Abstract:
The present invention is a mechanically assisted scissors that enhances user comfort, ease of use, and safety. The scissors includes first and second scissor members that have first and second blades and first and second handles, respectively. The scissors has a biasing means enclosed within a chamber, and a locking mechanism.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application is related to and claims the benefit of U.S. Provisional Application Ser. No. 60/734,488 on Nov. 8, 2005, the contents of which are incorporated herein by reference thereto. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     The present invention relates to shears and scissors, in particular, scissors that are mechanically assisted for easier use.  
         [0003]     Shears and scissors that are biased to an open position are known in the art. Biasing eliminates the need for the user to manually separate the blades after completing a cutting action. Many such biased, or mechanically assisted, shears employ a spring means for biasing the tool to an open position. The mechanical assistance offered by such spring-biased scissors often removes the need for finger and thumb loops in the scissors, which loops are helpful in manually separating the blades of conventional scissors that lack a biasing means. Spring-biased shears may be actuated simply by gripping the two handles to overcome the force of the biasing means, or by applying pressure from the thumb against one handle, while holding the other handle in the palm and fingers. For certain users, such as those suffering from arthritis or other lack of strength or dexterity in the fingers, using a grip-actuated mechanically assisted scissors is easier than using conventional, non-biased scissors with finger and thumb loops.  
         [0004]     In spite of these advantages, mechanically assisted scissors of the prior art present certain problems. One such problem is that these scissors often contain exposed metal springs, creating a danger of user injury through pinching by the spring. The designs in the prior art also expose the spring to air, moisture, and water, increasing the risk of corrosion and shortening the tool&#39;s useful life. A further problem with the designs of spring-biased scissors in the prior art is that these scissors, often lacking finger loops, may easily slip from the user&#39;s hand, creating a risk of injury to the user or damage to the tool. Other problems with the biased scissors of the prior art include discomfort for, and poor control by, the user because of poorly shaped or textured handles. Accordingly, there is a need for a mechanically assisted scissors that does not have an exposed biasing means that protects the user from risk of injury, that reduces the risk of damage to the tool by dropping, and that increases comfort of use.  
       SUMMARY OF THE INVENTION  
       [0005]     The mechanically assisted scissors of the present invention encloses a biasing means by providing a chamber around the pivot of the scissors in which the biasing means is positioned.  
         [0006]     The present invention may have ergonomically curved and textured handles to enhance user comfort and ease of use.  
         [0007]     The scissors of the present invention has a first scissor member that has a top handle and a first blade, and a second scissor member that has a bottom handle and a second blade. A pivot assembly pivotally connects the first scissor member to the second scissor member. The first scissor member has a first cavity, and the second scissor member has a corresponding second cavity. When the scissor members are pivotally connected, the first and second cavities are opposed to one another and align with one another, forming a chamber. This chamber houses a biasing means, for biasing said first scissor member and said second scissor member to an open position.  
         [0008]     The handles of the first and second scissor members may be angularly offset in relation to the blades of the first and second scissor members. The scissors can have a finger guard that extends from the bottom handle, and the scissors also may have a tether.  
         [0009]     In another embodiment, the present invention includes a scissors comprising a first scissor member comprising a top handle, a first cavity, and a first blade having a first inner surface. A second scissor member is also included comprising a bottom handle, a second cavity, and a second blade having a second inner surface. A pivot assembly connects the first scissor member and the second scissor member, whereby the first inner surface and the second inner surface are oriented to face one another, thereby aligning the first and second cavities with one another to form a chamber around the pivot assembly when the first and second scissor members are pivotally connected. A biasing means is located within the chamber for biasing the first scissor member and the second scissor member to an open position. An open angle limiter is peripheral to the chamber. Also included is a locking mechanism for restricting the first scissor member and the second scissor member to a closed position.  
         [0010]     In another embodiment, the present invention includes a scissors comprising a first and second scissor member. The first scissor member comprises a top handle and a first blade having a first inner surface. The first blade extends forward of the top handle and ends at a first distal end. The top handle extends rearwardly of the first blade and ends at a first proximate end. The top handle may be slightly curved, and the top handle may have a rigid base material and a resilient grip material. The second scissor member comprises a bottom handle and a second blade having a second inner surface. The second blade extends forward of the bottom handle and ends at a second distal end. The bottom handle extends rearwardly of the second blade and ends at a second proximate end. The bottom handle may be slightly curved, may have a finger guard, may have a rigid base material and a resilient grip material, wherein the grip material is ribbed. Also included is a pivot assembly, which connects the first scissor member and the second scissor member, whereby the first inner surface and the second inner surface are oriented to face one another. The first scissor member and the second scissor member are pivotable between an open position, wherein the first and second blades are oriented transversely to one another and a closed position, wherein the first and second blades are oriented approximately parallel to one another. The first scissor member has a first cavity and the second scissor member has a second cavity, whereby the first and second cavities are opposed to one another and aligned with one another when the first and second scissor members are pivotally connected to form a chamber around the means for pivotally connecting the first and second scissor members. Also included is a biasing means within the chamber for biasing the first scissor member and the second scissor member to an open position. An open angle limiter peripheral to the chamber also is included. A locking mechanism is also included for restricting the first scissor member and the second scissor member to a closed position. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]     Preferred embodiments of the invention are described below with reference to the following figures, which are provided for illustrative purposes only. The figures illustrate a best mode presently contemplated for carrying out the invention.  
         [0012]      FIG. 1  is a perspective view of one embodiment of the scissors of the present invention in a closed position.  
         [0013]      FIG. 2  is a left elevational view of the scissors of  FIG. 1  in a closed position.  
         [0014]      FIG. 3  is a right elevational view of the scissors of  FIG. 1  in a closed position.  
         [0015]      FIG. 4  is a left elevational view of the scissors of  FIG. 1  in an open position.  
         [0016]      FIG. 5  is an exploded perspective view of the scissors of  FIG. 1 .  
         [0017]      FIG. 6  is a right elevational view of the first scissor member of the scissors of  FIG. 1 .  
         [0018]      FIG. 7  is a left elevational view of the second scissor member of the scissors of  FIG. 1 .  
         [0019]      FIG. 8  is a cross-sectional view of the scissors of  FIG. 1  along line  8 - 8  shown in  FIG. 2 .  
         [0020]      FIG. 9  is a perspective view of another embodiment of the scissors of the present invention in a closed position.  
         [0021]      FIG. 10  is a left elevational view of the scissors of  FIG. 9 . 
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0022]      FIGS. 1-7  show an exemplary embodiment of a scissor assembly  10  according to the present invention. The scissor assembly  10  has a first scissor member  20 . The first scissor member  20  has a first blade  22  and a top handle  24 . The first blade  22  has a first inner surface  23 . As shown in  FIGS. 6 and 7 , the first blade  22  extends forwardly of the top handle  24  and ends at a first distal end  27 . The top handle  24  extends rearwardly of the first blade  22  and ends at a first proximate end  29 . The first scissor member  20  may have a rigid base material  40 , for example, metal or an appropriate engineering material, such as acetyl resin, acrylic resin, nylon, polyethylene, or acrylonitrile-butadiene-styrene (ABS) resin, more preferably ABS resin. For ergonomic reasons, the first scissor member  20  also may have a resilient and/or flexible grip material  42 , for example, an elastomer, preferably thermoplastic elastomer (TPE). Ergonomics and user comfort may be enhanced if the top handle  24  is slightly curved, as shown in the embodiment of  FIGS. 1-4 . The first scissor member  20  has a locking switch  102 , shown in  FIG. 5 , used to secure the scissors assembly  10  in a closed position, as shown.  
         [0023]     The scissor assembly  10  also has a second scissor member  30 . The second scissor member  30  has a second blade  32  and a bottom handle  34 . The second blade  32  has a second inner surface  33 . As shown in  FIGS. 6 and 7 , the second blade  32  extends forwardly of the bottom handle  34  and ends at a second distal end  37 . The bottom handle  34  extends rearwardly of the second blade  32  and ends at a second proximate end  39 . The second scissor member  30  may have a rigid base material  40 , for example, metal or an appropriate engineering material, such as acetyl resin, acrylic resin, nylon, polyethylene, or ABS resin, more preferably ABS resin. For ergonomic reasons, the second scissor member  30  also may have a resilient and/or flexible grip material  42 , for example, an elastomer, preferably TPE. Ergonomics and user comfort may be further enhanced if the bottom handle  34  is slightly curved and the grip material  42  is ribbed, as shown in the embodiment of  FIGS. 1-4 . In the embodiment shown in  FIGS. 1-7 , the second scissor member  30  has a finger guard  36  formed integrally with the second handle  34 .  
         [0024]     The handles  24 ,  34  may be formed by overmolding the flexible grip material  42  over the rigid base material  40  through any suitable process such as injection molding. The handles  24 ,  34  also may be ribbed, as shown in the bottom handle  34  of the embodiment of  FIGS. 2 and 3 . Scissors with handle overmolding and ribbing are known in the art, such as disclosed in pending U.S. patent application Ser. No. 11/231,303, which is incorporated herein by reference.  
         [0025]     A coating  25  may be disposed on the first blade  22  and second blade  32  to enhance hardness, durability, or resistance to corrosion, or to provide an aesthetically acceptable appearance. Suitable coatings may include titanium nitride, chromium nitride, or a combination of titanium nitride and chromium nitride. Suitable coatings are known in the art, such as disclosed in U.S. patent application Ser. No. 10/720,578, U.S. patent application Ser. No. 11/231,259, and U.S. patent application Ser. No. 11/231,151, which are incorporated herein by reference.  
         [0026]     Referring now to the embodiment in  FIG. 5 , the first scissor member  20  and second scissor member  30  are connected at a pivot assembly (not shown). The pivot assembly may be any suitable structure, such as a screw and a post, a rivet, or a nut-and-bolt assembly. As shown in  FIG. 5 , the pivotal assembly comprises a post  62  in the first scissor member  20 , an aperture  64  in the second scissor member  30 , a metal washer  66 , a plastic washer  68 , and a screw  70 . The two scissor members  20 ,  30  are pivotally connected by the screw  70 , driven through the washers  66 ,  68  and the aperture  64  in the second scissor member  30 , and into the post  62  of the first scissor member  20 . The screw  70  has a head  72  which may be concealed by a cover  74 . The washers  66 ,  68  and screw head  72  are received within a recess  79  in the second scissor member  30 . The metal washer  66  may have a notch  76  that secures to a corresponding nub  78  on recess  79  of the second scissor member  30 .  
         [0027]     As shown in  FIGS. 2-3  and  FIGS. 6-7 , the top handle  24  and bottom handle  34  may be angularly offset from the first and second blades  22 ,  32 . The angular offset enhances ease of use of the scissors assembly  10 , as it allows the blades  22 ,  32  to be positioned roughly parallel to a cutting surface (not shown) without requiring a user to grip the handles  24 ,  34  in the same parallel position. Alternately, as in the embodiment shown in  FIGS. 9 and 10 , the top handle  24  and bottom handle  34  may be substantially parallel to the first and second blades  22 ,  32 .  
         [0028]     Referring again to the embodiment of  FIG. 6 , the first scissor member  20  has a first cavity  80  around the post  62 . In  FIG. 7 , it can be seen that the second scissor member  30  has a corresponding second cavity  82  around the aperture  64 . The cavities  80 ,  82  are generally symmetrical, and align with one another to form a chamber (not shown). The chamber houses a biasing means such as a torsion spring  84 , as shown in  FIG. 5 . A first end (not shown) of the torsion spring  84  terminates within the first cavity  80 , and a second end  88  of the torsion spring  84  terminates within the second cavity  82 . The force of the torsion spring  84  biases the scissor assembly  10  into an open position, as shown in  FIG. 4 . The chamber may be substantially watertight, such as by application of a sealant (not shown) near the chamber formed by the first and second scissor members  20 ,  30 .  
         [0029]     The embodiments of  FIGS. 6 and 7  further show that the scissor assembly  10  may have an open angle limiter (not shown) comprising an arcuate recess  90  in the second scissor assembly  30  which receives a corresponding peg  92  extending from the first scissor assembly  20 . The arcuate recess  90  has a first end  91  and a second end  93 . The force of the torsion spring  84  forces the peg  92  to the first end  91  of the arcuate recess  90 , at which point the angle between the open first and second blades  22 ,  32  is limited by the length of the arcuate recess  90 . As a user applies opposing forces to the top and bottom handles  24 ,  34 , the peg  92  travels toward the second end  93  of the arcuate recess  90 .  
         [0030]     As shown in  FIGS. 5 and 8 , the scissors assembly  10  has a locking mechanism (not shown). As seen in the embodiment of  FIG. 5 , the locking mechanism may comprise a fin  100  integrally formed with and extending from the bottom handle  34 , and a locking switch  102 , which extends through an aperture  104  in the top handle  24 . The locking switch  102  has a button  106  that is wider than the aperture  104 , and a tang  108  that is narrower than the aperture  104 . The locking switch  102  also has a first side support  110  and a second side support  112 , which have a first flange  115  and a second flange  117 , allowing the switch  102  to be snap-fitted into the aperture  104 . The fin  100  has a first catch  114  and the tang  108  has a second catch  116 . The first and second catches  114 ,  116  are opposed to one another. When the scissors assembly  10  is in a closed position, a user may apply pressure to the button  106  to slidably move the locking switch  102  from an unlocked position (not shown) to a locked position as shown in  FIG. 8 . In the locked position, the first and second catches  114 ,  116  engage one another to prevent the force of the torsion spring  84  from biasing the scissors assembly  10  in to an open position as in  FIG. 4 .  
         [0031]      FIGS. 2-5  show an exemplary embodiment of the invention wherein the second scissor member  30  has a tether receiver  122  to which may be attached a tether (not shown), and the first scissor member  20  has a corresponding recess  124 , as shown in  FIG. 4 . The tether, such as a lanyard or a string, allows for convenient location, safekeeping and storage of the scissors assembly  10  by a user. In an alternate embodiment (not shown), the first scissor member  20  may have the tether receiver  122 , and the second scissor member  30  may have the recess  124 . In the embodiment shown in  FIGS. 2-5 , the tether receiver  122  also serves to limit the closed angle of the blades  22 ,  32  by ensuring that in a closed position, the recess  124  of the top handle  24  contacts the tether receiver  122  of the bottom handle  24  at a position that corresponds to the blades  22 ,  32  being substantially parallel.  
         [0032]     In general, while the present invention has been shown and described in terms of preferred embodiments, it is recognized that equivalents, alternatives, and modifications aside form those expressly stated are possible and within the scope of the invention.