US2764905A - Jewelers' tweezers - Google Patents

Description

Oct. 2, 1956 w. E. THoMs JEWELERS' TWEEZERS Filed March 5l, 1954 H FIL Lm JEWELERS TWEEZERSv Waldemar E. Thorns, Cleveland, Ohio Application March 31, 1954, Serial No. 420,005

2 Claims. (Cl. 81-43) This invention relates to improvements in jewelers tweezers, more particularly tweezers provided with removable and replaceable blades or points.

In order to properly function for handling tiny watch parts and for straightening or bending hairsprings for watches, jewelers tweezers must have very slender points. Consequently the points are delicate and easily dulled. They are also subject to breakage when the tweezers are laid down on the bench with less than extreme caution. In conventional tweezers the points are made integral with the arms of the tweezers. lf dulled or broken they may be resharpened if the user is skilled in that procedure, but at the expense of considerable time. They may also be sent to an expert for resharpening, but the cost of such work approaches more or less the cost of a new pair of tweezers plus the cost in time and money of transporting them. Where removable blades or points are provided, as in the present invention, the damaged or worn points may be removed and a new set installed by the user readily and with no appreciable loss of time.

One of the objects of the invention therefore is the provision of removable blades or points in jewelers tweezers.

Another object is the provision of tweezers having arms of substantial thickness and strength with provision for relieving them to promote flexibility and easy operation.

Another object is the provision of means for retaining said removable blades in operative position.

Still another object is the provision of means for adjustably mounting removable blades, whereby the blades after being removed and sharpened may be reinserted into the arms and adjusted to the most advantageous position.

Other objects and features of novelty will appear as I proceed with the description of those embodiments of the invention which, for the purposes of the present application, I have illustrated in the accompanying drawing, in which Fig. l is an edge view on an enlarged scale of a pair of tweezers constructed in accordance with the invention;

Fig. 2 is a plan view of the same, one arm being broken away to more clearly illustrate the invention;

Fig. 3 is a cross-sectional view on a still larger scale, the view being taken substantially on the line 3--3 of Fig. l;

Fig. 4 is an edge view of a modied form of the invention;

Fig. 5 is a plan view of the same with one arm broken away to better illustrate the invention, and

Fig. 6 is a cross-sectional view taken substantially 0n the line 6 6 of Fig. 4.

Referring first to Figs. l, 2 and 3 of the drawing, the tweezers are shown as comprising two arms 10 that may be substantially identical. Preferably they are made of aluminum or some other light weight metal. At their butt ends the arms are separated by a spacer 11. The arms and the spacer are held together by some suitable means such as locating pins 12 and screws 13.

On the inner side of each arm 10 there is formed a dovetail groove 14 which extends through at least a major nited States Patent portion ofthe length of the arm,4 but preferably throughout its entire, length. In.4 this, groove there is mounted' slidably but not'looselyy ablade,V 15, with beveled side edges which iit snugly the walls of the. dovetail groove 14, the. inner surface of the blade being finished tobe flush with the, inner surface of the arm.

In order to hold each blade against accidental movement longitudinally of its. arm I mount intheY arrn a threaded fastening 16 which in effect is an inverted screw with a conical head having a slope that is identical with that of the beveled edge of the blade. On its outer end the fastening, which extends through a hole in the arm, is provided with a screwdriver slot 17 or other means for turning the fastening in its threaded hole. When drawn up tightly by a suitable tool applied on the outer side of the arm the fastening firmly grips the blade and secures it against accidental movement.

When the operator desires to sharpen the points of the tweezers, he may remove the blades after loosening the fastenings 16. The points may then be sharpened and the blades slid back into the grooves after which the fastenings 16 are again tightened with blades projecting from the arms whatever distance is considered most advantageous. In some cases the blades may be sharpened without removing them from the arms. Such resharpening may be repeated any number of times if the blades as originally installed extend for the full length of the arms.

In the inner side of each of the arms just forward of the spacer 11 there is formed a wide transverse groove 20 which extends across the full width of the arm and constitutes a relief which renders the arm more flexible and hence more responsive to light pressure exerted by the user to bring the points together or into gripping position.

The form of the invention illustrated in Figs. 4, 5 and 6 is similar in most respects to that of the first described form. However the dovetail groove 24 in each arm does not extend throughout the length of the arm but terminates at 25. The blades 26 are shorter than the blades l5 and they are not adjustable lengthwise of the arms 10. At its rear end each blade is split as indicated at 27, and the two legs 31 on opposite sides of the split are bent outwardly and caused to take a permanent outward set tending to separate their rear ends a distance more than the width of groove 24.

On the terminal portions of the legs 31 knobs 28 are formed. A hole 29 is drilled crosswis-e of each arm from one edge thereof, the drill after passing through the groove entering the arm on the opposite side of the groove and forming a cavity 30. To insert the blade into the groove the two legs 31 are forced together suiciently to permit the knobs 28 to enter the groove.v The blade is then pushed rearwardly until the knobs reach the drilled holes 29 and 30, hereinafter termed cavities, when they spring out into the cavities, thereby anchoring the blade to the arm. This anchoring engagement is suiiiciently secure for the purpose, because in the use of the tweezers there is no load upon the blades tending to pull the latter out of the arms. When it is necessary to remove the blades their forwardly projecting ends may be grasped by a pair of pliers and a slight pull on the pliers will unseat the knobs 28 from the cavities 29 and 30, after which a steady pull will slide the blade entirely out of the arm.

Having thus described my invention, I claim:

l. In jewelers tweezers, a pair of resilient arms having butt ends joined together, each arm having an internal median longitudinal dovetail groove on its inner side, removable pointed blades having beveled edges adapted to fit and slide between the side of said dovetail grooves, said blades being flush with the inner surfaces of said arms, means for releasably securing said blades against movement, a spacer between the butt ends of said arms, said arms being relieved by transverse internal grooves Patented Oct.-` 2, 19.5.6l

3 adjacent said spacer, whereby the tweezers are rendered highly exible.

2. In jewelers tweezers, a pair of resilient arms having butt ends joined together, each arm having an internal longitudinal dovetail groove on its inner side running through at least the major part of the length of the arm, removable pointed blades having beveled edges adapted to t and slide between the sides of said dovetal grooves, and means for locking each of said blades in a selected longitudinal position comprising a threaded fastening mounted in a threaded hole in the arm and having a conical head on its inner end adapted to bear against and grip a beveled edge of the corresponding blade, and means on the outer end of said fastening for turning it in its threaded mounting.

References Cited in the le of this patent UNITED STATES PATENTS 385,076 Stohlmann June 26, 1888 389,925 Griscom Sept. 25, 1888 1,751,227 Behrman Mar. 18, 1930 1,758,490 Aderer May 13, 1930 2,500,629 Crookston Mar. 14, 1950

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