阅读说明：本技术 一种铸钢件生产用喷砂抛光装置 (Sand blasting burnishing device is used in steel casting production ) 是由 管雅倩 王义林 董学飞 于 2020-12-07 设计创作，主要内容包括：本发明涉及铸钢件生产装置技术领域,具体公开了一种铸钢件生产用喷砂抛光装置,包括喷砂枪,喷砂枪通过输送管和喷砂机相连接,喷砂枪的下方设置有夹紧台,喷砂枪和夹紧台均设置在加工箱内,加工箱顶部设置有开口,且开口外侧设置有水平的顶箱,顶箱内竖向设置有分隔板,且分隔板一侧水平设置有第一丝杆,第一丝杆上连接有第一螺母,第一螺母底部连接有第一连接柱,顶箱的底部设置有与第一连接柱滑动连接的第一滑槽,第一连接柱的底端连接有第一连接座,且喷砂枪设置在第一连接座的下方；夹紧台内对称设置有第一安装槽,通过设置的夹紧台,调整夹板的间距,方便对不同宽度的铸钢件进行夹紧,方便对铸钢件进行加工处理。(The invention relates to the technical field of steel casting production devices, and particularly discloses a sand blasting polishing device for steel casting production, which comprises a sand blasting gun, wherein the sand blasting gun is connected with a sand blasting machine through a conveying pipe, a clamping table is arranged below the sand blasting gun, the sand blasting gun and the clamping table are both arranged in a processing box, the top of the processing box is provided with an opening, a horizontal top box is arranged outside the opening, a partition plate is vertically arranged in the top box, a first lead screw is horizontally arranged on one side of the partition plate, the first lead screw is connected with a first nut, the bottom of the first nut is connected with a first connecting column, the bottom of the top box is provided with a first chute in sliding connection with the first connecting column, the bottom end of the first connecting column is connected with a first connecting seat, and the sand blasting gun is arranged below the first connecting seat; the symmetry is provided with first mounting groove in pressing from both sides tight platform, through the tight platform of clamp that sets up, adjusts the interval of splint, and the convenience is pressed from both sides tightly the cast steel piece of different width, and the convenience is processed cast steel piece.)

1. The utility model provides a steel casting production is with sandblast burnishing device, includes sand blasting gun (1), its characterized in that: the sand blasting gun (1) is connected with the sand blasting machine (3) through the delivery pipe (2), the clamping table (4) is arranged below the sand blasting gun (1), the sand blasting gun (1) and the clamping table (4) are both arranged in the processing box (20), the top of the processing box (20) is provided with an opening, a horizontal top box (10) is arranged outside the opening, a partition plate (11) is vertically arranged in the top box (10), a first screw rod (12) is horizontally arranged on one side of the partition plate (11), a first nut (13) is connected onto the first screw rod (12), a first connecting column (15) is connected to the bottom of the first nut (13), a first sliding chute (14) in sliding connection with the first connecting column (15) is arranged at the bottom of the top box (10), a first connecting seat (16) is connected to the bottom end of the first connecting column (15), and the sand blasting gun (1) is arranged below the first connecting seat (16); first mounting grooves (41) are symmetrically arranged in the clamping table (4), a third screw rod (42) is horizontally arranged in each first mounting groove (41), a third nut (43) is connected to each third screw rod (42), a first connecting block (44) which is vertically arranged is connected to the top of each third nut (43), a clamping plate (46) is connected to the top end of each first connecting block (44), and a second sliding groove (45) which is connected with the first connecting block (44) in a sliding manner is arranged on the clamping table (4);

a placing table (25) is arranged in the processing box (20), the clamping table (4) is arranged at the top of the placing table (25), a second mounting groove (26) is horizontally arranged in the placing table (25), a fourth screw rod (27) is horizontally arranged in the second mounting groove (26), a fourth nut (29) is connected onto the fourth screw rod (27), a second connecting block (28) is vertically connected onto the top of the fourth nut (29), the top of the second connecting block (28) is connected with the bottom of the clamping table (4), a third sliding groove (30) is arranged on the placing table (25), and the second connecting block (28) is in sliding connection with the third sliding groove (30).

2. The sand blasting and polishing device for producing the steel castings according to claim 1, wherein: a second screw rod (17) is arranged on the other side of the partition plate (11), a second nut (18) is connected onto the second screw rod (17), a second connecting column (151) is connected to the bottom of the second nut (18), the second connecting column (151) is in sliding connection with the first sliding groove (14), a second connecting seat (19) is connected to the bottom end of the second connecting column (151), and a water outlet nozzle (5) and a hot air nozzle (6) are arranged at the bottom of the second connecting seat (19).

3. The sand blasting and polishing device for producing the steel castings according to claim 1, wherein: a water storage tank (7) is arranged on one side of the processing tank (20), a water pump (8) and a hot air blower (9) are arranged on the top of the water storage tank (7), one side of the water pump (8) is connected with the water storage tank (7) through a pipeline, the other side of the water pump (8) is connected with a water outlet nozzle (5) through a pipeline, and the hot air blower (9) is connected with a hot air nozzle (6) through a pipeline.

4. The sand blasting and polishing device for producing the steel castings according to claim 1, wherein: the side wall of the processing box (20) is provided with a vent (22), two sides of the processing box (20) are connected with stop doors (23), and each stop door (23) is provided with a transparent observation window.

5. The sand blasting and polishing device for producing the steel castings according to claim 1, wherein: the clamping plates (46) are of L-shaped structures, elastic pads (47) are arranged on one side of each clamping plate (46), and the elastic pads (47) are of rubber material structures.

6. The sand blasting and polishing device for producing the steel castings according to claim 1, wherein: the two ends of the top box (10) are provided with openings, the outer sides of the two openings are provided with baffles, the outer side of each baffle is provided with a first driving motor (21), and one ends of the first screw rod (12) and the second screw rod (17) are connected with a motor shaft of the first driving motor (21) through connecting shafts.

7. The sand blasting and polishing device for producing the steel castings according to claim 1, wherein: connecting shafts are arranged at two ends of the fourth screw rod (27), the connecting shaft at one end of the fourth screw rod (27) is connected with a motor shaft of the second driving motor (24), and a shaft hole connected with the connecting shaft at the other end of the fourth screw rod (27) is formed in the placing table (25).

8. The sand blasting and polishing device for producing the steel castings according to claim 1, wherein: the sand blasting machine (3) is arranged on the outer side of the processing box (20), the control box is arranged at the top of the sand blasting machine (3), a plurality of control buttons are arranged on the control box, and the control buttons are electrically connected with the sand blasting machine (3), the water pump (8), the air heater (9), the first driving motor (21) and the second driving motor (24) correspondingly.

9. The sand blasting and polishing device for producing the steel castings according to claim 1, wherein: connecting shafts are arranged at two ends of each third screw rod (42), baffles are arranged at two ends of each clamping table (4), the connecting shafts at one ends of the third screw rods (42) penetrate through the baffles and are connected with rotating discs, and shaft holes connected with the connecting shafts at the other ends of the third screw rods (42) are formed in the clamping tables (4).

Technical Field

The invention relates to the technical field of steel casting production devices, in particular to a sand blasting and polishing device for steel casting production.

Background

The steel casting is a part made of cast steel, has similar performance with cast iron, but has better strength than the cast iron, has strong adaptability and variability in metallurgical manufacturing, can select different chemical compositions and structure control, and is suitable for the requirements of various different projects; mechanical properties and service performance can be selected in a larger range through different heat treatment processes, and the welding performance and the processing performance are good; in the production process of the steel casting, a sand blasting machine is needed to perform sand blasting polishing treatment on the steel casting, so that the surface of the steel casting can obtain certain cleanliness and different roughness, and the mechanical property of the surface of the steel casting is improved. The sandblast polishing equipment that uses at present, the sandblast in-process, if the fixed effect of steel casting is poor, can lead to the steel casting to shift, leads to the sandblast failure, causes the steel casting to damage, produces the loss, and the steel casting surface is stained with the dust and also can influence the effect of sandblast.

Disclosure of Invention

The invention aims to provide a sand blasting and polishing device for producing steel castings, which aims to solve the problems in the background technology.

In order to achieve the purpose, the invention provides the following technical scheme: a sand blasting polishing device for production of steel castings comprises a sand blasting gun, wherein the sand blasting gun is connected with a sand blasting machine through a conveying pipe, a clamping table is arranged below the sand blasting gun, the sand blasting gun and the clamping table are arranged in a processing box, the top of the processing box is provided with an opening, a horizontal top box is arranged outside the opening, a partition plate is vertically arranged in the top box, a first lead screw is horizontally arranged on one side of the partition plate, a first nut is connected onto the first lead screw, the bottom of the first nut is connected with a first connecting column, a first sliding groove in sliding connection with the first connecting column is arranged at the bottom of the top box, the bottom end of the first connecting column is connected with a first connecting seat, and the sand blasting gun is arranged below the first connecting seat; first mounting grooves are symmetrically formed in the clamping table, a third lead screw is horizontally arranged in each first mounting groove, a third nut is connected to each third lead screw, the top of each third nut is connected with a vertically arranged first connecting block, the top end of each first connecting block is connected with a clamping plate, and a second sliding groove in sliding connection with the first connecting block is formed in the clamping table;

the processing box is internally provided with a placing table, the clamping table is arranged at the top of the placing table, a second mounting groove is horizontally arranged in the placing table, a fourth screw rod is horizontally arranged in the second mounting groove, a fourth nut is connected onto the fourth screw rod, the top of the fourth nut is vertically connected with a second connecting block, the top of the second connecting block is connected with the bottom of the clamping table, a third sliding groove is formed in the placing table, and the second connecting block is connected with the third sliding groove in a sliding mode.

By adopting the technical scheme: the rotation of third lead screw drives the third nut and removes to first connecting block begins to remove, drives splint and removes, adjusts the interval of two splint, presss from both sides tightly the steel casting, and when the fourth lead screw rotated, drive the fourth nut and remove, drives the second connecting block and removes at the third spout, conveniently drives and presss from both sides tight platform and removes placing the platform, removes the steel casting to the below of sand blasting rifle.

Preferably, a second screw rod is arranged on the other side of the partition plate, a second nut is connected onto the second screw rod, a second connecting column is connected to the bottom of the second nut, the second connecting column is connected with the first sliding groove in a sliding mode, a second connecting seat is connected to the bottom end of the second connecting column, and a water outlet nozzle and a hot air nozzle are arranged at the bottom of the second connecting seat.

By adopting the technical scheme: the rotation of second lead screw drives the interior removal of second spiral shell, and the second spliced pole slides in first spout to drive the second connecting seat and remove, remove the position of going out water shower nozzle and hot-blast shower nozzle.

Preferably, a water storage tank is arranged on one side of the processing tank, a water pump and an air heater are arranged at the top of the water storage tank, one side of the water pump is connected with the water storage tank through a pipeline, the other side of the water pump is connected with a water outlet nozzle through a pipeline, and the air heater is connected with a hot air nozzle through a pipeline.

By adopting the technical scheme: the water pump conveys water in the water storage tank to the water outlet nozzle to clean the steel casting, and the hot air blower is operated to spray the water out of the hot air nozzle to dry the steel casting.

Preferably, the side wall of the processing box is provided with a vent, the two sides of the processing box are both connected with a stop door, and each stop door is provided with a transparent observation window.

By adopting the technical scheme: the ventilation opening is used for replacing air in the processing box, and the transparent observation window is used for conveniently observing the condition in the processing box.

Preferably, the splint are L-shaped structures, and one side of each splint is provided with an elastic cushion, and the elastic cushion is of a rubber material structure.

By adopting the technical scheme: the removal of splint is convenient presss from both sides tightly the cast steel of different width, conveniently processes.

Preferably, the two ends of the top box are provided with openings, the outer sides of the two openings are provided with baffles, the outer side of each baffle is provided with a first driving motor, and one ends of the first screw rod and the second screw rod are connected with a motor shaft of the first driving motor through a connecting shaft.

By adopting the technical scheme: the first driving motor is connected with the first screw rod and the second screw rod through the motor shaft respectively, and the first screw rod and the second screw rod are conveniently driven to rotate.

Preferably, the two ends of the fourth screw rod are provided with connecting shafts, the connecting shaft at one end of the fourth screw rod is connected with a motor shaft of the second driving motor, and a shaft hole connected with the connecting shaft at the other end of the fourth screw rod is formed in the placing table.

By adopting the technical scheme: the second driving motor is connected with the fourth screw rod through a motor shaft, and the fourth screw rod is conveniently driven to rotate.

Preferably, the sandblasting machine sets up in the outside of processing case, and the sandblasting machine top is provided with the control box, is provided with a plurality of control button on the control box, and control button corresponds electric connection with sandblasting machine, water pump, air heater, first driving motor and second driving motor.

By adopting the technical scheme: the control button drives the sand blasting machine, the water pump, the air heater, the first driving motor and the second driving motor to work.

Preferably, both ends of each third screw rod are provided with connecting shafts, both ends of each clamping table are provided with baffles, the connecting shafts at one ends of the third screw rods penetrate through the baffles and are connected with rotating discs, and shaft holes connected with the connecting shafts at the other ends of the third screw rods are formed in the clamping tables.

By adopting the technical scheme: the third screw rod is connected with the rotating disc through a connecting shaft, and then the rotating disc drives the third screw rod to rotate, so that the third nut is driven to move.

Compared with the prior art, the invention has the beneficial effects that: through the tight platform of clamp that sets up, the interval of adjustment splint, the convenience is pressed from both sides tightly the steel casting of different width, the convenience is processed the steel casting, the rotation of fourth lead screw, the fourth nut drives the second connecting block and slides in the third spout, it removes to drive the tight platform of clamp, the convenience removes the steel casting, go out the setting of water shower nozzle and hot air blast nozzle, the convenient steel casting to the sandblast polishing washs and dries, avoid the dust on the steel casting to influence the sandblast and handle, bring facility for sandblast work.

Drawings

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

FIG. 2 is an overall front view of the present invention;

FIG. 3 is a schematic view of the clamping table of the present invention;

fig. 4 is a bottom view of the second connecting seat of the present invention.

In the figure: 1. a sand blasting gun; 2. a delivery pipe; 3. a sand blasting machine; 4. a clamping table; 5. a water outlet nozzle; 6. a hot air shower nozzle; 7. a water storage tank; 8. a water pump; 9. a hot air blower; 10. a top box; 11. a partition plate; 12. a first lead screw; 13. a first nut; 14. a first chute; 15. a first connecting column; 151. a second connecting column; 16. a first connecting seat; 17. a second lead screw; 18. a second nut; 19. a second connecting seat; 20. a processing box; 21. a first drive motor; 22. a vent; 23. a shutter; 24. a second drive motor; 25. a placing table; 26. a second mounting groove; 27. a fourth screw rod; 28. a second connecting block; 29. a fourth nut; 30. a third chute; 41. a second mounting groove; 42. a third screw rod; 43. a third nut; 44. a first connection block; 45. a second chute; 46. a splint; 47. an elastic pad.

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.

In the description of the present invention, it should be noted that the terms "vertical", "upper", "lower", "horizontal", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of describing the present invention and simplifying the description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention.

In the description of the present invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

Referring to fig. 1-4, the present invention provides a technical solution: a sand blasting polishing device for producing steel castings comprises a sand blasting gun 1, wherein the sand blasting gun 1 is connected with a sand blasting machine 3 through a conveying pipe 2, the sand blasting machine 3 conveys materials into the sand blasting gun 1 through the conveying pipe 2 in work, the sand blasting gun 1 ejects the materials to perform sand blasting polishing treatment on the steel castings, a clamping table 4 is arranged below the sand blasting gun 1, the clamping table 4 is convenient for clamping the processed steel castings, the sand blasting gun 1 and the clamping table 4 are both arranged in a processing box 20, the processing box 20 is convenient for processing the steel castings, an opening is formed in the top of the processing box 20, a horizontal top box 10 is arranged outside the opening, a partition plate 11 is vertically arranged in the top box 10, a first lead screw 12 is horizontally arranged on one side of the partition plate 11 through a connecting shaft, a first nut 13 is connected onto the first lead screw 12, the first lead screw 12 rotates to drive the first nut 13 to move, the bottom of the first nut 13 is connected with a first connecting column 15, the bottom of the top box 10 is provided with a first sliding chute 14 which is in sliding connection with the first connecting column 15, the first nut 13 moves to drive the first connecting column 15 to slide in the first sliding chute 14, the bottom end of the first connecting column 15 is connected with a first connecting seat 16, the first connecting seat 16 is driven to move by the sliding of the first connecting column 15, the sand blasting gun 1 is arranged below the first connecting seat 16, and the movement of the first connecting seat 16 is convenient to drive the sand blasting gun 1 to move, so that the sand blasting part of the cast steel is moved, and the sand blasting treatment on the cast steel is fully performed; first mounting grooves 41 are symmetrically arranged in the clamping table 4, a third screw rod 42 is horizontally arranged in each first mounting groove 41, the third screw rods 42 are mounted in the first mounting grooves 41 through connecting shafts, each third screw rod 42 is connected with a third nut 43, the third screw rods 42 rotate to drive the third nuts 43 to move, the top of each third nut 43 is connected with a vertically arranged first connecting block 44, the third nuts 43 drive the first connecting blocks 44 to move, the top ends of the first connecting blocks 44 are connected with clamping plates 46, the movement of the first connecting blocks 44 drives the clamping plates 46 to move, the distance between the two clamping plates 46 is adjusted, a second sliding groove 45 connected with the first connecting blocks 44 in a sliding manner is arranged on the clamping table 4, and the first connecting blocks 44 slide in the second sliding groove 45;

a placing table 25 is arranged in the processing box 20, the clamping table 4 is arranged at the top of the placing table 25, a second installation groove 26 is horizontally arranged in the placing table 25, a fourth screw 27 is horizontally arranged in the second installation groove 26, the fourth screw 27 is installed in the second installation groove 26, a fourth nut 29 is connected on the fourth screw 27, a second connecting block 28 is vertically connected at the top of the fourth nut 29, the movement of the fourth nut 29 drives the second connecting block 28 to move, the top of the second connecting block 28 is connected with the bottom of the clamping table 4, the movement of the second connecting block 28 drives the clamping table 4 to move, a third sliding groove 30 is arranged on the placing table 25, and the second connecting block 28 is slidably connected with the third chute 30, and when the fourth screw 27 rotates, the fourth nut 29 is driven to move, so that the second connecting block 28 is driven to move in the third chute 30, and the clamping table 4 is conveniently driven to move on the placing table 25.

The other side of the partition plate 11 is provided with a second screw rod 17, a second nut 18 is connected to the second screw rod 17, the bottom of the second nut 18 is connected with a second connecting column 151, the second connecting column 151 is connected with a first chute 14 in a sliding manner, the bottom end of the second connecting column 151 is connected with a second connecting seat 19, the bottom of the second connecting seat 19 is provided with a water outlet nozzle 5 and a hot air nozzle 6, the second screw rod 17 rotates to drive the second nut 18 to move, so that the second connecting column 151 is driven to slide in the first chute 14, the second connecting seat 19 is conveniently driven to move, and the positions of the water outlet nozzle 5 and the hot air nozzle 6 are moved.

Processing case 20 one side is provided with water storage tank 7, water storage tank 7 top is provided with water pump 8 and air heater 9, water pump 8 one side is connected with water storage tank 7 through the pipeline, 8 opposite sides of water pump are connected with play water spray head 5 through the pipeline, air heater 9 is connected with hot air spray head 6 through the pipeline, water pump 8's work is spouted in carrying out the water pipe-line transportation to play water spray head 5 with the water in the water storage tank 7, wash the steel casting, air heater 9's work is to the steel casting after the washing drying process.

Be provided with vent 22 on the processing case 20 lateral wall, vent 22 plays the effect of ventilation, and the both sides of processing case 20 all are connected with shutter 23, and all are provided with transparent observation window on every shutter 23, and the processing condition of cast steel spare is conveniently observed to transparent observation window, through opening and shutting of shutter 23, conveniently gets cast steel spare from processing case 20 in and puts.

The clamping plate 46 is of an L-shaped structure, an elastic pad 47 is arranged on one side of each clamping plate 46, the elastic pad 47 is of a rubber material structure, a steel casting is placed on the clamping plate 46, and the elastic pad 47 is driven to be in contact with the steel casting through movement of the clamping plate 46 to compress the elastic pad 47.

The both ends of top case 10 all are provided with the opening, and two open-ended outsides all are provided with the baffle, and the outside of every baffle all is provided with first driving motor 21, and the one end of first lead screw 12 and second lead screw 17 all is connected with the motor shaft of first driving motor 21 from the area through the connecting axle, and first driving motor 21 during operation drives first lead screw 12 and second lead screw 17 through the motor shaft in area and carries out work to first nut 13 and second nut 18 remove.

The two ends of the fourth screw rod 27 are both provided with connecting shafts, the connecting shaft at one end of the fourth screw rod 27 is connected with a motor shaft of the second driving motor 24, a shaft hole connected with the connecting shaft at the other end of the fourth screw rod 27 is formed in the placing table 25, and when the second driving motor 24 works, the fourth screw rod 27 is driven to rotate through the motor shaft of the second driving motor, so that the fourth nut 29 moves.

The sand blasting machine 3 sets up in the outside of processing case 20, and the sand blasting machine 3 top is provided with the control box, is provided with a plurality of control button on the control box, and control button corresponds electric connection with sand blasting machine 3, water pump 8, air heater 9, first driving motor 21 and second driving motor 24, and control button control sand blasting machine 3, water pump 8, air heater 9, first driving motor 21 and second driving motor 24 carry out work.

The two ends of each third screw rod 42 are provided with connecting shafts, the two ends of the clamping table 4 are provided with baffles, the connecting shaft at one end of each third screw rod 42 penetrates through the baffles to be connected with a rotating disc, a shaft hole connected with the connecting shaft at the other end of each third screw rod 42 is formed in the clamping table 4, and the rotating disc drives the third screw rods 42 to rotate so as to drive the third nuts 43 to move.

The working principle is as follows: when in use, the device is electrified, a steel casting is placed on the clamping table 4, the rotating disc connected with the third screw rod 42 is manually driven to rotate, the third screw rod 42 is driven to rotate, the third nut 43 moves, the connecting block 44 is driven to slide in the second sliding groove 45, the clamping plate 46 is driven to move, the steel casting is clamped, then the stop door 23 is closed, the water pump 8 starts to work, the water in the water storage tank 7 is pumped out, through the spraying of the water outlet nozzle 5, when the first driving motor 21 works, the second screw rod 17 is driven to rotate, the second nut 18 drives the second connecting column 151 to slide in the first chute 14, the second connecting seat 19 is driven to move, the water outlet nozzle 5 is driven to move, cleaning the steel casting, after the cleaning is finished, operating the hot air blower 9, and simultaneously controlling the second connecting seat 19 to move to drive the hot air nozzle 6 to move so as to dry the steel casting;

the second driving motor 24 starts to work, the fourth screw rod 27 is driven to rotate through a motor shaft of the second driving motor, the fourth nut 29 starts to move, the second connecting block 28 is driven to slide in the third sliding groove 30, the clamping platform 4 starts to move to the bottom of the sand blasting gun 1, the sand blasting machine 3 starts to work, materials are conveyed through the conveying pipe 2 to be sprayed into the sand blasting gun 1, sand blasting polishing treatment is carried out on the steel casting, meanwhile, the first driving motor 21 works, the first screw rod 12 starts to rotate, the first nut 13 is driven to move, the first connecting column 15 slides in the first sliding groove 14, the first connecting seat 16 is driven to move, the sand blasting gun 1 moves, and sand blasting processing treatment is carried out on the steel casting.

It is worth noting that: the whole device realizes control over the device through the control button, and because the equipment matched with the control button is common equipment, the device belongs to the existing mature technology, and the electrical connection relation and the specific circuit structure of the device are not repeated.

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.