US 3827604 A
A solenoid-operated dispenser for dispensing liquid materials. The dispenser comprises a heated service module which contains static parts, a gun module which contains all of the movable parts of the dispenser, and a plug-in solenoid coil module, all three modules of which are resiliently held in an assembled relationship by a single threaded nut.
Description (OCR text may contain errors)
United States Patent [191 Hamilton et a1.
MODULAR SOLENOID-OPERATED DISPENSER Inventors: William M. Hamilton, Lorain; Alan B. Reighard, Bay Village; Simon Z. Tamny, Lorain, all of Ohio Nordson Corporation, Amhurst, Ohio Filed: Sept. 11, 1972 Appl. No.: 287,645
References Cited UNITED STATES PATENTS Steel 251/139 [451 Aug. 6, 1974 2,546,325 3/1951 Wasserlein 251/139 2,746,022 5/1956 Gilbert 339/92 M 2,761,109 8/1956 Hacker.... 339/75 P 3,159,444 12/1964 Stine 339/92 M 3,161,450 12/1964 Goodenough 339/92 R 3,408,008 10/1968 Cocks 222/146 R 3,430,816 3/1969 Nadherny et a1. 222/146 R 3,662,927 5/1972 Cocks 222/146 HE 3,687,216 8/1972 Tracy 251/139 Prirnary ExaminerRobert B. Reeves Assistant ExaminerH. Grant Skaggs, Jr. Attorney, Agent, or FirmWood, Herron & Evans  ABSTRACT A solenoid-operated dispenser for dispensing liquid materials. The dispenser comprises a heated service module which contains static parts, a gun module which contains all of the movable parts of the dispenser, and a plug-in solenoid coil module, all three modules of which are resiliently held in an assembled relationship by a single threaded nut.
13 Claims, 3 Drawing Figures MODULAR SOLENOID-OPERATED DISPENSER This invention relates to a dispenser or a gun for dispensing liquids in the form of beads, ribbons, or stripes in a desired pattern under high speed production conditions. More particularly, the invention relates to equipment for applying molten adhesives or so-called hot melts to substrates used in packaging, sealing or assembling a variety of products.
Liquid adhesives, or so-called hot melts, are commonly used where there is a need for a very short setting time for the material to set up and bond together two parts of a package or'two parts of an assembly. Typically, they are solid at room temperature and must be heated before they become molten so that they can be supplied to and dispensed from a gun. When heated to molten form, the materials change to a liquid which may be supplied to a dispensing gun at a relatively high pressure and then dispensed from the nozzle of the gun in the form of a continuous bead or ribbon or an intermittent deposit. The flow of material from the gun is controlled by a valve located internally of the gun adjacent the nozzle orifice.
A common production problem encountered with hot melt dispensing guns in high production facilities is that of interupting the production facility for relatively long periods of time in order to clean the gun of hot melt material which has become lodged therein or to replace worn out parts. Generally, cleaning requires disconnection of the service lines including the electrical service lines to the heater of the gun, disconnection of the liquid supply lines for supplying the molten material to the gun, and disconnection of the power lines for operating the gun. If the gun is a pneumatically operated gun, the power line is an air line to the gun; and if the gun is solenoid-operated, the power line is an electrical one. After disconnection of all lines, the gun generally must be broken apart in order to disconnect it from its mounting so as to enable a new or clean gun to replace it. All of this disconnection and disassembly is generally time-consuming and expensive because of the resulting loss of a production facility on which the gun is one relatively small component.
in U.S. Pat. No. 3,570,725, issued Mar. 16, 1971, and assigned to the assignee of this application, there is disclosed a modular type of pneumatically operated gun in which the gun may be removed from a service module as a separate unit and replaced without any timeconsuming disconnection of the service lines and disassembly of the gun. That modular gun has been well received in hot melt production facilities and has eliminated many of the problems set forth hereinabove. There is still, though, a need for a solenoid-operated modular gun to accomplish the same objectives and eliminate the time-consuming disassembly and reassembly problem normally associated with the cleaning and replacement of solenoid-operated hot melt dispensing guns in high speed production facilities.
It has therefore been one objective of this invention to provide a modular solenoid-operated dispensing system in which the gun portion of the dispenser may be easily and quickly replaced in the event that the gun portion needs to be cleaned or a component needs to be replaced.
Still another object of this invention has been to provide a solenoid-operated dispensing apparatus for dispensing hot melt or viscous liquids in which the solenoid coil of the gun may be easily and quickly replaced in the event that it fails while the remainder of the gun and system is fully operative.
The invention of this application which accomplishes these objectives comprises a three-module dispensing apparatus made from a service module, a gun module, and a solenoid module. All three modules are resiliently held in an assembled relation by a single threaded connector. The service module houses all of the essentially static components of the dispenser and includes a solenoid plug-in connector as well as an electrical heater for heating the service module and subsequently transmitting heat through contacting surfaces to the gun module so that the molten material contained in the gun remains in the molten state. The gun module contains all the movable components of the dispensing apparatus and is generally tubular in configuration. Over this tubular gun module the plug-in solenoid coil module is mounted and is resiliently held in an assembled relation by a single threaded connector which also holds the gun module mounted within an aperture of the service module.
The primary advantage of this modular construction of solenoid-operated dispenser with its plug-in solenoid electrical lead connection is that it enables the solenoid module to be quickly replaced in the event that it fails or the gun module to be easily and quickly replaced in the event that it becomes clogged or breaks down because of excessively worn parts. In unionized shops where union rules require an electrician to make all electrical repairs, it generally eliminates the need for the electrician to make this repair because of nonelectrical repairmen being permitted to pull electrical plugs but not connect or disconnect other types of electrical connectors. After replacement of a worn or clogged gun with a new clean one, or replacement of a failed coil, the failed component may be torn down and rebuilt without interruption of a production facility upon which the dispensing apparatus had previously been in use. This construction also has the advantage of facilitating repair and cleaning of the dispensing apparatus.
These and other objects and advantages of this invention will be more readily apparent from the following description of the drawings illustrating one preferred embodiment of the invention in which:
FIG. 1 is an exploded perspective view of a dispensing apparatus incorporating the invention of this application;
FIG. 2 is a cross sectional view of the apparatus; and
FIG. 3 is a cross sectional view of a portion of the dispensing apparatus but illustrating a second modification of solenoid plug-in electrical connector.
Referring to FIG. 1, it will be seen that the dispenser 10 of this application is assembled from three modules which are easily assembled and disaaaembled for purposes of cleaning or repairing the unit. Specifically, this dispenser 10 comprises a service module 11, a gun module 12, and'a solenoid coil module 13. These three modules are all resiliently held in an assembled relation by a resilient washer 14a and a single nut 14 threaded over one end 15 of the gun module 12, as is explained more fully hereinafter.
The service module 11 serves as a mounting block for the gun and solenoid coil modules as well as for an electrical control enclosure 16. This service module 11 is generally fixedly mounted, by means not shown, upon a slide block or some other fixed fastening located in a predetermined location relative to a substrate upon which molten liquid material is dispensed from the gun.
The service module 11 is comprised of a stepped block 17 which has two vertical bores through it. One of these bores 18 is counterbored and is adapted to receive an electric heating element 19. The other bore receives and supports the gun module 12.
Electrical power to the solenoid coil 20 is supplied via electrical leads 21 which are housed within the conventional electrical enclosure or so-called junction box 16. This box is fixedly mounted upon the top of the service block 17. The enclosure within the box 16 also houses an electrical thermostat 22 which controls the flow of electric power to the heater 19 and consequently determines the temperature of the block 17. Heat from the block 17 in turn is transmitted through the contacting surfaces of the service module block 17 and the gun module 12 into molten material contained interiorly of the gun.
It is to be noted that the electrical leads 21 from the junction box terminate in an electrical plug 23. This plug 23 fits within a recess 24 formed in the service module block 17. In order to prevent the plug from moving vertically in the recess 24 while still permitting it to be inserted horizontally, the plug 23 has a flange 25 which fits within transverse slots 26 formed in the service module recess 24. Consequently, the plug 23 may be inserted and removed from the service module by sliding it horizontally but it is locked by the flange 25 against vertical displacement.
The gun module 12 comprises a cylinder assembly 30, a nozzle assembly 31, a valve 32 for controlling the flow of pressurized molten material from the nozzle 31, and a valve plunger 33 for controlling actuation of the valve 32.
The cylinder assembly is made from four components, all of which are brazed together to form a sealed and joined unit. These components comprise an annular flange 35, a spring chamber sleeve 36, a nonmagnetic plunger guide sleeve 37, and a magnetic inlet fitting 38. The spring chamber sleeve 36 has a through bore 40 which is counterbored at the lower end and provides a large open chamber for the reception of a valve control spring 41. This bore 40 is also counterbored at its upper end as indicated at 42 so as to provide a seat for the lower end of the plunger guide sleeve 37. At its upper end, the plunger guide sleeve 37 receives the lower end 45 of the molten material inlet fit ting 38. There is preferably a conventional, copper shading ring 46 mounted within an annular recess machined from the lower end of the inlet fitting 38. The upper end of the inlet fitting is externally threaded for reception of the nut 14 which resiliently holds the three modules in an assembled relation, as is explained more fully hereinafter.
The nozzle assembly 31 of the dispensing gun is conventional and comprises a radially flanged gun seat through which there extends an axial bore 50. This axial bore is counterbored so that the lower small diameter end section may receive and be brazed to a carbide valve seat 51. The radial flange 53 of the nozzle gun seat is bolted to the flange 35 of the cylinder assembly by machine screws 55. There is preferably a metal ring 56 located between the lower end of the cylinder At its upper end the needle 57 is externally threaded and is received within an internally threaded bore 65 of the plunger. A lock nut 66 secures the needle in an axially adjusted position within the plunger.
Intermediate its ends, the needle supports a spring collar 70. This collar has a central hub 71 threaded over the threaded section of the needle and four arms 72 which extend radially from the hub 71 to support the lower end of the compression spring 41. At its upper end this spring rests against a shoulder 73 in the bore of the spring chamber sleeve 36. There is preferably a lock nut 75 threaded over the needle to lock the spring collar 70 in an adjusted position.
The plunger 33 is made from a magnetic stainless steel or other magnetic ferrous material so that it functions as the armature of the solenoid coil 20 within the cylinder. A gap between the lower end of the inlet fitting 38 and the top surface of the plunger permits the plunger to be moved upwardly by magnetic flux of the solenoid coil 20. When the plunger is in its uppermost position, the valve 32 is open so that pressurized molten material contained within the valve chamber 50 of the nozzle may exit through the valve passage 59.
In order for the molten material supplied to the gun via the inlet fitting 38 to flow through the axial passage 81 of the fitting 38 downwardly to the valve chamber 50, there are four radial grooves 84 and four intersecting longitudinal grooves 85 machined from the surface of the plunger. The radial grooves 84 in the top surface of the plunger are axially aligned with and intersect the longitudinal grooves 85 in the peripheral surface of the plunger so that each groove forms a continuous flow path along the exterior of the plunger from the lower end of the passage 81 into the spring changer 40 of the sleeve 36 and subsequently into the valve changer 50 of the nozzle assembly 31.
The solenoid coil module 13 comprises a tubular spool of Teflon or a similar dielectric material upon 7 which the wire of the coil 20 is wound. The ends of this wire terminate in a male plug 89, the electrical prongs of which are adapted to be received into the female receptacles of the service module mounted plug 23. Consequently, when the two plugs are electrically interconnected, an electrical connection is made between the leads 21 in the junction box and the windings of the coil 20. The two plugs are so positioned that assembly of the solenoid over the cylinder of the gun and onto the service module automatically makes this electrical connection. Similarly, removal of the solenoid module from over the cylinder of the gun module automatically breaks the electrical connection.
In order to form the plug 89 on the solenoid coil module, the wound coil and spool are placed in an injection mold and encased in a sheathing of plastic 88. In the course of applying the molded plastic sheating 88, the plug 89 is simultaneously molded onto the coil. The plastic encased coil is then placed in a magnetic metal enclosure 87. The enclosure comprises a steel sleeve 91 over which there is fitted a steel cap 92 and a lower flux retainer disc 93. The disc has a cutout recess 94 on one side through which the plug 89 extends.
The lower retainer flux ring 93, the sleeve 91, and the cap 92 are all sealed around the coil 20 so as to form a complete subassembly which may be assembled over the cylinder of the gun or removed therefrom as a complete unit. This module 13 is held in an assembled relation over the barrel by the nut 14 threaded over the end of the fitting 15 and over the resilient Washer 140. The
purpose of the resilient washer 14a is to accommodate relative thermal deflections among the service module 11, the gun 12, and solenoid module 13.
In operation, if the gun should become clogged or should fail for any reason, all that is required to remove it from the service module 11 so as to permit its replacement on the service module is to disconnect the supply hose and remove the nut 14 and resilient washer 14a from over the inlet fitting of the gun barrel. Upon removal of this nut and resilient washer, the complete gun may be dropped downwardly through the bore 96. Alternatively, if the coil should fail, all that is required to remove it is to remove this same nut 14 and resilient washer 14a and lift them from over the cylinder, and, in the process, disconnect the electrical connector of the solenoid with the leads 21. The solenoid coil module may then be replaced or the gun module may be replaced with a minimum of lost production time. After the gun module or the solenoid module has been removed from the service module, cleaning or disassembly may take place while the production line upon which the dispensing apparatus operates continues to function.
It is also to be noted that when one solenoid replaces another the plastic-encased coil may be removed and replaced in the metal housing 87 or encasement. This construction thus minimizes the cost of replacing a burnt out coil.
Referring now to FIG. 3, there is illustrated a second modification of plug-in connector for electrically connecting the solenoid module to the electrical leads 21 from the electrical junction box 16. Except for the difference in this electrical connection, though, the dispenser of FIG. 3 is identical to the dispenser of FIGS. 1 and 2 and, accordingly, identical components have been given identical numerical designations.
The solenoid module 13 of this modification of the dispenser comprises the same solenoid coil 20 wound upon the spool 90 as in FIG. 1. The plastic encasement 88 of the coil, though, has a female electrical connector plug 98 molded onto the top of the encasement 88 rather than a male connection on the bottom as in the FIG. 1 modification. This modification also differs in that the male plug 99 attached to the leads 21 is mounted within a washer 100 which is attached to the nut 14. The washer 100 is swaged onto a peripheral recess 101 of the nut 14 so that it rotates freely upon the nut. The plug 99 is fixedly mounted upon one side of the washer so that in the course of rotating the nut 14 to remove it from the fitting 38, the nonrotating washer 100 and attached plug 99' are automatically disconnected from the female plug 98 of the solenoid module 13. Similarly, in the course of threading the nut onto the fitting 38, the electrical connection is automatically made between the two plugs 98 and 99.
While we have described only a single preferred embodiment of our invention, persons skilled in this art will appreciate changes and modifications which may be made without departing from the spirit of our invention. Therefore, we do not intend to be limited except by the scope of the following appended claims.
Having described our invention, we claim:
1. Apparatus for dispensing a liquid from a pressurized source comprising i a service module having essentially only static parts, said service module including a mounting block having a gun module contacting surface of substantial area, said mounting block being adapted to be secured to a support, readily removable gun module attachable to and mountable upon said service module mounting block, said gun module including essentially all of the movable parts of said dispensing apparatus, said gun module including a discharge nozzle and a valve for controlling flow of viscous liquid from said nozzle, said gun module further including a cylinder and a movable plunger mounted within said cylinder, said plunger being operatively connected to said valve so as to effect opening and closing of said valve upon actuation of said plunger, said gun module having a service module mounting block contacting surface of substantial area,
heater means contained within said service module for heating said service module mounting block, said service module mounting block being operable to transmit heat through said contacting surface into said gun module so as to heat liquid contained within said gun module, and
a solenoid coil module mounted over said cylinder of said gun module, said solenoid coil module including an electrical solenoidcoil for controlling movement of said plunger within said cylinder,
said solenoid coil module being removable and replaceable on said dispensing apparatus without disassembly of said gun module and said gun module being removable and replaceable on said service module without disassambly of said gun module,
said solenoid coil module and said gun module being jointly secured to said service module mounting block by a single fastening element, and
said solenoid coil being encased within a housing, said solenoid coil module including an electrical plug extending through said housing, said electrical plug being adapted to make an electrical connection with a source of electrical power when said solenoid coil module is assembled with said service block module and said gun module.
2. The dispensing apparatus of claim 1 in which said heater means is an electrical heater mounted within said service module mounting block, said service module further including a thermostat for controlling the fiow of electrical power to said electrical heater.
3. The dispensing apparatus of claim 1 in which said service module mounting block has an aperture therein for the reception of said gun module, said gun module being mounted within said aperture, with at least a portion of said cylinder extending outwardly from said aperture, said solenoid coil module being mounted over said cylinder outwardly of said aperture.
4. The dispensing apparatus of claim 1 in which said fastening element is a threaded element.
5. The apparatus of claim 4 in which said threaded element has an electrical plug attached thereto, said plugs being so positioned that assembly of said modules and said threaded element automatically effects electrical interconnection of said plugs.
6. The'apparatus of claim 1 in which said service block module has an electrical plug mounted thereon, said plugs being so positioned that assembly of said solenoid coil module, said gun module, and said service block module automatically effects electrical interconnection of said plugs.
7. The dispensing apparatus of claim 1 in which said solenoid coil is encased in a molded plastic encasement,'said plastic encasement having said electrical plug formed as an integral portion thereof.
8. Apparatus for dispensing a viscous liquid from a pressurized source comprising a service block module having essentially only staticparts, said service block module including a mounting block adapted to be secured to a support, heating means contained within said service module mounting block, readily removable gun module attachable to and mountable upon said service module mounting block, said gun module including essentially all of the movable parts of said dispensing apparatus, said gun module including a discharge nozzle, a valve for controlling flow of viscous liquid from said nozzle, and spring means for biasing said valve to a closed position, said gun module further including a cylinder and a movable plunger mounted within said cylinder, said plunger being operatively connected to said valve so as to effect opening and closing of said valve upon actuation of said plunger, a solenoid coil module mounted over said cylinder of said gun module, said solenoid coil module including an electrical solenoid coil for controlling movement of said plunger within said cylinder,
a single fastening element for jointly securing said solenoid coil module and said gun module to said service module, and
said solenoid coil being encased within a housing,
said solenoid coil module including an electrical plug extending through said housing, said plug being adapted to make an electrical connection with a source of electrical power when said solenoid coil module is assembled with said service block module and said gun module.
9. The apparatus of claim 8 in which said service block module has an electrical plug mounted thereon, said plugs being so positioned that assembly of said solenoid coil module, said gun module, and said service block module automatically effects electrical interconnection of said plugs.
10. The dispensing apparatus of claim 8 in which said fastening element is a threaded element.
11. The apparatus of claim 10 in which said threaded element has an electrical plug attached thereto, said plugs being so positioned that assembly of said modules and said threaded element automatically effects electrical interconnection of said plugs.
12. The dispensing apparatus of claim 8 in which said service module has an aperture therein for the reception of said gun module, said gun module being mounted within said aperture with at least a portion of said cylinder extending outwardly from said aperture, and said solenoid coil module being mounted over said cylinder outwardly of said aperture.
13. The dispensing apparatus of claim 8 in which said solenoid coil is encased in a molded plastic encasement, said plastic encasement having said electrical plug formed as an integral portion thereof.