Patent Publication Number: US-6334774-B1

Title: Flow through applicator with resilient tip

Description:
BACKGROUND OF THE INVENTION 
     Flow through applicators have become a well accepted part of dentistry. Such applicators are usually operatively affixed to a source of liquid or gel material. The source usually has means for pressurizing the liquid-gel into and through the applicator. In many instances the source may be a loaded syringe On the other hand the source may be the applicator itself which may have a proximate chamber for containing a liquid. The chamber is fitted with a piston plug for driving the liquid out of the applicator. 
     In many instances the distal end of the applicator is fitted with bristles so that the liquid or gel flowing from the applicator can be distributed as by brushing back and forth for instance. Such bristles frequently overlap the bore out of which the liquid or gel is being expressed and thereby hinders the clear flow capability. 
     When no bristles are present the end of the applicator tube is too rigid for affecting good distribution when the distal tip of the applicator is used as a manually employed wiping distributor. If the applicator is constructed of a very resilient or flexible plastic good distribution can be obtained but the structure of the applicable does not have sufficient structurally integrity. 
     SUMMARY OF THE INVENTION 
     The present invention combines the use of a relatively hard or relatively rigid plastic for the main or major portion of the applicator with a less rigid or resilient plastic for the distal end of the applicator. 
     In the best mode the plastic parts are extruded consecutively so that the major portion of the applicator is extruded followed by the extrusion of the minor part, that is, the distal end. 
     In the preferred embodiment of fabrication, the applicator of the present invention is injection molded. It is begun by first loading the mold to produce the major part of the applicator followed by injecting the more resilient portion. It is also considered that the reverse may be contemplated where the minor portion may first be injected into the mold followed by injecting the more rigid plastic major portion. The less rigid plastic may be of a foam plastic material, preferably of a closed cell nature. 
     The concept of producing composite articles is already well known and can be seen in such patents as U.S. Pat. Nos. 3,086,249; 3,115,682; 3,558,751; 3,341,043; 4,293,520; 4,507,258; 4,715,504; 4,990,301; 5,792,397; 5,897,822 and 6,062,841. These patents are incorporated herein in their entireties by reference. 
     It is contemplated that the plastic materials applicable are well known. The selection is predicated on the major portion being rigid and having integrity and the resilient part being sufficiently soft and flexible to assist in the spreading and distribution. Applicable polymers are PVC, hard/soft; polycarbonate, ABS; ABS/polycarbonate alloys, acrylic, nylon 6.6 and various rubbers. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side view of one embodiment of the applicator. 
     FIG. 2 is a side view of second embodiment of the applicator. 
     FIG. 3 is a side view of a third embodiment of the applicator. 
     FIG. 4 is partial fragmentary and partial linear cross-section of the applicator with a syringe attached thereto. 
     FIG. 5 is a partial fragmentary and partial linear cross-section of another embodiment of the applicator with a syringe attached thereto. 
     FIG. 6 is a cross-section of the applicator of FIG. 2 with a fragmentary and partial view of the syringe. 
     FIG. 7 is a cross-section of the applicator of FIG. 3 with a fragmentary and partial view of the syringe. 
     FIG. 8 is a cross-section of the applicator of FIG. 1 with a fragmentary syringe and in cross-section. 
     FIG. 9 is a side view of another embodiment of the applicator with a partial thereof being in cross-section. 
     FIG. 10 is a side view of still another embodiment of the applicator with a compressible bulb. 
     FIG. 11 is a perspective view of the applicator of FIG.  1 . 
     FIG. 12 is a side elevation view of a dental capsule embodying the invention and having portions thereof broken away. 
     FIG. 13 is a sectional side view of FIG. 12 with some modification. 
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS 
     The applicator of the present invention is shown, generally, by reference numeral  10 . It consists of a number of portions. A male threaded portion  11  is at its proximate end. Then, progressing from the proximate to the distal end, the threaded portion  11  terminates in a radially extending flange  12 . The next portion is finger grip hub  13 . The finger grip hub  13  has a series of four equi-spaced longitudinal radially extending flanges. The finger grip hub  13  has extending therefrom an elongated tube  14 . The elongated tub terminates in a shoulder  15 . Distally longitudinally extending from the shoulder  15  is a relatively shorter tube  16  of somewhat smaller external diameter than tube  14 . 
     Demarcation line  17  of tube  14  is depicted to show that the material distally beyond is of a plastic material having relatively considerably more resiliency than the plastic material extending proximately of said line of demarcation. Although it is contemplated that the main portion may be constructed of metal and the more resilient portion of plastic. 
     In FIG. 2, the line of demarcation  17  separates the tube  14  from a distal tube  16 A which is essentially like tube  16  but tube  16 A does not have a shoulder  15  nor is of smaller diameter than tube  14 . 
     FIG. 3 is a third embodiment, which is like FIG. 2 except for at distal end  16 B which is bevelled at plane  17 . 
     FIG. 4 is a cross section view with the applicator  10  being secured to a conventional syringe  20  which is loaded with gel material  21 . The distal part  22  of the syringe  20  is a female portion being threaded on the inside of a cylinder to cooperate with thread  24  on the male portion  17 . The cylinder  23  abuts against flange  12 . The finger grip portion  13 , the tube  14  and the distal tube  16 B all have an interconnecting bore  25 . 
     In FIG. 5 a portion of the gel  21  in the syringe is shown to be expressed from the tube  14 . 
     FIG. 6 depicts the applicator with a cross-sectioned view in fragmentary condition of the cylinder  23  as it approaches a confronting relationship, leading to a screwing on of the syringe onto the applicator. 
     In FIG. 7 the cylinder  23  of the syringe is shown to have an inner concentric tube  28  which has a membrane  29  which is pierced by a spike  30  concentrically positioned in the male portion  17  of the applicator of the present invention. The forward portion  31  penetrates through membrane  29  whereby the contents of the syringe may be expressed into and through the applicator which in the embodiment shown terminates in a bevelled portion  16 B. 
     FIG. 8 shows the cylinder  23  of the syringe of FIG. 7 in screwed on position against flange  12 . 
     FIG. 11 is the applicator of FIG. 1 presenting a clear view of the applicator of the present invention. 
     FIGS. 9 and 10 depict a more radical departure of the present invention wherein instead of employing a syringe, the cylinder  23  is either cylinder  23 A in FIG. 9 or cylinder  23 B of FIG.  10 . In both instances the cylinder is part of a compressible bulb  39 . In FIG. 10 the set up does not include a pierceable membrane  29  so that when the bulb  30  is screwed on to threaded male portion  17  a deflection of the bulb will express the gel contents in the bulb  39  therefrom and through bore  25 . 
     FIG. 9, the membrane  29  must first be pierced by spike  30 , followed by screwing onto male portion  17  of the applicator, and then followed by squeezing the bulb  39  to express the gel material. In this embodiment it will be seen that the distal portion  16  is at an acute angle. This has been found desirable in some instances of application. 
     Referring to the drawings, there is shown in FIG. 12 a capsule  40  which depicts another embodiment of the present invention. As shown the capsule  40  has a body portion  40 A defining a chamber or reservoir  41  that is open at one end as indicated at  42 . In the illustrated embodiment of FIG. 12, a discharge nozzle  40 B is connected to the other end of the reservoir or chamber  41  that tapers inwardly toward the discharge orifice  43 . The entire nozzle  40 B may be of a plastic less rigid than the body portion  40 A which is more rigid. It is also contemplated that only a distal portion of the nozzle  40 B may be constructed of a resilient plastic. When the differences of plastic is sharply defined there will be a defined demarcation line  48 . If the area of change is gradual there will be no line of demarcation. A laterally outwardly extending flange  44  circumscribes the open end of the capsule body portion  40 A. In the assembled form of the capsule as seen in FIG. 12 a displaceable piston  45  is fitted into the open end  42  to seal the open end  42 . While the described capsule  40  is illustrated as having a specific geometric shape, it will be understood that the specific shape or size of the capsule is not critical to the invention, as the capsule may assume any of the shapes or size that are disclosed in patents known to those skilled in the art. The invention to be described would be operative in any dental capsule that includes a body portion defining a chamber that is opened at one end and has a discharge nozzle connected to the other end and which open end is adapted to be sealed by a displaceable piston. 
     In accordance with this invention, a gel  47 , is charged into a body portion  40 A or reservoir  41 . The filler  47  is saturated with a dental fluent low viscosity or liquid-like material. The open end  42  of the capsule  40  is then sealed by inserting therein a displaceable piston  45 . If desired, the discharge orifice  43  may be sealed by a sealing cap  46  to protect the contents of the capsule from any contaminants such as dirt, dust and to prevent evaporation or drying of the gel  47 . 
     To dispense gel  47 , the capsule  40  is placed in a suitable syringe. With the sealing cap  46  removed and upon the actuation of the syringe (not shown), the piston  45  is displaced so as to impart a compressive force onto the gel  47 , causing the gel contained therein to be squeezed out and dispensed through the discharge orifice  43 . The amount of compressive force imparted by the piston  45  by the syringe and onto the gel  47  determines the amount of gel that is dispensed. Thus, it will be apparent that the user can readily control the dispensing of the gel by regulating the amount of force that is applied by the piston  45  onto the filler. 
     FIG. 13 illustrates a slightly modified form of the invention. In this embodiment, the capsule  50  is virtually identical to that described with respect to FIG. 12 except the end of the discharge nozzle  50 B is initially sealed as indicated at  51  in the molding of the capsule  50 . In all other respects, capsule the molding of the capsule  50 . In all other respects, capsule  50  is identical to that described with respect to the embodiment of FIG.  12 . That is, the capsule  50  includes a body portion  50 A having an open end  52  circumscribed by a flange  54  and a piston  55  for sealing the open end  52 . Disposed within the body or reservoir  51  is a filler  57  saturated with a low viscosity dental material similar to that hereinbefore described. Again the distal part will be fabricated of a resilient plastic, i.e. of less rigid plastic than the major portion. So when the change of plastic is abrupt line  58  is a line of demarcation. 
     To dispense the liquid or fluent material, the dentist or user must first cut off the sealed end  51  of capsule  50  to form the discharge orifice. In all other respects, the operation of capsule  50  is similar to the hereinbefore described. Although, it can be available open or closed. As necessary additional information can be obtained from a review of the prior art embodied in U.S. Pat. No. 6,099,307, which is incorporated herein in its entirety by reference. 
     In all instances the applicator is constructed of a plastic material of relative rigidity. Furthermore, in all instances of the present invention the distal portion  16 ,  16 A and  16 B is constructed of a plastic that is less rigid and has greater resiliency so that the applicator may be stroked back and forth to distribute the expressed gel in a wiping or painting manner. The differences between the plastic of the main or major portion of the applicator and the minor portion of the applicator makes it possible to achieve the desirable results of good distribution on a receiving surface.