US 3670733 A
A flat member is incised at an angle of approximately 45 DEG to a straight section of its perimeter, and a narrow portion of the body adjacent to the 45 DEG angle is folded approximately 90 DEG to form a guide. The remaining downwardly extending portion on the other side of the incision is sharpened to form a straight blade which can be ground to a desired length to cut soft materials precisely to exact depths. To maximize safety, a rounded portion is formed rearwardly from the blade region. The blade edge is totally exposed below the plane of the guide, to help promote accuracy. The angle of the blade edge and the slight downward inclination of the unsharpened edge extending rearwardly from the point, allow the device to initiate and sustain a prescribed depth incision with relatively slight downward pressure required on the part of the user.
Description (OCR text may contain errors)
United States Patent Carlisle [4 1 June 20, 1972 54] PRECISE DEPTH CUTTER FOREIGN PATENTS OR APPLICATIONS  Inventor: Richard S. Carlisle, 1051 Broadway, 736,341 9/ 1955 Great Britain ..30/294 Thomwood, N.Y. 10594 Primary Examiner-Channing L. Pace  Filed: Sept. 14, 1970  App1.No.: 71,640 [571 ABSIRACT A flat member is incised at an angle of approximately 45 to a straight section of its perimeter, and a narrow portion of the  U.S. Cl. ..128/305, 30/286, 30/294, body adjacent to the angle is folded approximately to 76,104 R form a guide. The remaining downwardly extending portion  CL 17/32 1326b 29/00 1 on the other side of the incision is sharpened to form a straight  Field of Search ..30/164.9, 286, 294; 1281305, blade which can be ground to a desired length to cu f 128/ 1 6/ 104 R materials precisely to exact depths, To maximize safety, a rounded portion is formed rearwardly from the blade region.  References Cited The blade edge is totally exposed below the plane of the guide, to help promote accuracy. The angle of the blade edge and the UNITED STATES PATENT slight downward inclination of the: unsharpened edge extending rearwardly from the point, allow the device to initiate and 1,328,547 1/1920 Shaw ..30/294 Sustain a prescribed depth incision with relatively slight 1,639,996 8/1927 Groff ..128/305 X downward pressure required on the pan of the user 2,676,595 4/1954 Dyek aer ..128/305 2,706,482 4/1955 Griffitts ..128/314 7 Claims, 4 Drawing Figures IN VEN TOR.
WW4 4 a PRECISE DEPTH CUTTER BACKGROUND OF THE INVENTION 1. Field of the Invention There is provided a cutting device which can initiate and maintain the depth of an incision in soft materials accurately to within two (2) one-thousandths of an inch. Only slight downward pressure is required on the part of the user, as the blade edge and point are established at angles calculated toward this effect.
2. Brief Summary of the Invention In the practice of surgery, most procedures have involved the use of cutting devices which are controlled entirely by the surgeon. Various types and shapes of blades have been developed for specific procedures, but little consideration has been given to controlling the depth attained by a given movement of the knife across the soft tissues involved.
One specific procedure in surgery involves the initial incision through the skin. In this procedure, bacteria from hair follicles and sweat pores are gathered up by the knife blade and deposited along the bottom of the incision. The blade of this invention, in contrast, cuts the skin with an upward force, sweeping the bacteria up toward the surface rather than down into the incision.
In micro-surgery (eye surgery, vascular surgery, neuro-surgery, plastic surgery, etc.), the surgeon must take great pains to control the depth of incisions. The construction of this in vention can provide the exact cutting depth required for a procedure within approximately two-thousandths of an inch. This invention also makes possible prescribed depth scratches for use in skin and allergy research and testing procedures.
In office surgery, the possibility of cutting too deeply for minor procedures, such as lancing boils, removing sutures, etc., is prevented, while a method of simultaneously attaining the optimal depth is provided.
Commercial uses include a safer and more accurate device for biological dissecting kits and snake bite kits. It also serves as a safe and convenient surgical dressing knife.
For home use, the device provides a safe toy knife, sewing thread cutter, and splinter remover. (It removes surface splinters quickly with relatively slight tissue disruption or pain.)
It is accordingly the primary object of this invention to provide a sterilizable and disposable device to cut accurately in depth such materials as soft animal tissue, soft plastics, rubber, and certain paper materials.
The objects, features, and advantages of this invention will become more apparent from the following description and accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a side view of the device, adapted to be afiixable to a surgical knife handle.
FIG. 2 is an end view of the rear portion of the device of FIG. 1.
FIG. 3 is a bottom view of the device of FIG. 1.
FIG. 4 is an adaptation of the device of FIG. I, with an integral vinyl-coated handle. The device is shown in a cutting position in soft material.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS In carrying out a preferred embodiment of the device, flat, spring-tempered stainless steel, of a thickness between twothousandths and thirty-thousandths of an inch, is firststamped into an appropriate pattern or outline. The pattern body is then shear-cut at a point along a straight portion of the perimeter, at an angle of approximately The region on the 45 angle side is bent perpendicularly (or if a greater angle is desired, obtusely) to the plane of the pattern body, forming a guide. The region on the supplementary angle side remains in the plane of the pattern body, and the shear-cut edge, downwardly extending, becomes the blade.
FIG. 1 shows that a straight region 14 along the body perimeter is shaped to form an angle, indicated at 16, of 10 relative to guide 12. This angle is essential for initiatingentry of the blade point .18 into flat, smooth material. The angle of the blade 13 to the plane of the guide 12 will be approximately 45. The point angle 17 will therefore be approximately 35. A region 21 of the perimeter is shown to be slightly curved. This curved region, in advance of guide 12, helps the device toslide freely over soft materials. Slot 1 1 provides a means for affixing the device to a surgical knife handle.
A rear rounded portion 20 is formed to provide assurance that no unintentional cutting or damage occurs, while placing the device into, or removing it from an operating position, or while it is in use, either to the user or to the material on which it is being used.
FIG. 2 shows the location of the guide 12 relative to the plane of the body of the device 10.
FIG. 3 shows the blade point 18 relative to the plane of the guide 12. The forward portion of the guide 12 is shown to be at an angle, indicated at 19, of approximately 30. This relatively small angle is an additional feature in allowing the device to slide freely over soft material.
FIG. 4 shows an adaptation of the device with an integral abbreviated handle coated with vinyl plastic 22. The handle is designed so that the device can be pulled along a soft material 23, maintaining the continuance of an incising process with negligible downward pressure required on the part of the user. It is small enough to be concealable in the hand of the user, at times when this is appropriate, such as lancing a boil in a child patient.
1. A device for use in incising a prescribed depth into soft material upon a movement of said device across the surface of the material, comprising a thin, flat main body portion, an extending blade portion substantially in the plane of the main body, and'having a bladeedge disposed at an acute angle to the plane of an adjacent guide portion carried by the main body and disposed approximately perpendicularly to the plane of the main body portion, the blade edge protruding outwardly from the main body portion past the plane of said guide portion, the guide portion extending on both sides of an imaginary plane intersecting the blade edge at an intermediate region thereof and extending perpendicularly to the plane of the guide portion so as to support soft material directly opposite the material being incised, said guide portion terminating in an edge forming an acute of the guide portion adjacent the blade edge, the blade'edge ending at a point formed with an unsharpened substantially straight, edge in a plane which diverges from the blade end at an acute angle less than the angle formed by the blade edge and the plane of the guide.
2. A device as set forth in claim 1 wherein the outer perimeter of said guide portion forms an angle of less than 60 to the plane of said main body portion at the juncture of the end of the guide portion remote from its juncture with the blade portion, and the main body.
3. A device as set forth in claim 1 wherein a short region of the perimeter of said main body portion beginning at the juncture between the end of the guide portion remote from its juncture with the blade portion, and the main body, curves outwardly.
4. A device as set forth in claim I wherein said unsharpened substantially straight edge is disposed at an angle of approximately 10 to the plane of said guide portion, and extends to a juncture with a rounded tail portion which is substantially in the plane of the main body.
5, A device as set forth in claim 1 wherein, an abbreviated handle portion is formed as part of the main body, such that the device may be substantially concealed from view when held in the hand of the user in an operating position.
6. A device as set forth in claim 5 wherein, said handle portion is coated with a material suitable for gripping with the finger tips.
7. A method of making a device for incising a precise depth into soft material including the steps of:
I a. Stamping out a suitable pattern of sheet metal to form the main body of the device including a perimeter having a straight portion,
b. making a shear cut at an acute angle to the straight portion of the perimeter and folding at an angle of at least 80 5 to the plane of the pattern an edge region of the pattern adjacent to the acute angle side of the shear cut.
H Patent 3, 670, 733 June 20,1972
Dated Richard S. Carlisle Inventor(s) It is certified that error appears in the above-identified patent and that said Letters Patentare hereby corrected as shown below:
Page 1, claim 1, line 47; insert after- "acute" angle with the plane of the main body portion at the side Signed and sealed this 17th day of April 1975;
EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attestlng Officer Commissioner of Patents FORM PO-IOSO (1069) USCOMM-DC 60376-P69 U.S. GOVERNMENT PRINTING OFFICE l9 0-355-334.