US1152633A - Scissors or shears. - Google Patents

Description

Patented Sept. 7, 1915.

E. HOLTGRAVE.

SCISSORS 0R SHEARS.

APPLICATION FILED Nov.2 1. 1914.-

`nrtNs'r HoIxreeRiwn',A or noo'xniv, ivnw YORK. v l

` SCIsSQRsORsHER-s Specification of Iietters'xlatent.' l Patented Sept. '7, 1915.

Applicatonfled N ov'ejmber 27, 1914; SeriallNo. 874,110.

To all whom t may concern .9 i g l' Be it known that I, ERNST HLTGRAVE, citizen of the United Statesof America, re-

siding at Brooklyn, in the county ofKingsA and State of New York, have invented certain new and useful Improvements in Scissors or Shears, of which theV following is a specification.

The present invention relates to scissors or shears and particularly to an improvement on my former Letters PatentV No. 841,690, issued January 22, 1907, and has for its object to provide means for easily slackening and tightening the scissors or shears without the use of any tools.

My invention will be more fully understood by reference to the accompanying drawing in which similar reference characters denote corresponding parts and in which- Figure 1 is an elevation of my improved shears, the head of the bolt being out off; Fig. 2 is a section on line 2 2 of Fig. 1; Fig. 3 is an enlarged perspective plan view of the middle part of the upper blade showing the cam groove and the notches; Fig. 4 is a perspective bottom view of the member serving for tightening and slackening the scissors and Fig. 5 is a cross section on line 5-5 of Fig. 4.

In my former patent, the device for tightening or slackening the shears consists of a spring member adapted to move on the slanting part of the surface of the upper blade and according to the position of the spring on said surface the blade is more or less pressed against the lower blade. It has been found, however, that the device is not suiiiciently effective, particularly with large shears, first because the spring which has to be made thin so as to permit its easy manipulation by the hand of the user does not exert enough pressure on the blade and yields during the cutting action. Secondly, it aifects one of the blades only. The present invention obviates the above drawback.

a and b denote the two blades which at the point c are joined by a headed screw-bolt d. The screw-bolt is passed through perforations a', b made in the blades and is tightened as usually by` a nutV e. Between the head d of the screw-bolt and the upper blade a a member f is inserted which is in form of a circular disk preferably of sheet metal formed with a radial extension 7' which is bent to extend somewhat beyond the'surface-of the bladen when in operative position and which is formed with a downward'projection or nose f2. Arranged inthe :arc of a circle around the center of the bolt and on the level part a of the surface of the upper blade are a number of notches a? into either of which the nose f2 of the member f is adapted to engage after proper adjustment thereof, so as to lock it in adjusted p0- sition. Projecting from the lower surface of the member f is a wedge-shaped and circularly curved projection f3 which may be formed by stamping the disk-shaped part of the member f, as shown in Fig. 5. Formed in the part a of the upper or outer surface of the blade a is a groove a3 that surrounds the circular hole a and in shape corresponds to the projection f3.

The member f is so disposed relative to the blade a that normally, z'. e. when the shears are slackened, the highest part of the proj ection f3 will engage the deepest part of the groove and as the member is turned around the bolt the projection f3 will gradually rise to the surface of the blade acting thereby as a Wedge between the head el of the screwbolt and the blade a and consequently tighteningthe two blades very effectively. When the member is moved in opposite direction the projection f3 will descend into the deeper part of the groove, relaxing the pressure and slackening the blades. The adjustment of the degree of tightness or slackness between the blades is accomplished by hand by Vsomewhat raising and subsequently turning the finger f of the member f in the desired direction and to the desired extent. On releasing the finger after the proper adjustment has been obtained the nose f2 at the end of the linger will automatically engage the `corresponding notch a2 in the blade a and will lock the member f in the adjusted position. It will be seen that because of the member acting as a wedge directly between the screw-bolt and the upper blade both blades will be equally affected.

While I have described one form of construction of my device, it is understood that the same may be easily modified without departing from the spirit of my invention and I, therefore, do not wish to limit myself to the details described and shown.

WhatI claim and desire to secure by Letters Patent is:

Scissors or shears consisting oftwo blades, a headed bolt joining the said blades together, the blade opposite the head of the bolt having at the forward end of its flat l0 formed in the outer face of the sai-d blade to Secure the member in adjusted position, Substantially as and. for the purpose set forth.

In testimony whereof I aix my signature in presence of two witnesses.

ERNST HOLTGBRAVE..

Witnesses Y E. BURNHAM, D. KLEIN.

Gopies 0f; this patent may' he obtained for vse cents each, by addressingthe Commissioner of Patents,

Washjmgton,IlG.m

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