Abstract:
A pop up writing implement that includes a pump handle, an outer sleeve, an inner pen casing, a spring, a pen cartridge and a connector, which in one embodiment is U-shaped. The pen is expandable and contractible, making it small enough to easily carry in any typical pocket. The design of the pen protects against inadvertent markings, making it unnecessary for it to have a detached pen cap. The pen of the present invention also incorporates no screws, making it immune to screw loosening problems.

Description:
BACKGROUND OF THE INVENTION 
     1. Technical Field 
     This invention relates to a writing implement, and, more specifically, to an improved collapsible pen. 
     2. Background Art 
     Pens, especially ballpoint pens, have long been instrumental to everyday life. They are crucial to the performance of any task that requires a person to write things by hand, especially when this writing should be of a permanent nature. Pens are used, for example, for signing legal documents, taking notes in meetings and lectures, recording medical notes in patient records and writing letters. The typical person cannot imagine life without this simple writing implement. 
     Since pens are so popular and widely used, pens are often inscribed with advertising material, such as a company&#39;s logo or trademark. They are often given away at promotional events and set out for customers to use. This method of advertising is relatively inexpensive and provides wide coverage because a pen is often used by more than one person, or is invariably lost and found by another person. 
     Since pens are so useful, they are often carried with people where ever they go. This practice, does, however, have some drawbacks. For example, the typical pen is six or seven inches long, which often makes it difficult to comfortably carry in one&#39;s pocket. Pens of the typical length so carried will often jab the person carrying the pen. This is particularly true when a person is quite active, such as when performing strenuous physical exercise such as running, or working in the field. 
     Another disadvantage of the typical pen is that many pens require a cap to prevent them from inadvertently writing on unintended objects or leaking on one&#39;s clothing. These pen caps are often lost or separated from the pen, thus making the pen difficult to transport without the risk of ink leaking on one&#39;s belongings. 
     Yet another disadvantage related to prior writing implement designs, is that they are sometimes held together with screws. The screws tend to loosen with use over time, and the pen then falls apart, rendering it useless. 
     To prevent the common problems and disadvantages of the current pen configurations, an improved pen is required. This improved pen should be small enough to easily transport without injury. Such an improved writing implement would provide major advancements in functionality and practicality over the present technology. It would also prevent the writing instrument&#39;s inadvertent marking or writing on unintended objects without the need for an unattached cap. Additionally, such a writing implement should be held together with other than screws to avoid the aforementioned problem of the screw loosening. 
     SUMMARY 
     The present invention overcomes the common problems and disadvantages of prior writing implements by a pen that is expandable and contractible, and is small enough to be easily carried in any typical pocket. The design of the pen protects against inadvertent markings, making it unnecessary for it to have a detached pen cap. Furthermore, the pen of the present invention also incorporates no screws, making it immune to screw loosening problems. 
     The pop up pen of the present invention includes a pump handle with a curved or “hooked” end, an outer sleeve, an inner pen casing, a spring, a pen cartridge and a connector, which in one embodiment is U-shaped. The inner casing has two portions, that are joinable by matching threads. 
     When the pen is assembled, a protrusion on the pump handle, which has a hole therein, is lined up with two protrusions on the outer sleeve, which also each have holes, so that all of these holes are coaxial and the flat head at the hooked end of the pump handle engages a slot at the end of the pen&#39;s inner casing. The connector is then threaded through the holes such that the inner casing is held within the outer sleeve by the hooked end of the pump handle and the U-shaped connector. Before so assembling the pen, the spring is installed within the outer sleeve so that one edge of it rests on a ridge in the interior of the outer sleeve. The assembled inner casing, with the pen cartridge installed in it by inserting it within the inner casing portions and screwing them together, is then installed. Ridges on the outer surface of the inner casing and the interior of the outer sleeve capture the spring between them. 
     The pen, so assembled, can be extended and contracted to expose and conceal the writing tip of the pen cartridge at the end of the inner casing. 
     When the pen is in the contracted position, the flat head at the hooked end of the pump handle is engaged in the slot at the end of the inner casing and the length of the pump handle is generally parallel to the outer sleeve. In this position, the spring is fully extended and the writing tip is retracted so that it lies within the outer sleeve. 
     By grasping the pump handle at the end furthest away from its circular head and pulling it away from the outer sleeve, the circular head of the pump handle slides in the slot of the inner casing, acting as a cam, and extends through a slot of the outer sleeve. The inner casing, acting as a cam follower, slides forward and extends from the outer sleeve, exposing the writing tip of the pen cartridge. The spring is compressed between the ridge in the outer sleeve and the ridge on the inner casing. The pen in this position is ready to be used as a writing implement. 
     To retract the pen, the end of the pump handle is pivoted back toward the outer sleeve. The spring decompresses and the inner casing is retracted into the outer sleeve. In this retracted position the writing tip of the pen cartridge is within the outer sleeve and in this position the pen will not inadvertently mark on anything. 
     In an alternate embodiment of the pen of the present invention, the components of the pen are joined by a ring connector, vice a U-connector that is threaded through the holes of the protrusions. 
     The pen of the present invention is advantageous in that it is small enough to fit in one&#39;s pocket, especially when it is in its retracted position. It also does not require a separate pen cap to prevent it from inadvertently marking on anything. Since no screws are used to put together the pen, screw loosening problems are avoided. Furthermore, the outer shell can easily be imprinted with a company name, logo or slogan by conventional methods, so the pen can readily serve as an advertising vehicle. 
     In addition to the just described benefits, other objectives and advantages of the present invention will become apparent from the detailed description which follows hereinafter when taken in conjunction with the drawing figures which accompany it. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     The specific features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings where: 
     FIG. 1A is an exploded view of the parts of pen of one embodiment of the present invention. 
     FIG. 1B is a drawing of the outer sleeve of the pen of the present invention. FIG.  1 B( 1 ) is a cross sectional view of one end of the outer sleeve. FIG.  1 B( 2 ) is a side view of the outer sleeve of the pen. FIG.  1 B( 3 ) is a cross-sectional view of the other end of the outer sleeve. 
     FIG. 1C is a drawing of the inner sleeve of the pen of the present invention. FIG.  1 C( 1 ) is a cross sectional view of one end of the shorter portion of the inner casing. FIG.  1 C( 2 ) is a side view of the two inner casing portions of the pen. FIG.  1 C( 3 ) is a cross-sectional view of one end of the longer portion of the inner casing. 
     FIG. 2 is an assembled view of the pen of the present invention in the contracted position. 
     FIG. 3 is an assembled view of the pen of the presented invention in the expanded position. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In the following description of the preferred embodiments of the present invention, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. It is understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the present invention. For example, while the following description is directed toward a surfboard, the structures and process to be described are equally applicable to other water craft. 
     As shown in FIG. 1A, the pop up pen  10  of the present invention includes a pump handle  20 , an outer sleeve  40 , an inner pen casing  30  comprised of two parts  30   a  and  30   b,  a spring  50 , a pen cartridge  60  and connector  70 , which in one embodiment is U-shaped as shown. 
     As shown in FIGS. 1A,  1 B and  1 C, the outer sleeve  40  is generally cylindrical and hollow for receiving the inner pen casing  30 , the spring  50  and the pen cartridge  60 . At the first end the outer sleeve  40  there is a slot  42   a  for receiving the upper edge  22  of the pump handle  20 . The inner surface of the outer sleeve  40  has a slight ridge  44  around the circumference of the inner surface approximately two thirds of the distance from first end of the outer sleeve  40  having the slot  42   a.  The edge of the first end of the outer sleeve  40  is shaped at a slant. Attached at the outer edge of the first end of the outer sleeve  40 , directly opposite slot  42   a,  are two identically shaped protrusions  48   a  and  48   b,  each having a hole  49   a  and  49   b  for receiving a portion of the pump handle  20  and the connector  70 . Directly below the protrusions  48   a,    48   b,  and directly opposite the first slot  42   a,  is another smaller slot  42   b  sized so as to allow the very tip of the hooked end of the pump handle  20  to pass through it. 
     As shown in FIG. 1C, the inner pen casing  30  comprises two parts, a first longer portion  32  and a second shorter portion  34 . Both portions  32 ,  34  are generally cylindrical, hollow and shaped for receiving the pen cartridge  60 . The first longer portion  32  is closed at one end with the exception of having a slot  35  cut vertically therein for receiving the edge of the flat, hook shaped head  24  of the pump handle  20 . The first portion of the pen&#39;s inner casing  34  also has a ridge  37  around it, approximately a quarter of its length from the first closed end. The second end of the first longer portion  32  is threaded. The threads  39  are configured so as to mate with threads  31  of the second shorter portion  34  of the pen&#39;s inner casing  30 . The end opposite the threads  31  of the shorter portion&#39;s  34  has a hole  36  for receiving the tip of the pen cartridge  60 . 
     The pump handle  20  has a flat, hook shaped head  24 , as mentioned previously. This flat head  24  is shaped so as to fit into the slot  35  of the first longer portion of the pen inner casing  30 . The lower surface of the pump handle  20  has a protrusion  26  with a hole  27  therein. 
     When the pen  10  is assembled, the pump handle&#39;s protrusion  26  is lined up with the protrusions on the outer sleeve so that all holes  27 ,  49   a,    49   b  are coaxial and the flat head  24  of the pump handle  20  engages the slot  35  in the pen&#39;s inner casing  30 . The connector  70  is then threaded through the holes  27 ,  49   a,    49   b  such that the inner casing  30  is held within the outer sleeve  40  by the pump handle  20  and the connector  70 . Before so assembling the pen  10 , the spring  50  is installed within the outer sleeve  40  so that one edge of it rests on the ridge  44 . The assembled inner casing  30 , with the pen cartridge  60  installed in it by inserting it within the inner casing  30  portions  30   a  and  30   b  and screwing the threaded ends together, is then installed. The ridges  37  and  44  capture the spring  50  between them. 
     The pen, so assembled, can be extended and contracted to expose and conceal the writing tip  62  of the pen cartridge  60  at the end of the inner casing  30 . The contracted pen is shown in FIG.  2 . The extended pen is shown in FIG.  3 . 
     When the pen  10  is the contracted position the very tip of the curved head of the pump handle  20  is engaged in the slot  35  of the inner casing  30  and the length of the pump handle  20  is generally parallel to the outer sleeve  40 . In this position, the spring is fully extended and the writing tip is retracted so that it lies within the outer sleeve. 
     By grasping the pump handle  20  at the end furthest away from its circular head and pulling it away from the outer sleeve  40 , the circular head of the pump handle  20  slides in the slot  35  of the inner casing  30 , acting as a cam, and extends through slot  42   b  of the outer sleeve. The inner casing  30 , acting as a cam follower, slides forward and extends from the outer sleeve  40 , exposing the writing tip  62  of the pen cartridge  60 . The spring  50  is compressed between the ridge  44  in the outer sleeve and the ridge  37  on the inner casing  34   a.  The pen  10  in this position is ready to be used as a writing implement. 
     To retract the pen  10 , the end of the pump handle  20  is pivoted toward the outer sleeve  40 . The spring  50  decompresses and the inner casing  30  is retracted into the outer sleeve  40 . In this retracted position the writing tip  62  of the pen cartridge  60  is within the outer sleeve  40  and in this position the pen  10  will not inadvertently mark on anything. 
     It should be noted that other embodiments of the invention can use a connector other than a U-shaped connector, such as a ring-shaped connector that is placed through the holes  27 ,  49   a  and  49   b  to hold the pump handle  20 , outer sleeve  40  and inner casing  30  in proper operating position. Another connector that can be used is a pin or other device wherein the ends are larger than the holes  27 ,  49   a  and  49   b  in the protrusions extending from the outer sleeve. Any such connector that is placed through these holes to hold the pieces, and that is not a screw mechanism, is advantageous in that it will not be susceptible to coming apart due to loosening of the screw or screws holding it together. 
     Furthermore, the pen of the present invention is advantageous in that it is small enough to fit in one&#39;s pocket, especially when it is in its retracted position. One embodiment of the pen in its contracted position is approximately three inches long. The pen of the invention also does not require a separate pen cap to prevent it from inadvertently marking on anything, since when the pen&#39;s writing tip is retracted into the outer casing when the pen is in a collapsed state. Furthermore, because of these aforementioned advantages the pen makes a great vehicle for advertising. The outer shell can easily be imprinted with a company name, logo or slogan by conventional methods. 
     While the invention has been described in detail by specific reference to preferred embodiments thereof, it is understood that variations and modifications thereof may be made without departing from the true spirit and scope of the invention.