Snuffback-diversion flow valve system

Abstract

A valve assembly, for use in connection with the dispensing of hot melt adhesive material, comprises a snuffback valve member and a diversion flow valve member. The snuffback valve and diversion flow valve members are integrally connected together and are movable in opposite modes with respect to their valve seats such that when the snuffback valve member is seated upon its valve seat, the diversion flow valve member is unseated with respect to its valve seat, and vice versa. A recirculation fluid supply loop is fluidically associated with the diversion flow valve member, and when the diversion flow valve member is disposed at its unseated position, the hot melt adhesive material is recirculated so as not to pressurize the supply side of the snuffback valve member. Accordingly, when the snuffback valve member is unseated, the phenomena of bursting is effectively prevented. The geometries of the valve members and their valve seats are also predeterminedly related such that a neutral or negative pressure differential is created upon closure of the snuffback valve member and opening of the diversion flow valve member so as to prevent the occurrence of stringing.

What is claimed as new and desired to be protected by Letters Patent of the United States of America, is:  
     
         1 . A valve assembly for use in connection with the dispensing of fluid materials, comprising: 
 a housing;    a supply port defined upon said housing for introducing materials, to be dispensed, into said housing;    an exit port defined upon said housing for permitting materials to be conducted out of said housing;    a discharge outlet defined upon said housing for permitting materials to be dispensed from said valve assembly;    a first valve seat;    a first valve member movably disposed within said housing between a first position at which said first valve member is seated upon said first valve seat so as to prevent materials from being dispensed from said valve assembly through said discharge outlet, and a second position at which said first valve member is unseated with respect to said first valve seat so as to permit materials to be dispensed from said valve assembly through said discharge outlet;    a second valve seat; and    a second valve member fixedly connected to said first valve member so as to be movably disposed within said housing, and in conjunction with said first valve member, between a first position at which said second valve member is unseated with respect to said second valve seat when said first valve member is seated upon said first valve seat so as to permit materials to be conducted from said supply port to said exit port and not pressurize said first valve member seated upon said first valve seat, and a second position at which said second valve member is seated upon said second valve seat when said first valve member is unseated with respect to said first valve seat so as to prevent materials from being conducted from said supply port to said exit port and to permit materials to be conducted toward said discharge outlet so as to be dispensed from said valve assembly through said discharge outlet in a substantially consistent manner, without exhibiting bursting phenomena, throughout dispensing operation cycles.    
     
     
         2 . The valve assembly as set forth in  claim 1 , further comprising: 
 a material supply tank fludically connected to said exit port by means of a first fluid conduit;    a pump fluidically connected to said material supply tank by means of a second fluid conduit, and fluidically connected to said supply port by means of a third fluid conduit,    wherein said exit port, said first fluid conduit, said material supply tank, said second fluid conduit, said pump, said third fluid conduit, and said supply port define a recirculation loop with respect to said housing for the materials to be dispensed.    
     
     
         3 . The valve assembly as set forth in  claim 1 , wherein: 
 said first valve member comprises a first valve stem; and    said second valve member has a recess defined therein within which an end portion of said first valve stem of said first valve member is fixedly disposed so as to integrally connect said first and second valve members together.    
     
     
         4 . The valve assembly as set forth in  claim 3 , further comprising: 
 a cylinder chamber defined within said housing; and    a piston movably disposed within said cylinder chamber;    said second valve member comprising a second valve stem fixedly connected to said piston such that upon movement of said piston within said cylinder chamber, said first valve member is moved along with said second valve member as a result of said first valve stem of said first valve member being connected to said second valve member, and as a result of said second valve stem of said second valve member being connected to said piston.    
     
     
         5 . The valve assembly as set forth in  claim 4 , further comprising: 
 a CLOSE air port defined within said housing for introducing CLOSE air into said housing so as to impinge upon a first surface of said piston whereby said piston causes said first valve member to move to said first seated position with respect to said first valve seat; and    an OPEN air port defined within said housing for introducing OPEN air into said housing so as to impinge upon a second surface of said piston whereby said piston causes said first valve member to move said second unseated position with respect to said first valve seat.    
     
     
         6 . A valve assembly for use in connection with the dispensing of highly viscous materials, comprising: 
 a housing;    a supply port defined upon said housing for introducing highly viscous materials, to be dispensed, into said housing;    an exit port defined upon said housing for permitting highly viscous materials to be conducted out of said housing;    a discharge outlet defined upon said housing for permitting highly viscous materials to be dispensed from said valve assembly;    a first valve seat;    a first valve member movably disposed within said housing between a first position at which said first valve member is seated upon said first valve seat so as to prevent highly viscous materials from being dispensed from said valve assembly through said discharge outlet, and a second position at which said first valve member is unseated with respect to said first valve seat so as to permit highly viscous materials to be dispensed from said valve assembly through said discharge outlet;    a second valve seat; and    a second valve member fixedly connected to said first valve member so as to be movably disposed within said housing, and in conjunction with said first valve member, between a first position at which said second valve member is unseated with respect to said second valve seat when said first valve member is seated upon said first valve seat so as to permit highly viscous materials to be conducted from said supply port to said exit port and not pressurize said first valve member seated upon said first valve seat, and a second position at which said second valve member is seated upon said second valve seat when said first valve member is unseated with respect to said first valve seat so as to prevent highly viscous materials from being conducted from said supply port to said exit port and to permit highly viscous materials to be conducted toward said discharge outlet so as to be dispensed from said valve assembly through said discharge outlet in a substantially consistent manner, without exhibiting bursting phenomena, throughout dispensing operation cycles.    
     
     
         7 . The valve assembly as set forth in  claim 6 , further comprising: 
 a material supply tank fludically connected to said exit port by means of a first fluid conduit;    a pump fluidically connected to said material supply tank by means of a second fluid conduit, and fluidically connected to said supply port by means of a third fluid conduit,    wherein said exit port, said first fluid conduit, said material supply tank, said second fluid conduit, said pump, said third fluid conduit, and said supply port define a recirculation loop with respect to said housing for the highly viscous materials to be dispensed.    
     
     
         8 . The valve assembly as set forth in  claim 6 , wherein: 
 said first valve member comprises a first valve stem; and    said second valve member has a recess defined therein within which an end portion of said first valve stem of said first valve member is fixedly disposed so as to integrally connect said first and second valve members together.    
     
     
         9 . The valve assembly as set forth in  claim 8 , further comprising: 
 a cylinder chamber defined within said housing; and    a piston movably disposed within said cylinder chamber;    said second valve member comprising a second valve stem fixedly connected to said piston such that upon movement of said piston within said cylinder chamber, said first valve member is moved along with said second valve member as a result of said first valve stem of said first valve member being connected to said second valve member, and as a result of said second valve stem of said second valve member being connected to said piston.    
     
     
         10 . The valve assembly as set forth in  claim 4 , further comprising: 
 a CLOSE air port defined within said housing for introducing CLOSE air into said housing so as to impinge upon a first surface of said piston whereby said piston causes said first valve member to move to said first seated position with respect to said first valve seat; and    an OPEN air port defined within said housing for introducing OPEN air into said housing so as to impinge upon a second surface of said piston whereby said piston causes said first valve member to move said second unseated position with respect to said first valve seat.    
     
     
         11 . A valve assembly for use in connection with the dispensing of highly viscous materials, comprising: 
 a housing;    a supply port defined upon said housing for introducing highly viscous materials, to be dispensed, into said housing;    an exit port defined upon said housing for permitting highly viscous materials to be conducted out of said housing;    a discharge outlet defined upon said housing for permitting highly viscous materials to be dispensed from said valve assembly;    a first valve seat;    a first snuffback valve member movably disposed within said housing between a first position at which said first snuffback valve member is seated upon said first valve seat so as to prevent highly viscous materials from being dispensed from said valve assembly through said discharge outlet, and a second position at which said first snuffback valve member is unseated with respect to said first valve seat so as to permit highly viscous materials to be dispensed from said valve assembly through said discharge outlet;    a second valve seat; and    a second diversion flow valve member fixedly connected to said first valve member so as to be movably disposed within said housing, and in conjunction with said first snuffback valve member, between a first position at which said second diversion flow valve member is unseated with respect to said second valve seat when said first valve member is seated upon said first valve seat so as to permit highly viscous materials to be conducted from said supply port to said exit port and not pressurize said first snuffback valve member seated upon said first valve seat, and a second position at which said second diversion flow valve member is seated upon said second valve seat when said first snuffback valve member is unseated with respect to said first valve seat so as to prevent highly viscous materials from being conducted from said supply port to said exit port and to permit highly viscous materials to be conducted toward said discharge outlet so as to be dispensed from said valve assembly through said discharge outlet in a substantially consistent manner, without exhibiting bursting phenomena, throughout dispensing operation cycles.    
     
     
         12 . The valve assembly as set forth in  claim 11 , further comprising: 
 a highly viscous material supply tank fludically connected to said exit port by means of a first fluid conduit;    a pump fluidically connected to said highly viscous material supply tank by means of a second fluid conduit, and fluidically connected to said supply port by means of a third fluid conduit,    wherein said exit port, said first fluid conduit, said highly viscous material supply tank, said second fluid conduit, said pump, said third fluid conduit, and said supply port define a recirculation loop with respect to said housing for the highly viscous material to be dispensed.    
     
     
         13 . The valve assembly as set forth in  claim 11 , wherein: 
 said first snuffback valve member comprises a first valve stem; and    said second diversion flow valve member has a recess defined therein within which an end portion of said first valve stem of said first snuffback valve member is fixedly disposed so as to integrally connect said first snuffback and second diversion flow valve members together.    
     
     
         14 . The valve assembly as set forth in  claim 13 , further comprising: 
 a cylinder chamber defined within said housing; and    a piston movably disposed within said cylinder chamber;    said second diversion flow valve member comprising a second valve stem fixedly connected to said piston such that upon movement of said piston within said cylinder chamber, said first snuffback valve member is moved along with said second diversion flow valve member as a result of said first valve stem of said first snuffback valve member being connected to said second diversion flow valve member, and as a result of said second valve stem of said second diversion flow valve member being connected to said piston.    
     
     
         15 . The valve assembly as set forth in  claim 14 , further comprising: 
 an OPEN air port defined within said housing for introducing OPEN air into said housing so as to impinge upon a first surface of said piston whereby said piston causes said first snuffback valve member to move said second unseated position with respect to said first valve seat; and    a CLOSE air port defined within said housing for introducing CLOSE air into said housing so as to impinge upon a second surface of said piston whereby said piston causes said first snuffback valve member to move to said first seated position upon said first valve seat while said second diversion flow valve member is moved to said first unseated position with respect to said second valve seat.    
     
     
         16 . The valve assembly as set forth in  claim 15 , wherein: 
 said first snuffback valve member comprises a first valve seat engagement portion having a first predetermined structural geometry for engaging said first valve seat which has a predetermined structural geometry corresponding to said first predetermined structural geometry of said first valve seat engagement portion; and    said second diversion flow valve member comprises a second valve seat engagement portion having a second predetermined structural geometry for engaging said second valve seat which has a predetermined structural geometry corresponding to said second predetermined structural geometry of said second valve seat engagement portion;    said structural geometries of said first and second valve seat engagement portions and said first and second valve seats being substantially equal such that when said first snuffback valve member is moved toward said first valve seat so as to be seated upon said first valve seat, and said second diversion flow valve member is moved away from said second valve seat so as to be unseated with respect to said second valve seat, a zero pressure differential is developed within the highly viscous material being dispensed such that reverse flow of the highly viscous material being dispensed back toward said discharge outlet is effectively prevented so as to in turn effectively prevent the phenomena of stringing from occurring upon termination of a highly viscous material dispensing operation cycle.    
     
     
         17 . The valve assembly as set forth in  claim 15 , wherein: 
 said first snuffback valve member comprises a first valve seat engagement portion having a first predetermined structural geometry for engaging said first valve seat which has a predetermined structural geometry corresponding to said first predetermined structural geometry of said first valve seat engagement portion; and    said second diversion flow valve member comprises a second valve seat engagement portion having a second predetermined structural geometry for engaging said second valve seat which has a predetermined structural geometry corresponding to said second predetermined structural geometry of said second valve seat engagement portion;    said structural geometries of said second valve seat engagement portion and said second valve seat being greater than said structural geometries of said first valve seat engagement portion and said first valve seat such that when said first snuffback valve member is moved toward said first valve seat so as to be seated upon said first valve seat, and said second diversion flow valve member is moved away from said second valve seat so as to be unseated with respect to said second valve seat, a negative pressure differential is developed within the highly viscous material being dispensed such that reverse flow of the highly viscous material being dispensed back toward said discharge outlet is effectively prevented so as to in turn effectively prevent the phenomena of stringing from occurring upon termination of a highly viscous material dispensing operation cycle.    
     
     
         18 . A valve assembly for use in connection with the dispensing of hot melt adhesive material, comprising: 
 a housing;    a supply port defined upon said housing for introducing hot melt adhesive material, to be dispensed, into said housing;    an exit port defined upon said housing for permitting hot melt adhesive material to be conducted out of said housing;    a discharge outlet defined upon said housing for permitting hot melt adhesive material to be dispensed from said valve assembly;    a first valve seat;    a first snuffback valve member movably disposed within said housing between a first position at which said first snuffback valve member is seated upon said first valve seat so as to prevent hot melt adhesive material from being dispensed from said valve assembly through said discharge outlet, and a second position at which said first snuffback valve member is unseated with respect to said first valve seat so as to permit hot melt adhesive material to be dispensed from said valve assembly through said discharge outlet;    a second valve seat; and    a second diversion flow valve member fixedly connected to said first valve member so as to be movably disposed within said housing, and in conjunction with said first snuffback valve member, between a first position at which said second diversion flow valve member is unseated with respect to said second valve seat when said first valve member is seated upon said first valve seat so as to permit hot melt adhesive material to be conducted from said supply port to said exit port and not pressurize said first snuffback valve member seated upon said first valve seat, and a second position at which said second diversion flow valve member is seated upon said second valve seat when said first snuffback valve member is unseated with respect to said first valve seat so as to prevent hot melt adhesive material from being conducted from said supply port to said exit port and to permit hot melt adhesive material to be conducted toward said discharge outlet so as to be dispensed from said valve assembly through said discharge outlet in a substantially consistent manner, without exhibiting bursting phenomena, throughout dispensing operation cycles.    
     
     
         19 . The valve assembly as set forth in  claim 18 , further comprising: 
 a hot melt adhesive material supply tank fludically connected to said exit port by means of a first fluid conduit;    a pump fluidically connected to said hot melt adhesive material supply tank by means of a second fluid conduit, and fluidically connected to said supply port by means of a third fluid conduit,    wherein said exit port, said first fluid conduit, said hot melt adhesive material supply tank, said second fluid conduit, said pump, said third fluid conduit, and said supply port define a recirculation loop with respect to said housing for the hot melt adhesive material to be dispensed.    
     
     
         20 . The valve assembly as set forth in  claim 18 , wherein: 
 said first snuffback valve member comprises a first valve stem; and    said second diversion flow valve member has a recess defined therein within which an end portion of said first valve stem of said first snuffback valve member is fixedly disposed so as to integrally connect said first snuffback and second diversion flow valve members together.    
     
     
         21 . The valve assembly as set forth in  claim 20 , further comprising: 
 a cylinder chamber defined within said housing; and    a piston movably disposed within said cylinder chamber;    said second diversion flow valve member comprising a second valve stem fixedly connected to said piston such that upon movement of said piston within said cylinder chamber, said first snuffback valve member is moved along with said second diversion flow valve member as a result of said first valve stem of said first snuffback valve member being connected to said second diversion flow valve member, and as a result of said second valve stem of said second diversion flow valve member being connected to said piston.    
     
     
         22 . The valve assembly as set forth in  claim 21 , further comprising: 
 an OPEN air port defined within said housing for introducing OPEN air into said housing so as to impinge upon a first surface of said piston whereby said piston causes said first snuffback valve member to move said second unseated position with respect to said first valve seat; and    a CLOSE air port defined within said housing for introducing CLOSE air into said housing so as to impinge upon a second surface of said piston whereby said piston causes said first snuffback valve member to move to said first seated position upon said first valve seat while said second diversion flow valve member is moved to said first unseated position with respect to said second valve seat.    
     
     
         23 . The valve assembly as set forth in  claim 22 , wherein: 
 said first snuffback valve member comprises a first valve seat engagement portion having a first predetermined structural geometry for engaging said first valve seat which has a predetermined structural geometry corresponding to said first predetermined structural geometry of said first valve seat engagement portion; and    said second diversion flow valve member comprises a second valve seat engagement portion having a second predetermined structural geometry for engaging said second valve seat which has a predetermined structural geometry corresponding to said second predetermined structural geometry of said second valve seat engagement portion;    said structural geometries of said first and second valve seat engagement portions and said first and second valve seats being substantially equal such that when said first snuffback valve member is moved toward said first valve seat so as to be seated upon said first valve seat, and said second diversion flow valve member is moved away from said second valve seat so as to be unseated with respect to said second valve seat, a zero pressure differential is developed within the hot melt adhesive material being dispensed such that reverse flow of the hot melt adhesive material being dispensed back toward said discharge outlet is effectively prevented so as to in turn effectively prevent the phenomena of stringing from occurring upon termination of a hot melt adhesive material dispensing operation cycle.    
     
     
         24 . The valve assembly as set forth in  claim 22 , wherein: 
 said first snuffback valve member comprises a first valve seat engagement portion having a first predetermined structural geometry for engaging said first valve seat which has a predetermined structural geometry corresponding to said first predetermined structural geometry of said first valve seat engagement portion; and    said second diversion flow valve member comprises a second valve seat engagement portion having a second predetermined structural geometry for engaging said second valve seat which has a predetermined structural geometry corresponding to said second predetermined structural geometry of said second valve seat engagement portion;    said structural geometries of said second valve seat engagement portion and said second valve seat being greater than said structural geometries of said first valve seat engagement portion and said first valve seat such that when said first snuffback valve member is moved toward said first valve seat so as to be seated upon said first valve seat, and said second diversion flow valve member is moved away from said second valve seat so as to be unseated with respect to said second valve seat, a negative pressure differential is developed within the hot melt adhesive material being dispensed such that reverse flow of the hot melt adhesive material being dispensed back toward said discharge outlet is effectively prevented so as to in turn effectively prevent the phenomena of stringing from occurring upon termination of a hot melt adhesive material dispensing operation cycle.