US2660788A - Scissors with removable blade sections - Google Patents

Description

Dec. 1, 1953 M. L. COBB 2,660,788

SCISSORS WITH REMOVABLE BLADE SECTIONS Filed Aug. 10. 1950 Patented Dec. 1, 1953 SCISVSORSVVWITH REMOVABLE SECTIONS oFF cE BLADE Milton L. Cobb, Kansas City, Mb. v Application August 10, 1950, Serial No. 178,635

, 1 Claim. (Cl. 30-349) This invention relates to scissors, shears and similar cutting devices and more particularlyto removable or replaceable shank inserts or cutting blades therefor.

It is well recognized that one of the major inconveniences to which a worker who constantly uses scissors has to contend with is the problem of maintaining a sharp, keen cutting edge on the instrument in order to perform the best work. The barber must continually maintain these instruments sharp in order to obtain proper performance and give customer satisfaction; this handicap is also presented the surgeon who, in addition, is faced with the problem of sanitation of his surgical scissors.

It is, therefore, the most important object of this invention to present interchangeable cutting blades adapted to be mounted on the shanks of scissors and the like for easy and quick removal without damage to the latter.

Another important object of the present invention is to provide cutting blade inserts adapted to be mounted on scissor shanks that are economical to manufacture. a

..An important object of the invention hereof is to provide cutting blades that are sufficiently inexpensive to permit disposal thereof once they lost their cutting edge or have become contaminated. a

More minor objects of the present invention will'be made clear or become apparent as the following specification progresses, reference being had to the accompanying drawing, wherein:

Fig. 1 is a plan view of a pairof scissors; with the blades hereof in place. V

Fig. 2 is an exploded elevational view of the blade per se and securing means therefor.

Fig. 3 is anelevational view of one cutting unit, parts being broken away and in section to show details of construction.

Fig. 4 is an elevational view of the opposite side of said unit parts being in section for clearness.

Fig. 5 is a cross sectional View taken on line VV of Fig. 3.

Fig. 6 is a cross sectional viewltakenon line VI--VI of Fig. 4, and

Fig. 7 is a greatly enlarged cross-sectional view, similar to that of Fig. 6, and taken on line VI-VI of Fig. 4.

The scissors shown in the accompanying drawings are of the type usually employed by barber's, but the invention is obviously applicable to scissors, shears, or cutting implements of any type. These scissors broadly designated by the numeral l0 comprise handle members l2 and I4 swing- 2 ably interconnected attheir point of crossing by a pivot pin |6., The handle I 2 includes a projecting curved finger piece [8 extending from its looped end .20 and-the handle l4 terminates in a finger loop 22.

Extending from pivot i6 of the handle members l2 and I4 in opposed relationship to loops 26 and 22 are integral shank portions 24 and 26 respectively. These shanks 24 and 26 areof the usual beveled (in-substantially triangular crossseotion as is clearly seen in Figs. 5 and -6, but are not sharpened along their innermost edges i233 and 36 as is ordinarilythe case. 'In the con struction shown, the shanks 24 and 26 are gradually tapered longitudinally to their free pointed ends 32 and 34. The handles I2 and I4 and shanks 24 and 26 above mentioned, are preferably made of a good grade steel and may-be case hardened inorder to withstand long usage and wear, with the result'that at no time will there be any deleterious eflects resulting from the changing of the blades hereof.

' The inside faces 36' and 38 of shanks 24 and 26 respectively are slightly concave-in cross-section or set in order that the cutting edges of the replaceable blades may be brought together in a shearing. action without the unnecessary fric-. tion andjamming that usually occursv with the face-.to-face engagement scissors.

Disposed in each shank 24 and 26 along the innermost edge 28 and 30 thereof, is a longitudi-.. nal groove 40 that is preferably rectangular in cross-section. This groove 40 extends from points 32 or 3.4, as the case may be, toward handles l2 and I4, but preferablynot beyond pivot l6. A number of recesses 42 at the bottom of groove 40, each communicate with an openingl46 extending to the center longitudinal edge of shank 24 or 26..

The openings 46 are countersunkas at 54 to receive the headsof machine screws 58 to present smooth surfaces free from sharp edges that would otherwise snag or cut the operator or other persons. It isnotablethat only two recesses 42' and machine screws58 are shown for each shank;

24 and 26, but any number may be employed. depending on the length of the shank and the blade to be inserted therein.

The shanks 24 and 26 are each adapted to receive an elongated, complemental blade 66 that is seated in the grooves 40 with cutting edges 12 thereof projecting beyond the shank edges 28 and 30. Recesses 42 are formed to seat corresponding lugs 62 integral with blade 66 and provided with elongated notches 68 having threads of. the shanks of many.

. 3 in the sides thereof to receive machine screws 58. Blade 66 comprises a relatively thin, elongated strip of metal having a beveled longitudinal edge terminating in the keen cutting edge 12. Also, blade 66 is beveled on one end to present a point 16.

The major portion of blade 66 is confined within groove 40, to the end that it will be well supported, rigidly held in place by screws 58' and free from vibration when placed in operation. Also, it

is notable that beveled point 16 of blade 66 extends beyond the corresponding points 32 and 34 of shanks 24 and 26.

When blade 66 has to be changed for any one of a number of reasons, all that is necessary is to loosen screws 58, lift blade 66 out of groove 40. and replace the same with a new, sharp and sanitary blade. When screws 58 are then threaded into lugs 62 of the new blade 66, tightening of the screws 58 will cause the blade to become fully seated within the longitudinal groove 40. When the blade 66 is thus seated in the groove 40 the cutting edge 12 will coincide with and lie in an elongation of the surface of curvature of the face 36 or 38 of the shank 24 or 26 respectively. By virtue of this curvilinear alignment of the cutting edge I2 and the face 36 and 38;, the new blade 66 is thus coordinated with the contour of the shank 24' or 26.

In addition to causing the correct positioning of edge 12 of blade 66, the latter and lugs 62 are seated tightly and complementally in groove 40 and recesses 42 respectively, so as to present a strong and sturdy mounting. The blade 66 is not likely to become loose or displaced; and both the shanks of the implement, as well as the blades 66, are reinforced by the interlocking fit.

No damage can occur to the shanks 24 and 26 by the replacement of blades 66, since the screws 58 are threaded into lugs 62, only. Openings 46 receive screws 58 without threaded engagement between screws 58 and the shanks 24 and 26, the scissors being useable, therefore, for an indefinite period of time through use of disposable blades 66.

It to be noted in Figs. and 6 particularly that the blade 66, and the groove 40 therefor are at an angle to the axis 90 of the corresponding shank 24 or 26, that is, the axis 92 of. the groove slopes toward the convex faces 36 and 38 respectively. The recesses 42 are aligned with the transverse axis 90 of the shank. The outer wall of groove 40, terminating in edge 30, extends farther along the transverse axis 98 of the shanks 24 and 26 than does the inner wall of the groove,

terminating in edge 28, so that edge 28 is spaced farther from cutting edge 12 than is edge 30. This construction maintains the edge 12 wholly outside an extension of the concave face of the shank, so that only the edges 12 interengage during use of the scissors.

As blade 66 is inserted into the groove 40, the lugs 62' are positioned into the recesses 42 by the screws 58, so that the lugs 62 are in alignment with the shanks 24 and '26, and the blade '66 is held in the position illustrated in Figures 6 and '1.

It is noted that the inner end of blade 66 is rounded as at as a protection against injury during use. Also, to assure that the faces 36 do not interengage, a washer-like boss 8| on pin l6, preferably integral with the inner face of either or both of the shanks 24 and 26, is provided.

It is apparent that many details of construction, differing from the single modification herein illustrated, may be utilized without departing from the spirit of this invention as defined by the scope of the appended claim.

Having thus described the invention, what is claimed as. new and desired to be secured by Letters Patent is:

in a cutting instrument, an elongated shank having a transversely concave innermost face and a transversely convex outermost face, said faces converging as one longitudinal edge of the shank is approached, there being a longitudinal groove in said one edge of the shank, said groove being substantially rectangular shaped in crosssection and presenting a bottom wall and a pair of opposed side walls sloping toward said convex face at an angle to the transverse axis of the shank, said bottom wall being provided with a number of polygonal recesses, the shank having an opening therein for each recess extending from the latter to the opposite longitudinal edge of the shank, said openingsbeing disposed on said transverse axis of the shank whereby the same are at an angle relative to said side walls; an elongated cutting blade complemental with said groove and seated tightly therein; a lug on the innermost longitudinal edge of said blade for each recess respectively, the lugs being complemental with the recesses and being seated tightly therein, each lug having a laterally elongated notch aligned with a corresponding opening and provided with threads in the sides thereof, the opposite longitudinal edge of the blade being transversely bevelled, presenting a longitudinal cutting edge adjacent the concave face of the shank and spaced therefrom; and a screw for each lug within each of said openings and notches for drawing the blade into the groove, whereby to position the cutting edge of the blade in conformity with the transverse curvature of said concave face.

MILTON L. COBB.

References Cited in the file of this patent UNITED STATES PATENTS I France Jan. 14, 1885

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