Technical Field

The present invention relates to a system for cleaning adhesive applying devices, e.g. glue heads and associated connecting lines that are used in the production of business forms.

Background Art

In the business forms industry, it is a well- known fact that various devices associated with presses and collators include means for gluing paper or like record media in the manufacture of business forms.

The means for gluing the paper include gluing heads and lines connecting such heads with other devices such as valves, pumps, filters, drains, couplings, and associated items that comprise a gluing system.

As is generally known in the current state of the art, the gluing heads and associated devices along with the connecting lines ordinarily remain connected in the system whether the gluing system is being used continuously or not. It is also known that most gluing systems are of a type which eventually become clogged if they are not used in a generally continuous manner. Since the various devices remain connected in the present or current state of the art arrangements, it is seen that either the entire system must be flushed at one time or that certain devices and/or lines must be replaced if these items become completely clogged. Of course, it may be possible to clean individual devices, such as glue heads and/or connecting lines if these individual devices can be reasonably and easily disconnected from the system and if it is feasible to clean the items. It is also seen that while the entire system is being flushed, the

manufacturing equipment is down (out of operation) and production of the business forms is halted until the glue system has received proper maintenance. Thus a problem that has been experienced in the business forms industry is that of keeping the down time of manufacturing equipment to a minimum.

Disclosure of the Invention

It is an object of the present invention to provide an effective and convenient system for cleaning adhesive applying devices in a rapid manner.

According to the invention there is provided a system for cleaning adhesive applying devices, including a reservoir for solvent for said adhesive, and means for supplying said solvent to said reservoir, characterized by first connection means having a plurality of outlets, first pipe means connecting said first connection means to outlet means from said reservoir, air-operated pump means coupled to said first pipe means and operable to pump solvent from,said reservoir to said first connection means via said first pipe means, second connection means, compressed air supply means connected to said second connection means via second pipe means, and connected to said pump means via third pipe means, control valve means coupled to said third pipe means for starting and stopping said pump means, and a plurality of coupling means for respectively coupling a plurality of adhesive applying devices to said outlets of said first connection means whereby solvent may be pumped by said pump means through said devices for the purpose of removing adhesive material therefrom, each of said coupling means including a portion serving to close the relevant outlet of said first connection means when an adhesive applying device is disconnected from said first connection means, and said second connection means being adapted to be connected to one

or more adhesive applying devices, whereby air may be blown through such devices for the purpose of removing solvent therefrom after such devices have been cleaned by the pumping of solvent therethrough.

Brief Description of the Drawings

One embodiment of the invention will now be described by way of example with reference to the accompanying drawings, in which:-

Fig. 1 is a fluid flow diagram of various devices and connecting lines of a system in accordance with the invention for cleaning adhesive applying devices;

Fig. 2 is a top plan view of the system diagrammatically illustrated in Fig. 1;

Fig. 3 is a front elevational view of the system shown in Fig. 2; and

Fig. 4 is a side elevational view of the system shown in Fig. 2.

Best Mode for Carrying Out the Invention

Referring now to Fig. 1, the system shown therein includes a commercially available stainless steel sink 10 equipped with a tap 12 and a drain board 14. The tap 12 is connected to a cold water supply line 16 and to a hot water supply line 18. The sink 10 is used as a reservoir to provide a convenient means for holding or containing the cleaning agent which may be any of the solvent types and which preferably is water. While water is considered the universal solvent, other cleaning agents may be used in the flushing system, dependent upon supply, feasibility, and condition of the glue that requires flushing from the system.

A line 20 provides a supply of air at 100 psi (6.89 x 10^ pascals) maximum through a filter 22 that ensures the entrapment of foreign particles of certain

sizes before they can be introduced into the compressed air circuit of the system. The filter 22 is also used to prevent foreign particles larger than 25 microns from being introduced into the glue heads and glue lines which are purged of solvent after the flushing operation has been performed. A compressed air regulator 24 is connected in a line 26 to establish an operating pressure of 60 psi (4.13 x 10 ⁵ pascals) for the fluid pumping system. A compressed air oil lubricator 28 also is connected in the line 26 to provide oil lubrication to a control valve 30, and a line 31 connects the control valve 30 to an automatic cycling valve 32. The automatic cycling valve 32 is associated with and is a part of an air diaphragm pump 48. A needle valve 33 is provided in the line 31 to control the volume of air to the pump 48.

A line 34 is connected to the downstream side of the air filter 22 and a compressed air regulator 36 is connected in the line 34 to control the air pressure at 20 psi (1.38 x 10 ⁵ pascals) available at an air manifold 38. A line 37 connects the regulator 36 and a globe valve 40. The globe valve 40 is connected in the line 37 to control the volume of air available at the manifold 38.

The stainless steel sink 10 has a removable, flat top strainer 42 that is used to prevent large particles of debris from entering a drain pipe 44 located below the sink. A Y-type strainer 46 is provided in the drain pipe 44 to trap solid particles that may be of a size to pass through the strainer 42 and that may be large enough to cause the air pump 48 to malfunction or to become damaged. A line 47 connects the Y-type strainer 46 and the air pump 48. The control valve 30 is used to start and stop the air-operated pump 48. A line 50 connects the pump 48 and an in-line filter 52 that is used to trap solid

particles greater than 200 microns that may pass through the pump. A two-way ball valve 54 is connected in a line 56 from the filter 52 to provide ways and means for controlling the flushing system. A flexible hose 58 is connected to the downstream side of the ball valve 54 for the purpose of bypassing a portion of the recirculating system, and the hose empties into a drain 60.

A line 62 is connected to the in-line filter 52 and to an in-line cartridge filter 64 that is used to trap solid particles greater than 50 microns that may pass through the filter 52. A pressure gauge 66 is connected in the line 62 from the in-line filter 52 to the cartridge filter 64. A ball valve 65 and a gauge guard 67 are provided for the pressure gauge 66 . The filter 64 is connected to a two-way ball valve 70 by a line 68, and the ball valve is connected by a line 72 to a solvent manifold 74. A line 76 connects the manifold 74 to a second solvent manifold 78. The solvent manifolds 74 and 78 are positioned above the reservoir portion of the sink 10, and are each provided with a plurality of outlets. A needle valve 80 is connected to the solvent manifold 78 to control the volume and pressure available for flushing at the two manifolds 74 and 78. A flexible hose 82 is connected to the needle valve 80 for the purpose of bypassing a portion of the recirculating system and the hose empties into the sink 10. An adhesive applying device in the form of a glue head 86 and an associated glue line 88 is shown connected to the solvent manifold 74 in a typical flushing operation using the structure of the present invention.

Figs. 2, 3 and 4 are a top plan view, a front elevational view, and a side elevational view, respectively, of the cleaning system shown in Fig. 1. The sink tap 12 (Fig. 1) is connected to the cold water supply line 16 and to the hot water supply line

18 (Fig. 3) and has a 15 centimetres swing nozzle (not shown). The filter 22 (Fig. 2) in the air supply line 20 is provided to trap any foreign particles entering the compressed air circuit of the system. The air regulator 24 and the oil lubricator 28 along with the control valve 30 (Fig. 3) are provided in the air line 26 and the flow of air is through the line 31 to the needle valve 33 (Fig. 1), and through the cycling valve 32 to the pump 48. The air regulator 36 and the globe valve 40 (Fig. 3) are connected in the air line 34 to the air manifold 38.

The Y-type strainer 46 is connected in the drain line 44 from the sink 10 to the air pump 48 (Fig. 3), and the in-line filter 52 and the ball valve 54 are provided in a line 56 downstream of the pump 48 (Figs. 2 and 3) .

The cartridge filter 64 is connected in the line 62 and the gauge 66 is inserted between the in¬ line filter 52 and the cartridge filter 64 in the line 62 (Fig. 3). The line 68 connects the filter 64 and the ball valve 70. The line 72 connects the ball valve 70 and the solvent manifold 74.

The solvent manifolds 74 and 78 are each associated with a plurality of quick-connect coupling devices 90. (Fig. 3) for permitting an individual glue head/line to be flushed and cleaned, or a plurality of glue heads/lines to be flushed and cleaned simultaneously. The air manifold 38 is similar in construction to the solvent manifolds 74 and 78 and is associated with coupling devices similar to the devices 90 whereby glue heads and lines may be connected to the manifold 38, compressed air being used to purge the glue heads and lines of water or other solvent that remains in the heads and lines after the flushing and cleaning operation.

Each coupling device 90 includes a coupling body, a coupling insert, an insert seal, a

polyethylene tube fitting nut, a body plug, and a dust cover, all available from Colder Products Company, St. Paul, Minnesota, U.S.A. The coupling body of each device 90 includes an internal valve that permits flow of solvent through a glue head/line when the latter is connected to the manifold 74 or 78, and seals the relevant outlet of the manifold 74 or 78 when the glue head/line is disconnected. The coupling body is used to keep the system pressurized when only one glue head/line is being flushed and cleaned. The coupling body is provided with a latching device to prevent accidental uncoupling under system pressure, and the quick coupling feature is convenient in not requiring any tool when connecting and disconnecting the glue heads/lines to be flushed. Each coupling body is screwed into the body of the relevant manifold 38, 74 or 78 and remains with the manifold as a part of the cleaning system.

The coupling insert portion of each coupling device 90 remains attached to a glue head/line when the latter is disconnected from the manifold 38, 74 or 78. A shut-off feature of the coupling inserts server to keep a glue head/line filled with water, after disconnection from the manifold 74 or 78, until such time that the water is purged from the glue head/line when it is connected to the compressed air manifold 38.

The air diaphragm pump 48 is used to recirculate the water or solvent from the sink 10 through piping to the water manifolds 74 and 78 and, if desired, to the rinse hose 82, such pump 48 operating to force water under pressure through the glue heads/lines that are being flushed and cleaned. The water being flushed through the glue heads/lines returns into the reservoir or sink 10. The pump 48 also is used to pump water from the flushing system to a drain or another container, and the pump 48 also may

be used to flush and clean the element in the line filter 52.

The two-way ball valves 54 and 70 (Figs. 1 and 3) operate in an opening and closing arrangement to provide various ways for controlling the flushing system. A description of the different operating conditions, dependent upon the position of the two valves and assuming that the pump 48 is pressurized and that glue heads/lines are being flushed, is as follows:

Condition No. 1 ~ Valve 70 is closed and valve 54 is closed wherein the pump 48 stalls and water circulation is stopped.

Condition No. 2 — Valve 70 is open and valve 54 is closed wherein the pump 48 operates and water circulates through the system.

Condition No. 3 —* Valve 70 is open and valve 54 is open wherein water circulates through the system and pumps to the drain at the same time.

Condition No. 4 — Valve 70 is closed and valve 54 is open wherein the flow of water to the manifolds 74 and 78 is stopped and recirculation is stopped but allows water to be forced through the filter 52 which effectively flushes and cleans the filter and pumps water through the valve 54 and to the drain 60.

The in-line filter 52 traps foreign particles greater than 200 microns and is designed so that the filter can be manually cleaned by rotating a handle 92 (Figs. 1 and 3) on the top of the filter. The filter

52 also is provided with a bottom pipe connection that permits the filter to be flushed (foreign particles removed) without removing the filter from the system or dismantling the piping from the system. The filter 52 is an important item in the flushing system because it is sized to trap foreign particles that are approximately one-half the size of the smallest glue nozzle being flushed and cleaned. This filter permits the operator to conveniently flush the system at any time in that the filter 52 can be flushed during the flushing and cleaning cycle of a glue head/line, if required, and while the system is recirculating.

The in-line cartridge filter 64 is used to trap foreign particles greater than 50 microns and to prevent small particles of adhesive that may not be dissolved in water from entering the water flushing manifolds 74 and 78. The filter 64 also is used to ensure that the internal shut-off valves, located internally of the coupling body and the coupling insert of each glue head/line coupling device 90 of the system, are not held open by any solid particles that are recirculating during the flushing cycle and that are large enough to cause leaks and/or pressure loss in the system.

The pressure gauge 66 has a dial that registers 0-100 psi (0 - 6.89 x 10 ⁵ pascals) and uses glycerine to prevent gauge wear in a pulsating system. The gauge _. 66 is used to read an increase in pressure at the cartridge filter 64, thereby indicating when it is necessary to change the cartridge in the filter. The guard 67 is also provided for the gauge 66 to prevent the recirculating fluid of the system from entering the pressure gauge mechanism and possibly damaging the gauge. Additionally, the ball valve 65 is used to isolate the gauge 66 when filter inspection is not required.

In the operation of the flushing system, a glue head/line 86, 88, having attached thereto a coupling insert that will connect to a water manifold 74, 78, or to an air manifold 38, is disconnected from a business form production line (not shown). It should be noted that the production line may be provided with coupling bodies similar to the coupling bodies of the devices 90, whereby glue heads/lines may be disconnected from the production line for cleaning purposes, and be subsequently reconnected to the production line, without halting operation thereof. The glue head 86 and associated tubing normally are filled with glue when they are disconnected from the production line. The flushing system reservoir or sink 10 is filled with solvent (water) to a depth of approximately 15 to 20 centimetres. The operator connects one or more glue heads 86 which require flushing to the solvent manifold 74 or 78.

The pump 48 is started and solvent is pumped from the reservoir 10 through the piping and filtering system to the solvent manifolds 74 and 78 and through the glue heads 86 connected to the manifolds. The system recirculates the solvent from the reservoir 10 through the various devices and the manifolds 74 and 78 and through the connected glue heads 86 and drain back to the reservoir. The volume and pressure in the system are controlled by using the needle valve 80 (Fig. 1) which operates in bypassing solvent from the manifolds 74 and 78 back to the reservoir 10. The system continuously recirculates the solvent through the one or more glue heads 86 connected to the manifolds 74 and 78 until all adhesive has been purged or flushed and cleaned from the glue head(s). The time of the flushing cycle is sufficient so that the adhesive is dissolved by the solvent to prevent clogging of the filtering system.

After a glue head/line 86, 88 has been purged of adhesive and flushed clean with solvent, the glue head/line is disconnected from the solvent manifold 74 or 78 and is connected to the air manifold 38. The remaining solvent in the flushed glue head/line 86, 88 then is purged from the head by means of the compressed air. This operation is continued until the head/line 86, 88 is completely clean. The flushed and cleaned glue head/line 86, 88 is reconnected to the production line or is placed in storage until such head/line will be used in the production line.

The features and advantages of the cleaning system are the use of quick-disconnect couplings with internal double shut-off valves and the use of manifolds as a convenient means for connecting glue lines. The off-line pressurized pumping system provides means for simulating the on-line pressurized glue system and the filtering system ensures that the glue heads/lines are thoroughly cleaned. An individual glue head/line or multiple glue heads/lines can be flushed and cleaned by use of the manifolds and connections to the hot and cold water supply lines 18 and 16. Any solid particles that would clog glue heads/lines can be conveniently flushed from the system and down a drain thereby permitting continuous operation of the system. The flushing system can be totally recirculating and/or recirculating and draining simultaneously, and the air purging manifold provides a means to purge the flushed glue heads/lines of all cleaning solvents. The coupling insert attached to a glue head/line permits passage of liquid therethrough when the glue head/line is connected to the production line or to the manifold 74 or 78, but becomes closed when the glue head/line is disconnected from the production line or manifold. Thus, when a glue head/line is disconnected from the production line, the coupling insert serves to keep the glue

head/line filled with adhesive prior to cleaning. The maintaining of the adhesive or glue in the glue head/line prevents the disconnected glue head/line from drying out and becoming clogged before it can be flushed. The coupling insert of a glue head/line also provides an advantage after flushing with solvent and before purging a flushed line with compressed air because the flushed glue head/line will remain filled with solvent or contain a certain amount of solvent between the solvent flushing and the air purging operation. This feature keeps the glue head/line wet and prevents any dried glue particles from adhering to the head or line prior to one or more flushed glue heads/lines being purged with compressed air. The use of quick disconnect couplings in a production line allows the line to remain pressurized and operational thereby eliminating machine down time when glue heads or lines become clogged. The pumping pressure of the cleaning system can be varied for different solvent pumping pressures that may be required. The system component materials have been selected to be compatible with commonly used, water based, resin type adhesiveSc Various other commercially available or designed components can be used and sized to be compatible with differing conditions without affecting the basic system concept.

It will be appreciated that the cleaning system described above enables the effective and rapid cleaning of adhesive applying devices. Also, the system is of simplified construction by virtue of the fact that the same compressed air supply is used to operate the pump for the solvent and to supply compressed air to the air manifold.