Abstract:
A quick release and connect nozzle assembly for use with a material dispensing head including a nozzle engagement member on a portion of the dispensing head, a nozzle member having an aperture therethrough for operable communication with the dispensing head to provide dispensing of the material in a predetermined pattern, and a connecting member integral with the nozzle member for engagement with the engagement member of the dispensing head, wherein the connecting member is operable by hand and provides quick release and connection of the nozzle member from the dispensing head so as to enable cleaning or replacement of the nozzle member as desired.

Description:
This application is a continuation of application Ser. No. 08/119,309, filed Sep. 13, 1993, now abandoned. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to material dispensing systems, and more particularly to a quick release and connect nozzle assembly for use with a modular adhesive dispensing head wherein the nozzle assembly can be readily disconnected and connected from the dispensing head by hand so as to enable changing of nozzles to provide a different pattern or for enabling cleaning, and wherein further the assembly provides a positive physical indication which can be felt by a user so as to insure that the assembly is properly seated on the dispensing head. 
     2. Description of the Related Art 
     Material dispensing systems, such as those utilized for dispensing hot-melt adhesives, are typically air activated and include a modular dispensing head which enables adhesives to be dispensed in precise quantities and patterns. An example of such a dispensing head is generally illustrated in U.S. Pat. No. 5,121,930 which is owned by the assignee herein. 
     As FIG. 2 of that patent illustrates, the bottom of the dispensing head includes an apertured nozzle in the form of a nut which is threaded onto threads formed on the dispensing head. If the nozzle becomes clogged or a different nozzle is desired, a hand-tool must be utilized to unthread the nozzle from the dispensing head. 
     The hand-tool, however, can be difficult to maneuver due to the close quarters of the dispensing system, and the nozzle can fall into other portions of the equipment and be lost and/or cause jamming of the equipment. Additionally, due to the heat generated in such nozzles from operation of the system, an operator can be burned if not careful. 
     It therefore would be desirable to provide a nozzle assembly which can be readily disconnected and connected from the dispensing head which does not require the use of hand-tools and provides a positive indication to a user that the nozzle is properly seated. 
     SUMMARY OF THE INVENTION 
     The invention provides a quick release and connect nozzle assembly for use with a material dispensing head. The assembly includes a nozzle engagement member on a portion of the dispensing head and a nozzle member having an aperture therethrough for operable communication with the dispensing head so as to provide dispensing of the material in a predetermined pattern. A connecting member is also integral with the nozzle member for engagement with the engagement member of the dispensing head which is operable by hand and provides quick release and connection of the nozzle member from the dispensing head so as to enable cleaning or replacement of the nozzle member as desired. 
     The assembly preferably includes a bayonet type connection between the nozzle member and the dispensing head which also provides a positive physical indication which can be felt by a user so as to indicate that the nozzle member is properly seated. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Various other objects, features, and attendant advantages of the present invention will be more fully appreciated from the following detailed description, when considered in connection with the accompanying drawings in which like reference characters designate like or corresponding parts throughout the several views, and wherein: 
     FIG. 1 is a front elevational view of a prior art nozzle assembly illustrated as being attached to a modular hot-melt dispensing head with portions of the nozzle and dispensing head illustrated in cross-section; 
     FIG. 2 is a bottom perspective view of a nozzle assembly of the invention; 
     FIG. 3 is an exploded view of the nozzle assembly of FIG. 2; 
     FIG. 4 is a longitudinal cross-sectional view of the nozzle assembly of the invention and a portion of a dispensing head generally illustrating the bayonet type connection therebetween; 
     FIG. 5 is a longitudinal cross-sectional view of the nozzle member of the assembly of the invention illustrating a guide track for the bayonet pins; and 
     FIG. 6 is a front elevational view in partial section of another embodiment of the present invention utilized to retrofit existing dispensing heads. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to FIG. 3, the nozzle assembly of the invention is generally designated by the reference numeral 10. The nozzle assembly 10 includes a nozzle member 12, an O-ring 14 and a needle seat 16. In use, the needle seat 16 is preferably connected to a modular dispensing head 18, generally illustrated in dotted lines in FIG. 4, which dispenses material, such as a hot-melt adhesive, in predetermined quantities. 
     FIG. 1 illustrates an existing nozzle assembly 10a which is threadedly connected to a modular dispensing head 18a. Thus, as described above, the nozzle assembly 10a must be removed and installed utilizing hand-tools which can be difficult to accomplish. 
     As FIGS. 2-4 illustrate, the nozzle assembly 10 of the present invention, however, utilizes a quick disconnect and connect structure. Preferably, the quick connect structure is in the form of a bayonet type connection, but can vary so long as it functions as described herein. 
     As FIG. 4 illustrates, the dispensing head 18 includes a material flow path 20 through which a hot-melt adhesive flows in predetermined quantities and intervals. The needle seat 16 includes a cylindrical engagement portion 22, a shoulder 24, a seat portion 26, and a flow channel 28 formed therethrough for accepting material from the flow path 20 and providing the material to the nozzle member 12. To connect the needle seat 16 to the dispensing head 18, the shoulder 24 includes a plurality o of apertures 30 formed therethrough for accepting screws (not illustrated) which extend through the apertures 30 and engage threaded receptacles in the dispensing head 18. 
     To enable the nozzle member 12 to be connected to the needle seat 16, the cylindrical portion 22 of the needle seat 16 includes a pair of bayonet pins 32, one each on opposite sides of the cylindrical portion 22. As described in detail below, the pins 32 engage slots and guide tracks formed in the nozzle member 12 so as to provide the desired quick release and connecting. 
     As FIG. 5 illustrates, the nozzle member 12 is preferably circular in shape and includes a central bore 34 having an outlet orifice 36 and a bottom interior shoulder 38. To accommodate the O-ring 14, the interior shoulder 38 includes an annular recess 40 formed therein which extends about the orifice 36. The orifice 36 is illustrated as being circular and coaxial with respect to the central bore 34, but can be positioned to emit material in a variety of patterns and directions. 
     The nozzle member 12 is preferably made of metal, such as brass, and is knurled on its exterior to assist in gripping by hand. Alternatively, the nozzle member 12 can be made of a high temperature plastic, such as polyphenylene sulfide (PPS) or any other type of material. If made from plastic, the nozzle member 12 can be disposed of or recycled after use rather than being cleaned. 
     To accept the pins 32 and provide the desired bayonet type connection, the nozzle member 12 includes two slots 42 formed on opposite sides of the central bore 34. The slots 42 extend a predetermined distance into the nozzle member 12 and are slightly larger than the exterior dimensions of the pins 32. 
     To provide rotation between the pins 32 and the nozzle member 12 after the pins 32 are seated in the slots 42, the nozzle member 12 includes two semi-circular tracks 44, only one of which is illustrated in FIG. 5. Each track 44 accepts and guides a respective pin 32, extends around the nozzle member 12 and tapers downwardly with respect to FIG. 5 from the upper ends of slots 42 toward the interior shoulder 38. 
     To finally seat the nozzle member 12 with respect to the needle seat 16, the bottom of each track 44 includes a substantially flat semi-circular channel portion 46. The length of the channel 46 can vary and is slightly wider than the dimensions of the pins 32. 
     In operation, to connect the nozzle member 12 to the needle seat 16, the pins 32 of the needle seat 16 are first aligned with the slots 42 of the nozzle member 12. The nozzle member 12 is then inserted over the cylindrical portion 22 of the needle seat 16 until the pins 32 contact the bottom of the slots 42. The nozzle member 12 is then rotated in a clockwise direction causing the pins 32 to engage and ride within the tracks 44 thereby drawing the nozzle member 12 further over the cylindrical portion 22 of the seat 16 and toward the dispensing head 18. 
     Just before the pins 32 reach the bottom of the tracks 44 and enter the bottom channels 46, the cylindrical portion 22 of the needle seat 16 contacts the O-ring 14 disposed within the bottom region of the bore 34 of the nozzle member 12. Upon continued rotation of the nozzle member 12, the cylindrical portion 22 compresses the O-ring 14 thereby providing a seal therebetween. Further rotation of the nozzle member 12 causes the pins 32 to engage the end of the bottom channels 46. 
     As FIG. 4 illustrates, the compressive force provided by the O-ring 14 jams the pins 32 against top portions of the bottom channels 46 and substantially locks the nozzle o member 12 in place on the needle seat 16. It is also to be noted that upon engagement of the O-ring 14 with the cylindrical portion 22 of the needle seat 16, the compressive force provided by the O-ring 14 and the frictional engagement of the O-ring 14 with the cylindrical portion 22 can be felt by the user. When combined with engagement of the pins 32 with the end of the channels 46, a positive physical indication is provided to the user which assures that the nozzle member 12 is properly secured on the needle seat 16. 
     In order to disconnect the nozzle member 12 from the needle seat 16, the nozzle 12 is rotated in a counterclockwise direction until the pins 32 align with the slots 42. In this position, the nozzle member 12 can be removed from the needle seat 16. 
     Preferably, the bayonet type connection is provided so that full engagement between the nozzle member 12 and the needle seat 16 is provided as a result of one-half turn of the nozzle member 12 with respect to the needle seat 16. The particular degree of rotation of the nozzle member 12, however, can vary. 
     FIG. 6 illustrates another embodiment of the present invention where common elements are designated by the same reference numerals as in the embodiment of FIGS. 2-5. In this embodiment, the nozzle assembly 10c is provided for retro-fitting existing threaded needle seats 16c. 
     The assembly 10c includes a nozzle member 12c, an adaptor 50, including pins 32c, and a nut 52. The nut 52 draws a shoulder 54 of the adaptor 50 into engagement with the needle seat 16c. The nozzle member 12c is then attached to the adaptor 50 in a manner similar to that of assembly 10 illustrated in FIGS. 2-5. 
     It is to be noted that, upon loosening of the nut 52, the adaptor 50 and, in turn, the nozzle member 12c, can be rotated. This can be useful to adjust a nozzle member 12c having an orifice which dispenses at a predetermined angle so as to vary the dispersion angle. 
     Modifications and variations of the present invention are possible in light of the above teachings. It therefore is to be understood that within the scope of the appended claims the invention may be practiced other than as specifically described.