Abstract:
Die Erfindung betrifft ein Dosierventil (10) mit einem Schließkörper (12) und einem Ventilsitz (16), wobei der Schließkörper (12) zwischen einer Schließstellung, in der er auf dem Ventilsitz (16) aufsitzt und einen Materialauslass (14) verschließt, und einer Offenstellung, in der er vom Ventilsitz (16) abgehoben ist und den Materialauslass (14) freigibt, hin und her beweglich ist, mit einem mit dem Schließkörper (12) fest verbundenen Betätigungselement (20) und mit zwei Piezo-Aktoren (22, 24), zwischen denen das Betätigungselement (20) angeordnet ist, wobei das Betätigungselement (20) in der Schließstellung in einem Abstand zu einem ersten der Piezo-Aktoren (22) angeordnet ist, der kleiner ist als die maximale Längenänderung des ersten Piezo-Aktors (22), oder lose am ersten Piezo-Aktor (22) anliegt und in einem Abstand zum zweiten der Piezo-Aktoren (24) angeordnet ist, der größer ist als die maximale Längenänderung des ersten Piezo-Aktors (22), und wobei das Betätigungselement (20) in der Offenstellung in einem Abstand zum zweiten Piezo-Aktor (24) angeordnet ist, der kleiner ist als die maximale Längenänderung des zweiten Piezo-Aktors (24), oder lose am zweiten Piezo-Aktor (24) anliegt und in einem Abstand zum ersten Piezo-Aktor (22) angeordnet ist, der größer ist als die maximale Längenänderung des zweiten Piezo-Aktors (24).
Abstract:
In one aspect, an adhesive dispensing system includes a dispensing module having an inlet and an outlet, a supply of hot melt adhesive maintained at low pressure, and a low pressure liquid passageway communicating between the supply and the inlet of the dispensing module. Liquid material is received through the inlet at a low pressure, and the dispensing module rapidly develops high pressure at the outlet to jet the liquid material from the outlet. In another aspect, an apparatus for jetting liquid material includes a dispenser body having a liquid chamber. A piston is movably disposed within the liquid chamber, from a position wherein a piston tip is spaced from a complimentary shaped recess, to a position wherein the piston tip effectively seals off the recess, then to a position wherein the piston tip is received within the recess to displace a discrete volume of liquid material from the recess.
Abstract:
A melting system includes a hopper for receiving solid hot melt material, a heated conduit in communication with the hopper for melting the solid hot melt material, and a valve for allowing solid hot melt material to flow from the hopper to the heated conduit. The valve includes a disk movable between a closed position and an open position, a stem connected to the disk and an actuator for controlling the position of the disk. The disk prevents solid hot melt material from flowing from the hopper to the conduit in the closed position and allows solid hot melt material to flow from the hopper to the conduit in the open position.
Abstract:
An improved pneumatic jetting valve includes a housing with first and second chambers. A pneumatic piston is enclosed between the chambers. First and second solenoid valves are configured to respectively supply air pressure to the chambers and to exhaust the chambers. A controller is operable to regulate the pressurization and venting of the chambers. The controller controls the timing of control signals for the first and second solenoid valves to control the overlap time during which both the first and second chambers are pressurized. By controlling this overlap time, the controller controls the speed of the drive pin of the jetting valve and thereby the speed at which the valve closes to jet a droplet of material. This allows a valve speed to be selected that is most appropriate for the viscosity of the material being jetted. Numerous new methods for utilizing the improved jetting valve and system are disclosed.
Abstract:
The invention relates to a dosing system (1', 1'') for a liquid to viscous dosing material comprising an actuator system (2), which comprises at least one actuating element (29, 57), and a nozzle (13) having an outlet opening (19). According to the invention, the actuating element (29, 57) is first moved in a first partial movement upon a movement in a closure direction (V) so that it is separated from the closure element (15) at a proper stop location (31) and then meets the closure element on the stop location (31) and exerts an impulse (I) on the closure element (15). The invention also relates to a correspondingly designed dosing method.
Abstract:
An apparatus for conveying viscous material out of a barrel-like container having a container bottom and a container wall that extends upward from the container bottom has a follower plate for closing off the container, which plate is movable in the direction toward the container bottom, lying against the inner surface of the container wall, which surface faces the container interior, and which plate has a dome that extends upward from an underside intended to lie on the viscous material, which dome opens, in the center, into a material exit opening. The apparatus has a pump for conveying the viscous material through the material exit opening. At least one displacement body projects into the dome through the material exit opening and is connected with the pump for displacement of the material situated in the dome and/or air situated in the dome, and at least one closeable venting opening vents the dome.
Abstract:
A dispensing module and method of dispensing an adhesive includes a dispenser body having a valve element and a nozzle. The nozzle includes a nozzle member, a sealing zone, and a valve seat. The nozzle member includes a liquid passageway having a bore, a cylindrical surface, a second converging surface, and a shoulder. The sealing zone is defined by the cylindrical surface and extends from the bore toward the shoulder and engages the valve element to close a first volume of the liquid passageway from the inlet. The valve seat is defined by the shoulder and the second converging surface and has a circular line of contact that engages the valve element to close a second volume of the liquid passageway from the inlet. The first volume reduces to the second volume as the valve element moves distally along the sealing zone for discharging the adhesive.
Abstract:
A melting system includes a hopper for receiving solid hot melt material, a heated conduit in communication with the hopper for melting the solid hot melt material, and a valve for allowing solid hot melt material to flow from the hopper to the heated conduit. The valve includes a disk movable between a closed position and an open position, a stem connected to the disk and an actuator for controlling the position of the disk. The disk prevents solid hot melt material from flowing from the hopper to the conduit in the closed position and allows solid hot melt material to flow from the hopper to the conduit in the open position.