Abstract:
A non-contact switch mechanism for use within a hot melt adhesive applicator gun comprises, for example, a reed switch mechanism rigidly mounted within the handle housing of the applicator gun, and a magnet rigidly mounted upon a rearwardly extending finger portion of the trigger member. Accordingly, when the trigger member is actuated as a result of being depressed or squeezed, the magnet enters the vicinity of the reed switch thereby activating the same so as to effectively convert the same from an OPEN state to a CLOSED state. The switch mechanism controls, for example, a rotary gear pump for supply adhesive material under pressure to the applicator gun, as well as a solenoid air valve for supplying pressurized swirl air to the applicator gun. In lieu of the reed switch mechanism, a proximity switch mechanism, or an optical switch mechanism, may be utilized.

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS  
       [0001]    This patent application is related to U.S. patent application Ser. No. 09/947,476 filed on Sep. 7, 2001 in the name of Christopher D. Bryan et al. and entitled HOT MELT ADHESIVE HAND APPLICATOR. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    The present invention relates generally to hot melt adhesive hand applicator guns or implements, and more particularly to a new and improved non-contact switch mechanism incorporated within the handle portion of the applicator gun, and activated by means of the applicator gun trigger member, for operatively controlling, for example, a rotary gear pump by means of which adhesive material is supplied under pressure to the applicator gun, as well as a solenoid air valve by means of which pressurized air can be supplied to the nozzle assembly of the applicator gun in a swirl application mode for interaction with the adhesive material being dispensed.  
         BACKGROUND OF THE INVENTION  
         [0003]    As disclosed within the aforenoted patent application, hot melt adhesive applicator guns conventionally comprise trigger mechanisms which are utilized to actuate both a needle valve member of a needle valve assembly which controls the discharge or deposition of the hot melt adhesive material from the applicator gun nozzle assembly in accordance with a predetermined hot melt adhesive deposition pattern, as well as an electrical switch assembly which, in turn, is utilized to activate, for example, both an adhesive material rotary gear pump by means of which adhesive material is supplied under pressure to the applicator gun, and a solenoid air valve by means of which pressurized air can be supplied to the nozzle assembly of the applicator gun in a swirl application mode for interaction with the adhesive material being dispensed. As may best be appreciated from FIG. 1 which discloses, in effect, the handle portion of a hot melt adhesive applicator gun which may be similar to the applicator gun disclosed within the aforenoted patent application and which is generally indicated by the reference character  10 , an applicator gun trigger member  12  is pivotally mounted by means of a pivot pin, not shown, upon an upper needle valve actuator housing  14 , which is only partially shown. A handle housing  16  is integral with the needle valve actuator housing  14 , and a trigger cover or trigger guard  18  also integrally interconnects the handle housing  16  and the needle valve actuator housing  14 . A space  20  is therefore formed between the trigger guard or cover  18  and the trigger member  12  so as to permit an operator&#39;s fingers to be insert therewithin in order to accordingly actuate the trigger member  12  when a hot melt adhesive dispensing operation is to be performed.  
           [0004]    An electrical connector  22 , shown only partially, is fixedly mounted within a lower end portion of the handle housing  16  so as to provide electrical power from an external power source, not shown, to an electrical power cable  24  which is disposed internally within the handle housing  16 . The electrical power cable  24  is operatively connected to a microswitch assembly or mechanism  26  which is provided for controlling electrical power to, for example, both an adhesive material rotary gear pump, not shown, by means of which adhesive material is supplied under pressure to the applicator gun  10 , and a solenoid air valve, also not shown, by means of which pressurized air can be supplied to the nozzle assembly of the applicator gun  10  in a swirl application mode for interaction with the adhesive material being dispensed by the applicator gun  10 . The microswitch assembly or mechanism  26  is mounted upon a mounting bracket  27  fixedly mounted within the interior portion of the handle housing  16 , and has an external microswitch lever or finger  28  operatively connected thereto. It is further seen that the trigger member  12  is provided with a rearwardly extending cam member  30  wherein an upper surface portion thereof is normally disposed in contact with an undersurface portion of the microswitch lever or finger  28 . Accordingly, when the trigger member  12  is actuated as a result of being depressed or squeezed by operator personnel, the cam member  30  will effectively force the microswitch lever or finger  28  upwardly so as to cause the microswitch assembly or mechanism to be switched from an OPEN state to a CLOSED state whereby the aforenoted rotary gear pump and solenoid air valve components will be activated or energized for respectively supplying the adhesive and swirl air.  
           [0005]    In view of the fact that applicator guns are relatively compact in size, the microswitch assembly  26  itself is necessarily small and fragile. Periodically, the applicators are dismantled or disasembled for maintenance, repair, or the exchange of components, such as, for example, to exchange trigger members, or to change the orientation of the electrical connectors, the heater bodies, and the hanging brackets. Subsequently, of course, the applicators are re-assembled. Accordingly, it can be readily appreciated that when each applicator is opened or disassembled, the microswitch assembly  26  becomes exposed, which renders the microswitch lever or finger  28  particularly vulnerable in view of the relatively small thickness dimension of the microswitch lever or finger  28  as well as its cantilevered mounting upon the microswitch assembly  26 , all of which render the microswitch lever or finger  28  flexible and easily deformable. Periodically, then, it has been experienced that the microswitch lever or finger  28  will be dislodged or moved away from its normal position as has been illustrated in FIG. 1 so as to be disposed or located at an abnormal position as illustrated in FIG. 2. It can therefore be further appreciated that in lieu of the cam member  30  of the trigger member  12  being disposed beneath the microswitch lever or finger  28  such that the upper surface portion thereof can normally engage the undersurface portion of the microswitch lever or finger  28  and therefore bias the microswitch lever or finger  28  upwardly, when the trigger member  12  is depressed or squeezed, so as to activate the microswitch assembly or mechanism  26  whereby the microswitch assembly or mechanism  26  will be switched from an OPEN state to a CLOSED state, an end portion of the cam member  30  will engage an end portion of the microswitch lever or finger  28 . Accordingly, when the trigger member  12  is squeezed or depressed, the microswitch lever or finger  28  will not be properly actuated whereby, in turn, the microswitch lever or finger  28  will not activate the microswitch assembly  26  in accordance with the desired mode of operation.  
           [0006]    A need therefore exists in the art for a new and improved non-contact switch system wherein the various elements comprising the non-contact switch system are rigidly mounted upon the handle housing and trigger member components of the applicator gun such that none of the elements comprising the non-contact switch system can be inadvertently bent, moved, or dislodged from their normal positions so as to render the non-contact switch system inoperable due, for example, to a relative misalignment of any of the non-contact switch system elements.  
         OBJECTS OF THE INVENTION  
         [0007]    Accordingly, it is an object of the present invention to provide a new and improved non-contact switch system for use within hot melt adhesive applicator guns.  
           [0008]    Another object of the present invention is to provide a new and improved non-contact switch system for use within hot melt adhesive applicator guns wherein the non-contact switch system overcomes the various operational drawbacks and disadvantages of conventional PRIOR ART microswitch assemblies.  
           [0009]    An additional object of the present invention is to provide a new and improved non-cpontact switch system for use within hot melt adhesive applicator guns wherein the various operative elements of the non-contact switch system are rigidly attached upon the handle and trigger components of the hot melt adhesive applicator gun.  
           [0010]    A further object of the present invention is to provide a new and improved non-contact switch system for use within hot melt adhesive applicator guns wherein the various operative elements of the non-contact switch system are rigidly attached upon the handle and trigger components of the hot melt adhesive applicator gun so as to be incapable of being moved from their normal operative positions to undesirable abnormal inoperative positions thereby rendering the applicator gun inoperative when the trigger member is operatively depressed or squeezed.  
           [0011]    A last object of the present invention is to provide a new and improved non-contact switch system for use within hot melt adhesive applicator guns wherein the various operative elements of the non-contact switch system are rigidly attached upon the handle and trigger components of the hot melt adhesive applicator gun and are not disposed in physical contact with each other so as not to be forcefully moved from their normal operative positions to undesirable abnormal inoperative positions thereby rendering the applicator gun inoperative when the trigger member is operatively depressed or squeezed.  
         SUMMARY OF THE INVENTION  
         [0012]    The foregoing and other objectives are achieved in accordance with the teachings and principles of the present invention through the provision of a new and improved non-contact switch system for use within a hot melt adhesive applicator gun wherein the non-contact switch system comprises various elements thereof rigidly mounted upon the handle housing and trigger member components of the hot melt adhesive applicator gun. In this manner, when the applicator gun is opened or disassembled for repair, maintenance, or component part interchange procedures or operations, damage or misalignment of the various elements of the non-contact switch system is effectively prevented. In particular, the non-contact switch system can comprise, for example, a magnetic reed switch system, a proximity switch system, an optical switch system, or the like. Accordingly, in view of the fact that one of the elements of the non-contact switch system is mounted upon, for example, the handle housing component of the applicator gun, while the other one of the elements of the non-contact switch system is mounted upon the trigger member component of the applicator gun, when the trigger member is actuated as a result of being depressed or squeezed, the elements of the non-contact switch system will operatively cooperate together so as to effectively move, switch, or change the non-contact switch mechanism from an OPENED state to a CLOSED state so as to be capable of controlling, for example, a rotary gear pump for supplying pressurized adhesive material to the applicator gun, as well as a solenoid air valve for supplying swirl air to the applicator gun for controlling the deposition pattern of the dispensed hot melt adhesive material. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]    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:  
         [0014]    [0014]FIG. 1 is a partial, cross-sectional view of a conventional PRIOR ART hot melt adhesive applicator gun showing primarily the handle portion thereof within which there is disposed a microswitch assembly having its microswitch finger disposed in a normal operative position so as to be properly engaged by the applicator gun trigger member when the trigger member is depressed or squeezed;  
         [0015]    [0015]FIG. 2 is a partial, cross-sectional view similar to that of FIG. 1 showing, however, the disposition of the conventional PRIOR ART microswitch finger of the microswitch assembly disposed at an abnormal inoperative position so as not to be properly engageable by the applicator gun trigger member;  
         [0016]    [0016]FIG. 3 is a partial, cross-sectional view similar to that of FIGS. 1 and 2 showing, however, a first embodiment of a new and improved non-contact switch system wherein the non-contact switch system comprises a magnetic reed switch system having the reed switch mechanism and magnetic member elements respectively rigidly mounted upon the handle section and trigger member components of the applicator gun;  
         [0017]    [0017]FIG. 4 is a partial, cross-sectional view similar to that of FIG. 3 showing, however, a second embodiment of a new and improved non-contact switch system wherein the non-contact switch system comprises a proximity switch system having the proximity switch mechanism and the metal actuator member elements respectively rigidly mounted upon the handle section and trigger member components of the applicator gun; and  
         [0018]    [0018]FIG. 5 is a partial, cross-sectional view similar to that of FIGS. 3 and 4 showing, however, a third embodiment of a new and improved non-contact switch system wherein the non-contact switch system comprises an optical switch system having the photodetector and actuator member elements respectively rigidly mounted upon the handle section and trigger member components of the applicator gun.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0019]    Referring now to the drawings, and more particularly to FIG. 3 thereof, a first embodiment of a new and improved non-contact switch system, constructed in accordance with the principles and teachings of the present invention, is disclosed and is generally indicated by the reference character  110 . It is noted that the structural arrangement of the various components comprising the applicator gun as illustrated in FIG. 3 is quite similar to the arrangement of components comprising the applicator guns illustrated within FIGS. 1 and 2, and therefore a detailed description of the corresponding components will be omitted so as to concentrate the detailed description of this patent application upon those components which are different from those of the systems disclosed within FIGS. 1 and 2 and which therefore comprise the present invention. In addition, it is noted further that the corresponding components will be designated by corresponding reference characters, except that the reference characters will be within the 100 series. More particularly, as illustrated within FIG. 3, and in accordance with the principles and teachings of the present invention, the first embodiment of a new and improved non-contact switch system is disclosed and is generally indicated by the reference character  110 . The applicator gun trigger member is disclosed at  112  and the applicator gun handle housing or section is disclosed at  116 . A mounting bracket  127 , similar to the mounting bracket  27 , is fixedly mounted within the interior portion of the handle housing  116 , however, in lieu of the microswitch assembly  26  being mounted upon the mounting bracket  27 , a reed switch mechanism  132  is fixedly mounted upon the mounting bracket  127 . Reed switches per se are of course well-known in the art, and therefore, a detailed description of the same will be omitted herefrom in the interest of brevity. Briefly, however, it is understood that a reed switch basically comprises two reed members which are normally spaced apart from each other so as to define an OPENED state for the switch mechanism. When, however, a magnetic member or magnet is moved into the vicinity or region of the reed switch mechanism, the magnetic field of the magnetic member or magnet will effectively interact with one of the reed members of the reed switch mechanism so as to cause such reed member to move toward and into contact with the other reed member thereby changing the status of the reed switch mechanism from its OPENED state to a CLOSED state.  
         [0020]    In accordance with the principles and teachings of the first embodiment of the present invention, it is therefore seen that a magnet or similar magnetic member  134  is fixedly mounted upon the rearwardly projecting member or finger  130  of the trigger member  112 . In addition, it is noted that the reed switch mechanism  132  is mounted upon the mounting bracket  127  at a predetermined elevational level such that when the trigger member  112  is actuated as a result of being depressed or squeezed, whereby the rearwardly projecting member or finger  130  will be correspondingly moved rearwardly or toward the right as viewed in FIG. 3, then the magnetic member or magnet  134  fixedly mounted upon the trigger member finger  130  will be disposed within a predetermined or pre-defined vicinity or region of the reed switch mechanism  132  so as to activate the switch mechanism  132  and thereby change the state of the switch mechanism  132  from OPENED to CLOSED. Obviously, when the operator personnel releases the trigger member  112 , the trigger member  112  will be returned to its normal, non-depressed or non-squeezed state at which the magnetic member or magnet  134  has been effectively removed and is disposed remote from the vicinity or region of the reed switch mechanism  132  whereby the reed switch mechanism  132  will again attain or be disposed in its OPENED state. In view of the fact that the reed switch mechanism  132  is rigidly mounted upon the mounting bracket  127 , in view of the additional fact that the components of the reed switch mechanism  132  are effectively self-contained in that none of the operative components are externally exposed as is the case of the microswitch finger  28  of the microswitch mechanism  26 , and in view of the still further fact that the magnetic member or magnet  134  does not actually physically engage or contact any operative element of the reed switch mechanism  132 , none of the operative elements of the reed switch mechanism  132  are susceptible to inadvertent damage, bending or deformation forces, misalignment, or the like. Accordingly, the operative integrity of the switch system  110  remains intact despite repeated assembly or disassembly procedures or operations performed upon the applicator gun for the aforenoted repair, component exchange or re-orientation, or maintenance purposes.  
         [0021]    With reference now being made to FIG. 4, a second embodiment of a new and improved non-contact switch system, also constructed in accordance with the principles and teachings of the present invention, is disclosed and is generally indicated by the reference character  210 . It is noted that the structural arrangement of the various components comprising the second embodiment applicator gun as illustrated within FIG. 4 is quite similar to the arrangement of components comprising the first embodiment applicator gun of the present invention as illustrated within FIG. 3, and therefore a detailed description of the corresponding components will be omitted herefrom so as to concentrate the detailed description of this patent application upon those components of the second embodiment system which are different from those of the first embodiment system as disclosed within FIG. 3. In addition, it is noted further that the corresponding components will be designated by corresponding reference characters, except that the reference characters will be within the 200 series.  
         [0022]    More particularly, as illustrated within FIG. 4, and in accordance with the principles and teachings of the present invention, in lieu of the non-contact reed switch mechanism  132  of the first embodiment  110  of the present invention, a proximity switch mechanism  232  is fixedly mounted upon a corresponding mounting bracket  227 . Proximity switches per se are of course well-known in the art, and therefore, a detailed description of the same will be omitted herefrom in the interest of brevity. Briefly, however, it is understood that a proximity switch basically comprises two magnetic members which are normally spaced apart from each other so as to define an OPENED state for the switch mechanism. When, however, a metal member is moved into the vicinity or region of the proximity switch mechanism, the metal member causes a concentration of flux within one of the magnetic members of the proximity switch mechanism so as to cause the other one of the magnetic members to move toward and into contact with the first magnetic member thereby changing the status of the reed switch mechanism from its OPENED state to a CLOSED state.  
         [0023]    In accordance with the principles and teachings of the second embodiment of the present invention, it is therefore seen that a metal member  234  is fixedly mounted upon the rearwardly projecting member or finger  230  of the trigger member  212 . In addition, it is noted that the proximity switch mechanism  232  is mounted upon the mounting bracket  227  at a predetermined elevational level such that when the trigger member  212  is actuated as a result of being depress ed or squeezed, whereby the rearwardly projecting member or finger  230  will be correspondingly moved rearwardly or toward the right as viewed in FIG. 4, then the metal member  234  fixedly mounted upon the trigger member finger  230  will be disposed within a predetermined or pre-defined vicinity or region of the proximity switch mechanism  232  so as to activate the switch mechanism  232  and thereby change the state of the switch mechanism  232  from OPENED to CLOSED. Obviously, when the operator personnel releases the trigger member  212 , the trigger member  212  will be returned to its normal, non-depressed or non-squeezed state so as to effectively remove the metal member  234  from within the vicinity or region of the proximity switch mechanism  232  whereby the proximity switch mechanism  232  will again attain or be disposed in its OPENED state. In view of the fact that the proximity switch mechanism  232  is rigidly mounted upon the mounting bracket  227 , in view of the additional fact that the components of the proximity switch mechanism  232  are effectively self-contained in that none of the operative components are externally exposed as is the case of the microswitch finger  28  of the microswitch mechanism  26 , and in view of the still further fact that the metal member  234  does not actually physically engage or contact any operative element of the proximity switch mechanism  232 , none of the operative elements of the proximity switch mechanism  232  are susceptible to inadvertent damage, bending or deformation forces, misalignment, or the like. Accordingly, the operative integrity of the switch system  210  remains intact despite repeated assembly or disassembly procedures or operations performed upon the applicator gun for the aforenoted repair, component exchange or re-orientation, or maintenance purposes.  
         [0024]    With reference lastly being made to FIG. 5, a third embodiment of a new and improved non-contact switch system, as constructed in accordance with the principles and teachings of the present invention, is disclosed and is generally indicated by the reference character  310 . It is noted that the structural arrangement of the various components comprising the third embodiment applicator gun as illustrated within FIG. 5 is quite similar to the arrangement of components comprising the first and second embodiments of the applicator gun of the present invention as illustrated within FIGS. 3 and 4, and therefore a detailed description of the corresponding components will be omitted herefrom so as to concentrate the detailed description of this patent application upon those components of the third embodiment system which are different from those of the first and second embodiment systems as disclosed within FIGS. 3 and 4. In addition, it is noted further that the corresponding components will be designated by corresponding reference characters, except that the reference characters will be within the 300 series.  
         [0025]    More particularly, as illustrated within FIG. 5, and in accordance with the principles and teachings of the present invention, in lieu of the non-contact reed switch mechanism  132  and the proximity switch mechanism  232  of the first and second embodiments  110 ,  210  of the present invenvention, an optical switch mechanism  332  is fixedly mounted upon a corresponding mounting bracket  327 . Optical switches per se are of course well-known in the art, and therefore, a detailed description of the same will be omitted herefrom in the interest of brevity. Briefly, however, it is understood that an optical switch can comprise, for example, two components in the form of a phototransmitter and a photodetector. The switch can be such that an inactive or OPENED state of the switch is achieved when a light beam from the phototransmitter is continuously detected by the photodetector, however, when an actuator is interposed between the phototransmitter and photodetector so as to interrupt the transmission of the light beam from the phototransmitter to the photodetector, the switch is changed from its OPENED state to a CLOSED state. Alternatively, the switch can be such that an inactive or OPENED state of the switch is achieved when a light beam from the phototransmitter is not normally detected by the photodetector, however, when an actuator is disposed at a predetermined position so as to reflect the light beam from the phototransmitter back to the photodetector, the switch is changed from its OPENED state to a CLOSED state.  
         [0026]    In accordance then with the principles and teachings of the third embodiment of the present invention, it is therefore seen that an actuator  334  is fixedly mounted upon the rearwardly projecting member or finger  330  of the trigger member  312 . In addition, it is noted that the optical switch mechanism  332 , which comprises the phototransmitter, is mounted upon the mounting bracket  327  at a predetermined elevational level such that when the trigger member  312  is actuated as a result of being depressed or squeezed, whereby the rearwardly projecting member or finger  330  will be correspondingly moved rearwardly or toward the right as viewed in FIG. 5, then the actuator  334  fixedly mounted upon the trigger member finger  330  will be disposed within the path of the emitted light beam from the phototransmitter of the optical switch mechanism  332 . Accordingly, the actuator  334  can either interrupt the light beam being transmitted to a photodetector not shown but located, for example, within a lower portion of the handle housing  316 , or reflect the light beam back to a photodetector not shown but also located within the optical switch mechanism  332  along with the phototransmitter. In either case, such movement of the actuator  334  activates the switch mechanism  332  so as to thereby change the state of the switch mechanism  332  from an OPENED state to a CLOSED state. Obviously, when the operator personnel releases the trigger member  312 , the trigger member  312  will be returned to its normal, non-depressed or non-squeezed state so as to effectively remove the actuator  334  from its interruption position with respect to the optical switch mechanism  332  whereby the optical switch mechanism  332  will again attain or be disposed in its OPENED state. In view of the fact that the optical switch mechanism  332  is rigidly mounted upon the mounting bracket  327 , in view of the additional fact that the components of the optical switch mechanism  332  are effectively self-contained in that none of the operative components are externally exposed as is the case of the microswitch finger  28  of the microswitch mechanism  26 , and in view of the still further fact that the actuator  334  does not actually physically engage or contact any operative element of the optical switch mechanism  332 , none of the operative elements of the optical switch mechanism  332  are susceptible to inadvertent damage, bending or deformation forces, misalignment, or the like. Accordingly, the operative integrity of the switch system  310  remains intact despite repeated assembly or disassembly procedures or operations performed upon the applicator gun for the aforenoted repair, component exchange or re-orientation, or maintenance purposes.  
         [0027]    Thus, it may be seen that in accordance with the principles and teachings of the present invention, there has been disclosed several embodiments of a non-contact switch mechanism for use within a hot melt adhesive applicator gun wherein in view of the fact that the various operative components of the switch mechanism are rigidly mounted upon, for example, the trigger member and handle housing portion of the applicator gun, and that there is no physical contact between the operative components of the switch mechanism when the trigger member is actuated so as to activate the switch mechanism from its OPENED state to its CLOSED state, damage or deformation to the switch mechanism, or elements thereof, as has been experienced with PRIOR ART switch mechanisms, is effectively prevented.  
         [0028]    Obviously, many variations and modifications of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the present invention may be practiced otherwise than as specifically described herein.