Single-column numerical control vertical lathe
Technical Field
The invention relates to the technical field of numerically controlled lathes, in particular to a single-column numerically controlled vertical lathe.
Background
The single-column numerical control vertical lathe is a numerical control lathe for metal cutting machining, a column is taken as a main supporting component, the column is vertically arranged on a base, supports and guides other components of the lathe, a programmed machining program is input into a numerical control system, the numerical control system processes and computes the program, then a command signal is sent to a servo driving device of each coordinate axis of the lathe, a workbench, a tool rest and other moving components of the lathe are driven to move according to a preset track and parameters, thereby realizing automatic cutting machining of a workpiece, in the machining process, a tool is fixed on the tool rest, the workbench drives the workpiece to rotate, and the tool and the workpiece perform relative movement to finish machining operations such as inner and outer cylindrical surfaces, conical surfaces, end surfaces, grooving, chamfering and the like of the workpiece;
When a lathe is used for fixing a turning material, the material is usually clamped by a clamp, but the clamp cannot be adjusted under the condition of having more material in the turning process, so that the material cannot be driven to rotate at a high speed when turning resistance is large, and the turning of the material is affected.
Disclosure of Invention
In order to achieve the above purpose, the invention is realized by the following technical scheme:
A single column numerically controlled vertical lathe comprising:
The frame body is fixedly provided with a first motor at the bottom, and the output end of the first motor penetrates through the frame body and extends to the top of the frame body;
the adjusting mechanism is used for adjusting the position of a cutter of the lathe, is arranged on the outer side of the frame body, and is fixedly provided with the cutter mechanism;
The output end of the first motor is fixedly connected with a rotary table, the rotary table is rotatably arranged at the top of the frame body, strip grooves are uniformly formed in the top of the rotary table, air cylinders are fixedly arranged at the strip grooves of the rotary table, sliding blocks are slidably arranged at the strip grooves of the rotary table, the sliding blocks are positioned at the inner sides of the air cylinders and fixedly connected with the output ends of the air cylinders, arc groove blocks are fixedly connected with the tops of the sliding blocks, the arc grooves are formed in the outer sides of the arc groove blocks, the arc groove depths are gradually reduced from the central positions to the two sides, the arc groove depths are changed through the arc groove depths of the arc groove blocks to be matched with the clamping blocks, when turning resistance is large, when relative rotation occurs between a material and the rotary table, the clamping blocks are enabled to deform by utilizing friction force between turning materials and the clamping blocks, the characteristics that the clamping blocks slide in the arc grooves and the matched arc groove depths are gradually reduced from the central positions to the two sides, the inner clamping block is made to approach to the center position again, the clamping force is increased, the relative rotation between the material and the turntable is limited, the material is prevented from being driven to rotate at high speed due to larger turning resistance, the turning of the material is affected, the clamping block is slidably arranged at the arc groove of the arc groove block, the cushion block is clamped at the chute of the arc groove block, the two sides of the clamping block are limited in the process of clamping the material through the elastic deformation characteristic of the cushion block, the clamping block is positioned at the center position of the arc groove block when the material is clamped, the clamping block is positioned at the deepest part of the arc groove before turning, the arc groove block and the clamping block are matched when the material is turned, the clamping block is prevented from being positioned at one end of the arc groove when the material is clamped, the clamping block cannot be adjusted when the material is clamped, the clamping block synchronously positioned at the center position can ensure the positioning of the material when the material is clamped, the material is located at the rotation center position, the turning processing is prevented from being influenced by material deflection, the cushion block is made of elastic materials and is symmetrically installed along the center position of the axis of the arc groove block, the opposite surfaces of the cushion block are in contact with the two sides of the clamping block, the top parts of the two sides of the sliding block are fixedly provided with side clamping blocks, the opposite surfaces of the side clamping blocks are tightly attached to the two sides of the arc groove block, and the opposite surfaces of the clamping block are cambered surfaces.
Preferably, the adjustment mechanism includes the second motor, second motor fixed mounting is at the top of support body, just the output of second motor runs through the support body and extends to its bottom, the first screw rod of output fixedly connected with of second motor, the outside threaded connection first screw rod, the outside fixedly connected with connection diaphragm of first screw rod, the both ends slidable mounting of connection diaphragm has the connecting plate, the connecting plate is close to the top of support body one side and the outside fixed connection of support body, just logical groove has been seted up to the outside symmetry of connecting plate, the connecting plate passes through logical groove and the both ends sliding fit of connection diaphragm, the both ends fixedly connected with spout frame of connection diaphragm, the outside fixedly connected with third motor of spout frame, just the inner wall rotation of spout frame is connected with the second screw rod, the one end and the output fixedly connected with of third motor of second screw rod, the outside threaded connection second screw rod, the outside of second screw rod and the inner wall sliding fit of spout frame and the outside of spout frame, the both sides fixed connection cutter fixed connection groove and the outside of second screw rod frame, the both sides fixed connection of spout frame.
Preferably, the bottom of the second screw block is fixedly connected with a bottom strip, the top of the second screw block is fixedly connected with a top strip, the outer side of the top strip is in sliding fit with a clamping groove above the inner wall of the chute frame, the top of the top strip is symmetrically provided with grooves, the grooves of the top strip are rotationally provided with rotating balls, through the matching of the top strip and the bottom strip, when in sliding fit with the clamping groove of the chute frame, the turning resistance is larger, when the second screw block has an inclination trend, the inclination of the second screw block is limited, the second screw is prevented from being stressed bending, the screw is prevented from being broken or bent and deformed, the cutter cannot be driven to accurately move, the turning quality is influenced, the outer side of the bottom strip is in sliding fit with the clamping groove below the inner wall of the chute frame, just the both ends of sill bar are the inclined plane, the spout has been seted up to the bottom symmetry of sill bar, just equal slidable mounting in spout department of sill bar has the shovel groove strip, the non-opposite face of shovel groove strip is the inclined plane and with the inclined plane looks adaptation at sill bar both ends, through the inclined plane of shovel groove strip, when sliding in the draw-in groove, clear up the turning piece of below draw-in groove department, utilize the inclined plane at sill bar both ends simultaneously, with the piece derivation draw-in groove when sliding, avoid turning piece to pile up in draw-in groove department, influence the motion of cutter, elastic backing ring utilizes self elastic deformation simultaneously, cooperation shovel groove strip carries out the buffering when shovel groove strip clearance piece is obstructed, the equal fixed mounting of opposite face of shovel groove strip has the elastic backing ring.
Preferably, the cutter mechanism includes the fixing base, the one end of fixing base and the outside fixed connection of fixed plate, just the top fixedly connected with fourth motor of fixing base, the output of fourth motor runs through the fixing base and extends to its bottom, just the output fixedly connected with transmission shaft of fourth motor, the bottom fixedly connected with blade disc of transmission shaft, the sword groove has evenly been seted up in the outside of blade disc, just the sword groove department of blade disc all installs the turning tool bit, the inner wall threaded connection of sword tool bit has first bolt, the sword groove fixed connection of sword groove department of sword tool bit through first bolt and blade disc, the equal slidable mounting of sword groove department of sword disc has the side cardboard, side cardboard is installed along the axis central point symmetry of sword groove, just the opposite face of side cardboard is by last inclined plane to outside down, through the inclined plane of side cardboard, when the lathe tool bit cuts the material, restricts the lathe tool bit, avoids because the turning resistance is great, leads to the result in the tool groove to appear becoming flexible, influences the turning precision simultaneously when the lathe tool bit is by the inclined plane of going up to the lathe tool bit and is carried out the lathe tool bit down and is turned down by the upward movement, the side-turning tool bit is led to the fact the side cardboard to rotate the side of the side cardboard, the side cardboard is connected with the second side bolt, the side cardboard is fixed to the side bolt is broken, the side bolt is connected with the side bolt is turned.
The invention provides a single-column numerical control vertical lathe. The beneficial effects are as follows:
1. This single-column numerical control vertical lathe, through the arc groove depth variation and the clamp material piece cooperation of arc groove piece, when the turning, when turning resistance is great, when making the relative rotation appear between material and the carousel, utilize the frictional force between turning material and the clamp material piece, make clamp material piece compression pad deformation, slide in the arc groove, the cooperation arc groove depth is by central point to the characteristics that both sides reduce gradually, make interior clamp material piece be close to again to central point, increase the clamping force, the relative rotation between restriction material and the carousel, prevent that the material from being driven because the turning resistance is great, lead to can't be driven and carry out high-speed rotation, influence the turning of material.
2. This single-column numerical control vertical lathe, through the elastic deformation characteristics of cushion, at the in-process of centre gripping material, limit the both sides to press from both sides the material piece, make the material piece that presss from both sides when centre gripping material, be in the arc groove central point of arc groove piece put, make the material piece that presss from both sides before the turning, be in the deepest of arc groove, cooperation between arc groove piece and the material piece that presss from both sides when guaranteeing the turning, avoid pressing from both sides the material piece and be in the one end of arc groove when the centre gripping, can not adjust when leading to the turning, the material piece that presss from both sides in central point simultaneously can guarantee the location to the material when the centre gripping, make the material be in rotation central point, avoid the material skew to influence turning.
3. This single-column numerical control vertical lathe, through the cooperation of top strip and bottom strip, when sliding, with the draw-in groove slip adaptation of spout frame, turning resistance is great simultaneously, when making the second spiral shell piece appear the slope trend, restriction second spiral shell piece's slope avoids causing the second screw rod to appear the atress bending, leads to screw fracture or bending deformation, can't drive the cutter and carries out accurate removal, influences the quality of turning.
4. This single-column numerical control vertical lathe, through the inclined plane of shovel groove strip, when sliding in the draw-in groove, clear up the turning piece of below draw-in groove department, utilize the inclined plane at sill bar both ends simultaneously, derive the draw-in groove with the piece when sliding, avoid turning piece to pile up in draw-in groove department, influence the motion of cutter, elastic backing ring utilizes self elastic deformation simultaneously, cooperation shovel groove strip carries out the buffering when shovel groove strip clearance piece is obstructed.
5. This single-column numerical control vertical lathe, through the inclined plane of side cardboard, when lathe tool bit turning material, restrict lathe tool bit, avoid because turning resistance is great, lead to lathe tool bit to appear not hard up, influence turning precision, simultaneously by last inclined plane down when lathe tool bit from top to bottom moves the lathe tool bit, restriction lathe tool bit ground perk avoids causing the fracture of fixed lathe tool bit bolt, causes the cutter to fly to penetrate.
Drawings
FIG. 1 is a schematic diagram of a single column numerical control vertical lathe according to the present invention;
FIG. 2 is a bottom view of the structure of a single column numerically controlled vertical lathe according to the present invention;
FIG. 3 is a schematic view of a part of the structure of a single-column numerical control vertical lathe;
FIG. 4 is a side view of a portion of the structure of a single column numerically controlled vertical lathe according to the present invention;
FIG. 5 is a top view of a portion of the structure of a single column numerically controlled vertical lathe according to the present invention;
FIG. 6 is a schematic view of the position structure of the tool mechanism and the adjusting mechanism of the present invention;
FIG. 7 is a schematic view of the structure of the adjusting mechanism of the present invention;
FIG. 8 is a schematic view of a portion of the structure of the adjustment mechanism of the present invention;
FIG. 9 is a side view of a portion of the structure of the adjustment mechanism of the present invention;
FIG. 10 is a bottom view of the adjustment mechanism of the present invention;
FIG. 11 is a schematic view of the cutter mechanism of the present invention;
fig. 12 is a schematic view of a part of the structure of the cutter mechanism of the present invention.
In the figure, 1, a frame body; 2, a rotary table, 3, a cutter mechanism, 4, an adjusting mechanism, 5, a first motor, 6, a cylinder, 7, a sliding block, 8, an arc groove block, 9, a side clamping block, 10, a cushion block, 11, a clamping block, 31, a fixed seat, 32, a fourth motor, 33, a transmission shaft, 34, a cutter head, 35, a lathe tool head, 36, a side clamping plate, 37, a first bolt, 38, a second bolt, 401, a second motor, 402, a first screw, 403, a connecting plate, 404, a first screw block, 405, a connecting cross plate, 406, a chute frame, 407, a third motor, 408, a second screw block, 409, a second screw, 410, a fixed plate, 411, a rotary ball, 412, a bottom bar, 413, a top bar, 414, an elastic backing ring, 415 and a shovel groove bar.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
In a first embodiment, as shown in fig. 1 to 5, the present invention provides a technical solution:
A single column numerically controlled vertical lathe comprising:
the device comprises a frame body 1, wherein a first motor 5 is fixedly arranged at the bottom of the frame body 1, and the output end of the first motor 5 penetrates through the frame body 1 and extends to the top of the frame body;
The adjusting mechanism 4 is used for adjusting the position of a cutter of the lathe, the adjusting mechanism 4 is arranged on the outer side of the frame body 1, and the cutter mechanism 3 is fixedly arranged on the outer side of the adjusting mechanism 4;
The output end of the first motor 5 is fixedly connected with the turntable 2, the turntable 2 is rotatably arranged at the top of the frame body 1, strip grooves are uniformly formed in the top of the turntable 2, the air cylinders 6 are fixedly arranged at the strip grooves of the turntable 2, the sliding blocks 7 are slidably arranged at the strip grooves of the turntable 2, the sliding blocks 7 are positioned at the inner sides of the air cylinders 6, the outer sides of the sliding blocks 7 are fixedly connected with the output end of the air cylinders 6, after materials are placed at the top of the turntable 2, the sliding blocks 7 are driven to slide in the strip grooves of the turntable 2 through the air cylinders 6, so that the sliding blocks 7 move close to the center position, in the process of approaching, the sliding blocks 7 drive the clamping blocks 11 to approach materials through the arc groove blocks 8, the materials are clamped and fixed, meanwhile, the position of the clamping blocks 11 is limited by the cushion blocks 10 in the arc grooves of the arc groove blocks 8 during clamping, so that the clamping blocks 11 are positioned at the deepest center position of the arc grooves, the top of the sliding block 7 is fixedly connected with an arc groove block 8, an arc groove is formed in the outer side of the arc groove block 8, the depth of the arc groove gradually decreases from the center position to two sides, a clamping block 11 is slidably arranged at the arc groove of the arc groove block 8, a cushion block 10 is clamped at the chute of the arc groove block 8, the cushion block 10 is made of elastic materials and is symmetrically arranged along the center position of the axis of the arc groove block 8, opposite surfaces of the cushion block 10 are contacted with two sides of the clamping block 11, during machining, the first motor 5 drives the turntable 2 to rotate so as to drive materials to rotate, during turning of materials, friction occurs between a cutter and the materials during turning of the materials, at the moment, the clamping block 11 is synchronously driven to rotate through friction force during clamping between the clamping block 11 and the materials, during relative rotation occurs between the materials and the turntable 2, the cushion block 10 is compressed, so that the clamping block 11 slides in the arc groove of the arc groove block 8, the arc groove depth change of the arc groove blocks 8 is utilized, so that the clamping blocks 11 are mutually close again when rotating, the clamping force on materials is increased, the tops of the two sides of the sliding block 7 are fixedly provided with the side clamping blocks 9, the opposite surfaces of the side clamping blocks 9 are tightly attached to the two sides of the arc groove blocks 8, and the opposite surfaces of the clamping blocks 11 are cambered surfaces.
In the second embodiment, as shown in fig. 6 to 10, on the basis of the first embodiment, the adjusting mechanism 4 includes a second motor 401, the second motor 401 is fixedly installed at the top of the frame 1, and the output end of the second motor 401 penetrates through the frame 1 and extends to the bottom thereof, the output end of the second motor 401 is fixedly connected with a first screw 402, the outer side of the first screw 402 is in threaded connection with a first screw block 404, the outer side of the first screw block 404 is fixedly connected with a connecting transverse plate 405, two ends of the connecting transverse plate 405 are slidably installed with connecting plates 403, the top of one side of the connecting plates 403 close to the frame 1 is fixedly connected with the outer side of the frame 1, through grooves are symmetrically formed on the outer sides of the connecting plates 403, the second motor 401 is matched with the third motor 407 through an input program, the second motor 401 drives the first screw 402 to rotate, the connecting transverse plate 405 is driven to move up and down by using the threaded connection between the first screw 402 and the first screw block 404, the connecting transverse plate 405 drives the chute frame 406 to move up and down, the connecting plate 403 is in sliding fit with the two ends of the connecting transverse plate 405 through a through groove, the two ends of the connecting transverse plate 405 are fixedly connected with the chute frame 406, the outer side of the chute frame 406 is fixedly connected with a third motor 407, the inner wall of the chute frame 406 is rotationally connected with a second screw 409, one end of the second screw 409 is fixedly connected with the output end of the third motor 407, the outer side of the second screw 409 is in threaded connection with a second screw block 408, the outer side of the second screw block 408 is in sliding fit with the inner wall of the chute frame 406, one end of the second screw block 408 is fixedly connected with a fixed plate 410, the third motor 407 drives the second screw 409 to rotate by driving the second screw 409, the second screw block 408 transversely moves on the inner wall of the chute frame 406 by using the threaded connection between the second screw 409 and the second screw block 408, the second screw block 408 drives the cutter mechanism 3 through the fixed plate 410, the cutter mechanism 3 is driven by the adjusting mechanism 4 to realize up-and-down movement and transverse movement, the outer side of the fixing plate 410 is fixedly connected with the cutter mechanism 3, and clamping grooves are formed in the upper side and the lower side of the inner wall of the chute frame 406.
The bottom fixedly connected with sill bar 412 of second spiral shell piece 408, the top fixedly connected with roof bar 413 of second spiral shell piece 408, the outside of roof bar 413 and the draw-in groove slip fit of spout frame 406 inner wall top, and the top symmetry of roof bar 413 is seted up flutedly, in the in-process that second spiral shell piece 408 removed, through roof bar 413 and sill bar 412 in the draw-in groove of spout frame 406, simultaneously in the gliding in-process, roof bar 413 and sill bar 412 contact the draw-in groove of spout frame 406, resistance when turning material supports, limit the slope of second spiral shell piece 408 when turning resistance is great, avoid turning resistance to all to bear by second spiral shell piece 408 and second screw 409, the recess department of roof bar 413 all rotates and installs rotary sphere 411, the outside of sill bar 412 and the draw-in groove slip fit of spout frame 406 inner wall below, and both ends of sill bar 412 are the inclined plane, the spout is seted up to the bottom symmetry to the bottom of sill bar 412, and the spout department of sill bar 412 all slides and has the shovel groove bar, in the in-process that slides, roof bar 413 and sill bar 412 contact with the draw-in groove contact with sill bar 412 draw-in groove, the inclined plane is reduced to the opposite side 415 of the clearance groove 415, the clearance is opposite inclined plane, and the clearance groove 415 is not blocked up to the opposite inclined plane of the side 415 of the opposite side of the baffle bar 415.
In the third embodiment, as shown in fig. 11 to 12, based on the first and second embodiments, the cutter mechanism 3 includes a fixing seat 31, one end of the fixing seat 31 is fixedly connected with the outer side of a fixing plate 410, the top of the fixing seat 31 is fixedly connected with a fourth motor 32, the output end of the fourth motor 32 penetrates through the fixing seat 31 and extends to the bottom thereof, and the fourth motor 32 is driven to move with a transmission shaft 33 through the connection of the fixing seat 31 and the fixing plate 410, so that a cutter 34 drives the cutter to approach the material for turning, the output end of the fourth motor 32 is fixedly connected with the transmission shaft 33, the bottom end of the transmission shaft 33 is fixedly connected with a cutter 34, cutter grooves are uniformly formed in the outer side of the cutter 34, cutter heads 35 are mounted at the cutter grooves of the cutter 34, the inner wall of the cutter heads 35 are in threaded connection with first bolts 37, and the cutter heads 35 are fixedly connected with the cutter grooves of the cutter 34 through the first bolts 37.
The cutter groove of the cutter head 34 is provided with side clamping plates 36 in a sliding mode, the side clamping plates 36 are symmetrically arranged along the central position of the axis of the cutter groove, opposite faces of the side clamping plates 36 are inclined faces which incline from top to bottom to the outside, the inclined faces of the side clamping plates 36 are contacted with two sides of the cutter head 35, in the cutter head 34, the cutter head 35 is fixed at the cutter groove of the cutter head 34 through a first bolt 37, the cutter head 34 is utilized to drive the cutter head 35 to be close to a material, the cutter head 35 is contacted with the material rotating at a high speed, turning work is achieved, meanwhile, when the cutter head 35 is used for turning the material, the two sides of the cutter head 35 are limited through the side clamping plates 36 on the two sides, the cutter head 35 is clamped, the inner wall of the side clamping plates 36 is rotationally connected with a second bolt 38, and the side clamping plates 36 are fixedly connected with the inner wall of the cutter head 34 through the second bolt 38.
When the lathe turning machine is used, a worker puts a material to be turned into the top of the turntable 2 to be fixed through carrying equipment, drives the material to rotate through the first motor 5, then inputs a turning program by the worker, enables the adjusting mechanism 4 to be matched with the cutter mechanism 3, and enables the cutter mechanism 3 to move by the adjusting mechanism 4, so that the cutter mechanism 3 performs turning on the material.
When the turning material is fixed, after the material is put into the top of the turntable 2, the air cylinder 6 drives the sliding block 7 to slide in the strip groove of the turntable 2, so that the sliding block 7 moves towards the center position, in the approaching process, the sliding block 7 drives the clamping block 11 to be close to the material through the arc groove block 8, the material is clamped and fixed, meanwhile, in the clamping process, the cushion block 10 in the arc groove of the arc groove block 8 limits the position of the clamping block 11, the clamping block 11 is positioned at the deepest part of the center position of the arc groove, in the processing process, the first motor 5 drives the turntable 2 to rotate, thereby driving the material to rotate, in the turning process, the cutter rubs the material when turning the material, and limits the rotation of the material, in this time, the clamping block 11 is synchronously driven to rotate when the relative rotation occurs between the material and the turntable 2 through the friction force of the clamping block 11, the clamping block 11 slides in the arc groove of the arc groove block 8, and the clamping block 11 is enabled to be mutually close again when rotating by utilizing the change of the depth of the arc groove block 8, and the clamping block 11 is enabled to increase the clamping force to the material.
In the adjusting mechanism 4, through an input program, the second motor 401 is matched with the third motor 407, the second motor 401 drives the first screw rod 402 to rotate, the connecting transverse plate 405 is driven to move up and down by using the threaded connection between the first screw rod 402 and the first screw block 404, the connecting transverse plate 405 drives the chute frame 406 to move up and down, meanwhile, the third motor 407 drives the second screw rod 409 to rotate, the second screw block 408 transversely moves on the inner wall of the chute frame 406 by using the threaded connection between the second screw rod 409 and the second screw block 408, the second screw block 408 drives the cutter mechanism 3 through the fixing plate 410, and the cutter mechanism 3 is driven by the adjusting mechanism 4 to move up and down and transversely move.
In the process of moving the second screw block 408, the top bar 413 and the bottom bar 412 slide in the clamping groove of the chute frame 406, meanwhile, in the sliding process, the top bar 413 and the bottom bar 412 contact the clamping groove of the chute frame 406 to support the resistance when turning materials, the inclination of the second screw block 408 is limited when the turning resistance is large, the turning resistance is prevented from being born by the second screw block 408 and the second screw 409, meanwhile, in the sliding process, the top bar 413 is matched with the rotating ball 411 to reduce the sliding resistance, the inclined surfaces at two ends of the bottom bar 412 are matched with the shovel groove bar 415 to clean the clamping groove below, and the turning scraps are prevented from splashing to fall into the clamping groove to cause blockage.
In the cutter mechanism 3, through the connection of the fixing seat 31 and the fixing plate 410, the fourth motor 32 and the transmission shaft 33 are driven to move, so that the cutter head 34 drives the cutter to approach the material for turning, meanwhile, in the cutter head 34, the cutter head 35 is fixed at the cutter groove of the cutter head 34 through the first bolt 37, the cutter head 34 is utilized to drive the cutter head 35 to approach the material, so that the cutter head 35 contacts with the material rotating at a high speed, the turning work is realized, and meanwhile, when the cutter head 35 turns the material, the two sides of the cutter head 35 are limited through the side clamping plates 36 at the two sides, and the cutter head 35 is clamped.
It is noted that relational terms such as first and second, and the like are 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. Moreover, 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. Without further limitation, an element defined by the phrase "comprising one does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises an element.
Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made therein without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.