US844903A

US844903A - Shears and tension-screw.

Info

Publication number: US844903A
Application number: US33448206A
Authority: US
Inventors: Willis A Wilkins
Original assignee: Individual
Current assignee: Individual
Priority date: 1906-09-13
Filing date: 1906-09-13
Publication date: 1907-02-19
Anticipated expiration: 1924-02-19

Description

No. 844,903. f PATENTED FEB. 19, 1907.

- W. A. WILKINS.

$HEARS AND TENSION SCREW.

APPLICATION FILED SEPT.13.1906.

"Ilium TE Swank-L I Z/ A 565/7177:-

I album-n5 oNrrEn s' rn rns WILLIS A. WILKINS, OF EL PASO, TEXAS.

SHEARS AND TENSION-SCREW.

Specification of Letters Patent.

Patented Feb. 19, 1907.

Application filed September 13,1906. Serial No. 334,482.

tion, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention has relation to shears provided with a tension-spring at the pivotal or fulcrum point of the blades for maintaining a constant even lateral pressure on the blades for the purpose of keeping their cutting edges in contact with each other at all times.

It is the purpose of the invention, in addition to what is hereinbefore stated, to pre vent the nut on the pivot-bolt, as also the latter, from turning, thereby maintaining an even pressure on the tension-spring and preventing the loss of the nut.

It is also the object of the invention to prevent the eyes or finger-holes of the handlebars from coming together or in contact with each other, thereby preventing the thumb or fingers from being pinched between the eyes or from interfering with the action of the shears.

The annexed drawings, forming a part of this specification, show means embodying my improvements, in view of which the invention will first be described as to its construction and mode of operation and then be pointed out in the claims.

Of the said drawings, Figure 1 is a side ele vation of a pair of shears embodying my im provement. Fig. 2 is a view of the opposite side at the fulcrum or pivotal point. Fig. 3 is an edge elevation. Fig. 4 is a vertical sectional view through the parts of the fulcrumpoint. Fig. 5 is a sectional view showing the frusto-conical head of the pivot-bolt looking down on its inner side. Fig. 6 is a side view of the pivotbolt with the spring-adjusting nut turned thereon. Fig. 7 is a plan view at the pivoted point, showing the socket in the blade and the tension-spring in place therein, the pivot-bolt being represented in section. Fig. 8 is a bottom plan view of the thumbnut.

Similar figures of reference designate similar parts or features, as the case may be, wherever they occur.

giln the drawings, 10 designates one blade, and 11 the other blade, of a pair of shears, which blades are fulcrumed or pivoted on a bolt 12, passing through both blades and located, preferably, about one-quarter of an inch or more from the handle end than from the points of the blades in order to increase the leverage of the handles when the shears or scissors are used. The blade 1 l is'provided with a socket or recess 13, having inwardlyinclined sides around the hole made through said blade for the receipt of the shank 14 of the pivot-bolt 12, said socket being provided for the reception of the frusto-conical head 15 of the bolt, the outer surface of which is flush with the outer side of the shear-blade 11. The frusto-conical head of the bolt, or it may be the shank of the same, is provided with a lug 16, that is made tent in a recess 17 in the shear-blade to keep the bolt from turning in the hole through the shear-blades when in proper position. The upper or 0pposite blade 1.0 is provided with a round socket 18, into which is set a split annular spring 19 with a hole through its center sufliciently large to admit the pivot-bolt through, the outer or upper end of which is screw-threaded to have the nut 20 turned thereon. The outside of the said nut is milled or otherwise constructed to make it a thu1nbnut,so called, in order to obviate the use of a screw-driver in putting the parts together or taking them apart. The lower or inner end of the thumb-nut 20 is reduced in diameter or offset in order that the reduced portion 21 may enter the socket 18 and bear upon the spring 19 when the said thumb-nut is turned down on the screwthreaded portion of the pivot-bolt. The annular offset margin on the inner end of the thumb-nut, which is of greater diameter than the socket 18, rests or bears on the outer the margin of the said socket, and said marginal surface may be roughened, as at 22, as

may also the meeting surface of the nut, in order that when the nut is turned home on the pivot-bolt and bears on the shear-blade and spring it will not be loosened or turned off by the action of the spring thereon in the operation of the shear-blades. The construction of the nut and socket in the sh earblade just described are of importance in the invention, as is also the construction of the frusto-conical head, its lug, and the socket in the side of the shear-blade 11, since these features insure the maintenance of the bolt-spring and nut permanent in position after once having been adjusted. I

One of the handle bars of the blades is provided on its inner side with a sgnreinglug 23, the end of which is arlaptedv to come into contact with the opposite hanole-bar, and so prevent the finger-eyes 24. of the handles from coming together, and so pinching the thumb or fingers of the operating hand or allowing interference with the operation of the blades.

It is obvious that the improvements with. respect to the self-adjusting tension on the blades may readily be applied to the common form of shears or scissors by taking out the old pivot-screw, filing away the thread. thereon where it passes through the blades, and making a small inwardly-inclined recess in the shear-blade 11, and providing the head. of the bolt with a lug and a recess therefor, and fitting the upper blade 10 with a recess, as described, with a spring therein, and providing a thumb-nut for the outer end of the bolt or screw of the character described, and roughing the offset face of the bolt and the meeting surface of the shearblade, as explained.

The invention described. is at once simple in construction and efficient and ready of operation, obviating the use of a screwdriver to adjust it or put it together or take it apart, maintaining the bliLi'CS under the same tension at all times until they are practically worn out, and possessing other advantages hereinafter alluded to or made obvious by the described construction and mode of operation.

In roughing the offset surface of the thumb-nut and the opposing surface of the shear-blade it may take the character of radial ribs and grooves of shallow form, so as to holdor lock the nut against the action of too spring. Ordinarily, however, the friction between the surface of the offset part of the nut and the opposing surface of the blade will be sufficient to hold the nut against being loosened by the tension-spring. 'l he nut can be set down tight on the blade without un dulyincre asing the stress of the tension spring.

The spring around the pivot-bolt might be a helical spring of well-known form or a spring of other form and. subserve the purpose of the spring shown and described as well, and. so other mechanical changes may be made in the form and arrangement of parts without departing from the general nature or spirit of the invention.

' What is claimed as the invention is- 1. The combination with the blades of a pair of shears or scissors, one of which is provided with a socket having inwardlytaper stereos -on the screw-threaded part of the bolt, and

having its inner end reduced to enter the socket of the other blade and bear upon the said spring the annular offset surface of the nut resting or bearing on. the surface of the last-mentioned blade around the margin. of the pivot-hole.

2. The combination with the blades of a pair of shears or scissors, one of which is provided. with a socket having inwarilly-taper-' ing walls and a recess, a smooth hole being formed through both blades, an annular socket in the other blade, a spring in. said socket, a pivot-bolt having a frusto-eonical head and lug adapted to fit the socket and recess in the first-mentioned blade, and a smooth shank where extending through the pivot-holes of the blades but screw-threaded on its end, a thumb-nut adapted. to be turned on the screw-tlueaded part of the bolt, and having its inner end reduced to enter the socket of the other blade and bear upon the said spring, the annular ofl'set surface of the nut resting or hearing on the surface of the last-mentioned blade around the margin of the pivot-hole, the surface of the offset POP tion of the nut and the opposing surface of the blade being roughened to lock or hold the nut in place against the action of the spring.

'l he combination, with the shear-blades of the pivot-bolt having its head secured in one blade, and provided with a shank smooth in the part that extends through the blades and screw-threaded on its extended end, a round socket in the outside of the other blade, a spring surrounding the shank of the pivot-bolt in said socket, a thumb-mrt turned on said screw-tlnezided part of the bolt, said tlnunb-nut being reduced in diameter and having an offset at its inner end, the reduced part being adapted to enter the socket of the blade and bear upon the spring and the oil set surface bearing on the outside surface of the blade on the margin of the socket.

4t. lhe combination, with. the shear-blades of the pivot-bolt having its head secured in one blade, and provided with a shank smooth in the part that extends through the blades and screw-threaded on its extended end, a round socket in the outside of the other blade, a spring surrounding the shank of the pivot-bolt in said socket, a thumb-nut turned on said screw-threaded part of the bolt, said thumb-nut being reduced. in diaereter and having an offset at its inner end, the

In testimony whereof I aflix my signature in presence of twowitnesses.

WILLIS A. WILKINS.

Witnesses:

W. C. WHITE, I CHET. DEAN.