Abstract:
A fob for a key chain, lanyard, or the like, supports a razor blade, or other knife blade suitable for cutting through relatively thin articles. The razor blade is embedded within the interior of a substantially rectangular-shaped molded plastic housing or casing defining the fob casing. The fob casing includes a slot intercepting one short side and the razor blade embedded inside the fob casing is positioned so that its sharpened blade edge intercepts the slot at an angle a distance from the mouth or opening of the slot. A suitable opening is included in the fob casing to support a key ring, lanyard, or other supporting axillary device.

Description:
RELATED APPLICATION 
       [0001]    The present application claims priority for all purposes on and of my prior provisional application, Ser. No. 62/392,446, filed Jun. 2, 2016, entitled: Safety Knife Fob Apparatus. To perfect this claim, a duly executed Application Data Sheet under 37 CFR 1.76 is being filed concurrently with this application. The aforementioned, prior pending provisional application, Ser. No. 62/392,446, etc. and the Application Data Sheet hereby are incorporated in and made part of this application. 
     
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
       [0002]    The present invention relates generally to utility knives, and more particularly, to a novel safety knife or cutting tool comprising a razor blade embedded in a housing, which latter may be a key-chain fob. 
       Description of the Prior Art 
       [0003]    It is well known in the art to provide so-called “utility knives” generally characterized by a razor blade mounted in or carried by a handle. Because at various times the razor blade, or a portion thereof, extends out from the handle during use, such knives inherently are dangerous capable of causing accidents or injury. 
         [0004]    The following U.S. prior art patents are typical of utility knives which comprise a razor blade or the like supported in a housing or outer casing serving as the handle for the knife: U.S. Pat. No. 2,788,574 (Marcmann); U.S. Pat. No. 4,139,939 (Crooks); U.S. Pat. No. 4,320,576 (Beermann); U.S. Pat. No. 4,748,743 (Anderson et al); U.S. Pat. No. 4,939,839 (Gorst); U.S. Pat. No. 5,337,482 (Schmidt); and Des. 336,029 (Ragland et al). 
         [0005]    A clear need exists for a “safety” utility knife having a razor blade or other cutting member which is not dangerously exposed during use. That need is met by the present invention. Accordingly, a primary object of the present invention is the provision of a safety knife featuring a razor blade cutting tool mounted in a housing member where the sharp edge of the blade or tool is not dangerously exposed during use. Another object of the present invention is the provision of a blade housing or casing serving the dual function of a key-chain fob thereby enhancing ready access to the utility knife of the invention. 
       SUMMARY OF THE INVENTION 
       [0006]    To achieve the foregoing and other objects and advantages, the present invention, briefly summarized, provides a fob for a key chain, lanyard, or the like, where the fob supports a razor blade, or other knife blade, for cutting through relatively thin articles such as a seat belt strap, fabric clothing, plastic handcuff restraint, cardboard, paper, or the like. Preferably, the razor blade is embedded within the interior of a substantially rectangular-shaped molded plastic housing or casing. The fob casing includes a slot intercepting one short side and the razor blade embedded inside the casing is positioned so that its sharpened blade edge intercepts the slot at an angle a distance from the mouth or opening of the slot. In this manner the blade is recessed and thereby prevented from accidentally injuring the user. To use the fob-supported knife of the invention, the edge of the article being cut is received through the mouth or opening of the slot to engage the angled blade edge. Axial tension then is placed on the fob to cause the slot and the blade edge to move across or relative to the article in the slot thereby causing cutting of the article in a direction generally aligned with the slot. 
         [0007]    A suitable opening is included in the fob casing to support a key ring, lanyard, or other supporting axillary device. The fob according to the present invention is so inexpensive to fabricate, after several uses and consequent dulling of the blade, it merely may be thrown away, preferably to be recycled. The fob apparatus serves conveniently as a safe cutting appliance, or novelty, and additionally may have indicia such as a logo printed thereon to enhance its appeal or ornamental appearance. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    The invention will be better understood and the above objects as well as objects other than those set forth above will become more apparent after a study of the following detailed description thereof. Such description makes reference to the annexed drawing wherein: 
           [0009]      FIG. 1  is a schematic perspective taken from above right showing the fob of the invention in use cutting an article. 
           [0010]      FIG. 2  is an enlarged front view in elevation of the preferred embodiment of the invention shown in  FIG. 1 . 
           [0011]      FIG. 3  is a top plan view taken along line  3 - 3  in  FIG. 2 . 
           [0012]      FIG. 4  is an enlarged side or end view taken along line  4 - 4  in  FIG. 2 . 
           [0013]      FIG. 5  is an enlarged cross-sectional view taken along line  5 - 5  in  FIG. 4 . 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0014]    With reference to the drawings, a new and improved safety knife fob apparatus embodying the principles and concepts of the present invention will be described. 
         [0015]    Turning to  FIGS. 1-5 , there is shown a preferred embodiment of the safety knife fob apparatus of the invention generally designated by reference numeral  10 . In each of the figures, reference numerals are shown that correspond to like reference numerals that designate like elements shown in other figures. 
         [0016]    In the preferred embodiment, safety knife fob apparatus  10  comprises a substantially solid fob body member  12 , and a razor blade or other cutting blade  14  embedded within and supported by the fob body member  12 . Preferably, a conventional key ring  16  is suitably connected to the fob body member  12  and a key  18  or the like, in turn, is connected to the key ring  16  ( FIG. 1 ). 
         [0017]    Preferably, fob body member  12  comprises a substantially rectangular-shaped prism having a front face  20 , a rear face  22 , a right end  24 , a left end  26 , a top end  30 , and a bottom end  32 , substantially as depicted. A slot  34 , preferably of rectangular cross-sectional shape, extends from left end  26  substantially parallel to the imaginary longitudinal centerline or axis of body member  12  ultimately terminating in an end wall or “blind end”  36  recessed with respect to left end  26 . Slot  34  thus also has an imaginary central longitudinal axis extending substantially parallel to the imaginary central axis of fob body member  12 , and substantially parallel to top end  32  and bottom end  34  of body member  12 . In accordance with the invention, slot  34  defines a convenient entrance mouth or opening in left end  26  for receiving the edge of an article to be cut by blade  12  ( FIG. 1 ). 
         [0018]    Substantially as depicted in the  FIGS. 2-4 , fob body member  12  has a longitudinal extent or length “L,” a height “H,” and a thickness “t” whereas slot  34  has a longitudinal extent or length “S,” and a height “M.” Hence, the size of the mouth opening of cutting slot  34  in left end  26  is “M”×“t.” 
         [0019]    A thru opening  38 , preferably circular in shape, is located proximal to left end  26  and slot  34 , substantially as depicted. Preferably, the center of opening  38  is aligned with the imaginary longitudinal axis or centerline (not shown) of fob body member  12  as viewed in  FIG. 2 . The purpose of opening  38  is to provide an anchoring means on fob body member  12  for key ring  16  ( FIG. 1 ), or other similar appliance such as a lanyard, for example. 
         [0020]    Preferably razor blade  14  is transversely positioned interiorly of the fob body member housing substantially centrally thereof ( FIG. 3 ), and as best seen in  FIG. 5 , the embedded razor or cutting blade  14  is so positioned within the fob body member  12  such that its tip is pointed down and to the left as it intercepts and transcends slot  34  with the tip of the blade ultimately being received in the portion of the fob body extending below slot  34 . By this arrangement, it will be observed that the sharpened cutting edge  40  of blade  14  extends at an acute angle with respect to the imaginary central longitudinal axis of the fob body member  12  as indicated by arrow  42  ( FIG. 5 ). Moreover, the “effective length” of the angled cutting edge  40  of blade  12  within the compass of slot  34  is enhanced, and the cutting edge  40  per se always is recessed within slot  34  a minimum distance “d” with respect to left end end  26  ( FIG. 2 ). Because angled blade  12  is always so recessed within slot  34 , accidental injuries (cut or nicked fingers) to a user under virtually all use conditions of the apparatus  10  are eliminated. 
         [0021]    To fabricate the safety knife fob apparatus  10  of the invention, it is preferred to place razor blade  12  in a suitable mold cavity and to subsequently injection mold a suitable polymer around the blade as will occur to those of ordinary skill. The preferred polymer is a polyamide with glass-filled nylon being mostly preferred. Oblong opening  44  which passes through both the blade  14  and fob body member  12  can be used to receive a pin in the mold cavity suitable to maintain the blade in position as the polymer is molded about the blade. Finally, it will be appreciated that razor or cutting blade  14  can be fabricated in a known manner preferably of machined steel. 
         [0022]    In use, referring to  FIG. 1 , the safety knife fob apparatus  10  can be used conveniently to cut many different articles  46  by causing the fob body member  12  to advance in the direction of the desired cut after the edge of the article is received in the slot  34  of the fob member  12 . Cutting action is enhanced by grasping the key  18 , the key ring  16 , along with the fob body member  12  and applying tension or a pulling force in the desired direction of the cut. It will be appreciated that many different articles may be severed with the invention in an expedient manner such as seat belts webs, handcuff restraints, articles of clothing, paper containers, or cardboard, just to name a few examples. 
         [0023]    To further illustrate the invention without limiting same, the following dimensions and materials have been used in producing prototypical examples of the safety knife fob apparatus of the invention:
   Fob length: 2.5 in.   Fob height: 1.0 in.   Fob thickness: 0.190 in.   Slot length: 0.90 in.   Slot height: 0.014 in.   Blade recess: 0.20 in.   Blade angle: 60°   Exposed length of blade in slot: 0.650 in.   Fob housing material: glass-filled nylon (polyamide)   Blade material: steel   Weight of Fob w/Blade: 11 grams   Diameter of Key Ring Opening: 0.25 in.   
 
         [0036]    To summarize the many benefits or advantages of the unique safety knife fob apparatus of the invention, the latter may be carried conveniently as a key ring or on a lanyard and used especially in a an emergency to cut through seat belts straps, plastic handcuff restraints, clothing, cardboard packaging or boxes, or the like. The safety knife fob apparatus is relatively small in size, light in weight, and inexpensive to fabricate. Because of the provision of a thru-opening, keys or a lanyard easily can be attached to the fob member and then grasped during cutting actions to provide increased leverage thereby making cutting easier and more rapid. Because of the manner in which the blade is angled with respect to the cutting slot of the fob member, the recessed blade length is enhanced sufficient to cut relatively thick objects such as seat belt straps and plastic handcuff restraints. The flat end or bottom of the fob member provides a convenient surface to facilitate pushing of the fob member during cutting actions. The recessed blade construction characterized by the fob member housing or casing permits the fob member apparatus to be conveniently carried in one&#39;s pocket without accidentally causing cutting or nicking of the fingers. And finally, the thickness and strength of the molded plastic housing completely surrounding the razor or cutting blade affixed interiorly thereof, affords a relatively strong and durable fob member that resists breakage and prevents the cutting blade from easily being broken out and used separately (i.e. the invention is “childproof”). 
         [0037]    Hence, the proper scope of the present invention should be determined only by the broadest interpretation of the appended claims so as to encompass all such modifications as well as all relationships equivalent to those illustrated in the drawings and described in the specification.