US1315435A - Planoqraph co - Google Patents

Description

N; B. THOMPSON.

SHEARS 0R SCISSORS.

APPLICATION FILED JJULY 1. I916.

Patented Sept. 9,1919.

B y/ NVEN WITNESSES A'FI'OR NEY run COLUMBIA PLANOGRAI'I! cm, WASHINGTON, o. c.

NOAH B. THOMPSON, 0F MARYVILLE, MISSOURI.

- SHEARS OR SGISSORS.

Specification of Letters Patent.

Patented Sept. 9, 1919.

Application filed July 7, 1916. Serial No. 107,998.

To all whom it may concern:

Be it known that I, NOAI-I B. THOMPSON, a citizen of the United States, residing at Maryville, in the county of Nodaway and State of Missouri, have invented anew and useful Shears or Scissors, of which the following is a specification.

This invention relates to shears or scissors.

The object is to provide pivotal means for the blades of shears or scissors which will cause the said blades, when open, to pass each other at the cutting point with increased shear-cutting effect, when pressure is exerted by the hand of the operator.

Another object is to provide a pair of shears o1- scissors having means for pivoting the blades thereof in a manner to permit of quickly and easily increasing or decreasing the tension between the same, and which may be readily removed from the blades to permit of grinding or otherwise treating the separated blades.

The objects sought are. attained, in the present instance, without the use of slots or levers, thus eliminating all undue friction and producing the desired results in a simple and inexpensive manner to be hereinafter more fully described.

A full and complete understanding of the invention may be obtained from a consideration of the following detailed description, taken in connection with the accompanying drawing forming a part of this specification, it being understood that while the drawing shows a practical form of the invention, the latter is not confined to strict conformity therewith, but may be changed or modified, so long as such changes or modifications mark no material departure from the salient features of the invention, as specifically pointed out in the claim appended hereto.

In the drawing, in which like reference characters designate similar parts throughout the several figures Figure 1 is a side elevation of a pair of shears or scissors having the improved pivotal means applied thereto.

Fig. 2 is a detail view of the reverse side thereof.

Fig. 3 is a detail view, similar to Fig. 1, partly in section.

Fig. 4 is an enlarged vertical section taken on the line 4.-4: of Fig. 1.

Fig. 5 is a detail View of the centre}, por tien a? one blade,

Fig. 6 is a detail view of the central por tion of the other blade.

Fig. 7 is an enlarged detail view of the tension washer, and V Fig. 8 is an enlarged detail perspective view of the pivotal post.

In the drawing there is shown, in Fig. 1, a pair of shears or scissors comprising blades 1 and 2, which may be of any size,

shape or proportions, though, in the present instance, that type generally used by barbers illustrated.

The blades 1 and 2 are provided ,with the usual extensions or stems 3 and 4, respectively, having at their extremities the usual finger loops 5 and 6, one of which, preferably the latter, being provided with the ordinary extenslon 7 The blade 1 is beveled and ground, as in- 'dicated at 8, to provide a cutting edge, and

ewise formed, as indicated The parts thus the blade 2 is ii at 9, for the same purpose.

far described are of the ordinary construction and, obviously, may be altered in accordance with the various styles of shears or scissors in common use. i

The improved means for pivoting the blades together consists in placing the axis of rotation of the blades to one side of the median line thereof, so that the cutting edge of one of the blades is at a greater distance from the said axis of rotation than the cut ting edge of the other blade. To this end the blade 2 is provided with a threaded opening 10 passing entirely through the blade, the center of said opening being arranged below the median line ofthe blades 1 and 2, when the same are in closed position, as clearly illustrated in Fig. 4: of the drawing.

The blade 1 is provided with a smooth opening 11 therethrough, and in registering relation to the threaded opening 10 and of a diameter approximatelyequal to theinone-half its length and is adapted to be screwed into the opening 10, and the remaining smooth or unthreaded portion 14: thereof to fit freely within the registering opening 11 and to extend to within a short distance of the opposite side of the blade 1, as shown at 15 in Fig. 4:.

The pivotal post 12 is provided with an axial threaded bore 16 extending entirely through the same, and adapted to receive the threaded shank of a screw 17, which is of relatively small diameterand extends beyond the outer face of the blade 1 and is there provided with the usual enlarged head, slotted for the reception of a screwdriver.

A dished spring washer l9 isinterposed on the shank of the screw 17 between the head and the adjacent outer face of the blade 1, a suitable aperture 20 being provided centrally of the washer for this purpose. The washer is ofsuflicient diameter to extend beyond the wall of the smooth opening 11 of the blade 1, and is placed on the screw with the concave side thereof next to the said blade 1, so that the periphery of the said washer will bear against. the same.

7 The pivotal post 12 is provided With the usual slot/21 for the reception of a screwdriver, in order that the same may bevreadily applied in assembling the shears and maybe quickly removed therefrom when it is necessary to, grind orsharpenthe sep arated blades land 2. v

The screw 17 holds the blades from separation and it will be apparent that by simply tightening the same, increased tension is exerted on the blades throughthe medium of the'spring washerlfi); so. that the cutting edges 8 and 9am always forced into close contact with each other at the point of crossing when the blades are opened By arranging the axis of rotation of the blades torone side of the median line thereof, as shownin the drawing, it will be seen that the cuttingedge 8 of the blade 1 which is at a greater distance from the axis of rotation than'the cutting-edge 9,'is caused to pass the latter, in the operation of closing the blades in cu-tting,in an arcuate path of movement, tangential'or at anangle to the co-acting cutting edge 8, thus having a tendency to draw the material being cut into the gap of the closing blades 1 and 2.

The extended bearing portion lat ofthe pivotal post.12 is relatively large and thus provides a broad bearing for the blade 1 which will not readily wear and cause lost motion or wabbling between the blades. The large bearing for the blades is necessary owing to the fact that the pivot of the blades is located to one side of the longitudinal center line thereof. The large tension washer is necessary'to extend tension throughout the entire length of the blades during the cutting operation. If an ordinary bolt were used to pivot the blades to one side of the medial longitudinal line, the proper tension would not be obtained in all positions of the blades, with the result that the object being cut would be drawn between the blades, thus making cutting difiicult or even impossible. The end of the threaded por- ,tion of the post is flat and lies flush with the blades pivoted, said pivot comprising registering openings in the blades, the diameter of which openings equals substantially half the width of the blades, said openings lying to one side of the loiigitudinal center line of the blades, one of said openings be ing threaded and the other plain, a pivotal post in one piece exteriorly threade for a portion of its length to screw into the threaded opening substantially flush with the blade and having a slot for the recep tion of a tool, the remaining portion of the length of the post beyond the threads being plain and cylindrical in form and fitting revolubly within the other opening and terminating short of the outer face of'the corresponding blade, a resilient washer spanning the said plain opening and bearing on the blade about the same, and a tension screw extending through the washer and entering the said post, said screw being materially smaller in diameter than the post. In testimony that I claim the foregoing as my own, I have hereto aflixed my signature in the presence of two witnesses.

NOAH B.- THOMPSON.

Copies of this patentmay be obtainedvfor five cents each, by addressing the Commissioner of Patents,

7 v Washington, D. G.

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