Abstract:
A clip for a writing instrument has an external biasing mechanism separate from the connection of the clip to the writing instrument to avoid permanent deformation or breaking of the clip arm and wear on the writing instrument body. The biasing mechanism is a coil spring mounted on the clip arm between two supports for compression and flexion when the clip arm is pulled away from the side of the writing instrument.

Description:
FIELD AND BACKGROUND OF THE INVENTION 
     The present invention relates generally to the field of writing instruments and in particular to a new and useful pen clip having a bias spring held on the clip arm to provide a gripping force while reducing the likelihood of breaking due to wear. 
     Clips secured to the cap or barrel of a writing instrument for holding the writing instrument in a shirt pocket or on a pad of paper are generally known. Many prior clips are biased simply by a bent strip of metal, which form a U-shape, similar to a leaf spring. One end of the strip of metal is secured to a writing instrument barrel or cap. over time, flexion of the strip can lead to permanent deformation or the connecting strip breaking and the clip becoming irreparably detached from the writing instrument. 
     A pen clip of this type is illustrated by U.S. Pat. No. 1,923,153, in which the clip arm is made of a metal and has a small ball at the end to assist a person in putting the clip over the edge of a pocket. The clip relies upon the deformation of the clip arm so that the clip can be fit over a pocket edge. 
     U.S. Pat. No. 1,926,852 discloses a pen clip having a spring formed by a planar strip of metal connecting the clip arm to a pen cap. The spring is simply a resilient piece of metal secured to the pen cap at one end and having the clip arm mounted over the other end. The clip arm movement is limited by the upper end of the clip arm resting against the side of the cap and the surface of the spring. 
     Some prior pen clips include metal coils which are non-functional as springs and are used only to secure a clip to a writing instrument or other object. 
     U.S. Pat. No. 854,378, for example, has a pen clip formed from a single length of wire which is bent into a loop in the center to form a clip arm. The ends of the loop are wound together into a coil having the coil longitudinal axis parallel to the length of the clip arm. The coil is adapted to fit over varying diameter writing instruments, while the loop extends from one end of the coil to form a clip on the side of a writing instrument. The loop simply deforms away from the side of the pen or pencil that the coil has been fitted over. The coil is expected to tightly hold the clip to the pen and is not intended to deform or compress when the clip arm is pivoted away from the writing instrument. 
     U.S. Pat. No. 1,211,463 teaches a device holder having a coil holding a tube and gripping jaws formed by the ends of the coil which can be supported on a shirt pocket. The coil is not intended to compress or deform axially as the tube prevents that type of movement. The gripping jaws are biased closed by the coil and can hold objects. 
     Other clips have rigid clip arms with a perpendicular upper section connected to a writing instrument. The upper sections are used to pivotally w hold the clip to the writing instrument, such as in U.S. Pat. No. 2,468,699, which shows a pen clip mounted to a pen cap by a spring-biased fulcrum at the top of the pen cap. The clip arm may be pivoted away from the side of the pen cap, causing the upper end of the clip arm to move against a spring mounted perpendicular to the clip inside the writing instrument body. 
     A pen clip having the enclosed end inside the cap biased against a coil spring positioned vertically inside the cap is taught by U.S. Pat. No. 2,498,857. The clip arm extends out of the cap through a slot which permits the clip to pivot away from the side of the pen cap. The horizontal enclosed end of the cap is held between the upper end of the cap and the spring. The spring and clip enclosed end are mounted around a cylindrical threaded connector which also closes the end of the cap. 
     These types of clips suffer from the problem of complex manufacturing requirements to incorporate the spring mechanism inside the writing instrument. Further, the clip is not rigidly held to the writing instrument, but instead, has a flexible connection which is subject to breaking or wear which is not easily repairable. Since the upper end of the clip arm has to pass through the writing instrument body, the side of the writing instrument can be damaged, and the clip arm is still subject to breaking from excessive force applied to the bent portion. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a clip for a writing instrument which has a robust biasing mechanism external of the writing instrument body. 
     It is a further object of the invention to provide a clip using a coil spring to bias the clip arm. 
     Yet another object of the invention is to provide a clip biasing mechanism with a significantly reduced likelihood of breaking or permanently deforming. 
     A further object of the invention is to provide a clip for a writing instrument which is biased toward the writing instrument body and connected to the writing instrument body by two separate components. 
     Accordingly, a clip for a writing instrument has a clip arm with two ends, the upper end being threaded to receive a fastener, a spring fit over the upper end of the clip arm, and a flange adjacent the upper end having a diameter larger than the spring. A support arm having a hole therethrough extends perpendicularly from the writing instrument or a cap for the writing instrument near its top end. The threaded end of the clip arm is inserted through the hole from the bottom side so that the upper end of the spring rests against the bottom surface of the support arm. The fastener is secured to the upper end of the clip arm and holds the clip arm in the hold. The bottom edge of the fastener rests against the upper surface of the support arm. The spring is compressed slightly between the bottom surface of the support arm and the flange, so that in combination with the orientation of the support arm, the clip arm is biased toward the side of the writing instrument. 
     The clip can be connected to the cap or the body of a writing instrument. The clip can be used with pens, pencils, markers and non-marking stylii, among other types of writing instrument. The clip has a solid connection to the writing instrument with a separate, durable, flexible bias mechanism for holding the clip toward the writing instrument body. Although the bias spring is constricted partly by the support arm, they are separate components, so that using the bias mechanism does not require the support arm to flex or move. 
     The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which a preferred embodiment of the invention is illustrated. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the drawings: 
     FIG. 1 is a side elevational view of a cap for a writing instrument having a clip according to the invention; 
     FIG. 2 is an exploded side elevational view of a writing instrument having the clip of FIG. 1; 
     FIG. 3 is a perspective view of a fastener used with the clip of FIG. 1; 
     FIG. 4 is a top plan view of a clip support used with the clip of FIG. 1; 
     FIG. 5 is a perspective view of the clip arm of the clip of FIG. 1; 
     FIG. 6 is a perspective view of an alternate embodiment of the clip of FIG. 1; and 
     FIG. 7 is a perspective view of an alternate clip arm for use with the clip of FIG.  1 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to the drawings, in which like reference numerals are used to refer to the same or similar elements, FIG. 1 shows a writing instrument body  70  having a clip  10  extending to one side. In the embodiment of FIG. 1, the writing instrument body  70  is a pen cap. 
     As used herein, writing instrument is intended to broadly encompass those devices which having marking and/or non-marking tips used to write or draw, such as pencils, ball-point, gel ink and rolling ball pens, fountain pens, felt markers, highlighter pens and markers, and stylii, including PDA stylii, such as are used with touch-sensitive screens. The clip  10  can be secured to a writing instrument cap or to one end of the writing instrument body, as shown in FIG.  2 . 
     Referring again to FIG. 1, the body  70  has an upper section  70   a  which is separable from the body  70 . A support arm  60  is secured between body  70  and upper section  70   a  as will be described more fully below. The support arm  60  extends rigidly generally perpendicular to one side of the body  70 . The support arm  60  receives and holds a clip arm  20  adjacent the body  70  oriented generally parallel to the side of the body  70 . The clip arm  20  is preferably arranged so that the clip end  80  is positioned touching or nearly touching the body  70 . 
     A biasing mechanism is formed by coil spring  30  fit over the upper end of clip arm  20  and held between the lower surface of the support arm  60  and a flange  40  on the clip arm. A fastener  50  secures the clip arm  20  on the support arm  60  and fixes the compression of the coil spring  30 . The diameter of the flange  40  and outer diameter of the support arm  60  are both larger than the diameter of the coil spring  30 , so that the ends of the coil spring  30  are prevented from slipping over either of them and the coil spring subsequently falling off the clip arm  20 . 
     The coil spring  30  is placed at least slightly under compression, so that the clip arm  20  can be pivotally moved from the stationary resting position under force to a use position (shown in phantom in FIG.  1 ), but the coil spring  30  returns the clip arm  20  to its original resting position adjacent the writing instrument body  70  when the force is removed. The clip  10  can thus be used to secure the writing instrument body  70  to an object, such as over the edge of a shirt pocket or a note pad or other similar, planar objects. 
     FIG. 2 illustrates the clip  10  connected to the top end of a writing instrument body  70  that is part of a pen  100 . The pen  100  has upper end  70   a , upper writing instrument body  70 , lower body  75  and pen point  90 . Pen  100  may be of a type in which the upper writing instrument and lower bodies  70 ,  75  are twisted relative to each other to cause a writing tip to extend through the pen point  90  for use. The upper end  70   a  of the pen is adapted to receive a reduced diameter threaded connection  72  on upper writing instrument body  70  after the threaded connection  72  is inserted through body opening  62  in the support arm  60 . The support arm  60  is captured between the upper end  70   a  and upper writing instrument body  70 . 
     In an alternative embodiment, a male threaded section may be formed on upper end  70   a  which is inserted through body opening  62  and secured to a corresponding female fastener in the upper writing instrument body  70 . The support arm  60  is again captured between the upper end  70   a  and writing instrument body  70 . 
     As shown in FIG. 2, the clip arm  20  supports coil spring  30  between flange  40  and the lower surface of support arm  60 . The threaded upper end  25  of clip arm  20  is inserted through a hole  65  in the support arm. Tubular fastener  50  having a corresponding thread in channel  55  is secured to the threaded upper end  25  of the clip arm  20 . The outside diameter of tubular fastener  50  is larger than that of the hole  65 , so that fastener  50  may be tightened to compress coil spring slightly between the flange  40  and support arm  60  without passing through the hole  65 . The flange  40  provides a stepped upper surface for supporting the bottom end of the coil spring  30 . 
     FIGS. 3-5 display the fastener  50 , support arm  60 , and clip arm  20 , respectively, so that the features of each part are more clearly seen. In FIG. 3, the fastener  50  has channel  55  with threads  57  for securing to the clip arm  20 . 
     FIG. 4 shows one embodiment of the positions of the body opening  62  and hole  65 . As seen, the hole  65  is located at the end of a neck  67  extending from an annular portion  63  created by body opening  62 . The annular portion  63  is the portion of the support arm  60  which is held rigidly between the upper end  70   a  and writing instrument body  70 . The neck  67  is sized to provide a rigid support to the clip arm  20  connected through hole  65  and prevent the neck  67  or other parts of the support arm  60  from deforming when the clip arm  20  is pivotally moved in use. It should be noted that the support arm  60  could be formed integral with the writing instrument body  70 , eliminating the need for upper end  70   a . In such case, a neck  67  having a hole  65  would extend from one side of the writing instrument body  70 . 
     The clip arm  20  in FIG. 5 has flange  40  with upper surface  45  for supporting the lower end of the coil spring  30 . A ball  80  or other element is located at the end of the clip arm  20  forming the opening of the clip  10 . The ball  80  is helpful in passing the clip  10  over a shirt pocket or the edge of a paper pad when the clip  10  is used. 
     That the support arm  60  is a separate, rigid piece distinct from the clip arm  20  and coil spring  30 , is a feature of the invention which provides the benefit of a significantly reduced chance of breaking or permanently deforming the biasing mechanism for the clip  10 . Although the clip arm  20 , coil spring  30  and fastener  50  form a pivot connection through hole  65 , they move independently of the support arm  60  and do not cause the support arm  60  to deflect, deform or otherwise move. 
     The support arm  60  and other components may each be made of materials which can withstand frictional contact caused by the pivoting movement without significant deterioration or wear. Some erosion due to contact between components is expected, but this is considered preferable to having the clip arm break off from the writing instrument as a result of the spring wearing out as is common with known pen clips. While metals are preferred materials for the several components, as metals will provide the best wear between components, it is envisioned that plastics and other polymers could be used to make the clip  10  as well without significant detriment to achieving the objects of the invention. Alternatively, protective coatings could be used to reduce frictional wear between components. 
     FIG. 6 shows an alternative embodiment of the clip  10  in which a sheath or cover  35  is fitted over the coil spring between the support arm and flange  40  on the clip arm  20 . When the cover  35  is rigid, it is made sufficiently loose to permit pivoting of the clip arm  60 . Since the preferred size of the clip is not large, the amount of movement which must be accommodated is relatively small. Alternatively, the cover  35  can be a flexible material, such as fabric, rubber, or plastic mesh, among others, which covers the entire space between the support arm  60  and flange  40 , but bends when the clip arm  20  is moved to a use position. The flange  40  should be sized to have a diameter so that the coil spring  30  and cover  35  are both supported and prevented from falling off the clip arm  20 . 
     An alternative clip arm  20  is displayed in FIG. 7, in which the flange does not extend past the surface of the lower section of the clip arm  20 . Only a stepped upper flange surface  45  is formed to provide support for the coil spring  30  and cover  35  when it is used. 
     Preferably, the outer diameters of the flange  40 , support arm  60  around hole  65 , spring coil  30  and fastener  50  are the same, so that the clip  10  has the appearance of a continuous outer surface. When the cover  35  is used, the outer diameter of the coil spring  30  is reduced appropriately to permit the cover  35  to conform to the outer diameters of the other components instead. 
     While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.