Abstract:
An ink cartridge structure includes a resilient device coupled to an ink cartridge for absorbing impact energy acting on the ink cartridge for protection of the ink cartridge. The resilient device includes a connection bar mounted to the ink cartridge and is coupled to a retention bar that is accessible by a user with a resilient element therebetween so that the resilient element provides cushioning to the ink cartridge. The connection bar is partially fit into a hollow portion of the retention bar and forms a vent hole that is in communication with the ink cartridge so that when the retention bar, under the resilient support by the resilient element, is manually moved reciprocally with respect to the connection bar, air is pumped, through the vent hole, into the ink cartridge to force the ink contained in the ink cartridge to ward a writing tip.

Description:
BACKGROUND OF THE INVENTION 
     (a) Technical Field of the Invention 
     The present invention relates to a novel design of an ink cartridge structure, and in particular to an ink cartridge structure that comprises a resilient device for cushioning impact and thus protecting the ink cartridge from being damaged or incurring ink discontinuity, wherein the resilient device in arranged at an end of the ink cartridge and an upper end of the ink cartridge forms an internal thread to engage a threaded section formed on a connection bar for adjustability of the biasing force induced by the resilient device and thereby adjusting the force that the resilient device applies to the ink cartridge and wherein a vent hole is provided in the coupling between the resilient device and the ink cartridge so that when the resilient device is compressed, air is pumped into the ink cartridge through the vent hole to keep the ink contained in ink cartridge being driven toward a writing tip of the ink cartridge and discontinuity of ink supply is obviated. 
     (b) Description of the Prior Art 
     A conventional pen comprises a barrel in which an ink cartridge is received and fixed in position by threading engagement. Such a structure suffers easy damage to the writing tip or ball point of the ink cartridge due to the fact that no cushioning is provided to absorb impact energy that is applied to the writing tip or ball point when the writing tip is hit by for example an external force or falling onto the ground. When the ball point is damaged, the ball cannot roll smoothly and discharge of ink through the ball is interrupted. The worst case is that the pen is totally broken and cannot be used for writing. A solution to such a problem is a pen including a resiliently supported ink cartridge or ink tube as shown in  FIG. 1  of the attached drawings, wherein a pen is composed of a hollow barrel  1  having an upper end forming a recess  11 , an ink cartridge or ink tube  10  having an upper end forming a projection  101 , and a spring  12 . The spring  12  has an end received and retained in the recess  11  of the upper end of the barrel  1  and an opposite end supported on the projection  101  of the upper end of the ink cartridge  10  so that the ink cartridge  10  is subjected to the spring force of the spring  12  to resiliently extend and retract, whereby when the ink cartridge is subjected to an external impact, the spring  12  effects cushioning against the impact force by allowing the ink cartridge  10  to retract back into the barrel  1 . Thereafter, when the impact is removed, the spring force of the spring  12  drives the ink cartridge outward for writing. In this way, the ink cartridge can be protected from damage caused by external impact. However, such a spring-cushioning ink cartridge has the following disadvantages: 
     (1) The assembly of the barrel  1  and the ink cartridge  10 , as well s the spring  12 , requires first fitting parts into the barrel  1  and then closing the barrel  1  by threading operation. This is certainly very troublesome. 
     (2) With the ink contained in the ink cartridge  10  fully consumed, the whole pen has to be disposed of and a new pen has to be purchased, because due to the assembly, there is no substitute ink cartridge  10  that is available individually. This makes the pen an uneconomic device. 
     (3) The lines drawn with the conventional ink cartridge is of a fixed width and the line may get easily broken when the force applied to the pen in the writing process is too light. Other disadvantage is also known for discontinuous line that a pen that has been stowed in an up-side-down manner for a substantial period of time may draw. 
     Thus, it is desired to provide an ink cartridge for pens to overcome the above drawbacks. 
     SUMMARY OF THE INVENTION 
     The primary purpose of the present invention is to provide novel design of an ink cartridge structure and in particular to an ink cartridge structure that comprises a resilient device directly arranged at an end of the ink cartridge so that when a pen that incorporates the ink cartridge accidentally falls onto the ground, the resilient device effectively absorbs most of the impact energy so as to protect the ink cartridge from being damaged or incurring ink discontinuity. In accordance with the present invention, a connection bar is fit to an upper end of the ink cartridge with a resilient element provided thereon and a retention bar is fit to the resilient element so that the resilient element is directly coupled to the end of the ink cartridge. Thus, the ink cartridge structure can be simply deposited into a pen barrel and can be arbitrarily replaced by a new one. Compression of the resilient element allows for control of the up and down movement of the ink cartridge. The connection bar of the ink cartridge is provided with a threaded section to engage an internal thread formed in the upper end of the ink cartridge with adjustability of the penetration depth of the connection bar screwed into the ink cartridge to control the biasing force induced on the ink cartridge. A vent hole is formed in a fitting portion of the connection bar so that when the retention bar is depressed, an amount of air is pumped into the ink cartridge to drive the ink contained in the ink cartridge toward the writing tip of the ink cartridge thereby ensuring smooth writing without incurring ink discontinuity and allowing adjustment of line width scratched with the ink cartridge. 
     The foregoing object and summary provide only a brief introduction to the present invention. To fully appreciate these and other objects of the present invention as well as the invention itself, all of which will become apparent to those skilled in the art, the following detailed description of the invention and the claims should be read in conjunction with the accompanying drawings. Throughout the specification and drawings identical reference numerals refer to identical or similar parts. 
     Many other advantages and features of the present invention will become manifest to those versed in the art upon making reference to the detailed description and the accompanying sheets of drawings in which a preferred structural embodiment incorporating the principles of the present invention is shown by way of illustrative example. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a cross-sectional view of a conventional pen; 
         FIG. 2A  is a exploded view of an ink cartridge device in accordance with the present invention; 
         FIG. 2B  is a perspective view of the present invention. 
         FIG. 3  is a cross-sectional view of a pen in which the ink cartridge device of the present invention is embodied; 
         FIG. 4  is an exploded view of an ink cartridge device in accordance with another embodiment of the present invention; 
         FIG. 5  is a cross-sectional view of a resilient device of the ink cartridge device of the present invention; 
         FIG. 6  is a cross-sectional view illustrating a vent hole that is formed in a connection bar of the ink cartridge device of the present invention; 
         FIG. 7  is a cross-sectional view illustrating coupling between a retention bar and the connection bar of the ink cartridge device of the present invention; and 
         FIG. 8  is a cross-sectional view illustrating the condition when retention bar is depressed and thus moved with respect to the connection bar. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The following descriptions are of exemplary embodiments only, and are not intended to limit the scope, applicability or configuration of the invention in any way. Rather, the following description provides a convenient illustration for implementing exemplary embodiments of the invention. Various changes to the described embodiments may be made in the function and arrangement of the elements described without departing from the scope of the invention as set forth in the appended claims. 
     The present invention provides a design of an ink cartridge incorporating a resilient device, which ink cartridge, as particularly shown in  FIGS. 2A and 2B  that illustrate the ink cartridge device in accordance with the present invention, comprises an outer casing  4 , an ink cartridge bar  2 , a connection bar  21 , a resilient element  22 , and a retention bar  23 . The ink cartridge bar  2  is a hollow member forming in an upper end thereof a fitting hole  20  and is fit to an ink cartridge  5  or is integrally formed with the ink cartridge  5 , as shown in  FIG. 3 . The connection bar  21  has a lower end forming an insertion portion  210  and an upper end forming a fitting portion  211  and an intermediate section forming a sideway-projecting circumferential flange  212 . The connection bar  21  also forms a vent hole  213  in the fitting portion, preferably at a lower half thereof. The resilient element  22 , which in the embodiment illustrated comprises a helical spring, is fit onto the fitting portion  211  and is retained on the circumferential flange  212 . The retention bar  23  has a lower end forming a fitting portion  231  that is fit into the resilient element  22  and is also partially and movably fit over the fitting portion  211  of the connection bar  21  and an upper end forming a coupling ring  232  for coupling to the resilient element  22  at the time the resilient element  22  is fit thereto. Further, the upper end of the retention bar  23  forms an expanded end portion  230  that has an outside diameter that is greater than the diameter of the resilient element  22 . The top of the retention bar  23  bears against the inner top end of the outer casing  4  so that when a user holds the outer casing  4  to use the ink cartridge  5  to write on a piece of paper, the ink cartridge bar  2  will be forced to go upwardly thereby causing the retention bar  23  to be depressed in relation to the ink cartridge  5 . 
     The assembling of the ink cartridge will be described with reference to  FIGS. 2A ,  2 B and  3 . As shown, no matter being fit to or integrally formed with the ink cartridge  5 , the ink cartridge bar  2  has the fitting hole  20  formed on the upper free end thereof so that the connection bar  21  can use the insertion portion  210  on the lower portion thereof to fit to the fitting hole  20  of the upper end of the ink cartridge bar  2  for mounting and uses the circumferential flange  212  to abut against the upper end of the ink cartridge bar  2 . The resilient element  22  is then fit over the fitting portion  211  of the connection bar  21  and is retained by the circumferential flange  212 . The fitting portion  231  of the lower end of the retention bar  23  is of a hollow configuration that has a size slightly greater than the fitting portion  211  so that when the fitting portion  231  is fit into the resilient element  22 , the fitting portion  231  is also fit, at least partly, over the fitting portion  211  with the coupling ring  232  set in coupling with the resilient element  22  for mounting and positioning and the expanded end portion  230  engaging and fixed at an upper end of the resilient element  22 . Thus, when the expanded end  230  is subjected to forcible depression, the resilient element  22  is compressed, making the fitting portion  231  to move up and down with respect to the fitting portion  211 . Consequently, the ink cartridge device in accordance with the present invention can be pre-assembled for separately sale and replacement and there will be no need to discard the whole pen when the ink cartridge device runs out of ink. This makes the ink cartridge of the present invention more economic. 
     As to the coupling between the insertion portion  210  of the connection bar  21  and the ink cartridge bar  2 , reference is made to  FIGS. 4 and 5 , which illustrate another embodiment in accordance with the present invention, wherein the insertion portion  210  of the connection bar  21  forms an external thread  214  and the fitting hole  20  that is formed on the upper end of the ink cartridge bar  2  forms, on an inside surface thereof, an internal thread  201  engageable with the external thread  214  so that the connection bar  21  is threadingly fixed to the ink cartridge bar  2 . Further, based on the extent that the connection bar  2  is threaded into the ink cartridge bar  2 , the biasing force induced by the resilient element  2  can be adjusted so that the optimum biasing force can be provided to accommodate different writing styles and forces taken by different pen users. And multiple stage adjustment can be realized. 
     The vent hole  213  that is formed on the connection bar  21  will be described with reference to  FIG. 6 . The fitting portion  211  that constitutes the upper portion of the connection bar  21  forms in a lower half thereof the vent hole  213 , which is in communication with an interior space  2101  (see  FIGS. 5 and 7 ) formed inside the insertion portion  210  and which, when the insertion portion  210  is screwed into the fitting hole  20  of the upper end of the ink cartridge bar  2 , is set in communication with the ink cartridge  5 . When the retention bar  23  is depressed, the fitting portion  231  is moved up and down with respect to the fitting portion  211  of the connection bar  21  and air is expelled out of the interior space or bore  2310  of the retention bar  23 , as shown in  FIGS. 6 and 7 . However, when the fitting portion  231  is fit over the fitting portion  211  exceeding a predetermined length, which is determined by the location of the vent hole  213 , the fitting portion  213  extends beyond the vent hole  213  so that a portion of air that is expelled out of the bore  2310  of the retention bar  23  is forced into the interior space  2101  of the insertion portion  210  of the connection bar  21  through the vent hole  213  and communicates the ink cartridge  5  to induce an expulsion force that drives the ink contained in the ink cartridge  5  toward to writing tip of the ink cartridge thereby making writing more smoothly without any discontinuity of ink scratch. 
     When in use of the pen, the resilient device provided by the present invention protects the ink cartridge  5  from being damaged or ink discontinuity by impact by an external force due to falling of the pen. More particularly, the tension of the resilient device can be adjusted and set as desired by the penetration depth that the connection bar  21  screwed into the upper end of the ink cartridge bar  2  to ensure smooth writing and to effect regulation of writing line widths in accordance with force that is applied to write so that a single pen may provide writing lines of different sizes, such as 0.38, 0.5 or 0.7 mm, with completely no ink discontinuity. Further, the arrangement of the vent hole  213  also air to be pumped into the ink cartridge  5  by depressing the end portion  230  of the retention bar  23  to induce reciprocation of the retention bar  23  with respect to the connection bar  21 , whereby the ink contained inside the ink cartridge  5  can be forced toward the writing tip so that even the ink cartridge  5  is used to write in an up-side-down manner, ink discontinuity cannot occur. This is apparently a remarkable improvement over the known writing implements. 
     To this end, it is apparent the resilient device provided by the present invention, together with the simple construction of threading and vent hole, allows adjustment of depression force by adjusting the location of the connection bar by means of threading coupling so that the rigidness of the depression of ink cartridge can be selectively modified. Further, the vent hole allows for pumping of a given amount of air to the ink cartridge to ensure continuity of supply of ink so that the writing can be smoother and ink discontinuity can be obviated. 
     Although the present invention has been described with reference to the preferred embodiments thereof, it is apparent to those skilled in the art that a variety of modifications and changes may be made without departing from the scope of the present invention which is intended to be defined by the appended claims. 
     It will be understood that each of the elements described above, or two or more together may also find a useful application in other types of methods differing from the type described above. 
     While certain novel features of this invention have been shown and described and are pointed out in the annexed claim, it is not intended to be limited to the details above, since it will be understood that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and in its operation can be made by those skilled in the art without departing in any way from the spirit of the present invention.