Device for the melting and measured discharge of thermoplastic adhesive
AssigneeHilti Aktiengesellschaft
InventorsErich Leibhard, Franz Popp
Life of this patent
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Abstract
In a device for the melting and measured discharge of a thermoplastic adhesive, a sealing sleeve conveys the solid thermoplastic adhesive into the inlet end of a melting chamber. The sealing sleeve is formed of a temperature resistant, poor heat conductive material with good sliding properties, such as polytetrafluoroethylene. Further, the sealing sleeve is provided with slots extending in the axial direction of the sleeve from the end more remote from the melting chamber toward the melting chamber.
Claims18
Device for the melting and measured discharge of a thermoplastic adhesive comprising walls forming a melting chamber having an inlet end through which a body of solid thermoplastic adhesive of variable cross sectional size and shape is introduced into said melting chamber and an outlet end spaced from said inlet end for discharging melted thermoplastic material from said melting chamber, an axially extending sealing sleeve positioned at said inlet end of said melting chamber so that the solid thermoplastic material can be passed through said sealing sleeve and into said inlet end of said melting chamber, said sealing sleeve arranged to be in surface contact with the outside surface of the body of solid thermoplastic adhesive for preventing melted adhesive from flowing rearwardly through said sleeve out of said melting chamber, wherein the improvement comprises that said sealing sleeve is formed of a temperature-resistant poor heat-conductive material having good sliding properties, said sealing sleeve having a first end located at the inlet end of said melting chamber and a second end spaced axially outwardly from said melting chamber in the direction away from said melting chamber, and said sealing sleeve having slots dividing said second end of said sealing sleeve into independently movable resilient lugs, said slots extending in the axial direction of said sealing sleeve through said second end toward said first end with said slots spaced apart around the circumference of said sealing sleeve.
Device, for the melting and measured discharge of a thermoplastic adhesive comprising walls forming a melting chamber having an inlet end through which solid thermoplastic adhesive is introduced into said melting chamber and an outlet end spaced from said inlet end for discharging melted thermoplastic material from said melting chamber, an axially extending sealing sleeve positioned at said inlet end of said melting chamber so that the solid thermoplastic material passes through said sealing sleeve and into said inlet end of said melting chamber, wherein the improvement comprises that said sealing sleeve is formed of a temperature-resistant poor heat-conductive material having good sliding properties, said sealing sleeve having a first end located at the inlet end of said melting chamber and a second end spaced axially outwardly from said melting chamber in the direction away from said melting chamber, and said sealing sleeve having slots extending in the axial direction thereof from said second end toward said first end with said slots spaced apart around the circumference of said sealing sleeve, a spring element laterally enclosing said sealing sleeve with said spring element applying an inwardly directed force to said sealing sleeve, and said spring element extends in the axial direction of said sealing sleeve for at least the length of said slots within said sealing sleeve.
Device for the melting and measured discharge of a thermoplastic adhesive comprising walls forming a melting chamber having an inlet end through which solid thermoplastic adhesive is introduced into said melting chamber and an outlet end spaced from said inlet end for discharging melted thermoplastic material from said melting chamber, an axially extending sealing sleeve positioned at said inlet end of said melting chamber so that the solid thermoplastic material passes through said sealing sleeve and into said inlet end of said melting chamber wherein the improvement comprises that said sealing sleeve is formed of a temperature-resistant poor heat-conductive material having good sliding properties, said sealing sleeve having a first end located at the inlet end of said melting chamber and a second end spaced axially outwardly from said melting chamber in the direction away from said melting chamber, and said sealing sleeve having slots extending in the axial direction thereof from said second end toward said first end with said slots spaced apart around the circumference of said sealing sleeve, a spring element laterally enclosing said sealing sleeve with said spring element applying an inwardly directed force to said sealing sleeve, and said spring element comprises a sheath-like member formed of an elastic rubber material.
Device for the melting and measured discharge of a thermoplastic adhesive comprising walls forming a melting chamber having an inlet end through which a body of solid thermoplastic adhesive of variable cross sectional size and shape is introduced into said melting chamber and an outlet end spaced from said inlet end for discharging melted thermoplastic material from said melting chamber, an axially extending sealing sleeve positioned at said inlet end of said melting chamber so that the solid thermoplastic material can be passed through said sealing sleeve and into said inlet end of said melting chamber, said sealing sleeve arranged to be in surface contact with the outside surface of the body of solid thermoplastic adhesive for preventing melted adhesive from flowing rearwardly through said sealing sleeve out of the inlet end of said melting chamber, wherein the improvement comprises that said sealing sleeve is formed of a temperature-resistant poor heat-conductive material having good sliding properties, said sealing sleeve having a first end located at the inlet end of said melting chamber and a second end spaced axially outwardly from said melting chamber in the direction away from said melting chamber, said sealing sleeve having slots dividing said second end of said sealing sleeve into independently movable resilient lugs, said slots extending in the axial direction of said sealing sleeve through said second end toward said first end with said slots spaced apart around the circumference of said sealing sleeve, and means laterally enclosing the axially extending portion of said sealing sleeve having slots therein for preventing the flow of the melted adhesive outwardly through said slots.
Dependencies are inferred from the claim text.