Patent Publication Number: US-8112894-B2

Title: Retractable pocket clip for knife

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Patent Application 60/814,912, filed on Jun. 17, 2006. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT 
     Not Applicable. 
     FIELD OF THE INVENTION 
     This invention relates to pocket knives, and more particularly to a novel retractable pocket clip for such a knife. 
     DISCUSSION OF RELATED ART 
     Clips for retaining a pocket knife, and other objects, onto a pair of pants or a pants pocket are known in the art. Generally such clips are elongated and protrude from one side of the object. In the case of a pocket knife, such a clip is exemplified by U.S. Design Pat. No. 487,628, which protrudes from one side of the knife. While such a clip does help retain a knife onto an object such as a pants pocket, it is obtrusive in situations where the user does not wish to use such a clip. Such a clip can snag on items undesirably when not being used to retain the knife on an object. A similar type of clip, but used on a tape measure, can be found in U.S. Pat. No. 5,038,985 to Chapin. U.S. Pat. No. 4,773,159 to Casazza, Jr., on Sep. 27, 1988 teaches a pair of similar clips. All of these types of clips are non-retractable and, as such, tend to snag on items unintentionally. 
     To overcome the aforementioned drawbacks, retractable belt and pocket clips have been devised. For example, US Patent Application 2002/0153395 to Martinez on Oct. 24, 2002, teaches a retractable belt clip that pivots away from the knife, similar to the manner in which the knife blades of such a device pivot. U.S. Pat. No. 6,941,604 to Ackeret on Sep. 13, 2005 teaches a similar pivotable clip. One considerable drawback of such pivoting clips is that the space between the clip and the knife necessarily decreases in depth when moving towards the pivot point of such a clip. This tends to catch material in a scissors-type grip and can even sometimes damage such material, particularly fabric material such as pant or shirt pockets. Further, such clips do not tend to retain the knife well to objects when the objects are mobile, since such clips necessarily bind the object towards their pivot points and specifically not at their distal ends. As a result, the object is pinched only in a small area, and as such the knife can easily become dislodged if jolted. 
     US Patent Application 2004/0129746 to Lee et al. on Jul. 8, 2004, and US Patent Application 2006/0113985 to Gist et al. on Jun. 1, 2006 (FIG. 3), both teach retractable belt clips for objects, in one case a phone and in another case a hand tool. Such clips overcome the disadvantages heretofore mentioned, but are not readily adapted to pocket knives due to their size and structure. It is not obvious how to incorporate such clips into a pocket knife and still maintain room for a pivoting knife blade, or other knife tools. Further, such clips appear to be manufactured out of plastic, which is an undesirably weak material for use as a pocket knife clip. 
     Therefore, there is a need for an inexpensive, easily used retractable pocket knife clip that is sufficiently strong to withstand the rigors experienced by pocket knives, yet still reliably hold such a knife to a belt, pants pocket, or the like. The needed device would be extendible quickly into a usable, extended position, and would just as easily be collapsed into its retracted position. Such a needed device would be of relatively small volume so as to allow room for folding knife blades and other knife tools. The present invention accomplishes these objectives. 
     SUMMARY OF THE INVENTION 
     The present device is a folding knife comprising at least two rigid plates and at least one knife blade that is pivotally attached therebetween. A retractable clip of the present invention includes a base portion slidably fixed between two of the at least two rigid plates. The base portion includes a generally rectangular guide slot formed therethrough, and the knife includes a guide pin fixed between the two rigid plates of the knife and traversing the guide slot of the base portion. The retractable clip further includes an elongated clip member. 
     In use, when in a retracted position, the retractable clip is substantially contained between the two rigid plates of the knife. Alternately, in an extended position, the clip member of the retractable clip laterally extends outwardly away from between the two rigid plates of the knife, the guide slot and guide pin cooperating to prevent further extension of the clip member and the base portion past a certain point. As such, when the retractable clip is in the extended position and an object, such as a pants or shirt pocket for example, is positioned between the clip member and the knife, the retractable clip facilitates retention of the knife on the object by friction. 
     The base portion preferably further includes a serrated finger pad at one side of the peripheral edge. The finger pad is generally parallel to the guide slot and at least partially protrudes from between the two rigid plates of the knife. As such, a person&#39;s finger or fingernail may press against the finger pad to force the retractable clip to slide back and forth between the retracted and extended positions. 
     The base portion may further include a pair of detents that cooperate with a spring-biased protrusion of at least one of the rigid plates of the knife, such when the clip is in either the retracted or extended positions the protrusion is aligned with one of the detents to provide a tactile resistance when moving the retractable clip. 
     The present device is an inexpensive, easily-used retractable pocket knife clip that is sufficiently strong to withstand the rigors experienced by pocket knives, yet still will reliably hold such a knife to a belt, pants pocket, or the like. The present invention is extendible quickly into a usable, extended position, and just as easily may be collapsed into its retracted position in which the clip cannot inadvertently snag stray items. The current device fills a relatively small volume so as to allow room for folding knife blades and other knife tools. Other features and advantages of the present invention will become apparent from the following more detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a top plan view of the invention, illustrating a clip member of the invention in an extended position; 
         FIG. 2  is a right-side elevational view of the invention; 
         FIG. 3  is a cross-sectional view of the invention, taken generally along lines  3 - 3  of  FIG. 2 , and illustrating the clip member in the extended position; 
         FIG. 4  is a top plan view of the invention, illustrating a clip member of the invention in a retracted position; 
         FIG. 5  is a cross-sectional view of the invention, taken generally along lines  3 - 3  of  FIG. 2 , and illustrating the clip member in the retracted position; 
         FIG. 6  is a left-side elevational view of a person carrying the knife of the present invention in a pocket, the clip member in the extended position and engaged with the pocket; 
         FIG. 7  is a cross-sectional view of the invention, taken generally along lines  7 - 7  of  FIG. 3 ; and 
         FIG. 8  is a cross-sectional view of the invention, taken generally along lines  8 - 8  of  FIG. 3 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       FIG. 1  illustrates a folding knife  10  comprising at least two rigid plates  40 , each fixed generally parallel to each with a plurality of rigid spacers  12 , thereby forming a space  14  between each two adjacent rigid plates  40 . At least one knife blade  30  is pivotally attached between two of the at least two rigid plates  40 , the knife blade  30  pivotable between a retracted position  34  ( FIG. 5 ) and an extended position  36  ( FIG. 2 ). The knife blade  30  and each rigid plate  40  are preferably made from a hardened steel, alloy, or other suitably rigid metallic material. 
     A retractable clip  20  of the present invention includes a base portion  50  slidably fixed between two of the at least two rigid plates  40  ( FIGS. 1 ,  3 ,  5 ). The base portion  50  includes a top surface  54 , a bottom surface  56 , and a peripheral edge  58  joining the top and bottom surfaces  54 , 56  and generally perpendicular thereto. The base portion  50  includes a generally rectangular guide slot  60  formed therethrough ( FIGS. 3 and 5 ). The knife  20  includes a guide pin  70  fixed between the two rigid plates  40  of the knife  10  and traversing the guide slot  60  of the base portion  50 . Preferably the retractable clip  20  is also made from a steel alloy, or other suitably rigid metallic material. 
     The retractable clip  20  further includes an elongated clip member  80  that is fixed at one end  84  to the base portion  50  ( FIG. 1 ). The clip member  80  has a top surface  82  that is preferably coplanar with the top surface  54  of the base portion  50 , and a bottom surface  86  that is generally coplanar with the bottom surface  56  of the clip member  50 . A clip member peripheral edge  88  joins the top and bottom surfaces  82 , 86  of the clip member  80 . Preferably, a long axis  65  of the guide slot  60  is generally orthogonal to a longitudinal axis  15  of the knife and a longitudinal axis  85  of the elongated clip member  80  ( FIGS. 1 and 3 ). 
     In use, when in a retracted position  90  ( FIG. 4 ), the retractable clip  20  is substantially contained between the two rigid plates  40  of the knife  10  with one side  64  of the guide slot  60  contacting the guide pin  70 . Alternately, in an extended position  95 , the clip member  80  of the retractable clip  20  laterally extends outwardly away from between the two rigid plates  40  of the knife  10  and a second side  66  of the guide slot  60  contacts the guide pin  70  to prevent further extension of the clip member  80  and the base portion  50 . Preferably the clip member  80  includes at a second end  87  thereof a retention bulb  110  projecting away from the clip member peripheral edge  88  and towards the knife  10  ( FIG. 3 ). As such, when the retractable clip  80  is in the extended position  95  and an object  120 , such as a pants or shirt pocket for example, is positioned between the clip member  80  and the knife  10 , the retention bulb  110  facilitates retention of the knife  10  on the object  120  by friction. 
     The base portion  50  preferably further includes a serrated finger pad  100  at one side of the peripheral edge  58 . The finger pad  100  is generally parallel to the guide slot  60  and at least partially protrudes from between the two rigid plates  40  of the knife  10 . As such, a person&#39;s finger or fingernail (not shown) may press against the finger pad  100  to force the base portion  50  and clip member  80  to slide back and forth between the retracted and extended positions  90 , 95 . 
     The base portion  50  may further include a detent  130  on the bottom surface  56  thereof. The detent  130  cooperates with a spring-biased protrusion  140  of at least one of the rigid plates  40  of the knife  10  ( FIGS. 3 and 7 ), such when the clip  80  is in the retracted position  90  the protrusion  140  is aligned with the detent  130  to provide a tactile resistance when moving the retractable clip  20  from the retracted position  90 . Similarly, a second detent  135  on the bottom surface  56  of the base portion  50  may be included that cooperates with the spring-biased protrusion  140  such that when the clip  80  is in the extended position  95 , the protrusion  140  is aligned with the detent  135  to provide a tactile resistance when moving the retractable clip  20  from the extended position  95 . The spring-biased protrusion  140  may be formed by cutting an elongated U-shaped section  145  in one of the rigid plates  40  ( FIG. 3 ), for example. 
     The detent  130 , in an alternate embodiment (not shown), may be formed in an inward surface  89  of the peripheral edge  58  of the base  50  ( FIG. 3 ). As such, the spring-biased protrusion  140  may engage such a detent  130  along an axis orthogonal to the inward surface  89 . Clearly other detent means and methods of exerting a spring bias upon them may be devised by those skilled in the art to create the desired effect of providing tactile feedback when the retractable clip  80  is moved back and forth from its retracted and extended positions  90 , 95 . 
     While a particular form of the invention has been illustrated and described, it will be apparent that various modifications can be made without departing from the spirit and scope of the invention. For example, the exact placement of the detents  130 , 135 , and the exact shape of the clip member  80  may be altered depending upon the design of the particular knife  10  into which the retractable clip  20  is to be installed. Further, the exact shape of the guide slot  60  may be a rounded rectangle as opposed to a squared-off rectangle. The scope and spirit of the present invention may extend to a knife  10  complete with the retractable clip  20 , or to the retractable clip  20  by itself for incorporating into any suitable type of knife  10 , folding or otherwise. Accordingly, it is not intended that the invention be limited, except as by the appended claims.