US1620226A - Scissors - Google Patents

Description

March 8 y Q I M. PARKER SCISSORS Filed Aug. 20, 1921 ATTORNEYS "trouble.

Patented Mar. 8, 1927.

U NIT STAT ES OBGANEABK BQ O EW ORK,

serssons.

Application filed August 20, 1921'.

of scissors is .-expensive and timeeonsuming' and shortens the life of the mstrument.

Moreover, because of this grinding and the continual presentation of anew cutting edge the blade o't-the ordinary scissor-sis made ot'cutlery steeltln'oughout, a construction which is not only XPGIISlVQ, but one-which introduces manufacturing difficulties. The use of-co-mpound blades is old, but in such construction the blade is made of a heavy piece of steel permanently or semipermanently attached to a setter-metal shank. The problem of drop-forging the shank is thereby simplified, but-itstill remainsnecessary to resharpen the blade, and :to grind itwith serrated cuttingedge commonly found in scissors,-particularly barber's shears.-

A- light, cheap blade, readily attached to. and detached from the shank, and so inexpensive that it might be replaced when dulled atless than the cost ot' resharpening, would solve the problem. Such a blade must,

however, be held in tight contact with itsshank to their extreme outerco-term1nus,as

otherwise any space between them would be likely to catch a hair or thread and cause The blademust also be designed tor quick and easypositioning and removal and must nevertheless be securelylocked in position duringuse. Moreover, as the blade must be inexpensive it should'be ground straight. but for-this reason mustbe flexible enough to conform to the curve of the shank.

It'is accordingly the object of this invention to design a pair of scissors having such light. cheap, replaceable blades, readily attachable and detachable and firmly held upon} heir shanks when in use. Themanner in which this is accomplished will be apparent from the following' description and its accompanylng drawings. Although two preferred embodiments of the invention have been shown and described it is obvious that the principles involved are not limited to these specific forms.

In these drawings Fig. 1 is an elevation of a pair of scissors equipped with removable blades in accordance with this invention and shown in Wide open position. Fig. 2 is an enlarged section through the shank taken in line 22 of Fig. 1; Fig. 3 is a similar View taken upon line 3-3 of Fig. 1; Fig. 4 is a fragmentary longitudinal section taken on Serial N0. 493,935.

line 4-4 ot'Fig. 1; Fig. 5 is an elevation of' oneof the shanks with the blade-removed; Fig. 6' is a. view similar to Fig. 1, but;showing. a. modified formof blade; Figs. 7, Sand 9iare enlarged sections taken on line 77, 88 and 9 9 respectively of Fig. 6..

The scissors shown in these views are of the type commonly employed'sbybarbers;but it is. ofcourse, obviousthatthe invention is applicableto scissors andshears of any type.

These scissorsshown :in Fig. 1- are provided with the ordinary shanks l'pivoted together about-a kingpin 2. The inner. face. ofeach shank is provided with a dovetail-strip3 slightly raised above the face. ofithe shank and extending from the tipabofut two thirds to. three-fourths the distance. tothe-pivot, as shown mostclearly in Fig. 5. The-blade 4 is provided witha; corresponding dovetail groove-5 extendingitsentire length- The working 'face of the shank is provided near its inner end withan upstanding projection Ghaving. an inclined facetapering upwardly andito the rear, as-shewnin Fig. 4. The blade isprovided with a corresponding aperture 7 which cooperates withvtheprojection.

6..[0 lock the blade against. longitudinal movement. hen a-bladeisto be positioned upon its shank the scissors are opened to the extcnded position shown: in .Fig. 1 and the blade slipped longitudinallyalon g the shank, the dovetail strip 3 entering'the groove 5 in the blade. lVhen the rear end of the blade encounters the projection .6 :is rides up over it, this flexing movementv beingpermitted because at that point the dovetail stri p 3rhas been cut away. Upon further sliding movement the. aperture 7 coincides withzthe projection .6. and :the. blade snaps into place.

Innthe torm shown in Figs. 6, 7, 8 and 9 a narrower blade is used, which extends for only a part of the width of the shank face, whereas in the foregoing form the blade is coextensive with the working face of the shank. In this form the shank is the female member, being provided with a longitudinal dovetail groove 7, which corresponds with a dovetail strip 8 on the blade, as shown most clearly in Fig. 7. In this form a projection or pin 9 projecting upwardly from the groove 7 near its inner end acts as the locking member and cooperates with an aperture 10 in the blade to prevent longitudinal displacement. In order to permit this locking member to function, which necessitates a flexing of the'blade to ride over it, the undercut of the groove 7 is cut away near its inner end, as shown in Figs. 6 and 8. Thus, for the inner end of the blade the dovetail connection is inoperative, and it is possible for the blade to flex as it rides over the pin 9 into locking position. It would, of course, be possible in this case to remove the overhang from the dovetail portion 8 of the blade, just as in the form shown in the other figures it would be possible to remove the undercut from the blade, but as the blade is the cheaper part and must be made in quantity, all the machine work possible should be done on the permanent shank.

Both forms of blades described above are designed to be positively held in tight contact with their respective thanks from their extreme co-terminus to a point well back along the blade. This prevents any outward springing of the blade near its tip and the opening up of a space which might catch upon a hair or thread. Besides, the dovetailed connection between blade and shank extending to their co-terminus presents a broken line at the tip of the scissors, and hence precludes the possibility 01" a hair or thread slipping between blade and shank. That part of the blade not positively held in contact with the shank is held in position by the mutual opposition of the shanks during ordinary use, and it is only when a blade is to be positioned or removed that the scissors are opened so wide that this mutual opposition is not eifective. The means locking the blade against longitudinal displacement are simple and effective, the operation being dependent upont-he resiliency of the blade itself. This resiliency and flexibility also make it possible for the blade to conform to the transverse curve, so common in scissors. The blade can also adapt itself to a slight twist in the shank. It is a simple matter to position such a blade, and an equally simple matter to remove one when it has become dulled and the necessity for replacing it by a fre h one has arisen.

This invention has been illustrated as ap plied to scissors, and it is in this connection that it will undoubtedly [ind its greatest usefulness. but it is obvious that the same principles involved might be applied. to cut lery of other forms.

I claim:

1. In removable blade scissors, the combination of a shank and a removable flexible blade, dovetail connection between the two along their outer lengths holding the blade in positive contact with the shank, an upstanding projection near the inner end of the shank, a hole in the inner end of the blade designed to cooperate with the pin to lock the blade against longitudinal displacement, the dovetail connection between the shank and the blade being cut away near their inner ends to permit the blade to flex and ride over the pin to locking position.

2. In removable blade scissors, the combination of a shank and a removable flexible blade, sliding connection between the two along their outer lengths holding the blade in positive contact with the shank, an upstaneing projection near the inner end of the shank, a hole in the inner end of the blade designed to cooperate with the pin to lock the blade against longitudinal displacement, the sliding connection between the shank and the blade being cut away near their inner ends to permit the blade to flex and ride over the pin to locking position.

3. In scissors having a removable blade, means for positively holding the blade in contact with its supporting shank throughout the outer length of the blade, contact at the inner end depending upon the normal opposition of the other shank, and cooperating lock members on the shank and the inner end of the blade, the mounting of the blade on the shank being such as to permit flexing of the inner end of the blade toward and away from the shank to engage and disengage the lock members.

4. In scissors having a removable blade, means for positively holding the blade in contact with its supporting shank throughout the outer length f the blade, contact at the inner end. depending upon the normal opposition of the other shank, and automatically operable means locking the blade against longitudinal displacement.

In testimony whereof I aliix my signal are.

lllOliGAN PARKER.

CERTIFICATE OF CORRECTION.

Patent No. 1,620,226; Granted March 8. 1927, to

word "is MORGAN PARKER It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 1, line 90, for the read "it"; page 2, line 100, after the word "displacement" insert a eomma and the words the inner end of the blade being flexible toward and away .from the shank"; and that the said Letters Patent should be read with thesecorrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 26th day of April, A. D. 1927.

a Mr J, Moore, Scale Acting Commissioner of Patents

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