Abstract:
The fountain-pen comprises a large capacity reserve reservoir ( 3 ) for the ink, with a piston type valve ( 14 ) that can be operated to fill the pen by suction, and a smaller supply reservoir ( 10 ) which is adjacent to the nib ( 5 ) and supplies ink to it; the piston type valve ( 14 ) is provided in order to hermetically close and open the passage between said reserve reservoir ( 3 ) and the supply reservoir ( 10 ) so as to transfer ink from said reserve reservoir ( 3 ) to said supply reservoir ( 10 ) and shut off said supply reservoir ( 10 ) from the reserve reservoir ( 3 ).

Description:
FIELD AND BACKGROUND OF THE INVENTION 
     The problem with fountain-pens has always been that they are prone to ink leaks as a result of changes in pressure and/or temperature. These changes occur when there is a drop in pressure in mountainous areas or on airplanes, or when passing from low temperatures to high temperatures. These changes cause the air contained in the reservoir to expand which results in a corresponding quantity of ink leaking out through the nib, if the latter is pointing downward; the greater the change in pressure, the more ink leaks out. Also, the more air is contained in the reservoir, the more ink will leak out through the nib. 
     In the fountain-pen&#39;s one-hundred-year-plus history, this problem has only partially been solved by attaching fins to the ink-conveying member. The purpose of these fins, which can be seen underneath the nib of any fountain-pen, is to trap small leaks and prevent them from flooding into the cap. The limitations of such a system are that the fins have a limited capacity and work effectively only with very small reservoirs, such as for example a cartridge (capacity of approx. 0.8 cc). With a reservoir of approximately 3 cc the usefulness of the fins is very limited. This problem means that the writing span of fountain-pens currently available is very short, given an average reservoir capacity of approximately 1 cc. 
     SUMMARY AND OBJECTS OF THE INVENTION 
     The object of the invention is to enable the pen to be filled with any quantity of ink, the volume of ink depending only on the dimensions of the pen and the plunger, while still preventing ink leaks. 
     These and other objects and advantages will become apparent from the following text. 
     According to the invention, the fountain-pen—which has a reservoir for the ink together with means for filling it - comprises a smaller supply reservoir which is adjacent to and supplies the nib, and a manually operated valve which hermetically closes and opens the passage between the abovementioned reserve reservoir and the supply reservoir; by operating the valve ink can be transferred from said reserve reservoir to said supply reservoir. 
     A fountain-pen can be of the type comprising a piston type valve which slides along the wall of said reservoir and is attached to a rod which extends outside the pen, passing through a sealing bush, and is fixed to an end piece for manually operating said piston type valve so as to fill the pen by means of suction. In this case the piston type valve also constitutes said valve for closing and opening the passage between the two reservoirs; said valve engages in a seat formed by a component which delimits said supply reservoir. 
     Said component which delimits said supply reservoir is advantageously transparent and allows the amount of ink in said supply reservoir to be visible. 
     Said piston type valve may be able to move to a limited degree on the rod, between two limits, so that engagement of shaped parts opens or closes a passage between the valve and the rod. 
     The end piece that operates the valve can be screwed onto the body of the reserve reservoir until it reaches a position in which it shuts off the passage between the valve and the rod and in which said piston type valve bears in a leaktight manner against its seat. 
     A better understanding of the invention will be gained by reading the description and examining the appended drawing which shows a non-limiting practical example of said invention. In the drawing: 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows an external view of a pen according to the invention with some parts in section; 
     FIGS. 2,  3 ,  4  and  5  show, in isolation, the pen in axial section and in various positions that can be assumed for the stages of filling the pen, transferring the ink from one reservoir to the other and closing the reservoirs off from each other; and 
     FIG. 6 shows a detail of a piston type valve contained in the pen. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     As illustrated in the accompanying drawing, the reference  1  denotes the main body of the pen which contains a reservoir  3  of greater capacity which forms the reserve reservoir;  5  denotes the nib,  7  denotes the part adjacent to the nib and forming the grip;  9  denotes a component which is located between the grip  7  and the main body  1  and which delimits a supply reservoir  10  having the functions indicated below. The reference  11  denotes the closure cap and  12  denotes an end piece which is designed to be screwed onto and unscrewed from the body  1  so as to operate an internal member which fills the pen and transfers the ink from the reserve reservoir  3  to the supply reservoir  10  which has a much smaller volume than the reserve reservoir  3 . The nib  5  is inserted into a part  5 A which is housed inside the grip  7 , being screwed into an extension  9 A of the component  9  delimiting the supply reservoir  10 . The component  9  is screwed in a leaktight manner onto the body  1 , and the supply reservoir  10  is then in communication with the reserve reservoir  3 , the latter having a widened portion  3 A for the purposes that will be discussed below in connection with the system for filling the pen by means of suction. The component  9  forms an annular abutment seat for the purposes indicated below. 
     Sliding inside the reserve reservoir  3 —which, apart from the widened portion  3 A, is cylindrical—is a piston type valve  14  which may be made from a relatively elastic material and is attached to a piston rod  16  which is fixed to the end piece  12  by means of a replaceable part  12 A secured inside a cavity in the end piece; the piston rod  16  passes through a sleeve  18  fitted with sealing rings  18 A, within which the rod  16  can slide with the use of a suitable silicone lubricant or the like. Inside the reservoir  3  the piston rod  16  (see also FIG. 6) has a sealing disk  16 A, followed by a cone  16 B and a shaped split shank  16 C; the piston type valve  14  engages around the areas  16 B,  16 C of the end of the rod  16  and slides along the cylindrical internal surface of the reserve reservoir  3 , an internal axial passage made in the valve  14  forming a sliding and sealing seat for the shaped parts  16 A,  16 B and  16 C of the internal end of the rod  16 . As a result of this configuration, the piston type valve  14  can move between the flange  16 A and the protruding shaped part of the shaped shank  16 C, respectively assuming the position shown in FIG. 6, in which a rod passage  20  is formed between the end of the rod and the piston type valve  14 , and the position shown in FIGS. 4 and 5, in which this passage is hermetically closed as a result of the piston type valve  14  bearing against the flange  16 A and against the conical part  16 B of the internal end of the rod  16 . 
     The component  9  has, in particular, the end  9 B which forms an annular abutment seat for the front peripheral edge  14 A of the piston type valve  14 , which is on the right-hand side in FIGS. 2 to  6 . 
     The sleeve  18 , which is fixed in place at the opposite end of the body  1  to that attached to the component  9 , has a screw thread  18 B onto which the end piece  12  can be screwed and force fitted by virtue of a screw thread  12 B found on the internal portion  12 A of said end piece; in this way the end piece  12  can, as shown in FIGS. 4 and 5, be screwed onto the screw thread  18 B on the sleeve  18 , forming a secure closure. 
     In the closed position shown in FIGS. 4 and 5, when the end piece  12  is screwed onto the screw thread  18 B of the sleeve  18 , it pushes the rod  16  against the piston type valve  14  and pushes the peripheral edge  14 A of said valve against the edge  9 B which forms the seat for said piston type valve  14 . This shuts off the passage between the supply reservoir  10  and the reserve reservoir  3 ; only the supply reservoir  10 , which has a limited capacity of, for example, about 0.6 to 0.8 cm 3 , remains in communication with the nib, while the larger capacity of the reserve reservoir  3  is cut off from the supply reservoir  10 , and ink is supplied to the nib  5  by this reservoir  10 . There are therefore no changes in the volume of the contents of the supply reservoir  10 —or any changes are at most very slight—and the disadvantages mentioned earlier which occur as a result of a drop in external pressure or an increase in external temperature are avoided. 
     Once the contents of the supply reservoir  10  have been used up, all the user needs to do is to unscrew the end piece  12  part of the way off the screw thread  18 B and thereby also pull the rod  16  a little way back from the piston type valve  14  and/or pull the piston type valve  14  away from the seat  9 B formed by the component  9 ; this movement opens the passage between the two reservoirs  3  and  10  and ink can then flow from the reserve reservoir  3  into the supply reservoir  10 , after which—by screwing the end piece  12  back on—the piston type valve  14  is brought back into the closed position and the passage between the two reservoirs  10  and  3  is shut off. 
     When the pen needs to be refilled with ink, all the user has to do is unscrew the end piece  12  as usual and slide it back so as to bring the piston type valve  14  into the position shown in FIG.  2 . The part of the pen from which the nib  5  projects is then immersed into the bottle of ink and the piston type valve  14  is slid from the position shown in FIG. 2 to that shown in FIG. 3, thereby creating a certain degree of vacuum behind said piston type valve  14  in the reservoir  3 , until the piston type valve  14  reaches the widened portion  3 A as shown in FIG. 3, at which point the vacuum created sucks up the ink which more or less completely fills the reserve reservoir  3  as well as the supply reservoir  10 . The end piece  12  is then screwed back onto the screw thread  18 B and this shuts of f the passage between the reservoir  3  and the reservoir  10  so that the user can once again write without encountering the disadvantages discussed earlier caused by changes in pressure and/or temperature. 
     The configuration described also enables the ink contained in the pen, in both the reservoir  10  and the reservoir  3 , to be easily emptied out by sliding the rod  16 , so that said pen can then be filled with a different type of chosen ink. 
     The limited capacity of the supply reservoir  10  avoids the disadvantages described above; moreover, what can be the very large capacity of the reserve reservoir  3  means that, compared with the writing spans possible hitherto, the pen can be used for much longer periods of time without having to refill it with ink, and without the disadvantages encountered with conventional pens. 
     It should be understood that the drawing shows only one example, given solely as a practical demonstration of the invention, and that the forms and configurations of said invention may vary without thereby departing from the scope of the concept on which said invention is based. The presence of reference numerals in the appended claims has the purpose of facilitating reading of the claims with reference to the description and the drawing, and does not limit the scope of protection represented by the claims.