Surgery – Instruments – Cutting – puncturing or piercing
Reexamination Certificate
1998-09-29
2001-01-23
Dawson, Glenn K. (Department: 3761)
Surgery
Instruments
Cutting, puncturing or piercing
C606S167000, C030S194000
Reexamination Certificate
active
06176866
ABSTRACT:
BACKGROUND OF THE INVENTION
In the scissor art, it is necessary to maintain the blades in contact with one another so that a clean cut can be made. This applies to surgical scissors and conventional scissors as well. Over a period of time the blades may become loose at the hinge point causing the blade surfaces to disengage and cause a ragged or incomplete cut. Another problem develops when the blades become warped and contact between the opposing surfaces for cutting is uneven. Finally, the blades themselves become dull and ineffective after use. This dullness may be remedied periodically by having the scissors sharpened but there is a cost involved and the scissors are out of service during the interval. More importantly, dull blades can be dangerous and fail to perform the expected task which is to provide a precise clean cut.
The prior art includes U.S. Pat. No. 5,320,636 to Slater on endoscopic scissors with cammed surface end effectors; U.S. Pat. No. 5,314,440 on a microsurgical scissor apparatus; and, U.S. Pat. No. 5,395.386 to Slater on endoscopic pericardial scissors.
Special use surgical scissors are disclosed in U.S. Pat. Nos. 5,275,607; 5,219,354; 5,591,173; 5,002,554; 5,346,500; and, 5,275,607.
Bipolar electrical scissors are shown in U.S. Pat. Nos. 5,658,281; 5,514,134; 5,540,685; and, 5,569,243.
Other patents of general interest include U.S. Pat. Nos. 5,531,755; 5,569,298; 5,556,407; and, 5,583,845. None of the foregoing patents discloses the unique scissors proposed in this application.
In addition to the patents cited above, the prior art is the conventional scissor and variations thereof. Applicant has invented a new and improved scissor called the EVERCUTT™ which maintains the blades in contact and provides a strong torque to facilitate cutting. A spring and mobile blade assembly maintains the mobile and stationary blades in contact so that the edges provide a clean shearing cut. Furthermore, the spring urged mobile blade includes a twisted edge which facilitates contact with the edge of the opposing blade and minimizes the need for sharpening.
In addition, the continuous contact of the blades at the cutting edge renders the scissors ambidextrous since they function equally well whether operated by a left handed or right handed person. It is not believed that similar scissors exist having the unique design and advantages stated herein.
SUMMARY OF THE INVENTION
This invention relates to scissors and particularly to a new and improved scissors wherein a mobile spring blade is maintained in constant contact with a rigid blade for cutting purposes.
A scissor comprises a rigid blade with a fixed shape and an adjustable spring blade both pinned securely together at the end of the blade portions. The blades also comprise elongated leg portions extending outwardly from the junction of the blade portions and terminating in curved finger loops or a manipulating handle. The adjustable spring blade comprises a blade with spring like properties of the cutting edge which is continuously maintained in rotation around the fixed axis of the non-cutting edge of said rigid blade. When the scissors are open, the line of the cutting edge of the spring blade penetrates the plane of the opposing blade. This penetration stops when the scissors are closed.
In said embodiment, the rotation of the spring blade cutting edge may be clockwise or counter-clockwise but is always directed towards the sharp edge of the opposing blade of the scissors and thus continuously engages the sharp edge of the opposing blade at the cutting point. Furthermore, the fixed axis of the non-cutting edge of the spring blade and the cutting edge of the stationary blade cross each other during use forming a variable angle. When the scissor is closed, the axis of the non-cutting edge of the spring blade is parallel to the axis of the non-cutting edge of the rigid blade. The cutting edge of the spring blade penetrates the plane formed by these axes so that when the scissors are activated, the cutting edge of the rigid blade and the cutting edge of the spring blade come into contact at only one point. With the scissors open, a certain point of the base of the cutting edge of each blade is in contact with a corresponding point of the base of the other cutting edge. The tip of the cutting edge of the spring blade lies beyond the plane formed by the axis of the cutting and non-cutting edges of the fixed blade and the axis of the non-cutting edge of the spring blade as the scissors are closed. The previous point of contact of the sharp edge of the spring blades moves away from the plane so that the line of the cutting edge of the spring blade ceases to penetrate the plane of the stationary blade when the scissors are in a closed position.
In an alternate embodiment, the scissors comprise a first conventional limb having a blade cutting portion at one end and an intermediate lever portion terminating in a finger loop. The cooperating limb with the mobile blade is hinged to the first blade at a point between the blade and the lever portion. The mobile blade is mounted to a spring and frame at one end which are attached to a lever portion of the limb terminating in a finger loop. In one embodiment, the mobile blade may be detachable from the aforementioned assembly.
The spring urges the mobile blade into constant contact under pressure with the stationary blade for cutting purposes. The mobile blade portion has a slight twist at its edge to effectuate the improved blade contact which is limited to the cutting edge only. Not only does this design result in an optimum cut with a higher torque, but the blades rarely need sharpening. The scissors are particularly useful in conventional and laparoscopic surgery and in any situation when a clean precise cut is needed.
A further embodiment involves the use of two opposing spring blades which bring additional pressure to bear at the cutting edge.
Accordingly, it is an object of this invention to provide a new and improved scissors having a spring blade.
Another object of this invention is to provide a new and improved surgical scissor having a rigid blade and a cooperating spring blade which penetrates the plane of the rigid blade when open to provide a continuous variable cutting point as the scissors is closed.
Another object of this invention is to provide a new and improved scissors wherein a spring blade is twisted at its edge to maintain engagement with the opposing rigid blade during cutting.
A further object of this invention is to provide a new and improved scissors wherein one of the cutting blades is engaged by spring means to maintain contact with the opposing blade.
A still further object of this invention is to provide a new an improved surgical scissors having a pair of adjustable spring blades which cooperate at a cutting point as the blades are closed.
Another object of this invention is to provide a new and improved scissors with ambidextrous qualities which produces a reliable and predictable cut.
A more specific object of this invention is to provide a new and improved scissors having a conventional blade engaged by a mobile blade having a twisted spring urged edge to maintain pressured contact with the conventional blade for superior cutting.
REFERENCES:
patent: 714087 (1902-11-01), Woods
patent: 874847 (1907-12-01), Hulse
patent: 3052026 (1962-09-01), Muller
patent: 5314440 (1994-05-01), Shapiro
Dawson Glenn K.
Joel, ESQ Richard A.
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