Patent Publication Number: US-2020290228-A1

Title: Utility knife having safety guard and method of using the same

Description:
FIELD OF THE INVENTION 
     The embodiments of the present invention relate to a utility knife having a safety guard to prevent accidental injuries. 
     BACKGROUND 
     Utility knives use razor blades to cut open boxes or cut other articles. The primary drawback with utility knives is the inevitable cutting of one&#39;s own hand, wrist or arm while using the utility knife to cut an article. 
     It would be advantageous to develop a utility knife with a safety guard which retracts when using the utility knife and automatically deploys once a cutting action is stopped. 
     SUMMARY 
     Accordingly, one embodiment of the present invention is a cutting device comprising: a housing containing a cutting blade with a portion of said cutting blade extending from said housing; a safety guard having an end positioned proximate to said cutting blade portion extending from said housing; and a spring-biased safety guard release connected to an elongated member, said elongated member in communication with an arcuate, flat spring extending from a second end of said safety guard, said spring-biased safety guard release mechanism configured to allow said one end of said safety guard to move into said housing responsive to pressure thereon. 
     In use, when depressed, the safety guard release unlocks the safety guard causing the safety guard, when pressed, along with the cutting blade portion extending from the housing, against an article to be cut, to retract into the housing leaving the cutting blade unguarded. In one embodiment, the safety guard release mechanism is a single operation device meaning that each time the user removes pressure from the cutting blade extending from the housing, the user will need to once again activate the safety guard release mechanism to cause the safety guard to unlock. The single operation design creates an additional layer of safety. 
     Other variations, embodiments and features of the present invention will become evident from the following detailed description, drawings and claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates an inner view of a utility knife housing opened along a longitudinal center-line according to the embodiments of the present invention; 
         FIG. 2  illustrates an inner view of one side of the housing of the utility knife with some components removed according to the embodiments of the present invention; 
         FIG. 3  illustrates an inner view of one side of the housing of the utility knife with all components in position according to the embodiments of the present invention; 
         FIG. 4  illustrates a close-up inner view of one side of the housing of the utility knife showing a safety guard release according to the embodiments of the present invention; 
         FIGS. 5A and 5B  illustrate a safety guard according to the embodiments of the present invention; 
         FIGS. 6A and 6B  illustrates a safety guard release elongated member according to the embodiments of the present invention; 
         FIGS. 7A and 7B  illustrate a safety guard release mechanism according to the embodiments of the present invention; 
         FIGS. 8A through 8C  illustrate operation of the utility knife according to the embodiments of the present invention; and 
         FIG. 9  illustrates a flow chart detailing operation of the utility knife according to the embodiments of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     For the purposes of promoting an understanding of the principles in accordance with the embodiments of the present invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended. Any alterations and further modifications of the inventive feature illustrated herein, and any additional applications of the principles of the invention as illustrated herein, which would normally occur to one skilled in the relevant art and having possession of this disclosure, are to be considered within the scope of the invention claimed. 
     The individual parts of the utility knife may be fabricated of metals, plastics, composites, alloys, polymers and combinations thereof The individual parts of the utility knife may be fabricated using suitable techniques including molding, machining, rapid prototyping, casting and combinations thereof. 
     In broadest terms, the utility knife described herein includes a housing, cutting blade, safety guard having an arcuate, flat spring extending from one end and a safety guard release mechanism.  FIG. 1  shows a utility knife housing  100  cut along its length into two pieces  100 - 1 ,  100 - 2  to reveal the inner components thereof (some in position and others removed to allow all components to be observed). As shown, the utility knife housing  100  is configured to at least partially contain a cutting blade  110 , safety guard  120 , safety guard spring  130 , safety guard release button  140 , safety guard release spring  150 , safety guard elongated member  160 , safety guard release plate  170  and safety guard release pins  180 - 1 ,  180 - 2 .  FIG. 2  shows housing piece  100 - 2  with safety guard spring  130  and safety guard release plate  170  in position. 
       FIGS. 3 and 4  show housing piece  100 - 2  with the safety guard  120 , safety guard spring  130 , safety guard release button  140 , safety guard release spring  150 , safety guard elongated member  160 , plate  170  and safety guard release pins  180 - 1 ,  180 - 2  in position. 
       FIGS. 5A and 5B  show the safety guard  120  according to the embodiments of the present invention. The safety guard  120  comprises a cutting blade guard at one end  120 - 1  and an arcuate, flat spring  125  extending from a second end thereof. One end  127  of the arcuate, flat spring  125  is wider and flatter than the main body of the arcuate, flat spring  125  for reasons set forth below. 
       FIGS. 6A and 6B  show the safety guard release elongated member  160  according to the embodiments of the present invention. The safety guard release elongated member  160  includes two pin openings  162 - 1  and  162 - 2  and a stepped down end  164  having a reduced thickness for reasons set forth below. 
       FIGS. 7A and 7B  illustrate a safety guard release mechanism according to the embodiments of the present invention. The safety guard release mechanism includes a safety guard release button  140 , safety guard release spring  150 , safety guard elongated member  160  and safety guard release pins  180 - 1 ,  180 - 2  which operate collectively to unlock the safety guard  120  during a cutting action. 
     To prevent a user from being cut by the cutting blade  110 , a portion of the safety guard  120  extends from the housing  100  parallel to the cutting blade  110 . In this manner, the safety guard  120  prevents a user from inadvertently contacting the cutting blade  110 . The safety guard  110  is in a default locked or home position unless the safety guard release mechanism is activated using the safety guard release button  140  and pressure is applied to the safety guard  120  via a cutting action. Pressing the safety guard release button  140  unlocks the safety guard  120  such that applying pressure to the one end  120 - 1  of the safety guard  120  allows the exposed portion of the safety guard  120  to move into the housing  100  allowing the portion of the cutting blade  110  extending from the housing  100  to cut an article. 
       FIGS. 8A through 8C  show operation of the utility knife in conjunction with flow chart  200  detailing operation of the utility knife according to the embodiments of the present invention. As shown in  FIG. 8A , once a user presses the safety guard release button  140 , the rotatably connected safety guard elongated member  160  rotates slightly in direction of arrow A about pin  180 - 1  from its home position.  FIGS. 3 and 4  show the home position of the safety guard elongated member  160 . As the safety guard elongated member  160  rotates, the safety guard elongated member  160  forces the arcuate, flat spring  125  to move in a direction of arrow B away from its home position as shown in  FIGS. 3 and 4 . The home position of the arcuate, flat spring  125  is maintained by wall  171  of plate  170  upon which end  127  of arcuate, flat spring  125  rests. As the arcuate, flat spring  125  moves away from its home position against the wall  170 , end  127  encounters and slides up ramp  172  of plate  170  permitting the safety guard  120  to rotate about point  121  (spring  130 ) such that end  120 - 1  of the safety guard  120  moves into the housing  100 . Once the end  127  slides up the ramp, a portion  128  of the arcuate, flat spring  125  elevates such that it may move onto stepped down end  164  of safety guard elongated member  160 . End  127  of safety guard  120  now rests on top of the ramp  172  proximate the wall  171 . In this manner, as soon as pressure is released from the cutting blade  110 , the safety guard  120  returns to its home position even if the safety guard release button  140  is still being pressed. Returning to the home position occurs since stepped down end  164  permits the arcuate, flat spring  125  to slide down the ramp  172  until end  127  once again rests against wall  171  of plate  170 . Spring  130  acts to return the safety guard  120  to its home position once pressure is removed from the cutting device  110 . Once safety guard release button  140  is no longer pressed, spring  150  pushes the safety guard release button  140  to its home position which causes the safety guard elongated member  160  to also move to its home position. 
     Flow chart  200  details the operation of the utility knife  100 . At  205 , the user presses the safety guard release button  140 . At  210 , the safety guard elongated member  160  rotates caused by the connected safety guard release button  140 . At  215 , the rotating safety guard elongated member  140  forces the arcuate, flat spring  125  to move. At  220 , end  127  of the arcuate, flat spring  125  slides up ramp  172  of plate  170 . At  225 , once end  127  is completely up the ramp, a portion of the arcuate, flat spring  125  moves onto stepped down end  164  of safety guard elongated member  160 . At  230 , once pressure is released from the cutting blade  110 , the arcuate, flat spring  125  slides down the ramp  172  until end  127  once again rests against wall  171  of plate  170 . Once a user stops pressing the safety guard release button  140 , spring  150  returns the safety guard release button  140  and the utility knife  100  to its home position. 
     Although the invention has been described in detail with reference to several embodiments, additional variations and modifications exist within the scope and spirit of the invention as described and defined in the following claims.