Cleaning mechanism for automatic spraying device for rubber production and operation method
Technical Field
The invention relates to the technical field of rubber production, in particular to a cleaning mechanism for an automatic spraying device for rubber production and an operation method.
Background
The traditional Chinese patent document with the bulletin number of CN211359330U discloses a rubber production coloring device, which is used for providing a rubber product with various colors, generally coloring the rubber product by two modes of early-stage addition and later-stage spraying, and the formed rubber product is generally subjected to surface coloring by spraying pigment through the coloring device, but the traditional coloring device has limited spraying angle, uneven coloring can be caused, color difference areas are caused on the surface of the product, and the multi-shaft mechanical arm is adopted for spraying, so that the cost is high, the spraying efficiency can be greatly reduced, and the quick production of the product is not facilitated; the solution is that the height difference between the inner ring and the outer ring can be adjusted through the first hydraulic telescopic rod and the second hydraulic telescopic rod, and the direction of the atomizing nozzle on the inner ring is adjusted through the height difference, so that the spray painting angle is adjusted, the spray painting four corners are reduced, and the color difference or the insufficient spray in the local area is prevented from leaking the ground color; and moreover, the outer ring is driven by the incomplete gear to repeatedly and transversely rotate, so that the tail end of the liquid supply pipe is driven to synchronously move, the left-right direction regular change of the inner ring atomizing nozzle is realized, the spraying effect is more uniform, and the chromatic aberration generated by uneven spraying is reduced.
According to the scheme and the prior art, more pigment residues are easily adhered to the nozzle positions of the coloring spraying device for rubber products after long-time use, so that the spraying coloring operation of different colors is influenced, and the problem of blockage is possibly caused; existing spraying devices lack a corresponding cleaning mechanism to remove their residues.
Therefore, a cleaning mechanism for an automatic spraying device for rubber production is needed to solve the problem that the spraying and coloring device for rubber products lacks a cleaning auxiliary mechanism in the prior art, and improve the working benefit of rubber spraying and coloring.
Disclosure of Invention
The invention aims to provide a cleaning mechanism for an automatic spraying device for rubber production and an operation method thereof, so as to solve the problem that a spraying and coloring device for rubber products lacks a cleaning auxiliary mechanism in the prior art, which is proposed in the background art, and improve the working benefit of rubber spraying and coloring.
In order to achieve the above purpose, the present invention provides the following technical solutions: a cleaning mechanism for an automatic spraying device for rubber production comprises a cleaning auxiliary assembly and a cleaning brush assembly; the cleaning auxiliary assembly is arranged on the bearing frame, the bearing frame is fixedly arranged on the conveying device, the supporting frame is connected to the bottom side of the conveying device, rubber products are placed on the conveying device, the conveying device conveys the rubber products, the spraying box is symmetrically connected to the inner side of the bearing frame, one end of the spraying box is connected with the coloring pigment connecting pipe, the spray heads are arranged at the bottom side equidistance of the spraying box, the cleaning auxiliary assembly is arranged at the side position of the spraying box, and the cleaning brush assembly is arranged in the cleaning auxiliary assembly.
Preferably, the cleaning auxiliary assembly comprises a telescopic control cylinder, a connecting disc, a rotary control motor, a connecting rotating shaft, a connecting block body, a butt joint slot, a first connecting threaded hole, a fastening screw, a butt joint plugboard, a positioning clamping groove, a connecting extension plate, a spraying limiting frame, an end limiting plate, a containing clamping groove, a second connecting threaded hole, a placing clamping body, a stabilizing clamping groove, a bearing plate, a fastening threaded column and a handle; the telescopic control cylinder is fixedly arranged at the top of the bearing frame, one end of the telescopic control cylinder extends to the inner side of the bearing frame, the end part of the telescopic control cylinder is fixedly provided with a connecting disc, the rotary control motor is fixedly arranged at the bottom side of the connecting disc, an output shaft of the rotary control motor is fixedly connected with a connecting rotating shaft, a connecting block body is fixedly arranged at the bottom end of the connecting rotating shaft, butt joint slots are symmetrically arranged at two sides of the connecting block body, first connecting threaded holes are symmetrically arranged at side positions of the butt joint slots, fastening screws are arranged in the first connecting threaded holes in a threaded manner in a matched manner, the butt joint slots are matched and spliced with the butt joint plugboard, positioning clamping grooves are symmetrically arranged on the butt joint plugboard, the butt-joint inserting plate is fixedly arranged at one end of the connecting extending plate, the other end of the connecting extending plate is fixedly provided with a spraying limiting frame, the end part of the spraying limiting frame is fixedly provided with an end limiting plate, the spraying limiting frame is provided with a holding clamping groove, two ends of the holding clamping groove are symmetrically provided with second connecting threaded holes, and hold the draw-in groove and place the looks adaptation joint of card, place the fixed bottom side that sets up at the loading board of card body, the both ends of placing the card body are provided with firm draw-in groove, fastening screw thread post and second connecting screw hole looks adaptation threaded connection, and the fixed handle that is provided with of one end of fastening screw thread post, be provided with cleaning brush subassembly on the loading board.
Preferably, the positioning clamping groove is provided with a circular groove, the positioning clamping groove is corresponding to the first connecting threaded hole in arrangement position and the number of the arrangement groups is the same, and one end of the fastening screw is in fit and clamping connection with the positioning clamping groove.
Preferably, the fixing clamping groove is a circular groove, and the fixing clamping groove is corresponding to the second connecting threaded hole in setting position and the same in setting group number, and is in fit and clamping connection with one end of the fastening threaded column.
Preferably, the handle is a cylindrical handle, and the outer side wall of the handle is sleeved with a rotary auxiliary anti-skid sleeve.
Preferably, the cleaning brush assembly comprises a connecting thread groove, an external thread bearing column, a rotary auxiliary bump, a bucket-shaped drainage groove, a storage groove, a cleaning brush main body, an auxiliary cotton ball, an arc-shaped elastic piece, an auxiliary round hole, a residue absorbing cotton ball and a dirt removing barb; the utility model discloses a cleaning brush, including outer thread bearing post, connecting screw thread recess equidistance sets up on the loading board, and connecting screw thread recess and outer thread bearing post looks adaptation threaded connection, the fixed supplementary lug that is provided with of rotation of one end avris position equidistance of outer thread bearing post, bucket formula drainage groove sets up on the terminal surface of outer thread bearing post one end, and the bottom of bucket formula drainage groove is provided with stores the recess, store the recess setting in the outer thread bearing post, cleaning brush main part equidistance is the annular setting on the terminal surface of outer thread bearing post one end, and is provided with supplementary cotton ball on the cleaning brush main part fixedly, the fixed arc elastic disc that is provided with of tip equidistance of cleaning brush main part, run through on the arc elastic disc and be provided with supplementary round hole, and the fixed scrubbing barb that is provided with of symmetry on the arc elastic disc lateral wall.
Preferably, the storage groove is a cylindrical groove, and the axes of the storage groove and the external thread bearing column are on the same straight line.
Preferably, the number of the arc-shaped elastic sheets arranged at equal intervals is eight, the eight arc-shaped elastic sheets form an elastic spherical shell, and the residue absorbing cotton balls are placed in the elastic spherical shell.
Preferably, the four dirt removing barbs are arranged on the outer side of the arc-shaped elastic sheet, two dirt removing barbs are arranged on the upper half part of the arc-shaped elastic sheet, and the dirt removing barbs are downward; two arc elastic sheets are arranged at the lower half part of the arc elastic sheet, and the dirt removing barbs are upward.
The application method of the cleaning mechanism for the automatic spraying device for rubber production comprises the following steps:
the rubber product is carried through conveyor, when through bearing the frame position, carries out the spraying work of coloring to the rubber product through the spraying box and the shower nozzle that set up on bearing the frame, cleans the spout residue of shower nozzle after the spraying work is accomplished, cleans through the cooperation use between clean auxiliary assembly and the clean brush subassembly that sets up promptly.
Compared with the prior art, the invention has the beneficial effects that:
The cleaning mechanism for the automatic spraying device for rubber production is mainly used for cleaning the nozzle residues of the spray nozzle at the bottom side of the spraying box through the cooperation of the cleaning auxiliary component and the cleaning brush component, so that the problems of influence on the spraying coloring work of different colors and blockage are avoided; therefore, the invention provides a corresponding cleaning mechanism for removing residues, and improves the working benefit of rubber spraying and coloring.
Drawings
FIG. 1 is a schematic diagram showing the connection of an automatic spraying device for rubber production;
FIG. 2 is an enlarged schematic view of a partial structure connection of FIG. 1 according to the present invention;
FIG. 3 is a schematic view of the connection of the inventive carrier to the spray box, cleaning assistance assembly, and cleaning brush assembly;
FIG. 4 is a schematic view of the attachment of the cleaning auxiliary assembly to the cleaning brush assembly of the present invention;
FIG. 5 is a schematic view of the connection of the cleaning auxiliary assembly structure of the present invention;
FIG. 6 is an enlarged schematic view of the partial structural connection of FIG. 5 in accordance with the present invention;
FIG. 7 is a schematic view of the connection of the spray coating limit frame and the end limit plate structure in the cleaning auxiliary assembly of the present invention;
FIG. 8 is an enlarged schematic view of a partial structural connection of FIG. 7 in accordance with the present invention;
FIG. 9 is a schematic view of the structural connection of the carrier plate and the cleaning brush assembly of the present invention;
FIG. 10 is a schematic view of a cleaning brush assembly according to the present invention;
FIG. 11 is a schematic view showing the connection of the main cleaning brush body structure of the cleaning brush assembly according to the present invention;
FIG. 12 is an enlarged schematic view of a partial structural connection of FIG. 11 in accordance with the present invention;
FIG. 13 is a schematic view showing the attachment of the replacement assembly to the cleaning brush main body structure of the present invention;
Fig. 14 is an enlarged schematic view of a part of the structure of fig. 13 according to the present invention.
In the figure: the cleaning device comprises a conveying device 1, a supporting frame 2, a rubber product 3, a bearing frame 4, a spraying box 5, a coloring pigment connecting pipe 6, a spray head 7, a cleaning auxiliary assembly 8, a telescopic control cylinder 801, a connecting disc 802, a rotary control motor 803, a connecting rotating shaft 804, a connecting block 805, a docking slot 806, a first connecting threaded hole 807, a fastening screw 808, a docking plug 809, a positioning clamping groove 810, a connecting extension plate 811, a spraying limiting frame 812, an end limiting plate 813, a containing clamping groove 814, a second connecting threaded hole 815, a placing clamping body 816, a stabilizing clamping groove 817, a bearing plate 818, a fastening threaded column 819, a handle 820, a cleaning brush assembly 9, a connecting threaded groove 901, an external threaded bearing column 902, a rotating auxiliary bump 903, a bucket-shaped drainage groove 904, a storage groove 905, a cleaning brush main body 906, an auxiliary cotton ball 907, an arc-shaped elastic piece 908, an auxiliary round hole 909, a residue absorbing cotton ball 910, a dirt removing barb 911, a cleaning cotton ball 1001, a connecting auxiliary body 1002, a cleaning auxiliary scraping bar 1003 and a scraping convex particle 1004.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below. Embodiments of the present invention are intended to be within the scope of the present invention as defined by the appended claims.
Embodiment one: referring to fig. 1 and 5, a cleaning mechanism for an automatic spraying device for rubber production comprises a cleaning auxiliary assembly 8 and a cleaning brush assembly 9; the cleaning auxiliary assembly 8 is arranged on the bearing frame 4, the bearing frame 4 is fixedly arranged on the conveying device 1, the supporting frame 2 is connected to the bottom side of the conveying device 1, rubber products 3 are placed on the conveying device 1, the conveying device 1 conveys the rubber products 3, the inner side of the bearing frame 4 is symmetrically connected with the spraying box 5, one end of the spraying box 5 is connected with the coloring pigment connecting pipe 6, the nozzle 7 is equidistantly arranged on the bottom side of the spraying box 5, the cleaning auxiliary assembly 8 is arranged at the side position of the spraying box 5, and the cleaning brush assembly 9 is arranged in the cleaning auxiliary assembly 8; the rubber product 3 is conveyed through the conveying device 1, and when the rubber product 3 passes through the position of the bearing frame 4, the rubber product 3 is subjected to coloring spraying work through the spraying box 5 and the spray head 7 which are arranged on the bearing frame 4, and after the spraying work is finished, the nozzle residues of the spray head 7 are cleaned, namely, the cleaning auxiliary assembly 8 and the cleaning brush assembly 9 are matched for use.
Further solves the problem that the spraying and coloring device of the rubber product in the prior art lacks a cleaning auxiliary mechanism, and improves the working benefit of rubber spraying and coloring.
Embodiment two: on the basis of the first embodiment, referring to fig. 2-4 and 6-8, the cleaning auxiliary assembly 8 includes a telescopic control cylinder 801, a connecting disc 802, a rotary control motor 803, a connecting shaft 804, a connecting block 805, a docking slot 806, a first connecting threaded hole 807, a fastening screw 808, a docking board 809, a positioning clamping groove 810, a connecting extension plate 811, a spraying limiting frame 812, an end limiting plate 813, a receiving clamping groove 814, a second connecting threaded hole 815, a placing clamping body 816, a stabilizing clamping groove 817, a bearing plate 818, a fastening threaded column 819, and a handle 820; the telescopic control cylinder 801 is fixedly arranged at the top of the bearing frame 4, one end of the telescopic control cylinder 801 extends to the inner side of the bearing frame 4, a connecting disc 802 is fixedly arranged at the end part of the telescopic control cylinder 801, a rotary control motor 803 is fixedly arranged at the bottom side of the connecting disc 802, an output shaft of the rotary control motor 803 is fixedly connected with a connecting rotating shaft 804, a connecting block 805 is fixedly arranged at the bottom end of the connecting rotating shaft 804, docking slots 806 are symmetrically arranged at two sides of the connecting block 805, first connecting threaded holes 807 are symmetrically arranged at side positions of the docking slots 806, fastening screws 808 are arranged in the first connecting threaded holes 807 in a matched threaded manner, the docking slots 806 are matched and inserted with the docking plug 809, positioning clamping grooves 810 are symmetrically arranged on the docking plug 809, circular grooves are formed in the positioning clamping grooves 810, the positioning clamping grooves 810 correspond to the first connecting threaded holes 807 in the setting positions, the same in the number of setting groups, and one ends of the fastening screws 808 are matched and clamped with the positioning clamping grooves 810; the docking board 809 is fixedly arranged at one end of the connecting extension board 811, the other end of the connecting extension board 811 is fixedly provided with a spraying limiting frame 812, the end part of the spraying limiting frame 812 is fixedly provided with an end limiting board 813, the spraying limiting frame 812 is provided with a holding clamping groove 814, two ends of the holding clamping groove 814 are symmetrically provided with second connecting threaded holes 815, the holding clamping groove 814 is in adaptive clamping connection with the holding clamping body 816, the holding clamping body 816 is fixedly arranged at the bottom side of the bearing board 818, two ends of the holding clamping body 816 are provided with stable clamping grooves 817, fastening threaded columns 819 are in adaptive threaded connection with the second connecting threaded holes 815, one end of the fastening threaded columns 819 is fixedly provided with a handle 820, and the bearing board 818 is provided with a cleaning brush assembly 9; the fixing clamping groove 817 is a circular groove, the fixing clamping groove 817 and the second connecting threaded hole 815 are corresponding in arrangement position and same in arrangement group number, and the fixing clamping groove 817 is in fit and clamping connection with one end of the fastening threaded column 819; the handle 820 is a cylindrical handle, and the outer side wall of the handle 820 is sleeved with a rotary auxiliary anti-skid sleeve; the spraying limiting frame 812 is pushed down by the telescopic control cylinder 801 until the cleaning brush assembly 9 arranged at the top end of the spraying limiting frame 812 reaches the bottom position of the spray head 7, and then the spraying limiting frame 812 is driven to rotate by the arranged rotary control motor 803, so that the cleaning brush assembly 9 cleans residues of the spray nozzle 7; and the carrying plate 818 can be disassembled, so that the cleaning brush assembly 9 can be conveniently and integrally operated and maintained at a later stage.
Further solves the problem that the spraying and coloring device of the rubber product in the prior art lacks a cleaning auxiliary mechanism, and improves the working benefit of rubber spraying and coloring.
Embodiment III: on the basis of the second embodiment, referring to fig. 5 and 9-12, the cleaning brush assembly 9 is equidistantly disposed on the supporting plate 818, and the cleaning brush assembly 9 includes a connecting threaded groove 901, an external threaded supporting column 902, a rotation auxiliary bump 903, a bucket-shaped drainage groove 904, a storage groove 905, a cleaning brush main body 906, an auxiliary cotton ball 907, an arc-shaped elastic piece 908, an auxiliary round hole 909, a residue absorbing cotton ball 910, and a dirt removing barb 911; the connecting thread grooves 901 are equidistantly formed in the bearing plate 818, the connecting thread grooves 901 are in adaptive threaded connection with the external thread bearing column 902, a rotation auxiliary projection 903 is fixedly arranged at the side position of one end side of the external thread bearing column 902 at equal intervals, the bucket-shaped drainage groove 904 is formed in the end face of one end of the external thread bearing column 902, the bottom end of the bucket-shaped drainage groove 904 is provided with a storage groove 905, the storage groove 905 is a cylindrical groove, and the axial leads of the storage groove 905 and the external thread bearing column 902 are on the same straight line; the storage groove 905 is arranged in the external thread bearing column 902, the cleaning brush main body 906 is equidistantly and annularly arranged on the end face of one end of the external thread bearing column 902, the cleaning brush main body 906 is fixedly provided with auxiliary cotton balls 907, the end part of the cleaning brush main body 906 is equidistantly and fixedly provided with arc-shaped elastic pieces 908, eight arc-shaped elastic pieces 908 are equidistantly arranged, an elastic spherical shell is formed by the eight arc-shaped elastic pieces 908, and residue absorbing cotton balls 910 are placed in the elastic spherical shell; auxiliary round holes 909 are formed in the arc-shaped elastic pieces 908 in a penetrating manner, and dirt removing barbs 911 are symmetrically and fixedly arranged on the outer side walls of the arc-shaped elastic pieces 908; four dirt removing barbs 911 are arranged outside the arc-shaped elastic sheet 908, two dirt removing barbs 911 are arranged at the upper half part of the arc-shaped elastic sheet 908, and the direction of the dirt removing barbs 911 is downward; two dirt removing barbs 911 are arranged on the lower half part of the arc-shaped elastic sheet 908; the purpose of the bucket-type drainage groove 904 and the storage groove 905 arranged in the external thread bearing column 902 is to have a certain storage function on clean residues or liquid pigment, so that the waste can be prevented while splashing is avoided as much as possible; the external thread bearing post 902 is fixedly arranged on the bearing plate 818 through being in threaded connection with the connecting thread groove 901, so that when the cleaning brush main body 906 on one external thread bearing post 902 is destroyed and needs to be replaced, the cleaning brush main body can be partially replaced, the whole replacement is not needed, the use benefit is improved, and under long-time working, when all the cleaning brush assemblies 9 on the bearing plate 818 need to be replaced or detached and maintained, the bearing plate 818 can be directly detached and can be integrally detached; the auxiliary cotton ball 907 and the elastic spherical shell on the cleaning brush main body 906 are used for cleaning the spray head 7, and the effect of arranging the dirt removing barbs 911 on the elastic spherical shell is that the elastic spherical shell and the dirt removing barbs 911 are matched to clean residues on the inner side of the spray nozzle 7, namely the elastic spherical shell enters the spray nozzle 7, the dirt removing barbs 911 arranged on the outer side wall of the elastic spherical shell scrape the inner side wall of the spray nozzle, or adhering and solidifying impurities are scraped and loosened, and when the subsequent cleaning brush reaches the position, the condensed residues can be scraped, so that the cleaning work quality of the cleaning brush is improved; the residue absorbing cotton ball 910 arranged in the inner cavity of the elastic ball shell can absorb the liquid pigment, so that splashing is avoided as much as possible; the residue absorbing cotton ball 910 provided herein swings along with the swing of the elastic ball shell and the cleaning brush main body 906, so that not only can liquid pigment in the cleaning process be adsorbed, but also the cleaning agent can be directly sprayed on the residue absorbing cotton ball 910 when the corresponding cleaning agent is needed in the cleaning process, thereby improving the turnover utilization rate and avoiding waste;
The brush main body 906 is made of a high-elasticity hard plastic structure, when the brush main body 906 rotates along with the spraying limiting frame 812 in the forward and backward directions, part of elastic spherical shells on the external thread bearing column 902 are elastically inserted into the inner side of the nozzle of the spray head 7, the nozzle is ejected out under the action of the moving spraying limiting frame 812, the inner side of the nozzle of the spray head 7 is scraped and cleaned during the process, and the cleaning effect of the inner side of the nozzle of the spray head 7 is achieved along with repeated rotation of the spraying limiting frame 812 in the forward and backward directions for a plurality of times;
Further solves the problem that the spraying and coloring device of the rubber product in the prior art lacks a cleaning auxiliary mechanism, and improves the working benefit of rubber spraying and coloring.
Embodiment four: on the basis of the third embodiment, referring to fig. 13-14, the present invention further provides a replacement component, where the replacement component includes a cleaning cotton ball 1001, a connection auxiliary body 1002, a cleaning auxiliary scraping bar 1003, and a scraping protrusion 1004; the cleaning cotton balls 1001 are fixedly provided on the cleaning brush main body 906 in two, wherein one cleaning cotton ball 1001 is fixedly provided at an end portion of the cleaning brush main body 906, and cleaning auxiliary scraping strips 1003 are provided between the cleaning cotton balls 1001 on the adjacent cleaning brush main bodies 906, the cleaning auxiliary scraping strips 1003 and the cleaning cotton balls 1001 are fixedly connected through the connection auxiliary body 1002, and scraping convex particles 1004 are equidistantly provided on the cleaning auxiliary scraping strips 1003.
The replacement component is arranged here, so that on one hand, the cleaning flexibility is improved, on the other hand, impurity particles which are difficult to clean at the side of the glue spraying opening can be scraped, the scraping convex particles 1004 arranged on the cleaning auxiliary scraping strip 1003 are arranged in a straight line at equal intervals, and the adjacent scraping convex particles 1004 are arranged in a staggered manner, so that the missing scraping caused by scraping during the cleaning operation is avoided, and the cleaning effect is further improved;
According to fig. 5 to 6 and 13, the cleaning brush main body 906 having the elastic spherical shell and the auxiliary scraping strip 1003 is provided on the two bearing plates 818, respectively, and the inner side and the side of the shower head 7 can be cleaned simultaneously when the spraying limiting frame 812 rotates, so that the cleaning effect is excellent;
Further solves the problem that the spraying and coloring device of the rubber product in the prior art lacks a cleaning auxiliary mechanism, and improves the working benefit of rubber spraying and coloring.
Fifth embodiment: on the basis of the fourth embodiment, referring to fig. 1 to 14, the invention provides a method for using a cleaning mechanism for an automatic spraying device for rubber production, comprising the following steps:
Step one: conveying the rubber product 3 by the conveying device 1;
Step two: when the rubber product 3 passes through the position of the bearing frame 4, the rubber product 3 is subjected to coloring spraying work through the spraying box 5 and the spray head 7 which are arranged on the bearing frame 4, namely, the spraying work is carried out on the rubber product 3 through the matching use of the spraying box 5 and the spray head 7;
Step three: after the spraying work is finished, the nozzle residues of the spray head 7 are cleaned, namely, the spray head is cleaned through the matched use between the cleaning auxiliary assembly 8 and the cleaning brush assembly 9, the spraying limiting frame 812 is pushed down through the telescopic control cylinder 801 until the cleaning brush assembly 9 arranged at the top end of the spraying limiting frame 812 reaches the bottom position of the spray head 7, and the spraying limiting frame 812 is driven to rotate through the rotary control motor 803, so that the nozzle residues of the spray head 7 are cleaned by the cleaning brush assembly 9; the purpose of arranging the bucket-shaped drainage groove 904 and the storage groove 905 in the external thread bearing column 902 is to have a certain storage function on clean residues or liquid pigment, so that the waste can be prevented while splashing is avoided as much as possible; the external thread bearing post 902 is fixedly arranged on the bearing plate 818 through being in threaded connection with the connecting thread groove 901, so that when the cleaning brush main body 906 on one external thread bearing post 902 is destroyed and needs to be replaced and maintained, the cleaning brush main body can be partially detached and replaced, the whole replacement is not needed, and the use benefit is improved; the replacement component is arranged in the process, so that impurity particles which are difficult to clean at the side of the glue spraying opening can be scraped, and the cleaning flexibility of the glue spraying opening is further improved.
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.