Abstract:
A system for cleaning clogged orifices of a fluid head includes both apparatus and method by which reverse flow of a cleaning solution is combined with providing the vibrational energy of an ultrasonic frequency generator to the fluid head. A liquid pump and a filter interconnect between the input terminal of a fluid head to be cleaned and the input to the cleaning chamber of the apparatus so that a liquid cleaning solution reverse flushes the clogged fluid head, while the ultrasonic frequency generator is providing vibrational energy to break loose stubborn clogs.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention, generally, relates to fluid heads used in several environments and, more particularly, to a system for cleaning these fluid heads. 
     With the introduction of ink jet printers, much concern has evolved over the tendency of the small holes in their print heads becoming clogged. Therefore, at first, much effort was spent on avoiding these clogs, but as the printer technology developed and as the use of a fluid head in other and different equipment, such as recorders, for example, cleaning of the fluid heads has become more necessary rather than convenient. 
     2. Related Background Art 
     U.S. Pat. No. 4,296,418 to Yamazaki et al. describes printing apparatus to sense a clog automatically and to clear the nozzle by flushing with air and a solvent. 
     U.S. Pat. No. 5,128,690 to Nozawa describes apparatus using heat and pressure to create a liquid flow to flush foreign matter from the discharge openings. 
     European patent No. 0 292 779 describes a component cleaning method where internal passages of ink nozzle printing heads are cleaned by flushing with liquid; ultrasonic waves cause a vibratory cavitation in the internal passages. 
     Japanese patent No. 4-39055 describes the cleaning of an ink jet nozzle using jettisoned cleaning fluid against the surface of an ink jet nozzle; the wash material is accumulated in a chamber and discharged by suction pumps. 
     Japanese patent No. 7-329310 describes cleaning jet nozzles of a textile printing machine by placing an ultrasonic vibration plate underneath the ink jet nozzle. 
     Japanese patent No. 56-106868 describes a method of clearing a clogged nozzle using ultrasonic vibrations to crush or dissolve the clogged material and flush it to the outside. 
     IBM Technical Disclosure Bulletin No. 1802, November, 1974, describes an anti-clogging ink jet chamber having an ultrasonic driver connected to it so the chamber does not have to be removed. 
     Now, however, these prior efforts, when used with present day apparatus, are proving to be either disappointing in their effectiveness or completely inadequate. Fluid heads used with today&#39;s apparatus involve materially different structures. 
     For example, the ink discharged, in early days, was through “openings” in an ink chamber. Then, technology advanced, or improved, to a point where ink was discharged through small holes. 
     Next, the “holes” were reduced to very small; then “tiny holes”. In many apparatus today using fluid heads, ink, or other solution, is passed through “orifices” that measure in the thousandths of an inch and spacing between them is comparable. 
     Today, when a fluid head becomes clogged, methods that were completely satisfactory yesterday, are totally in-effective. 
     SUMMARY OF THE INVENTION 
     It is an important object of the present invention to provide a method of cleaning fluid heads that have become either permanently or intermittently clogged. 
     It is also an important object of the present invention to provide apparatus that cleans today&#39;s fluid heads effectively at a cost that is equally attractive. 
     Briefly, a structure that is in accordance with the principles of the present invention includes a housing with a chamber to receive a fluid head, means to hold a fluid head within the chamber, a pump, a filter, an ultrasonic frequency vibrator, and hoses to interconnect the respective components. A method that is in accordance with the present invention involves retaining a clogged fluid head within the chamber of the housing, filling the chamber to a predetermined level with a solvent that is impervious to both the fluid head and to chamber plastic, connecting a pump with a means to filter the fluid to the chamber to move the fluid in a back-flow direction through the fluid head, and inducing vibrations in the fluid in an ultrasonic frequency range. 
     The above, other and further objects, advantages and features of the present invention will become clear from a perusal of the following detailed description of a presently preferred embodiment. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a view in elevation of a structural arrangement of components interconnected to obtain the benefits of the invention. 
     FIG. 2 is an illustration of orifices in a fluid head along the line  2 — 2  in FIG. 4 that has clogs of foreign material to be removed by the present invention. 
     FIG. 3 is a view in perspective of a fluid head with which the present invention is functional. 
     FIG. 4 is a view taken along the line  4 — 4  in FIG. 3 illustrating the orifice arrangement in the fluid head. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring first to FIG. 1 of the drawings, a housing  10  identifies generally the apparatus arranged according to the principles of the present invention. It is significant that the housing  10  is a stand alone structure, and it is formed to provide a chamber  11  of sturdy construction not only to withstand vibrations itself but to transmit the vibrations to a fluid head  12  to be unclogged and flushed. 
     The fluid head  12  is supported firmly within the chamber  11  by two brackets  13  and  14 . Since these brackets can be formed in any desired manner to suit an individual preference, further details on the particular support brackets  13  and  14  is not considered to be necessary here, since it may divert attention from the principal structural arrangement that characterizes the invention. 
     It is also significant to note that the fluid head  12  is supported with its inlet terminal  15  up, where its input connection  16  can be readily attached to a liquid flow tube  17 . The surface with the clogged orifices, identified generally by the numeral  18 , is facing down toward the bottom surface of the chamber  11 . 
     Continuing the description of the apparatus of the invention, the liquid flow tube  17  is connected from the fluid head inlet terminal  15  to a pump  19 , and a liquid flow tube  20  connects the liquid output side of the pump  19  to a filter  21 . From the filter  21 , a liquid flow tube  22  connects to an inlet of the chamber  11 . 
     An ultrasonic frequency generator is identified generally by the numeral  23  and is located firmly at the bottom surface of the chamber  11 . From this location, the ultrasonic frequency generator  23  provides vibrational energy through the housing  10 , through the chamber  11 , through the support brackets  13  and  14  that clamp a fluid head  12  firmly within the chamber for cleaning. 
     A cleaning liquid  24  fills the chamber  11  to a predetermined level, indicated by the reference numeral  25 , is sufficient to cover about one-half of the fluid head  12  in its supported position within the chamber. 
     The cleaning liquid  24  is any desired solution with general cleaning characteristics, but it should not be of a type that could harm or produce damage to the material of which the fluid head  12  is formed. It has been found that usually a cleaning solution that does not attack, or is otherwise harmful to, material known throughout the commercial world as PVC, CPVC or poly-propylene is entirely satisfactory for this cleaning solution. 
     Cleaning the fluid head  12  has proven to be more difficult than was ever anticipated, and the difficulty is largely due to its enclosed structure. The many extremely small orifices that make up the fluid heads of today&#39;s equipment are unusually susceptible to becoming clogged with debris of many sizes that enter with the spray solutions. The fluid head  12  has a single inlet port and many extremely small outlet orifices. 
     The foreign matter entering the fluid head  12  with the solution during use will enter through the large terminal  15 , and if that foreign matter cannot exit through one of the orifices, it can clog the orifice. Many of these clogged orifices are not easily, or readily, unclogged. 
     With the ink used in many of the printers today and with the other fluids used with other wet process equipment, these clogs cannot be removed even with reverse flushing. Such reverse flushing, however, has been quite effective in the past. 
     In FIG. 2 of the drawings, a plurality of orifices are identified by the numeral  26 . As described hereinabove, these orifices  26  are extremely small, and in this view, the numeral  27  illustrates foreign matter and debris that clogs an orifice. 
     FIG. 3 illustrates a fluid head  12  inverted from the position as seen in FIG.  1  and in FIG.  2 . Here the surface  18  with orifices  26  is facing up, and the inlet terminal  15  with its fluid input connection  16  is facing down. 
     FIG. 4 is an enlarged view of only a part of the fluid head  12  in the same position illustrated in FIG.  3 . In this view, the orifices  26  can be seen more clearly as being arranged in two rows. Of course, the particular number of the rows as well as their arrangement is related to the equipment with which the fluid head is used, rather than related to the method of the present invention of affecting their cleaning. 
     The method in accordance with the present invention has been found to be unusually effective in clearing stubborn clogs as well as cleaning the entire fluid head. To describe the method in detail, refer to FIG. 1 of the drawings. 
     The method of using the apparatus described above in order to accomplish removal of foreign matter and other debris clogging the respective orifices  26  requires the housing  10  with the chamber  11  with suitable brackets  13  and  14  to clamp the fluid head  12  firmly in the particular position illustrated. 
     The chamber  11  is filled with a cleaning solution to a level so that with all components connected and operating, the solution covers about one-half of the fluid head  12 . The fluid head is supported so that the orifices are completely submerged and so that the orifices face, generally, the input direction of the cleaning solution flow to maximize the reverse flow cleaning. 
     The chamber  11  is subjected to vibrations at an ultrasonic frequency level during the cleaning operation. With the cleaning solution passing through the fluid head in a direction opposite that in which a dye, or other fluid, flows during a functioning of the equipment normally, this can be referred to as reverse flow during cleaning according to the present invention. 
     Therefore, with a combination of reverse flow of the cleaning solution while the clogged fluid head is subjected to ultrasonic vibrations, even the most stubborn clogged orifice is cleaned. 
     While the present invention has been described in substantial detail, various modifications may be made without departing from the spirit and scope of the invention, which is defined by the following claims.