Hot melt adhesive delivery system

Claim 1

A system for intermittent supply of a molten thermoplastic, which comprises: (a) an extruder comprising a barrel having a single screw therein, said extruder equipped with means to rotate the screw and with means to start and stop the screw rotating means and having a first zone for receiving solid thermoplastic, a second zone for melting the thermoplastic and a third zone for metering the molten thermoplastic from the extruder, said third zone having a discharge end; (b) a reservoir containing the thermoplastic in the form of solid granules, the reservoir being attached to the barrel of the extruder at the receiving zone and having a throat communicating with the extruder barrel through which the solid granules are fed to the extruder; (c) cooling means at the receiving zone of the barrel of the extruder to allow the thermoplastic therein to remain in granular form until it is passed to the melting zone of the extruder; (d) heating means in the barrel of the extruder to progressively heat and melt the thermoplastic in the melting zone and maintain it molten in the metering zone; (e) a heated manifold to receive the molten thermoplastic from the discharge end of the extruder, to maintain it in the molten state and to distribute it to at least one heated hose; and (f) an applicator attached to the delivery end of said at least one heated hose, said applicator comprising a housing, an applicator barrel to receive the molten thermoplastic from the heated hose, the applicator barrel terminating in a nozzle from which the molten thermoplastic is discharged, a valve in the applicator barrel to allow the molten thermoplastic to flow through the applicator barrel and be discharged from the nozzle, means to open the valve which also actuates the starting means for the screw-rotating means of the extruder and means to close the valve which also actuates the stopping means for the screw-rotating means; wherein an accumulator is attached to the manifold, said accumulator comprising a piston cylinder to receive molten thermoplastic from the manifold, a piston to deliver molten thermoplastic from the cylinder to the manifold, a piston ram connected to the piston, a piston ram control, means to actuate the piston ram control, said piston having an exhaust stroke and an intake stroke means to de-actuate the extruder screw-rotating means, and heating means attached to the piston cylinder to maintain the thermoplastic in the piston cylinder in the molten state, wherein the piston cylinder (at the exit to the manifold and the piston are tapered to allow substantially complete elimination of the molten thermoplastic from the accumulator at completion of the exhaust stroke of the piston, wherein the piston is equipped with a flexible metallic compression seal which bears against the piston cylinder.. to wipe the wall of the piston cylinder clean of molten thermoplastic on the exhaust stroke of the piston, wherein during discharge of molten thermoplastic from the applicator the piston ram control is actuated to cause the piston to deliver molten thermoplastic from the piston cylinder into the manifold, wherein during the valve closed position of the applicator, the piston ram control and the screw-rotating means of the extruder are actuated to allow the extruder to deliver molten thermoplastic via the manifold to the piston cylinder, and wherein when the piston cylinder is full of molten thermoplastic during the valve closed position of the applicator, the extruder screw-rotating means is de-actuated; and wherein the manifold is equipped with a pressure overload sensing means which actuates a circuit breaking means and shuts off power to the system when the pressure of the molten thermoplastic reaches a set overload value.

Claim 2

A system for intermittent supply of a molten thermoplastic, which comprises: (a) an extruder comprising a barrel having a single screw therein, said extruder equipped with means to rotate the screw and with means to start and stop the screw rotating means and having a first zone for receiving solid thermoplastic, a second zone for melting the thermoplastic and a third zone for metering the molten thermoplastic from the extruder, said third zone having a discharge end; (b) a reservoir containing the thermoplastic in the form of solid granules, the reservoir being attached to the barrel of the extruder at the receiving zone and having a throat communicating with the extruder barrel through which the solid granules are fed to the extruder; (c) cooling means at the receiving zone of the barrel of the extruder to allow the thermoplastic therein to remain in granular form until it is passed to the melting zone of the extruder; (d) heating means in the barrel of the extruder to progressively heat and melt the thermoplastic in the melting zone and maintain it molten in the metering zone; (e) a heated manifold to receive the molten thermoplastic from the discharge end of the extruder, to maintain it in the molten state and to distribute it to at least one heated hose; and (f) an applicator attached to the delivery end of said at least one heated hose, said applicator comprising a housing, an applicator barrel to receive the molten thermoplastic from the heated hose, the applicator barrel terminating in a nozzle from which the molten thermoplastic is discharged, a valve in the applicator barrel to allow the molten thermoplastic to flow through the applicator barrel and be discharged from the nozzle, means to open the valve which also actuates the starting means for the screw-rotating means of the extruder and means to close the valve which also actuates the stopping means for the screw-rotating means; wherein an accumulator is attached to the manifold, said accumulator comprising a piston cylinder to receive molten thermoplastic from the manifold, a piston to deliver molten thermoplastic from the cylinder to the manifold, a piston ram connected to the piston, a piston ram control, means to actuate the piston ram control, said piston having an exhaust stroke and an intake stroke means to de-actuate the extruder screw-rotating means, and heating means attached to the piston cylinder to maintain the thermoplastic in the piston cylinder in the molten state, wherein the piston cylinder (at the exit to the manifold and the piston are tapered to allow substantially complete elimination of the molten thermoplastic from the accumulator at completion of the exhaust stroke of the piston, wherein the piston is equipped with a flexible metallic compression seal which bears against the piston cylinder.. to wipe the wall of the piston cylinder clean of molten thermoplastic on the exhaust stroke of the piston, wherein during discharge of molten thermoplastic from the applicator the piston ram control is actuated to cause the piston to deliver molten thermoplastic from the piston cylinder into the manifold, wherein during the valve closed position of the applicator, the piston ram control and the screw-rotating means of the extruder are actuated to allow the extruder to deliver molten thermoplastic via the manifold to the piston cylinder, and wherein when the piston cylinder is full of molten thermoplastic during the valve closed position of the applicator, the extruder screw-rotating means is de-actuated; and wherein the manifold is equipped with a pressure overload sensing means which actuates a circuit breaking means and shuts off power to the system when the pressure of the molten thermoplastic reaches a set overload value.

Claim 3

A system for intermittent supply of a molten thermoplastic, which comprises: (a) an extruder comprising a barrel having a single screw therein, said extruder equipped with means to rotate the screw and with means to start and stop the screw-rotating means, and having a first zone for receiving solid thermoplastic, a second zone for melting the thermoplastic, and a third zone for metering the molten thermoplastic from the extruder, said third zone having a discharge end (b) a reservoir containing the thermoplastic in the form of solid grannules, the reservoir being attached to the barrel of the extruder at the receiving zone and having a throat communicating with the extruder barrel, through which the solid granules are fed from the reservoir to the extruder; (c) cooling means at the receiving zone of the barrel of the extruder to allow the thermoplastic therein to remain in granular form until it is passed to the melting zone of the extruder; (d) heating means in the barrel of the extruder to progressively heat and melt the thermoplastic in the melting zone and maintain it molten in the metering zone; and (e) a heated manifold to receive the molten thermoplastic from the discharge end of the extruder, to maintain it in the molten state and to distribute it to at least one applicator; said at least one applicator comprising a housing, an applicator barrel to receive the molten thermoplastic from the manifold, the applicator barrel terminating in a nozzle from which the molten thermoplastic is discharged, heating elements and heat sensors attached to the applicator barrel to allow the thermoplastic to be maintained in the molten state, means in the applicator barrel to allow the molten thermoplastic to flow through the applicator barrel and be discharged from the nozzle, and means to actuate and de-actuate the flow-allowing means; wherein the means to actuate the flow-allowing means in the applicator barrel also actates the starting means for the screw-rotating means of the extruder; wherein the means to de-actuate the flow-allowing means in the applicator barrel also actuates the stopping-means of the screw-rotating means of the extruder; wherein an accumulator is attached to the manifold, said accumulator comprising a piston cylinder to receive molten thermoplastic from the manifold, a piston to deliver molten thermoplastic from the cylinder to the manifold, a piston ram connected to the piston, a piston ram control, means to actuate the piston ram control, means to de-actuate the extruder screw-rotating means, and heating means attached to the piston cylinder to maintain the thermoplastic in the piston cylinder in the molten state, wherein during discharge of molten thermoplastic from the applicator the piston ram control is actuated to cause the piston to deliver molten thermoplastic from the piston cylinder into the manifold, wherein during the valve closed position of the applicator the piston ram control and the screw-rotating means of the extruder are actuated to allow the extruder to deliver molten thermoplastic via the manifold to the piston cylinder, wherein when the piston cylinder is full of molten thermoplastic during the valve closed position of the applicator, the extruder screw-rotating means is de-actuated.

Claim 4

A system for intermittent supply of a molten thermoplastic, which comprises: (a) an extruder comprising a barrel having a single screw therein, said extruder equipped with means to rotate the screw and with means to start and stop the screw-rotating means, and having a first zone for receiving solid thermoplastic, a second zone for melting the thermoplastic, and a third zone for metering the molten thermoplastic from the extruder, said third zone having a discharge end (b) a reservoir containing the thermoplastic in the form of solid grannules, the reservoir being attached to the barrel of the extruder at the receiving zone and having a throat communicating with the extruder barrel, through which the solid granules are fed from the reservoir to the extruder; (c) cooling means at the receiving zone of the barrel of the extruder to allow the thermoplastic therein to remain in granular form until it is passed to the melting zone of the extruder; (d) heating means in the barrel of the extruder to progressively heat and melt the thermoplastic in the melting zone and maintain it molten in the metering zone; and (e) a heated manifold to receive the molten thermoplastic from the discharge end of the extruder, to maintain it in the molten state and to distribute it to at least one applicator; said at least one applicator comprising a housing, an applicator barrel to receive the molten thermoplastic from the manifold, the applicator barrel terminating in a nozzle from which the molten thermoplastic is discharged, heating elements and heat sensors attached to the applicator barrel to allow the thermoplastic to be maintained in the molten state, means in the applicator barrel to allow the molten thermoplastic to flow through the applicator barrel and be discharged from the nozzle, and means to actuate and de-actuate the flow-allowing means; wherein the means to actuate the flow-allowing means in the applicator barrel also actates the starting means for the screw-rotating means of the extruder; wherein the means to de-actuate the flow-allowing means in the applicator barrel also actuates the stopping-means of the screw-rotating means of the extruder; wherein an accumulator is attached to the manifold, said accumulator comprising a piston cylinder to receive molten thermoplastic from the manifold, a piston to deliver molten thermoplastic from the cylinder to the manifold, a piston ram connected to the piston, a piston ram control, means to actuate the piston ram control, means to de-actuate the extruder screw-rotating means, and heating means attached to the piston cylinder to maintain the thermoplastic in the piston cylinder in the molten state, wherein during discharge of molten thermoplastic from the applicator the piston ram control is actuated to cause the piston to deliver molten thermoplastic from the piston cylinder into the manifold, wherein during the valve closed position of the applicator the piston ram control and the screw-rotating means of the extruder are actuated to allow the extruder to deliver molten thermoplastic via the manifold to the piston cylinder, wherein when the piston cylinder is full of molten thermoplastic during the valve closed position of the applicator, the extruder screw-rotating means is de-actuated.

Claim 5

A system for intermittent supply of a molten thermoplastic, which comprises: (a) an extruder comprising a barrel having a single screw therein, said extruder equipped with means to rotate the screw and with means to start and stop the screw-rotating means, and having a first zone for receiving solid thermoplastic, a second zone for melting the thermoplastic, and a third zone for metering the molten thermoplastic from the extruder, said third zone having a discharge end (b) a reservoir containing the thermoplastic in the form of solid granules, the reservoir being attached to the barrel of the extruder at the receiving zone and having a throat communicating with the extruder barrel, through which the solid granules are fed to the extruder; (c) cooling means at the receiving zone of the barrel of the extruder to allow the thermoplastic therein to remain in granular form until it is passed to the melting zone of the extruder; (d) heating means in the barrel of the extruder to progressively heat and melt the thermoplastic in the melting zone and maintain it molten in the metering zone; (e) a heated manifold to receive the molten thermoplastic from the discharge end of the extruder, to maintain it in the molten state and to distribute it to at least one heated hose; and (f) an applicator attached to the delivery end of said at least one heated hose, said applicator comprising a housing, an applicator barrel to receive the molten thermoplastic from the heated hose, the applicator barrel terminating in a nozzle from which the molten thermoplastic is discharged, a valve in the applicator barrel to allow the molten thermoplastic to flow through the applicator barrel and be discharged from the nozzle, means to open the valve which also actuates the starting means for the screw-rotating means of the extruder, and means to close the valve, which also actuates the stopping means for the screw-rotating means; wherein the manifold is equipped with a pressure overload sensing means which actuates a circuit breaking means and shuts off power to the system when the pressure reaches a set overload value; wherein an accumulator is attached to the manifold, said accumulator comprising a piston cylinder to receive molten thermoplastic from the manifold, a piston to deliver molten thermoplastic from the cylinder to the manifold, a piston ram connected to the piston, a piston ram control, said piston having an exhaust stroke and an intake stroke, means to actuate the piston ram control, means to de-actuate the extruder screw-rotating means, and heating means attached to the piston cylinder to maintain the thermoplastic in the piston cylinder in a molten state, wherein during discharge of molten thermoplastic from the applicator the piston ram control is actuated to cause the piston to deliver molten thermoplastic from the piston cylinder into the manifold, wherein during the valve closed position of the applicator, the piston ram control and the screw-rotating means of the extruder are actuated to allow the extruder to deliver molten thermoplastic via the manifold to the piston cylinder, wherein when the piston cylinder is full of molten thermoplastic during the valve closed position of the applicator, the extruder screw-rotating means is de-actuated, wherein the piston cylinder at the exit to the manifold and the piston are tapered to allow substantially complete elimination of the molten thermoplastic from the accumulator at completion of the exhaust stroke of the piston, wherein the piston is equipped with a flexible metallic compression seal which bears against the piston cylinder to wipe the wall of the piston cylinder clean of molten thermoplastic on the exhaust stroke of the piston.

Claim 6

A system for intermittent supply of a molten thermoplastic, which comprises: (a) an extruder comprising a barrel having a single screw therein, said extruder equipped with means to rotate the screw and with means to start and stop the screw-rotating means, and having a first zone for receiving solid thermoplastic, a second zone for melting the thermoplastic, and a third zone for metering the molten thermoplastic from the extruder, said third zone having a discharge end (b) a reservoir containing the thermoplastic in the form of solid granules, the reservoir being attached to the barrel of the extruder at the receiving zone and having a throat communicating with the extruder barrel, through which the solid granules are fed to the extruder; (c) cooling means at the receiving zone of the barrel of the extruder to allow the thermoplastic therein to remain in granular form until it is passed to the melting zone of the extruder; (d) heating means in the barrel of the extruder to progressively heat and melt the thermoplastic in the melting zone and maintain it molten in the metering zone; (e) a heated manifold to receive the molten thermoplastic from the discharge end of the extruder, to maintain it in the molten state and to distribute it to at least one heated hose; and (f) an applicator attached to the delivery end of said at least one heated hose, said applicator comprising a housing, an applicator barrel to receive the molten thermoplastic from the heated hose, the applicator barrel terminating in a nozzle from which the molten thermoplastic is discharged, a valve in the applicator barrel to allow the molten thermoplastic to flow through the applicator barrel and be discharged from the nozzle, means to open the valve which also actuates the starting means for the screw-rotating means of the extruder, and means to close the valve, which also actuates the stopping means for the screw-rotating means; wherein the manifold is equipped with a pressure overload sensing means which actuates a circuit breaking means and shuts off power to the system when the pressure reaches a set overload value; wherein an accumulator is attached to the manifold, said accumulator comprising a piston cylinder to receive molten thermoplastic from the manifold, a piston to deliver molten thermoplastic from the cylinder to the manifold, a piston ram connected to the piston, a piston ram control, said piston having an exhaust stroke and an intake stroke, means to actuate the piston ram control, means to de-actuate the extruder screw-rotating means, and heating means attached to the piston cylinder to maintain the thermoplastic in the piston cylinder in a molten state, wherein during discharge of molten thermoplastic from the applicator the piston ram control is actuated to cause the piston to deliver molten thermoplastic from the piston cylinder into the manifold, wherein during the valve closed position of the applicator, the piston ram control and the screw-rotating means of the extruder are actuated to allow the extruder to deliver molten thermoplastic via the manifold to the piston cylinder, wherein when the piston cylinder is full of molten thermoplastic during the valve closed position of the applicator, the extruder screw-rotating means is de-actuated, wherein the piston cylinder at the exit to the manifold and the piston are tapered to allow substantially complete elimination of the molten thermoplastic from the accumulator at completion of the exhaust stroke of the piston, wherein the piston is equipped with a flexible metallic compression seal which bears against the piston cylinder to wipe the wall of the piston cylinder clean of molten thermoplastic on the exhaust stroke of the piston.

Claim 7

A system for intermittent supply of a molten thermoplastic, which comprises: (a) an extruder comprising a barrel having a single screw therein, said extruder equipped with means to rotate the screw and with means to start and stop the screw-rotating means, and having a first zone for receiving solid thermoplastic, a second zone for melting the thermoplastic, and a third zone for metering the molten thermoplastic from the extruder, said third zone having a discharge end, (b) a reservoir containing the thermoplastic in the form of solid granules, the reservoir being attached to the barrel of the extruder at the receiving zone and having a throat communicating with the extruder barrel through which the solid granules are fed to the extruder; (c) cooling means at the receiving zone of the barrel of the extruder to allow the thermoplastic therein to remain in granular form until it is passed to the melting zone of the extruder; (d) heating means in the barrel of the extruder to progressively heat and melt the thermoplastic in the melting zone and maintain it molten in the metering zone; (e) a heated manifold to receive the molten thermoplastic from the discharge end of the extruder, to maintain it in the molten state and to distribute it to at least one heated hose; and (f) an applicator attached to the delivery end of said at least one heated hose, said applicator comprising a housing, an applicator barrel to receive the molten thermoplastic from the heated hose, the applicator barrel terminating in a nozzle from which the molten thermoplastic is discharged, a valve in the applicator barrel to allow the molten thermoplastic to flow through the applicator barrel and be discharged from the nozzle, means to open the valve which also actuates the starting means for the screw-rotating means of the extruder, and means to close the valve, which also actuates the stopping means for the screw-rotating means; wherein the manifold is equipped with a pressure overload sensing means which actuates a circuit breaking means and shuts off power to the system when the pressure reaches a set overload value; wherein an accumulator is attached to the manifold, said accumulator comprising a piston cylinder to receive molten thermoplastic from the manifold, a piston to deliver molten thermoplastic from the cylinder to the manifold, a piston ram connected to the piston, a piston ram control, means to actuate the piston ram control, means to de-actuate the extruder screw-rotating means, and heating means attached to the piston cylinder to maintain the thermoplastic in the piston cylinder in the molten state, wherein during discharge of molten thermoplastic from the applicator the piston ram control is actuated to cause the piston to deliver molten thermoplastic from the piston cylinder into the manifold, wherein during the valve closed position of the applicator, the piston drive control and the screw-rotating means of the extruder are actuated to allow the extruder to deliver molten thermoplastic via the manifold to the piston cylinder, and wherein when the piston cylinder is full of molten thermoplastic during the valve closed position of the applicator, the extruder screw-rotating means is de-actuated.

Claim 8

A system for intermittent supply of a molten thermoplastic, which comprises: (a) an extruder comprising a barrel having a single screw therein, said extruder equipped with means to rotate the screw and with means to start and stop the screw-rotating means, and having a first zone for receiving solid thermoplastic, a second zone for melting the thermoplastic, and a third zone for metering the molten thermoplastic from the extruder, said third zone having a discharge end, (b) a reservoir containing the thermoplastic in the form of solid granules, the reservoir being attached to the barrel of the extruder at the receiving zone and having a throat communicating with the extruder barrel through which the solid granules are fed to the extruder; (c) cooling means at the receiving zone of the barrel of the extruder to allow the thermoplastic therein to remain in granular form until it is passed to the melting zone of the extruder; (d) heating means in the barrel of the extruder to progressively heat and melt the thermoplastic in the melting zone and maintain it molten in the metering zone; (e) a heated manifold to receive the molten thermoplastic from the discharge end of the extruder, to maintain it in the molten state and to distribute it to at least one heated hose; and (f) an applicator attached to the delivery end of said at least one heated hose, said applicator comprising a housing, an applicator barrel to receive the molten thermoplastic from the heated hose, the applicator barrel terminating in a nozzle from which the molten thermoplastic is discharged, a valve in the applicator barrel to allow the molten thermoplastic to flow through the applicator barrel and be discharged from the nozzle, means to open the valve which also actuates the starting means for the screw-rotating means of the extruder, and means to close the valve, which also actuates the stopping means for the screw-rotating means; wherein the manifold is equipped with a pressure overload sensing means which actuates a circuit breaking means and shuts off power to the system when the pressure reaches a set overload value; wherein an accumulator is attached to the manifold, said accumulator comprising a piston cylinder to receive molten thermoplastic from the manifold, a piston to deliver molten thermoplastic from the cylinder to the manifold, a piston ram connected to the piston, a piston ram control, means to actuate the piston ram control, means to de-actuate the extruder screw-rotating means, and heating means attached to the piston cylinder to maintain the thermoplastic in the piston cylinder in the molten state, wherein during discharge of molten thermoplastic from the applicator the piston ram control is actuated to cause the piston to deliver molten thermoplastic from the piston cylinder into the manifold, wherein during the valve closed position of the applicator, the piston drive control and the screw-rotating means of the extruder are actuated to allow the extruder to deliver molten thermoplastic via the manifold to the piston cylinder, and wherein when the piston cylinder is full of molten thermoplastic during the valve closed position of the applicator, the extruder screw-rotating means is de-actuated.

Claim 9

A system for intermittent supply of a molten thermoplastic, which comprises: (a) an extruder comprising a barrel having a single screw therein, said extruder equipped with means to rotate the screw and with means to start and stop the screw-rotating means, and having a first zone for receiving solid thermoplastic, a second zone for melting the thermoplastic, and a third zone for metering the molten thermoplastic from the extruder, said third zone having a discharge end; (b) a reservoir containing the thermoplastic in the form of solid granules, the reservoir being attached to the barrel of the extruder at the receiving zone and having a throat communicating with the extruder barrel, through which the solid granules are fed from the reservoir to the extruder; (c) cooling means at the receiving zone of the barrel of the extruder to allow the thermoplastic therein to remain in granular form until it is passed to the melting zone of the extruder; (d) heating means on the barrel of the extruder to progressively heat and melt the thermoplastic in the melting zone and maintain it molten in the metering zone; and (e) a heated manifold to receive the molten thermoplastic from the discharge end of the extruder, to maintain it in the molten state and to distribute it to at least one applicator; said at least one applicator comprising a housing, an applicator barrel to receive the molten thermoplastic from the manifold, the applicator barrel terminating in a nozzle from which the molten thermoplastic is discharged, heating elements and heat sensors attached to the applicator barrel to allow the thermoplastic to be maintained in the molten state, means in the applicator barrel to allow the molten thermoplastic to flow through the applicator barrel and be discharged from the nozzle, and means to actuate and de-actuate the flow-allowing means; wherein the means to actuate the flow-allowing means in the applicator barrel also actuates the starting means for the screw-rotating means of the extruder, and wherein the means to deactuate the flow-allowing means in the applicator barrel also actuates the stopping-means of the screw-rotating means of the extruder; wherein an accumulator is attached to the manifold, said accumulator comprising a piston cylinder to receive molten thermoplastic from the manifold, a piston to deliver molten thermoplastic from the cylinder to the manifold, a piston ram connected to the piston a piston ram control, said piston having an exhaust stroke and an intake stroke, means to actuate the piston ram control, means to de-actuate the extruder screw-rotating means, and heating means attached to the piston cylinder to maintain the thermoplastic in the piston cylinder in the molten state, wherein during discharge of molten thermoplastic from the applicator the piston ram control is actuated to cause the piston to deliver molten thermoplastic from the piston cylinder into the manifold, wherein during the valve closed position of the applicator the piston ram control and the screw-rotating means of the extruder are actuated to allow the extruder to deliver molten thermoplastic via the manifold to the piston cylinder, and wherein when the piston cylinder is full of molten thermoplastic during the valve closed mode of the applicator, the extruder screw-rotating means is de-actuated.

Claim 10

A system for intermittent supply of a molten thermoplastic, which comprises: (a) an extruder comprising a barrel having a single screw therein, said extruder equipped with means to rotate the screw and with means to start and stop the screw-rotating means, and having a first zone for receiving solid thermoplastic, a second zone for melting the thermoplastic, and a third zone for metering the molten thermoplastic from the extruder, said third zone having a discharge end; (b) a reservoir containing the thermoplastic in the form of solid granules, the reservoir being attached to the barrel of the extruder at the receiving zone and having a throat communicating with the extruder barrel, through which the solid granules are fed from the reservoir to the extruder; (c) cooling means at the receiving zone of the barrel of the extruder to allow the thermoplastic therein to remain in granular form until it is passed to the melting zone of the extruder; (d) heating means on the barrel of the extruder to progressively heat and melt the thermoplastic in the melting zone and maintain it molten in the metering zone; and (e) a heated manifold to receive the molten thermoplastic from the discharge end of the extruder, to maintain it in the molten state and to distribute it to at least one applicator; said at least one applicator comprising a housing, an applicator barrel to receive the molten thermoplastic from the manifold, the applicator barrel terminating in a nozzle from which the molten thermoplastic is discharged, heating elements and heat sensors attached to the applicator barrel to allow the thermoplastic to be maintained in the molten state, means in the applicator barrel to allow the molten thermoplastic to flow through the applicator barrel and be discharged from the nozzle, and means to actuate and de-actuate the flow-allowing means; wherein the means to actuate the flow-allowing means in the applicator barrel also actuates the starting means for the screw-rotating means of the extruder, and wherein the means to deactuate the flow-allowing means in the applicator barrel also actuates the stopping-means of the screw-rotating means of the extruder; wherein an accumulator is attached to the manifold, said accumulator comprising a piston cylinder to receive molten thermoplastic from the manifold, a piston to deliver molten thermoplastic from the cylinder to the manifold, a piston ram connected to the piston a piston ram control, said piston having an exhaust stroke and an intake stroke, means to actuate the piston ram control, means to de-actuate the extruder screw-rotating means, and heating means attached to the piston cylinder to maintain the thermoplastic in the piston cylinder in the molten state, wherein during discharge of molten thermoplastic from the applicator the piston ram control is actuated to cause the piston to deliver molten thermoplastic from the piston cylinder into the manifold, wherein during the valve closed position of the applicator the piston ram control and the screw-rotating means of the extruder are actuated to allow the extruder to deliver molten thermoplastic via the manifold to the piston cylinder, and wherein when the piston cylinder is full of molten thermoplastic during the valve closed mode of the applicator, the extruder screw-rotating means is de-actuated.

Claim 13

A system for intermittent supply of a molten thermoplastic, which comprises: (a) an extruder comprising a barrel having a single screw therein, said extruder equipped with means to rotate the screw and with means to start and stop the screw-rotating means, and having a first zone for receiving solid thermoplastic, a second zone for melting the thermoplastic, and a third zone for metering the molten thermoplastic from the extruder, said third zone having a discharge end; (b) a reservoir containing the thermoplastic in the form of solid granules, the reservoir being attached to the barrel of the extruder at the receiving zone and having a throat communicating with the extruder barrel, through which the solid granules are fed to the extruder, wherein the reservoir is equipped with a solenoid-actuated valve to control the supply of thermoplastic granules from the reservoir to the extruder, said solenoid being actuated by a tuning control (c) cooling means at the receiving zone of the barrel of the extruder to allow the thermoplastic therein to remain in granular form until it is passed to the melting zone of the extruder; (d) heating means in the barrel of the extruder to progressively heat and melt the thermoplastic in the melting zone and maintain it molten in the metering zone; and (e) a heated manifold to receive the molten thermoplastic from the discharge end of the extruder, to maintain it in the molten state and to distribute it to at least one applicator; said at least one applicator comprising a housing an applicator barrel to receive the molten thermoplastic from the manifold, the applicator barrel terminating in a nozzle from which the molten thermoplastic is discharged, heating elements and heat sensors attached to the applicator barrel to allow the thermoplastic to be maintained in the molten state, means in the applicator barrel to allow the molten thermoplastic plastic to flow through the applicator barrel and be discharged from the nozzle, and means to actuate and de-actuate the flow-allowing means; wherein the means to actuate the flow-allowing means in the applicator barrel also actuates the starting means for the screw-rotating means of the extruder, wherein the means to de-actuate the flow-allowing means in the applicator barrel also actuates the stopping-means of the screw-rotating means of the extruder, and wherein during discharge of molten thermoplastic from the applicator said timing control actuates the solenoid to close the reservoir slide valve at a time in the range of 5 to 15 seconds before the flow-allowing means in the applicator barrel is de-actuated and the extruder screw-rotating means is stopped.

Claim 14

A system for intermittent supply of a molten thermoplastic, which comprises: (a) an extruder comprising a barrel having a single screw therein, said extruder equipped with means to rotate the screw and with means to start and stop the screw-rotating means, and having a first zone for receiving solid thermoplastic, a second zone for melting the thermoplastic, and a third zone for metering the molten thermoplastic from the extruder, said third zone having a discharge end; (b) a reservoir containing the thermoplastic in the form of solid granules, the reservoir being attached to the barrel of the extruder at the receiving zone and having a throat communicating with the extruder barrel, through which the solid granules are fed to the extruder, wherein the reservoir is equipped with a solenoid-actuated valve to control the supply of thermoplastic granules from the reservoir to the extruder, said solenoid being actuated by a tuning control (c) cooling means at the receiving zone of the barrel of the extruder to allow the thermoplastic therein to remain in granular form until it is passed to the melting zone of the extruder; (d) heating means in the barrel of the extruder to progressively heat and melt the thermoplastic in the melting zone and maintain it molten in the metering zone; and (e) a heated manifold to receive the molten thermoplastic from the discharge end of the extruder, to maintain it in the molten state and to distribute it to at least one applicator; said at least one applicator comprising a housing an applicator barrel to receive the molten thermoplastic from the manifold, the applicator barrel terminating in a nozzle from which the molten thermoplastic is discharged, heating elements and heat sensors attached to the applicator barrel to allow the thermoplastic to be maintained in the molten state, means in the applicator barrel to allow the molten thermoplastic plastic to flow through the applicator barrel and be discharged from the nozzle, and means to actuate and de-actuate the flow-allowing means; wherein the means to actuate the flow-allowing means in the applicator barrel also actuates the starting means for the screw-rotating means of the extruder, wherein the means to de-actuate the flow-allowing means in the applicator barrel also actuates the stopping-means of the screw-rotating means of the extruder, and wherein during discharge of molten thermoplastic from the applicator said timing control actuates the solenoid to close the reservoir slide valve at a time in the range of 5 to 15 seconds before the flow-allowing means in the applicator barrel is de-actuated and the extruder screw-rotating means is stopped.