阅读说明：本技术 一种箱包加工生产用注塑设备 (Injection molding equipment is used in case and bag processing production ) 是由 王再德 王胜得 王琼 王印 于 2020-11-01 设计创作，主要内容包括：本发明公开了一种箱包加工生产用注塑设备,包括底板、下料箱、下料机构、输送机构、成型机构,底板的顶部一端设有下料箱,下料箱的底部四周均固定连接有支撑杆,下料箱的顶部一端固定连接有下料斗,下料箱的内部设有下料机构,本发明设置有下料机构、输送机构以及成型机构,通过下料机构便于更好的熔塑用原料进行下料,且通过气缸控制阀板在下料通道内移动从而更好的控制下料的速率,通过输送机构便于更好的对塑料颗粒进行输送,通过电磁阀便于更好的对融化的液态塑料下料时进行控制,通过成型机构便于更好的控制液态塑料注塑成型,通过伺服电机便于更好的带动滚轮转动,从而使模具盒沿着导轨进行移动,从而更好的进行注塑以及脱模。(The invention discloses an injection molding device for processing and producing bags, which comprises a bottom plate, a blanking box, a blanking mechanism, a conveying mechanism and a forming mechanism, wherein the blanking box is arranged at one end of the top of the bottom plate, supporting rods are fixedly connected to the periphery of the bottom of the blanking box, the blanking hopper is fixedly connected to one end of the top of the blanking box, and the blanking mechanism is arranged in the blanking box. Thereby the mould box moves along the guide rail, and injection molding and demolding are better carried out.)

1. The utility model provides a case and bag processing production is with injection moulding device, includes bottom plate (1), feed box (2), unloading mechanism (5), conveying mechanism (10), forming mechanism (11), its characterized in that: a blanking box (2) is arranged at one end of the top of the bottom plate (1), supporting rods (3) are fixedly connected around the bottom of the blanking box (2), one end of the top of the blanking box (2) is fixedly connected with a blanking hopper (4), a blanking mechanism (5) is arranged inside the blanking box (2), the bottom of the blanking box (2) is fixedly connected with a connecting box (6), the top of the inner wall of the connecting box (6) is provided with a blanking channel (7), one side of the connecting box (6) is fixedly connected with a mounting box (8), one side of the connecting box (6) is fixedly connected with a conveying pipeline (9), the bottom of the blanking box (2) is provided with a conveying mechanism (10), one end of the top of the bottom plate (1) far away from the blanking box (2) is provided with a forming mechanism (11), an electric cabinet (12) is fixedly arranged on one side of the top of the bottom plate (1);

the blanking mechanism (5) comprises a mounting seat (51), a blanking motor (52), a stirring rod (53), a top seat (54), a stirring blade (55), a blanking port (56), a cylinder (57), a sliding groove (58) and a valve plate (59), the top fixedly connected with mounting seat (51) of the blanking box (2), the top fixedly mounted with the blanking motor (52) of the mounting seat (51), an output shaft of the blanking motor (52) penetrates through the inside of the blanking box (2) and is fixedly connected with the stirring rod (53), the top fixedly connected with the top seat (54) of the inner wall of the blanking box (2), the top seat (54) is rotatably connected with the stirring rod (53), the bottom fixedly connected with the stirring blade (55) of the stirring rod (53), the bottom of the inner wall of the blanking box (2) is provided with the blanking port (56), the top fixedly connected with the cylinder (57) of the mounting box (8), one side of the top of the inner wall of the connecting box (6) is provided with a sliding groove (58), a piston rod of the air cylinder (57) extends to the inside of the sliding groove (58) and is fixedly connected with a valve plate (59), and the valve plate (59) is connected with the sliding groove (58) in a sliding mode.

2. An injection molding device for luggage processing production according to claim 1, wherein: the conveying mechanism (10) comprises a conveying motor (101), a conveying shaft (102), an auger piece (103), a heating pipe (104), an electric heating wire (105), a supporting column (106), an elbow (107), a conveying hopper (108) and an electromagnetic valve (109), wherein the conveying motor (101) is fixedly arranged inside the mounting box (8), an output shaft of the conveying motor (101) extends to the conveying shaft (102) inside the conveying pipeline (9) and is fixedly connected with the conveying shaft, the auger piece (103) is fixedly connected outside the conveying shaft (102), the heating pipe (104) is fixedly connected with one end outside the conveying pipeline (9), the electric heating wire (105) is fixedly arranged inside the heating pipe (104) at equal intervals, the electric heating wire (105) is in contact with the outer wall of the conveying pipeline (9), and the supporting column (106) is fixedly connected to the bottom of the heating pipe (104), the bottom of support column (106) and the top fixed connection of bottom plate (1), one side fixedly connected with return bend (107) of pipeline (9), the defeated hopper (108) of bottom fixedly connected with of return bend (107), the one end fixed mounting of defeated hopper (108) has solenoid valve (109), workbin (2) are linked together with connecting box (6) through feed opening (56) and unloading passageway (7) down, defeated hopper (108) are linked together with connecting box (6) through return bend (107) and pipeline (9).

3. An injection molding device for luggage processing production according to claim 2, wherein: the forming mechanism (11) comprises a guide rail (111), a side plate (112), a connecting plate (113), rollers (114), a mounting plate (115), a fan (116), a lower die box (117), an upper die box (118), a ventilation cooling pipe (119), an air outlet (1110), a limiting plate (1111), a U-shaped groove (1112), a feed inlet (1113), a servo motor (1114), a driven bevel gear (1115) and a driving bevel gear (1116), wherein two guide rails (111) are fixedly connected to one end of the top of the bottom plate (1), the two ends of each guide rail (111) are fixedly connected with the side plates (112), the connecting plate (113) is arranged at the top of each guide rail (111), the rollers (114) are symmetrically and rotatably connected to the bottom of the connecting plate (113), two grooves matched with the sizes of the rollers (114) are formed in the top of each guide rail (111), and the connecting plate (113) is in sliding connection with the, the utility model discloses a mould structure of a roller, including gyro wheel (114), one side fixedly connected with mounting panel (115), the top fixedly connected with fan (116) of mounting panel (115), the top fixedly connected with lower mould box (117) of connecting plate (113), the top one end of lower mould box (117) is connected with upper mould box (118) through the hinge rotation, ventilation cooling tube (119) have all been dug to the inside of lower mould box (117) and upper mould box (118), the output and ventilation cooling tube (119) of fan (116) are linked together, the top and the fixedly connected with air outlet (1110) of upper mould box (118) that ventilation cooling tube (119) extend to, the top fixedly connected with limiting plate (1111) of upper mould box (118), U type groove (1112) has been dug to the top one end of limiting plate (1111), feed inlet (1113) has been dug to the bottom one end of U type groove (1112), feed inlet (1113) and the inside of last mould box (118) and bed die box (117) are linked together, the bottom fixedly connected with servo motor (1114) of connecting plate (113), pivot middle part fixedly connected with driven bevel gear (1115) between gyro wheel (114), the output fixedly connected with initiative bevel gear (1116) of servo motor (1114), driven bevel gear (1115) are connected with initiative bevel gear (1116) meshing.

4. An injection molding device for luggage processing production according to claim 3, wherein: the U-shaped groove (1112) is matched with the bottom of the material conveying hopper (108) in size.

5. An injection molding device for luggage processing production according to claim 1, wherein: the blanking channel (7) is of an X-shaped structure.

6. An injection molding device for luggage processing production according to claim 1, wherein: the stirring blade (55) is of a spiral structure, and the size of the top of the stirring blade (55) is larger than that of the bottom of the stirring blade.

7. An injection molding device for luggage processing production according to claim 1, wherein: the outside equidistance of mounting box (8) is excavated there is the bar radiating groove.

8. An injection molding device for luggage processing production according to claim 3, wherein: the blanking motor (52), the air cylinder (57), the conveying motor (101), the heating wire (105), the electromagnetic valve (109), the fan (116) and the servo motor (1114) are all electrically connected with the electric cabinet (12).

The technical field is as follows:

the invention belongs to the field of injection molding equipment, and particularly relates to injection molding equipment for luggage processing production.

Background art:

the luggage is a general term for bags, and is a general term for various bags for holding articles, including general shopping bags, handbags, purses, backpacks, single shoulder bags, satchels, waist bags, various draw-bar cases and the like, and the market of the travel luggage is an important component of the luggage market, which accounts for about 40% of the total global luggage market, and the global luggage market includes the travel luggage market, the business luggage market and the leisure luggage market, and the travel luggage market includes travel luggage, such as luggage and draw-bar cases. The business package is mainly used for business purposes. The business bag is characterized in that the portable computer and the documents are convenient to carry, and the business bag is usually in the form of a pull-type mobile office luggage, a portable briefcase or a computer bag. The leisure bag is mainly used for daily life and comprises backpacks, ladies and men shoulder bags and towable luggage bags of different styles, and the colors, sizes, styles and materials of the leisure bag are different. The travel bag is a bag article which is made of various leathers, artificial leathers, synthetic leathers and textiles as fabrics by adopting hot pressing or vacuum forming, injection molding and sewing processes and has the function of containing and carrying clothes; the capacity of travel case and bag is great, the function is used, and the material has characteristics such as wear-resisting, waterproof, corrosion-resistant, and when travel case and bag carried out processing injection moulding, current processing equipment unloading was slow, and plastic granules blocked in pipeline department easily, influences unloading plastics, and plastic granules carries inconvenient control when moulding plastics simultaneously, the speed that unable better control plastics were carried, and the drawing of patterns is comparatively complicated, uses comparatively.

The invention content is as follows:

the present invention is directed to solving the above problems and providing a solution to the disadvantages of the prior art.

In order to solve the above problems, the present invention provides a technical solution:

an injection molding device for luggage processing production comprises a bottom plate, a blanking box, a blanking mechanism, a conveying mechanism and a forming mechanism, wherein a blanking box is arranged at one end of the top of the bottom plate, supporting rods are fixedly connected to the periphery of the bottom of the blanking box, a blanking hopper is fixedly connected to one end of the top of the blanking box, the blanking mechanism is arranged inside the blanking box, a connecting box is fixedly connected to the bottom of the blanking box, a blanking channel is formed in the top of the inner wall of the connecting box, a mounting box is fixedly connected to one side of the connecting box, a conveying pipeline is fixedly connected to one side of the connecting box, the conveying mechanism is arranged at the bottom of the blanking box, the forming mechanism is arranged at one end, away from the blanking box, of the top of the bottom plate, and an electric cabinet;

unloading mechanism includes mount pad, unloading motor, puddler, footstock, stirring leaf, feed opening, cylinder, spout, valve plate, the top fixedly connected with mount pad of unloading case, the top fixed mounting of mount pad has the unloading motor, the output shaft of unloading motor runs through to the inside and the fixedly connected with puddler of unloading case, the inner wall top fixedly connected with footstock of unloading case, the footstock rotates with the puddler to be connected, the bottom fixedly connected with stirring leaf of puddler, the inner wall bottom of unloading case is excavated there is the feed opening, the top fixedly connected with cylinder of mounting box, the spout has been excavated to inner wall top one side of connecting box, the piston rod of cylinder extends to the inside and the fixedly connected with valve plate of spout, valve plate and spout sliding connection.

As preferred, conveying mechanism includes conveyor motor, defeated material axle, auger piece, heating pipe, heating wire, support column, return bend, defeated hopper, solenoid valve, the inside fixed mounting of mounting box has conveyor motor, conveyor motor's output shaft extends to pipeline's inside and the defeated material axle of fixedly connected with, the outside fixedly connected with auger piece of defeated material axle, pipeline's outside one end fixedly connected with heating pipe, the inside equidistance fixed mounting of heating pipe has the heating wire, the heating wire contacts with pipeline's outer wall, the bottom fixedly connected with support column of heating pipe, the bottom of support column and the top fixed connection of bottom plate, one side fixedly connected with return bend of pipeline, the bottom fixedly connected with defeated hopper of return bend, the one end fixed mounting of defeated hopper has the solenoid valve, the workbin is linked together through feed opening and unloading passageway and connecting box, the material conveying hopper is communicated with the connecting box through a bent pipe and a conveying pipeline.

Preferably, the forming mechanism comprises a guide rail, a side plate, a connecting plate, a roller, a mounting plate, a fan, a lower die box, an upper die box, a ventilation cooling pipe, an air outlet, a limiting plate, a U-shaped groove, a feed inlet, a servo motor, a driven bevel gear and a driving bevel gear, wherein two guide rails are fixedly connected with one end of the top of the bottom plate, the side plates are fixedly connected with the two ends of the guide rail, the connecting plate is arranged at the top of the guide rail, the roller is symmetrically and rotatably connected with the bottom of the connecting plate, two grooves matched with the size of the roller are formed in the top of the guide rail, the connecting plate is slidably connected with the guide rail through the roller, the mounting plate is fixedly connected with one side of the roller, the fan is fixedly connected with the top of the mounting plate, the lower die box is, the inside of bed die box and last mould box is all excavated there is the ventilation cooling pipe, the output and the ventilation cooling pipe of fan are linked together, the top and the fixedly connected with air outlet of last mould box that the ventilation cooling pipe extends to, the top fixedly connected with limiting plate of going up the mould box, the top one end of limiting plate is excavated there is U type groove, the bottom one end in U type groove is excavated there is the feed inlet, the feed inlet is linked together with the inside of last mould box and bed die box, the bottom fixedly connected with servo motor of connecting plate, pivot middle part fixedly connected with driven bevel gear between the gyro wheel, servo motor's output fixedly connected with initiative bevel gear, driven bevel gear is connected with the meshing of initiative bevel gear.

Preferably, the U-shaped groove is matched with the bottom of the conveying hopper in size.

Preferably, the blanking channel is of an X-shaped structure.

Preferably, the stirring blade is of a spiral structure, and the top of the stirring blade is larger than the bottom of the stirring blade.

Preferably, the outer side of the mounting box is equidistantly provided with strip-shaped heat dissipation grooves.

Preferably, the blanking motor, the air cylinder, the conveying motor, the heating wire, the electromagnetic valve, the fan and the servo motor are electrically connected with the electric cabinet.

The invention has the beneficial effects that:

the plastic melting device is provided with the blanking mechanism, the conveying mechanism and the forming mechanism, the blanking mechanism is convenient for better blanking raw materials for melting plastic, the air cylinder is used for controlling the valve plate to move in the blanking channel so as to better control the blanking speed, the conveying mechanism is convenient for better conveying plastic particles, the electromagnetic valve is convenient for better controlling the blanking of the melted liquid plastic, the forming mechanism is convenient for better controlling the injection molding of the liquid plastic, and the servo motor is convenient for better driving the idler wheel to rotate, so that the mold box moves along the guide rail, and the injection molding and the demolding are better performed.

Description of the drawings:

for ease of illustration, the invention is described in detail by the following detailed description and the accompanying drawings.

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

FIG. 2 is a front view of the present invention;

FIG. 3 is a schematic view of the internal structure of the present invention;

FIG. 4 is an enlarged view at A in FIG. 3;

FIG. 5 is a schematic view of the internal structure of the forming mechanism of the present invention;

FIG. 6 is a top view of a limiting plate of the present invention;

fig. 7 is a bottom view of the base plate of the present invention.

In the figure: 1-bottom plate, 2-blanking box, 3-support rod, 4-blanking hopper, 5-blanking mechanism, 51-mounting seat, 52-blanking motor, 53-stirring rod, 54-top seat, 55-stirring blade, 56-blanking port, 57-cylinder, 58-chute, 59-valve plate, 6-connecting box, 7-blanking channel, 8-mounting box, 9-conveying pipeline, 10-conveying mechanism, 101-conveying motor, 102-conveying shaft, 103-packing auger sheet, 104-heating pipe, 105-heating wire, 106-supporting column, 107-bent pipe, 108-conveying hopper, 109-electromagnetic valve, 11-forming mechanism, 111-guide rail, 112-side plate, 113-connecting plate, 114-roller, 114-rolling wheel, 115-mounting plate, 116-fan, 117-lower die box, 118-upper die box, 119-ventilation cooling pipe, 1110-air outlet, 1111-limit plate, 1112-U-shaped groove, 1113-feed inlet, 1114-servo motor, 1115-driven bevel gear, 1116-driving bevel gear and 12-electric cabinet.

The specific implementation mode is as follows:

as shown in fig. 1 to 7, the following technical solutions are adopted in the present embodiment: an injection molding device for processing and producing bags and suitcases comprises a bottom plate 1, a blanking box 2, a blanking mechanism 5, a conveying mechanism 10 and a forming mechanism 11, a blanking box 2 is arranged at one end of the top of the bottom plate 1, supporting rods 3 are fixedly connected around the bottom of the blanking box 2, one end of the top of the blanking box 2 is fixedly connected with a blanking hopper 4, a blanking mechanism 5 is arranged inside the blanking box 2, the bottom of the blanking box 2 is fixedly connected with a connecting box 6, the top of the inner wall of the connecting box 6 is provided with a blanking channel 7, one side of the connecting box 6 is fixedly connected with a mounting box 8, one side of the connecting box 6 is fixedly connected with a conveying pipeline 9, the bottom of the blanking box 2 is provided with a conveying mechanism 10, one end of the top of the bottom plate 1, which is far away from the blanking box 2, is provided with a forming mechanism 11, and one side of the top of the bottom plate 1 is fixedly provided with an electric cabinet 12;

the blanking mechanism 5 comprises a mounting seat 51, a blanking motor 52, a stirring rod 53, a top seat 54, a stirring blade 55, a blanking port 56, a cylinder 57, a sliding groove 58 and a valve plate 59, the top fixedly connected with mounting seat 51 of the blanking box 2 is provided with the blanking motor 52, the output shaft of the blanking motor 52 penetrates through the inner part of the blanking box 2 and the fixedly connected with stirring rod 53, the top seat 54 of the inner wall top of the blanking box 2 is fixedly connected with the top seat 54, the top seat 54 is rotatably connected with the stirring rod 53, the stirring blade 55 is fixedly connected with the bottom of the stirring rod 53, the blanking port 56 is arranged at the bottom of the inner wall of the blanking box 2, the cylinder 57 is fixedly connected with the top of the mounting box 8, the sliding groove 58 is arranged on one side of the inner wall top of the connecting box 6, the piston rod of the cylinder 57 extends to the inner part of the sliding groove 58 and the fixedly connected with, valve plate 59 and spout 58 sliding connection, through unloading mechanism 5 be convenient for better melt plastics with the raw materials unloading, and thereby move the speed of better control unloading in unloading passageway 7 through cylinder 57 control valve plate 59.

Wherein, conveying mechanism 10 includes conveyor motor 101, defeated material axle 102, auger piece 103, heating pipe 104, heating wire 105, support column 106, return bend 107, defeated material fill 108, solenoid valve 109, the inside fixed mounting of mounting box 8 has conveyor motor 101, the output shaft of conveyor motor 101 extends to the inside and the defeated material axle 102 of fixedly connected with of pipeline 9, the outside fixedly connected with auger piece 103 of defeated material axle 102, the outside one end fixedly connected with heating pipe 104 of pipeline 9, the inside equidistance fixed mounting of heating pipe 104 has heating wire 105, heating wire 105 contacts with pipeline 9's outer wall, the bottom fixedly connected with support column 106 of heating pipe 104, the bottom of support column 106 and the top fixed connection of bottom plate 1, one side fixedly connected with return bend 107 of pipeline 9, the bottom fixedly connected with defeated hopper 108 of return bend 107, defeated hopper 108's one end fixed mounting has solenoid valve 109, workbin 2 is linked together with connecting box 6 through feed opening 56 and unloading passageway 7, defeated hopper 108 is linked together with connecting box 6 through return bend 107 and pipeline 9, is convenient for better carrying plastic granules through conveying mechanism 10, can heat the plastic granules in pipeline 9 through heating wire 105, makes it melt, controls when being convenient for better the liquid plastics unloading that melts through solenoid valve 109.

Wherein, the forming mechanism 11 comprises a guide rail 111, a side plate 112, a connecting plate 113, a roller 114, a mounting plate 115, a fan 116, a lower mold box 117, an upper mold box 118, a ventilation cooling pipe 119, an air outlet 1110, a limiting plate 1111, a U-shaped groove 1112, a feed inlet 1113, a servo motor 1114, a driven bevel gear 1115, a driving bevel gear 1116, two guide rails 111 fixedly connected to one end of the top of the bottom plate 1, the two ends of the guide rail 111 are fixedly connected with the side plate 112, the top of the guide rail 111 is provided with the connecting plate 113, the bottom of the connecting plate 113 is symmetrically and rotatably connected with the roller 114, two grooves matched with the size of the roller 114 are cut on the top of the guide rail 111, the connecting plate 113 is slidably connected with the guide rail 111 through the roller 114, one side of the roller 114 is fixedly connected with the mounting plate 115, the top of the mounting plate 115 is fixedly, the top one end of lower mould box 117 is connected with last mould box 118 through the hinge rotation, the inside of lower mould box 117 and last mould box 118 has all been dug ventilation cooling pipe 119, the output and the ventilation cooling pipe 119 of fan 116 are linked together, the top and the fixedly connected with air outlet 1110 of last mould box 118 that ventilation cooling pipe 119 extends to, the top fixedly connected with limiting plate 1111 of going up mould box 118, U type groove 1112 has been dug to the top one end of limiting plate 1111, feed inlet 1113 has been dug to the bottom one end of U type groove 1112, feed inlet 1113 is linked together with the inside of last mould box 118 and lower mould box 117, the bottom fixedly connected with servo motor 1114 of connecting plate 113, pivot middle part fixedly connected with driven bevel gear 1115 between gyro wheel 1115, the output fixedly connected with drive bevel gear 1116 of servo motor 1114, driven bevel gear is connected with the meshing of drive bevel gear 1116, be convenient for better control liquid plastics injection moulding through forming mechanism 11, be convenient for make the faster cooling shaping of plastics through fan 116 and ventilation cooling pipe 119, be convenient for better drive gyro wheel 114 through servo motor 1114 and rotate to make the mould box remove along guide rail 111, thereby better moulding plastics and drawing of patterns.

The U-shaped groove 1112 is matched with the bottom of the material conveying hopper 108 in size, so that the bottom of the material conveying hopper 108 is better butted with a feeding hole 1113 at the bottom of the U-shaped groove 1112, and plastics can be conveyed to the interiors of the two mold boxes for cooling and shaping.

Wherein, unloading passageway 7 is X type structure, and the better control plastic granules of being convenient for drops.

Wherein, stirring leaf 55 is the screw-tupe structure, the top size of stirring leaf 55 is greater than the bottom, and the plastic granules in the workbin 2 is gone down in the better stirring of being convenient for prevents that the granule from blocking the influence unloading speed.

Wherein, the bar radiating groove has been opened and chiseled to the outside equidistance of mounting box 8, is convenient for better dispel the heat to conveying motor 101.

The blanking motor 52, the air cylinder 57, the conveying motor 101, the heating wire 105, the electromagnetic valve 109, the fan 116 and the servo motor 1114 are all electrically connected with the electric cabinet 12, so that the equipment can be controlled better.

Specifically, the method comprises the following steps: an injection molding device for processing and producing cases, when in use, firstly, the device is moved to a designated position, then the device is electrified, plastic particle raw materials are poured into a blanking box 2 from a blanking hopper 4 through external equipment, a blanking motor 52 is started, plastic particles in the blanking box 2 are stirred through the rotation of a stirring blade 55, the plastic particles fall from a blanking port 56 and continuously fall into a connecting box 6 through a blanking channel 7, a valve plate 59 is pushed through a cylinder 57 so as to control the falling rate of the plastic particles, a conveying motor 101 is started, an auger piece 103 is driven to rotate through a conveying shaft 102 so as to drive the plastic particles to move towards a forming mechanism 11, when the plastic particles pass through a heating pipe 104, the plastic particles are heated and melted through heat conduction by starting an electric heating wire 105, liquid plastic is concentrated above a conveying hopper 108 through a bent pipe 107, open the valve of solenoid valve 109, then liquid plastics drop to in the mould box, when being full of liquid plastics in the mould box, close the valve of solenoid valve 109, and open fan 116, the cooling air current of continuation flows out from air outlet 1110 behind the ventilation cooling pipe 119, to the cooling of mould box continuation, make liquid plastics can cool off the shaping fast, after the plastics shaping, drive gyro wheel 114 through opening servo motor 1114 and rotate, and then make the mould box move to the one side of keeping away from conveying mechanism 10 along guide rail 111, then close fan 116, and open upper die box 118 through the handle of upper die box 118 one side, and take out the mould, then make the mould box resume the normal position through servo motor 1114 reversal, and repeat the above-mentioned operation, can continuously mould plastics.

While there have been shown and described what are at present considered to be the fundamental principles of the invention and its essential features and advantages, it will be understood by those skilled in the art that the invention is not limited by the embodiments described above, which are merely illustrative of the principles of the invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the invention as defined by the appended claims and their equivalents.