Patent Publication Number: US-6210063-B1

Title: Knock type applicator

Description:
TECHNICAL FIELD 
     This invention relates to a knock type applicator or a coating device which contains a suitable coating liquid such as, a writing and painting liquid such as India ink, paint and ink, a cosmetic liquid such as eye liner and lip color, a writing correction liquid, and adhesives, and serves to move a prescribed member by knocking it so that a valve mechanism disposed in the applicator is opened to discharge the liquid. 
     BACKGROUND OF THE INVENTION 
     Heretofore, there has been known an applicator (a coating device) which comprises a cylindrical shell with a coating liquid storage chamber defined therein, a coating body such as a pen point and a writing tip secured to an opening portion formed in a distal end of the cylindrical shell, and a valve mechanism disposed between the coating body and the coating liquid storage chamber. 
     In a coating device of the type as described, a knock portion disposed on the cylindrical shell is knocked or pushed to move a movable member disposed in the coating liquid storage chamber and the movable member, in turn, moves a valve element to open the valve mechanism so that the coating liquid is ready to be discharged from the storage chamber to an object to be coated. 
     However, the conventional device has such problems that when the device is not used for a long period of time or when the cover member is left removed, the coating liquid stored in the coating body and between the coating body and an inner wall of the opening portion of the distal end of the cylindrical shell is prone to create a hardened substance, a gelled substance and a viscous substance due to evaporation of moisture and solvent thereby choking the flow passage for the coating liquid, and therefore, a smooth flow of the coating liquid is interrupted. 
     Various attempts and proposals have been made in order to solve the above problems. 
     For example, Japanese Utility Model Publication No. 2-309 of 1989 discloses a writing device with a side knock valve having a writing body with a valve element fixed thereto and capable of containing therein a liquid, and the writing body is slidably inserted in a cavity formed in a distal end of a cylindrical shell, and a pigment ink flow passage formed between an outer surface of the writing body and an inner surface of the distal end of the cylindrical shell, and at least a part of the resilient cylindrical shell is defined as a resilient body, the resilient body being displaced by knocking the cylindrical shell so that the valve element and writing body will be slidingly moved simultaneously. 
     With respect to this utility model publication, the coating body is slidingly moved simultaneously with the opening operation of the valve element which is made by knocking the cylindrical shell, for the purpose of flowing ink smoothly by recovering the ink flow passage, just in case the flow passage is choked with ink composition which has been hardened by drying, in such a manner as to peel off and/or crush the lumps of ink. 
     Although the writing device of the above utility model publication can recover a region of the coating liquid flow passage between the coating body and the inner wall of the distal end portion of the cylindrical shell, it is impossible for this device to recover a region of the coating liquid flow passage in the coating body which passage is choked with the hardened substance, gelled substance and viscous substance of the coating liquid. 
     This is especially true when the coating body is a writing/painting brush because when the coating liquid stored in the writing tip is hardened or gelled or becomes viscous, fibers constituting the writing tip are mutually adhered, thereby making it impossible to feed and coat the coating liquid smoothly. 
     SUMMARY OF THE INVENTION 
     In view of the above, it is, therefore, an object of the present invention to provide a knock type applicator or a coating device in which when it occurs that a coating liquid can not be discharged smoothly due to adhesion of fibers of a writing tip caused by a hardened substance, a gelled substance and a viscous substance created by the coating liquid in the writing tip, the hardened substance, etc. are peeled off or crushed by a sliding movement of the writing tip so that the coating liquid can be discharged again in a smooth manner. 
     In order to achieve the above object, the present invention employs a construction in which ribs are formed in an inner wall of an opening portion formed in a distal end of a cylindrical shell in a lengthwise direction of the cylindrical shell, and the diameter of an inscribed circle connecting apexes of the ribs is dimensioned smaller than the maximum diameter of the writing tip. 
     The employment of this construction makes it possible to discharge the coating liquid smoothly again by loosening the mutually adhered fibers which constitutes the writing tip, by peeling off and/or crushing the hardened substance, gelled substance and viscous substance created by the coating liquid. 
     In the knock type applicator according to the present invention, the ribs formed on the inner wall of an opening portion of a distal end of the cylindrical shell bite or project into the writing tip which advances in operative connection with a valve element during a knocking operation. As a consequence, the writing tip is cracked by the ribs projected therein. At that time, the hardened substance, gelled substance and viscous substance which are created from the coating liquid in the writing tip are peeled off successfully from the fibers of the writing tip. Thus, an ink flow passage in the writing tip can be recovered. 
     Since an end face of the opening portion formed in the distal end of the cylindrical shell serves as a fulcrum for the writing tip to make a flexible bowing movement, the ribs bite or project deep into the writing tip to crack it so that the hardened substance, gelled substance and the viscous substance in the writing tip are peeled off and/or are crushed from the fibers of the writing tip and discharged outside the writing tip together with the coating liquid. Therefore, the writing tip is hardly adhered after the coating liquid is discharged. 
     In the case where the flow passage in the writing tip can not be completely recovered in spite of a sliding movement of the writing tip and biting of the ribs during a coating operation, it can be contemplated that the adhered writing tip is loosened by rubbing it to the surface of a sheet of paper or loosened by fingers or other similar means, in order to remove the hardened substance, gelled substance and viscous substance. At that time, the above-mentioned means is carried out while slidingly moving the writing tip. By doing so, even that part of the writing tip received in the interior of the cylindrical shell can be loosened during a coating operation, i.e., discharging operation. In this way, the adhered writing tip can be loosened over a comparatively large range of area and the hardened substance, etc. can be removed. 
     The present invention has such other additive structural features as described hereinafter, in addition to the above-mentioned construction as a basic feature. The other additive structural features are: a force for connecting the writing tip and valve element together is smaller than a biasing force exerted to the valve element, and a joining distance between the writing tip and the valve element is longer than a moving distance of the valve element during a knocking operation of a knock portion. 
     Employment of these additive structural features makes it possible to prevent escape and breakage of the writing tip liable to occur during a removing operation of the hardened substance, gelled substance and viscous substance in the writing tip after peeling off and/or crushing of the hardened substance, etc. by a knocking operation. 
     For removing the hardened substance, etc., it is an ordinary practice that the writing tip is projected from the cylindrical shell as far as possible by a knocking operation and then the writing tip is picked up with fingers. If the knocking force exerted to the knock portion is released accidentally or by mistake during a removing operation, the valve element is moved backward and the writing tip is moved relatively forward. At that time, if the connecting force between the writing tip and the valve element is smaller than the biasing force exerted to the valve element, there is such a fear that the writing tip is escaped from the valve element, thus making it unable to carry out a coating operation. In contrast, if the connecting force between the writing tip and the valve element is larger than the biasing force exerted to the valve element, there is a fear that a part of the writing tip, which is comparatively small in strength, is broken because the writing tip resists the biasing force exerted to the valve element, thus again making it unable to carry out a coating operation. 
     By employing the above-mentioned additive structural features, the above problems can be solved amicably and even if the knocking force is released by mistake, the writing tip does not escape from the valve element. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a vertical sectional view of a knock type applicator during a non-knocking operation, according to an embodiment (Embodiment 1) of the present invention; 
     FIG. 2 is a vertical sectional view of an essential portion thereof, during a knocking operation; 
     FIG. 3 is a cross sectional view of a front shell according to Embodiment 1; 
     FIG. 4 is a vertical sectional view of the essential portion showing a state in which a pressing force exerted to a knock portion is released when the writing tip is in a held position, during knocking operation; 
     FIG. 5 is a vertical sectional view of a knock type applicator according to another embodiment (Embodiment 2) of the invention, showing the elements during a non-knocking operation; 
     FIG. 6 is a vertical sectional view of the coating device shown in FIG. 5, showing the elements during a knocking operation; 
     FIG. 7 is a cross sectional view of a front shell according to a further embodiment (Embodiment 3) of the invention; and 
     FIG. 8 is a cross sectional view of a front shell according to a further embodiment (Embodiment 4) of the invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIGS. 1 to  4  show Embodiment 1 of the present invention. In those Figures, reference numeral  1  denotes a rear shell having a coating liquid storage chamber  2  defined therein and reference numeral  3  denotes a front shell whose front portion (upward portion in FIG. 1) is in the form of a reduced-diameter portion and whose rear portion is in the form of an enlarged-diameter portion. 
     The front shell  3  is fixedly inserted into an opening portion formed in a distal end of the rear shell until a flange portion  3   b  formed on an outer wall of the enlarged-diameter portion of the front shell  3  is brought into abutment with a front end face of the rear shell  1 , thereby forming a cylindrical shell. The front shell  3  has a stepped portion  3   a  formed on an inner wall of the reduced-diameter portion. Since this stepped portion  3   a  is provided as an abutment portion with respect to a coating body as later described, it may take any desired configuration inasmuch as it can abut with the coating body. For example, ribs may be formed on the front shell  3  or a hole may be formed in the reduced-diameter portion so that the hole is reduced in diameter forwardly. 
     A writing tip  4  is slidably disposed in an opening portion formed in a distal end of this cylindrical shell. 
     The writing tip  4  is composed of a plurality of natural fibers such as those of weasels (or martens), horses and pigs, synthetic resin fibers such as nylon, polyethylene terephthalate and acrylic fibers, or a mixture thereof converged in a lengthwise direction. The writing tip  4  includes, at one part thereof, a straight portion  4   b  whose rear end face is fixed, by heat welding or bonding to form a flange portion  4   a  and, at the other part, a tapered portion  4   c  which is reduced in outer diameter towards a front end face thereof. 
     A writing tip fixing tube  5  is a tubular sleeve-like member having a through hole which comprises an enlarged-diameter hole portion  5   a  and a reduced-diameter hole portion  5   b . This sleeve-like member has a larger outside diameter than an inside diameter of the opening portion formed in the distal end of the cylindrical shell and also serves as a connecting portion between the writing tip  4  and a valve element as later described. 
     The writing tip  4  is fixedly held between the stepped portion  5   c  and a front end face of a valve element which will be described presently, with a front portion thereof projecting from the opening portion in the distal end and with the flange portion  4   a  formed on a rear end portion thereof being in abutment with a stepped portion  5   c  which is formed on a boundary between the enlarged-diameter hole portion  5   a  and the reduced-diameter hole portion  5   b  which hole portions are both formed in the writing tip fixing tube  5 . 
     A plurality of ribs  3   c  are formed on the inner wall of the opening portion of the front shell  3  so that the ribs  3   c  are formed in the distal end in a lengthwise direction (see FIG.  3 ). The height of the ribs is dimensioned such that the diameter of the inscribed circle connecting the apexes of the ribs  3   c  is smaller than the maximum outside diameter of the writing tip  4 . 
     With respect to the height of the ribs  3   c , the higher the height is, the greater the striking or biting amount of the ribs  3   c  into the writing tip  4  is. Therefore, it becomes easier to peel off and crush the viscous substance, etc. However, increased height of the ribs  3   c  is associated with such inconveniences that size of the crack in the writing tip  4  is increased with the result of difficulties in discharging the coating liquid and, as a matter of fact, the number of ribs  3   c  is limited. Therefore, the height and number of the ribs can appropriately be set within a range satisfying the above conditions, in accordance with physical properties of the coating liquid and the use of the coating device. 
     In the writing tip  4 , the ribs  3   c  and the tapered portion  4   c  are in confronting relation during non-knocking operation and the ribs  3   c  and the straight portion  4   b  are in confronting relation during knocking operation. Accordingly, the ribs  3   c  and the writing tip  4  are away from each other during non-knocking operation, while the former  3   c  bites or project into the latter  4  during a knocking operation. 
     There is a provision of a valve mechanism interposed between the writing tip  4  and the coating liquid storage chamber  2 . 
     This valve mechanism is comprised of a cover member  6  formed with a bottom portion  6   a  and a valve element  7  formed with a valve portion  7   a . The valve element  7  is brought into abutment with the seat portion  6   a  by a spring member, which will be described presently. 
     The cover member  6  is comprised of a front reduced-diameter sleeve-like portion  6   b  and a rear enlarged-diameter sleeve-like portion  6   c . A circumferential projection  6   d  directing inward is formed on an inner wall of the reduced-diameter sleeve-like portion  6   c  and the seat portion  6   a  is formed on a front end face of this circumferential projection  6   d . The cover member  6  is fixedly press-fitted to the inner wall of the rear shell  1  by the enlarged-diameter sleeve-like portion  6   c  and serves to cover the coating liquid storage chamber  2  defined in the rear shell  1 . 
     The valve element  7  is comprised of a front sleeve-like portion  7   b  and a rear sleeve-like portion  7   c . A valve portion  7   a  is formed between the front sleeve-like portion  7   b  and the rear sleeve-like portion  7   c . The front sleeve-like portion  7   b  and valve portion  7   a  of the valve element  7  are slidably disposed in the reduced-diameter sleeve-like portion  6   a  of the cover member  6 . The valve element  7  is biased backward (namely, towards the knock member  10 ) by a resilient member  8  such as a coiled spring. 
     The valve element  7  and the writing tip  4  are connected together with the front sleeve-like portion  7   b  of the valve element  7  slidably inserted into the writing tip fixing tube  5  for a fixed overlapping length. In Embodiment 1, the overlaying distance between the valve element  7  and the fixing tube  5  is equal to the insertion length of the front sleeve-like portion  7   b  into the writing tip fixing tube. It is preferred that the overlapping length is set longer than the moving distance of the valve element  7  during knocking operation for the purpose of prevention of dropping or escape of the writing tip. 
     When a knocking force is released with the writing tip  4  held as shown in FIG. 4, the valve element  7  moves backward but the front sleeve-like portion  7   b  of the valve element  7  is still left inserted in the rear portion of the writing tip fixing tube  5 . Therefore, the positional relationship between the writing tip  4  and the valve element  7  is recovered by knocking again. 
     At that time, the connecting force between the writing tip  4  and the valve element  7 , i.e., between the front sleeve-like portion  7   b  of the valve element  7  and the writing tip fixing tube  5  is preferably smaller than the biasing force of the spring member  8  with respect to the valve element  7 . By doing so, breakage of the writing tip  4  (especially, flange portion  4   a ) can be prevented. The connecting force can appropriately be set by adjusting the outside diameter of the front sleeve-like portion  7   b  and the inside diameter of the writing tip fixing tube  5 . 
     The rear rod-like portion  7   c  of the valve element  7  is fixedly inserted in a front portion of a connecting sleeve-like member  9  which is disposed in the coating liquid storage chamber  2  defined in the rear shell  1 . The sleeve-like member  9  has a rear portion inserted in a sleeve-like knock member  10  having a bottom which is formed on a rear end of the coating liquid storage chamber  2 . 
     The knock member  10  has a bellows-like movable portion  10   a . It is fixedly inserted to the outer side of the reduced-diameter sleeve-like portion  1   a  formed on the rear end of the rear shell  1 . 
     It should be noted, however, that the knock portion can employ the method known per se and is, by no means, limited to the constructions shown in the embodiment of the invention. 
     An operation of the applicator according to Embodiment 1 will now be described. 
     By knocking or pressing the knock button (not shown), the bellows-like movable member  10   a  is contracted to move the sleeve-like member  9  forward. In accordance with movement of the sleeve-like member  9 , the valve element  7  moves forward against the spring force of the spring member  8 , to thereby open the valve mechanism. Since the writing tip  4  is connected to the valve element  7  at that time, they move forward together. Since the ribs  3   c  of the front shell  3  bite or project into the writing tip  4  due to the forward movement of the writing tip  4 , the writing tip is cracked forwardly at the area where the ribs project into. 
     When the valve mechanism is placed into an opened state, the coating liquid in the coating liquid storage chamber moves into the front shell  3  and discharged outside through gaps among the fibers of the writing tip  4  and a gap between the writing tip and the inner wall of the opening portion formed in the distal end of the front shell  3 . The coating liquid discharged outside the front shell  3  is absorbed by and stored in the distal end portion of the writing tip  4  so that it is ready to be coated. 
     Even in the case where the space for the coating liquid to pass through is not sufficiently large due to presence of the hardened substance, gelled substance and viscous substance of the coating liquid in the writing tip  4 , the hardened substance, etc. present at that portion of the writing tip into which the ribs project are peeled off and/or crushed. As a consequence, the coating liquid is absorbed by and stored in that portion so as to be ready for coating. 
     FIGS. 5 and 6 show Embodiment 2 according to the present invention. 
     Embodiment 2 is same as Embodiment 1 except that the writing tip  4  is replaced by a writing tip  104  with no tapered portion. 
     Since the ribs  103   c  of a front shell  103  (corresponding to the member represented by reference numeral  3  in FIG. 1) bite or project into the writing tip  104  even during non-knocking operation unlike previous Embodiment 1, the front end portion of the writing tip is cracked. As a consequence, the coating liquid discharged in the front shell during knocking operation is supplied to the front end of the writing tip through the crack even after the knocking operation is canceled. This makes it possible to discharge the coating liquid over a wide range of area in a stable manner. 
     Since the position where the ribs bite or project comes relatively closer to the rear end of the writing tip due to advancement of the writing tip during a knocking operation, crack in the distal end of the writing tip is enlarged compared with that during a non-knocking operation. Since the hardened substance, gelled substance and viscous substance of the coating liquid present at the portion where crack widely spreads are peeled off or crushed at that time, the same effects as in Embodiment 1 can be obtained. 
     Here, it should be understood that the ribs may take various configurations and shapes as desired. 
     FIG. 7 shows Embodiment 3. Embodiment 3 is same as Embodiment 1 except that a front shell  203  is provided with ribs  203   c  each having an acute apex. 
     In Embodiment 3, when compared with Embodiment 1, since the apex of each rib first contacted by the writing tip during knocking operation is acute, resistance encountered by the ribs when they bite into the writing tip is small and therefore, the writing tip is not unnecessarily deformed. Accordingly, those employing the ribs each having an acute apex exhibit such features that the writing tip is readily restored to the state before the knocking operation is made, during non-knocking operation. 
     FIG. 8 shows Embodiment 4 which is the same as Embodiment 1 except that a front shell  303  is provided with ribs  303   c  having a straight portion  303   d  and a tapered portion  303   e.    
     In Embodiment 4, when compared with Embodiment 1, since the ribs, when the writing tip contacts the advanced ribs at the time of the knocking operation, bite into the writing tip from the tapered portion, resistance encountered by the ribs when they bite into the writing tip is small and therefore, the writing tip is not unnecessarily deformed. Accordingly, it exhibits such features that the writing tip is readily restored to the state before the knocking operation is made, during non-knocking operation. 
     The present invention has been described with reference to the preferred embodiments thereof, but it should be noted that the present invention is not limited to those embodiments but many changes can be made without departing from the scope of the appended claims.