Abstract:
A top for a writing instrument comprises a body of transparent material, an insert encapsulated within the body, and at least one display face defined by portions of the insert for displaying an image through the body to the exterior. The transparent material is advantageously a clear silicone rubber.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates to caps for writing instruments or simply for positioning on the end of sticks to be used by children in play, said caps having amusement or play value, and to writing instruments or sticks equipped with such caps.  
       BACKGROUND TO THE INVENTION  
       [0002]     U.S. Pat. No. 4,509,875 discloses a felt pen having a bar-shaped main body and transparent caps for writing tips at opposed ends of the main body, the pen caps being arranged so that the pen can stand at either end.  
         [0003]     U.S. Pat. No. 6,149,333 discloses a ball-point pen or other writing instrument having a shaft about 10 mm in diameter and about 130 cm long which engages balls of rubbery elastic material at each end and of diameter about 35 mm, being hopefully large enough to minimise the risk of a ball being inadvertently swallowed by an infant, and one of the balls acting as the cap of the pen. When the pen is dropped or thrown, the balls cause the pen to bounce in an allegedly entertaining fashion. The balls are typically of a bright colour such as orange or red and may be made of a conventional rubber or of a silicone rubber. Alternatives to a spherical shape include polyhedral shapes with indented surfaces like the indentations of a golf-ball. The writing mechanism may be that of a ball-point pen, a pen with a fibre-tip nib or a conventional fountain pen mechanism.  
       SUMMARY OF THE INVENTION  
       [0004]     Am object of the invention is to provide a novelty top or cap structure for a pen or other writing instrument that has additional amusement or play value.  
         [0005]     In one aspect the invention provides a top or cap for a writing instrument comprising a body of clear or transparent material, an insert encapsulated within the body, and at least one display face defined by portions of the insert for displaying an image through the body to the exterior.  
         [0006]     The invention also relates to a writing instrument having a shaft provided at one or both ends with a top or cap as aforesaid.  
         [0007]     It is considered that a pen with a ball at one end can be dropped or thrown and will have amusing bounce characteristics also. Furthermore the cap with the molded-in image-bearing inserts, which are easy to change to present a range of e.g. collectable images, will have amusement value independent of bounce. 
     
    
     BREIF DESCRIPTION OF THE DRAWINGS  
       [0008]     How the invention may be put into effect will now be explained, by way of example only, with reference to the accompanying drawings, in which:  
         [0009]      FIG. 1  is an exploded perspective view of a first embodiment of a pen having a removable cap shown in alternative positions;  
         [0010]      FIG. 2  is a view of one end of the pen with the cap fitted thereon;  
         [0011]      FIG. 3  is a diagrammatic view of one end of the pen with an encapsulatable insert and a pair of adhesive labels; and  
         [0012]      FIGS. 4   a - 4   c  are a diagrammatic longitudinal section, underneath view and transverse section of the cap;  
         [0013]      FIG. 5  is a view of a two-part moldable-in insert for a second embodiment of the pen and cap together with a clip for fitting into the insert after it has been moulded into the transparent rubber;  
         [0014]      FIG. 6  is a diagrammatic transverse section of the cap with the moulded-in insert and the clip of  FIG. 5 ; and  
         [0015]      FIG. 7  is a diagrammatic longitudinal section of the cap with the moulded-in insert and the clip of  FIG. 5  and with part of the pen inserted into the cap. 
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0016]     As seen in  FIG. 1 , a generally ball-shaped pen-top  1  of diameter e.g. about 33 mm formed in a high-bounce grade of transparent silicone rubber has a moulded-in insert  2  and is a snap fit onto an end of a writing instrument such as a ball-point or fibre-tip pen  3 . The insert  2  is of a plastics material having a higher melting point than the cure temperature of the silicone rubber and has a pair of oppositely directed faces whose shape is complementary to the shape of the pen-top, in this instance circular. As is apparent from  FIG. 4   b , when the insert is viewed in end profile the faces  2   a ,  2   b  are biconvex. Design-carrying labels  4  are adhered to the opposed faces of the insert  2  before it is encapsulated in the silicone rubber to form the pen-top. Because of its shape the clear rubber of the pen-top acts as a magnifier so that ahthough the image on the labels  4  are smaller than the ball, they appear full-size or nearly so.  
         [0017]     Various changes may, of course be made to the described embodiment without departing from the invention.  
         [0018]     The body may be formed of any moldable optically clear plastics material if the amusement value of the images is required but bounce characteristics are not, for example nucleated polypropylene, polystyrene, ethylene-α-olefin copolymers, polycarbonates, polysulphone, polyether sulphones, polyethylene terephthalate, glycol-modified polyethylene terephthalate, polyethylene naphthalate. As previously explained, preferred are optically clear elastomers, e.g. silicone elastomers which are frequently based on polydimethylsiloxane.  
         [0019]     The insert may be of metal or plastics having a higher melting point than that of the body, and conveniently may be of e.g. acetal, polypropylene, hard rubber, acrylonitrile-butadiene-styrene (ABS) or nylon. Instead of the use of adhesive labels  4 , an image may if desired be printed directly onto the surfaces  2   a ,  2   b  using e.g. an ink jet printer and an ink that is adherent to the insert  2 .  
         [0020]     Shapes other than spherical may be used for the cap, e.g. a cylindrical shape, and the moulded-in insert may have a single image-carrying surface or it may have three or more image-carrying surfaces. The images may be graphics, alphanumeric or a combination of alphanumerics and graphics.  
         [0021]     The writing instrument  3 , whose dimensions are similar to the prior art pen may be a ball-pen, a roller-ball pen, a fibre-tipped pen, a felt-tipped pen, or a pencil. It may have a single ball top at one end or it may have a top at one end and a cap at the other, the shapes of the top and the cap being the same or different. Other possibilities include: 
        Single/double ball on the end of a stick     Single/double non ball shape on the end of a pen/stick for playing a game (closest to wall, in a target zone etc)     3D Character molded in ball/shape as well as or in addition to the use of a molded insert     Image on outside of ball/shape.        
 
         [0026]      FIGS. 5-7  relate to a further embodiment wherein the insert for the top comprises first and second abutting portions for assembly prior to formation e.g. by molding of the body of transparent material. In some embodiments, the insert may comprise an insert body e.g. of polycarbonate or other relatively rigid material and clip means of nylon, ABS or other relatively resilient material snap located in the insert body after formation of the body of transparent material.  
         [0027]     In  FIG. 5 a  two-part molded-in insert comprises first and second halves  10 ,  12  of polycarbonate or other suitable plastics material having planar abutting blind faces that locate together by means of pegs  14  that are received in sockets  16 . Part cylindrical concave surfaces are provided on the blind faces of the insert halves  10 , 12  to define, when the insert is assembled, a pen-receiving cavity. The sides of the surfaces  18  are bounded by planar surfaces  20  that are generally parallel to but recessed below the abutting planar surfaces to define clip-receiving spaces. The blind ends of surfaces  18  lead to clip location half sockets  22 . Clip-retaining faces  24  are formed at the outer ends of the surfaces  22 .  
         [0028]     Also shown in  FIG. 5  is a bifurcated spring clip  26  of ABS, nylon or other suitable plastics material having at its intended inner end a locating stud  28 . When the transparent silicone rubber has been molded around the assembled insert  10 , 12 , the clip can be inserted through the open end of the cap into the cylindrical cavity, where its stud  28  locates in the socket defined at  22 , and its arms fit between the surfaces  20  and snap locate behind the retaining faces  24 .  
         [0029]     To make a cap, the insert halves  10 , 12  are offered together after which the resulting cylindrical cavity defined by surfaces  18  receives a steel insert for supporting the insert halves during the molding process and reducing or preventing deformation. The clear silicone rubber is then molded around the insert halves to form the outer portion of the cap, after which the steel insert is withdrawn and the spring clip is inserted into place. The pen  3  can then be fitted into the cap as shown in  FIG. 7 .