has been seted up to curb plate (211) lower extreme, the square groove has been seted up to limiting plate (212) lower extreme, install bearing board (22) through the sliding fit mode in the vertical spout, both ends are connected through the spring between putting work or material rest (21) about bearing board (22), the square groove of seting up on limiting plate (212) is passed through the sliding fit mode in bearing board (22), curb plate (211) upper end middle part is from last down evenly being provided with rubber strip (213).

3. The composite suspension insulator mandrel machining system of claim 1, wherein: the drying box is characterized in that the left and right symmetrical lower end of the drying box (1) is provided with guide frames (1a), the upper end of each guide frame (1a) is communicated with two discharge ports which are positioned on the same side of the drying box (1), the lower end of each guide frame (1a) is provided with a guide port, and the driven rack (316) and the driving rack (314) are connected with the lower end of each guide frame (1a) in a sliding fit mode.

4. The composite suspension insulator mandrel machining system of claim 1, wherein: translation frame (26) include connecting rod (261) and translation piece (262), and connecting rod (261) are installed in sliding plate (23) upper end that is connected with connecting plate (24) inboard, and connecting rod (261) upper end is connected with translation piece (262) lower extreme through sliding fit mode, and translation piece (262) upper end is installed on stoving case (1) inner wall through sliding fit mode, and translation piece (262) are the right trapezoid structure of invering.

5. The composite suspension insulator mandrel machining system of claim 1, wherein: the lower end of the rotating lug (33) is of an uneven cambered surface structure.

6. The composite suspension insulator mandrel machining system of claim 1, wherein: the distance between the front end and the rear end of the guide groove is more than twice of the circumference of the connecting gear (315).

Technical Field

The invention relates to the field of electric power, in particular to a composite suspension insulator mandrel machining system.

Background

The composite insulator comprises a core rod, a sheath, an umbrella skirt, hardware fittings and the like, wherein the core rod is mainly made of epoxy glass fiber, and the sheath and the umbrella skirt are made of high-temperature vulcanized silicone rubber. Its advantages are small size of head, light weight, high strength and long creepage distance.

Wherein in the forming process of composite insulator, need polish the plug, polish the back and wash its surperficial dust to avoid appearing the bad phenomenon of bonding, do not avoid the plug to take place the moisture absorption after the washing, need in time dry the plug.

At present, the following problems exist in the drying process of the core rod: a. when the drying oven is used for drying the core rods, the core rods are often stacked together, and the positions of the core rods are kept unchanged during drying, so that the drying time of the stacked contact parts of the core rods is longer than that of other parts, and the overall drying efficiency is reduced; b. after drying of a batch of core rods is completed, the core rods are taken out after the drying oven is stopped by a worker, and then the core rods to be dried in the next batch are put in, so that the drying oven cannot continuously perform drying operation.

In order to solve the problems, improve the drying efficiency of the core rod and shorten the whole drying time, the invention provides a composite suspension insulator core rod processing system.

Disclosure of Invention

In order to achieve the purpose, the invention adopts the following technical scheme to realize the purpose:

a composite suspension insulator mandrel processing system comprises a drying box, a material placing mechanism and an auxiliary mechanism, wherein the material placing mechanism is installed in the drying box, the auxiliary mechanism is arranged in the middle of the material placing mechanism, the auxiliary mechanism is installed in the middle of the drying box, discharge ports are formed in the lower end of the drying box, the number of the discharge ports is four, the four discharge ports are arranged in a left-right symmetrical mode in a mode of being two-by-two arranged in one group, and air pipes are arranged in the drying box;

the material placing mechanism comprises material placing frames, four material placing frames, sliding plates, connecting plates, a moving frame and a translation frame, wherein the material placing frames are arranged in a drying box, the number of the material placing frames is four, the four material placing frames are arranged in a group in a bilaterally symmetrical mode, the material placing frames are positioned right above a discharge port, the lower end of each material placing frame is provided with the corresponding bearing plate, the bearing plates are of a frame structure, the front side and the rear side of each bearing plate are symmetrically provided with sliding grooves, the sliding plates are arranged in the sliding grooves in a sliding fit mode, the left sliding plates and the right sliding plates which are adjacent to each other on the same side of the drying box are connected through the corresponding connecting plates, the moving frame is arranged on the side wall of the sliding plate connected with the inner side of the corresponding connecting plates and is of an L type structure, the upper end of the moving frame is tightly attached to an auxiliary mechanism, the translation frame is arranged at the upper end of the sliding plate connected with the inner side of the connecting plates, the upper end of the translation frame is connected with the inner wall of the drying box in a sliding fit mode, the sliding plates after the core rods to be dried are placed in the material placing frames one by one another, the core rods are stacked from top to bottom, the lower end of the sliding frame and the sliding frame can be tightly attached to the sliding frame, the sliding frame can be moved by the sliding frame, the.

The auxiliary mechanism comprises a driving branched chain, a rotating shaft, a rotating lug and a lifting rod, the drying oven comprises a guide rod, a fixed plate, a lifting plate and an extrusion block, wherein a driving branched chain is arranged at the bottom end of the drying oven, the upper end of the driving branched chain is connected with the lower end of a rotating shaft, the rotating shaft is of a hollow structure with an opening at the upper end, a rotating lug is arranged on the outer side of the upper end of the rotating shaft, the lower end of the rotating lug is attached to the upper end of a moving frame, the inner side of the rotating shaft is connected with the side wall of the lifting rod in a threaded fit mode, the upper end of the lifting rod is connected with the lower end of the guide rod in a sliding fit mode, the upper end of the guide rod is arranged below the fixed plate, the guide rod is of a square structure, the fixed plate is arranged in the drying oven; the rotating shaft is driven to rotate in a reciprocating manner by the driving branched chain, in the rotating process of the rotating shaft, the rotating lug generates downward thrust with different sizes on the upper end of the moving frame, the size of the thrust is changed, the height of the moving frame is changed, and therefore the purpose of driving the moving frame to do up-and-down reciprocating movement is achieved, meanwhile, under the limiting action of the guide rod, the lifting rod cannot rotate synchronously along with the rotating shaft, and therefore the lifting rod can only move up and down relative to the rotating shaft (corresponding to the principle of a screw nut), when the lifting plate connected with the lifting rod drives the extrusion block to move upwards, the extrusion block generates outward thrust on the translation frame, so that the sliding plate is driven to move outwards, when the sliding plate moves to the outer side of the limiting plate, the core rod loses the bearing force of the sliding plate, otherwise, when the extrusion block moves downwards, the extrusion block generates inward, so that the sliding plate can move to the inner side of the limiting plate to support the mandril of the next batch.

The drying oven is characterized in that the driving branched chain comprises a driving motor, a rotating frame, a guide frame, a driving rack, a connecting gear and a driven rack, the driving motor is installed at the bottom end of the drying oven through a motor base, the upper end of an output shaft of the driving motor is connected with the rear end of the rotating frame, the front end of the rotating frame is provided with a convex column, the convex column is tightly attached to a guide groove formed in the guide frame, the guide frame is installed at the lower end of the driving rack, the rear end of the driving rack is meshed with the front end of the connecting gear, the front end of the connecting gear is meshed with the front end of the driven rack, the upper end of the connecting gear is connected with the lower end of a rotating shaft, the driving rack and the driven rack are both installed at; the driving motor drives the rotating frame to rotate in the guide groove in a reciprocating mode, the driving rack can be driven to do reciprocating motion left and right in sequence in one rotating period of the rotating frame, the connecting gear can rotate forwards and backwards in the period, and continuous drying operation of the core rod is achieved.

Preferably, the material placing frame comprises two side plates, a limiting plate and a rubber strip, the two side plates are symmetrically arranged in the drying box from left to right, the limiting plate is symmetrically arranged between the two side plates from front to back, the lower end of each side plate is provided with a vertical chute, the lower end of each limiting plate is provided with a square groove, a bearing plate is arranged in each vertical chute in a sliding fit mode, the upper end and the lower end of each bearing plate are connected with the material placing frame through springs, each bearing plate penetrates through the square groove formed in each limiting plate in a sliding fit mode, the rubber strip is uniformly arranged in the middle of the upper end of each side plate from top to bottom, so that when the bearing plate drives the mandrel to move up and down, the mandrel can turn over by a certain angle under the friction force of the rubber strip and the mandrel, the contact area between the mandrel and hot air is increased, when the, and falls into the material guiding frame from the material outlet and finally falls out from the material guiding opening.

Preferably, the drying box lower extreme bilateral symmetry installs the guide frame, and guide frame upper end is linked together with two discharge gates that lie in drying box with one side, and the guide mouth has been seted up to guide frame lower extreme, and driven rack and initiative rack all are connected with guide frame lower extreme through the sliding fit mode.

Preferably, the translation frame includes connecting rod and translation piece, and the connecting rod is installed in the sliding plate upper end that is connected with the connecting plate inboard, and the connecting rod upper end is connected with translation piece lower extreme through the sliding fit mode, and translation piece upper end is installed on the stoving incasement wall through the sliding fit mode, and the translation piece is the right trapezoid structure of invering.

Preferably, the lower end of the rotating lug is of an uneven cambered surface structure so as to drive the moving frame to perform vertical reciprocating linear motion.

Preferably, the distance between the front end and the rear end of the guide groove is greater than twice of the perimeter of the connecting gear, so that the connecting gear can drive the rotating lug on the rotating shaft to rotate for multiple times in one movement period, the core rod can reciprocate up and down for multiple times in the drying process, the contact area between the core rod and hot air is increased, the drying efficiency is improved, and the drying comprehensiveness is ensured.

The invention has the beneficial effects that:

1. according to the composite suspension insulator mandrel processing system provided by the invention, the mandrels to be cleaned are stacked and placed on the material placing mechanism from top to bottom, and then the mandrels are driven by the auxiliary mechanism to move up and down in the drying process, so that the contact area between the mandrels and hot air is increased, the drying comprehensiveness is ensured, and after drying is finished, the mandrels can automatically fall off the material placing mechanism, and the next processing flow can be conveniently entered.

2. According to the material placing mechanism provided by the invention, the core rods in the material placing frame are in a state of being stacked from top to bottom, the moving frame is driven by the auxiliary mechanism to move up and down, and the sliding plate connected with the moving frame also moves along with the moving frame, so that the relative positions of the core rods and the air pipe are changed, the contact area of the core rods and hot air is increased, meanwhile, the sliding plate gradually moves outwards during drying, when the upper end of the sliding plate is not attached to the lower end of the core rods any more, the core rods lose bearing force and slide downwards, and the core rods fall out of the drying rack 1 and then enter the next processing.

3. The auxiliary mechanism provided by the invention can drive the moving frame to reciprocate up and down in the drying process so as to change the relative position of the air pipe and the core rod, and can push the translation frame to move outwards so as to enable the core rod to automatically fall from the material placing mechanism after the drying time reaches a certain length.

Drawings

The invention is further illustrated with reference to the following figures and examples.

FIG. 1 is a front cross-sectional view of the present invention;

FIG. 2 is a right side view of a part of the structure of the drying box, the material placing mechanism and the auxiliary mechanism of the present invention;

FIG. 3 is a top cross-sectional view of the support plate, slide plate, connecting plate and movable frame of the present invention;

FIG. 4 is a bottom view of the drive chain of the present invention;

FIG. 5 is a right sectional view of the drying box, the material loading frame, the supporting plate and the sliding plate according to the present invention.

Detailed Description

The embodiments of the invention will be described in detail below with reference to the drawings, but the invention can be implemented in many different ways as defined and covered by the claims.

As shown in fig. 1 to 5, a composite suspension insulator mandrel processing system comprises a drying box 1, a material placing mechanism 2 and an auxiliary mechanism 3, wherein the material placing mechanism 2 is installed in the drying box 1, the auxiliary mechanism 3 is arranged in the middle of the material placing mechanism 2, the auxiliary mechanism 3 is installed in the middle of the drying box 1, discharge ports are formed in the lower end of the drying box 1, the number of the discharge ports is four, four discharge ports are symmetrically arranged in a left-right mode in a mode of being two-by-two arranged in a group, and air pipes are arranged in the drying box 1;

the drying box 1 is characterized in that the guide frames 1a are symmetrically arranged at the left and right of the lower end of the drying box 1, the upper ends of the guide frames 1a are communicated with two discharge ports located on the same side of the drying box 1, a guide port is formed in the lower end of the guide frame 1a, and the driven rack 316 and the driving rack 314 are connected with the lower end of the guide frame 1a in a sliding fit mode.

The core rod feeding mechanism 2 comprises material placing frames 21, bearing plates 22, sliding plates 23, connecting plates 24, moving frames 25 and translation frames 26, the material placing frames 21 are installed in the drying box 1, the number of the material placing frames 21 is four, every two of the four material placing frames 21 are distributed in a left-right symmetrical mode, the material placing frames 21 are located right above a discharge port, the bearing plates 22 are installed at the lower ends of the material placing frames 21, the bearing plates 22 are of a frame structure, sliding grooves are symmetrically formed in the front side and the rear side of each bearing plate 22, the sliding plates 23 are installed in the sliding grooves in a sliding fit mode, the sliding plates 23 which are adjacent to each other in the left direction and the right direction and located on the same side of the drying box 1 are connected through the connecting plates 24, the moving frames 25 are installed on the side walls of the sliding plates 23 connected with the inner sides of the connecting plates 24, the moving frames 25 are of an L type structure, the upper ends of the moving frames 25 are closely attached to the auxiliary mechanism 3, the sliding plates 23 are installed at the upper ends of the sliding frames 26 connected with the inner walls of the drying box 1 in a sliding fit mode, after the core rods are placed in the material placing frames 21 one by one another, the sliding frame, the core rods are closely attached to the lower ends of the sliding frames, the core rods can be closely attached to the core rods, the core rods can be attached to the core rod moving frames when the core rods, the core rods are not moved by the core rods, the core rods.

The material placing frame 21 comprises side plates 211, two limiting plates 212 and two rubber strips 213, the two side plates 211 are symmetrically arranged in the drying box 1 from left to right, the limiting plates 212 are symmetrically arranged between the two side plates 211 from front to back, the lower ends of the side plates 211 are provided with vertical sliding grooves, the lower ends of the limiting plates 212 are provided with square grooves, the vertical sliding grooves are internally provided with bearing plates 22 in a sliding fit mode, the upper and lower ends of the bearing plates 22 are connected with the material placing frame 21 through springs, the bearing plates 22 penetrate through the square grooves formed in the limiting plates 212 in a sliding fit mode, the middle parts of the upper ends of the side plates 211 are uniformly provided with the rubber strips 213 from top to bottom, so that when the bearing plates 22 drive the core rods to move up and down, the core rods can turn over a certain angle under the friction force of the rubber strips 213 and the core rods, the contact area between the core rods and, therefore, the material can slide down from the middle of the supporting plate 22, and fall into the material guiding frame 1a from the material outlet, and finally fall out from the material guiding opening.

The translation frame 26 comprises a connecting rod 261 and a translation block 262, the connecting rod 261 is installed at the upper end of the sliding plate 23 connected with the inner side of the connecting plate 24, the upper end of the connecting rod 261 is connected with the lower end of the translation block 262 in a sliding fit mode, the upper end of the translation block 262 is installed on the inner wall of the drying box 1 in a sliding fit mode, and the translation block 262 is of an inverted right-angle trapezoidal structure.

The auxiliary mechanism 3 comprises a driving branch chain 31, a rotating shaft 32, a rotating lug 33, a lifting rod 34, a guide rod 35, a fixing plate 36, a lifting plate 37 and an extrusion block 38, the driving branch chain 31 is installed at the bottom end of the drying box 1, the upper end of the driving branch chain 31 is connected with the lower end of the rotating shaft 32, the rotating shaft 32 is of a hollow structure with an open upper end, the rotating lug 33 is installed at the outer side of the upper end of the rotating shaft 32, the lower end of the rotating lug 33 is attached to the upper end of the moving frame 25, the lower end of the rotating lug 33 is of an uneven cambered surface structure to drive the moving frame 25 to do vertical reciprocating linear motion, the inner side of the rotating shaft 32 is connected with the side wall of the lifting rod 34 in a threaded fit mode, the upper end of the lifting rod 34 is connected with the lower end of the guide rod, the left side and the right side of the lifting rod 34 are symmetrically provided with lifting plates 37, the lower ends of the lifting plates 37 are provided with extrusion blocks 38, each extrusion block 38 is of an isosceles trapezoid structure, and the front side wall and the rear side wall of each extrusion block 38 are closely attached to the side wall of the translation frame 26 in a sliding fit mode; the rotating shaft 32 is driven to rotate in a reciprocating manner by the driving branched chain 31, in the rotating process of the rotating shaft 32, the rotating lug 33 generates downward thrust with different sizes on the upper end of the moving frame 25, the height of the moving frame 25 is changed along with the change of the thrust, so that the purpose of driving the moving frame 25 to do up-and-down reciprocating movement is achieved, meanwhile, under the limiting action of the guide rod 35, the lifting rod 34 cannot rotate synchronously with the rotating shaft 32, and therefore can only move up and down relative to the rotating shaft 32 (corresponding to the principle of a screw nut), when the lifting plate 37 connected with the lifting rod 34 drives the extrusion block 38 to move up, the extrusion block 38 generates outward thrust on the translation frame 26, so as to drive the sliding plate 23 to move outward, when the sliding plate 23 moves to the outer side of the limiting plate 212, the core rod loses the bearing force of the sliding plate 23, otherwise, when the extrusion block 38 moves downward, the pressing block 38 exerts an inward pulling force on the translation carriage 26, so that the sliding plate 23 can move to the inner side of the limiting plate 212 to support the next batch of core rods.

The driving branched chain 31 comprises a driving motor 311, a rotating frame 312, a guide frame 313, a driving rack 314, a connecting gear 315 and a driven rack 316, the driving motor 311 is installed at the bottom end of the drying box 1 through a motor base, the upper end of an output shaft of the driving motor 311 is connected with the rear end of the rotating frame 312, a convex column is arranged at the front end of the rotating frame 312 and clings to a guide groove formed in the guide frame 313, the guide frame 313 is installed at the lower end of the driving rack 314, the rear end of the driving rack 314 is meshed with the front end of the connecting gear 315, the front end of the connecting gear 315 is meshed with the front end of the driven rack 316, the upper end of the connecting gear 315 is connected with the lower end of the rotating shaft 32, the driving rack 314 and the driven rack 316 are both installed at the bottom end of the drying box 1 in a sliding fit; the driving motor 311 drives the rotating frame 312 to rotate in the guide groove in a reciprocating manner, and in a rotating period of the rotating frame 312, the driving rack 314 can be driven to move in a reciprocating manner from left to right in sequence, so that the connecting gear 315 can rotate forwards and backwards in the period, and continuous drying operation of the core rod is realized.

The distance between the front end and the rear end of the guide groove is larger than twice of the perimeter of the connecting gear 315, so that the connecting gear 315 can drive the rotating lug 33 on the rotating shaft 32 to rotate for multiple times in one movement period, the core rod can reciprocate up and down for multiple times in the drying process, the contact area between the core rod and hot air is increased, the drying efficiency is improved, and the drying comprehensiveness is ensured.

The foregoing illustrates and describes the principles, general features, and advantages of the present invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are given by way of illustration of the principles of the present invention, and that various changes and modifications may be made without departing from the spirit and scope of the invention as defined by the appended claims. The scope of the invention is defined by the appended claims and equivalents thereof.