US2305156A - Box lock pivot and method of assembling same - Google Patents

Description

Dec. 15, 1942. F. u, GUBl. K l 2,305,156

BOX LOCK PIVOT AND METHOD OFASSEMBLING SAME Filed April 17,1941 l IIA INVENTQR Helm/Kd, 620,554

. Burku ATToRNEY Patented Dec. 15, 1942 BOX LOCK PIVOT AND METHOD OF ASSEMBLING SAME Frank J. Grubel, Glendale, Long Island, N. Y., as-

signor to Edward Weck tr Company, .-Inc., Brooklyn, N. Y., a corporation of New York Application April 17, 1941, serial No. 388,972

8 Claims.

This invention relates to an improved box lock pivot for surgical forceps or the like and the method of assembling the pivot pin with the box lock.

Box locks for forceps or the like are old and well known and it has been the usual practice to use a rivet or the like as the pivot. One side or lever of the forceps was provided with a box like intermediate section formed by milling a rectanglar slot through the side or lever and the other side or lever was provided with a bar like section machined to t the slot in the box and at the end of this bar like section were diagonal shoulders which cooperated with diagonal end portions of the box. These levers were assembled by heating the box and spreading it open far enough to receive the jaw and bar section of the other lever. The box was again heated and then the'levers were assembled and closed andthe sides of the box hammered against the sides of the bar. The bar and box were drilled with a through-opening to receive a pivot pin which was riveted in position which in a number of instances caused the sides of the box to be drawn up too tightly against the sides of the bar making it necessary to provide for the proper clearance between the bar and the sides of the box by opening and closing the levers after injecting oil and nely ground emery into the box lock joint. ends of the pivot pin and grind down the ends flush with the adjacent parts of the levers. In these constructions the area of the outer surface of the levers occupied by the pivot pin could not be used for the purpose of .receiving trademark or patent markings.

Among the objects of my invention is an improved box lock pivot construction in which the pivot pin is seated-in recesses in the inner faces of the sides of the box and is entirely concealed by the, sides of the box thereby obviating the necessity of finishing operations above referred to and providing for a continuous surface for the reception of trade-mark or patent markings.

Another object of the invention is the provi- Other objects of the invention will appear from the following description taken in connection with thedrawing, in which- Fig. l isa disassembled View of the sides or levers and pivot pin used in my improved method e l of construction;

It was also necessary to cut off the Fig. 2 shows the sides or levers pin of the forceps assembled;

Fig. 3 is a section on the line 3 3 of Fig. 2, showing the relation of the pivot pin to the elements of the box lock; Y

Fig. 4 is a top plan view of the forceps embodying my invention; and

Fig. 5fis a transverse section on the line 5-5 of Fig. 4. Y

My invention has been shown in connection with `a haernostatic forceps of well known construction in which the side or lever I0 is provided with the usual box lock section II, and in which the other side or lever I3 is provided with an intermediate Vbar like section I4 adjacent the end of which are diagonal shouldersV I5 and IB cooperating with diagonal shoulders I'I and I8 on the ends of the boxr of the first mentioned side or lever. The sides or levers are provided with jaws I9 and 20 and with ring handles 2l and 22 provided with cooperating catch elements 23 and 24. In the usual construction the sides of the box and the bar are drilled to receive a pivot pin which is secured in position by upsetting the ends of the pin. It has been the practice toopen the box far enough to receive the jawof lthe lever in which the cooperating bar is formed and to assemble the same and close them as indicated in Fig. 4, from which it will appear thaty the engagement between the jaws causes the shoulders to be brought and pressed into engagement as the handles are latched. Just before these levers were so assembled and closed and the pivot the box was heated and after the assembly the sides of the box were closed against the bar.

`The box and bar were then drilled to receive the -In order to avoid the various objections mentioned, I employ a pivot pin 25 which is of less Y length than the combined thickness of the sides of the box and the bar and preferably of hard material, and provide the lever provided with the bar with a pivot pin receiving hole of a size to provide for a close flt of the pivot pin in order that the same'may be assembled as shown in Fig. 3 with its lower end preferably flush with the lower face of the bar of the box joint. In the preferred method of assembly the pivot pin makesY its own seats in the sides of the box as the box is closed' against the sides of the bar.

In the course of experiment ball pins and pins with spherical ends were used but it was found that these pins when the box was closed by a hammer blow on the upper side ofthe box were driven in certain instances entirely through the bar and into the lower side of the box and it was found most diicult to control the nal position of the pivot pin with respect to the sides of the box. It was also found that when both ends of the pin were round that the levers or sides of the forceps could be wabbled, thus providing `an l unsatisfactory construction. For the purpose of preventing the possibility of wabbling the sides or levers with respect to each other and also for the purpose of locating the pivot pin in the proper relation with respect to the elements of the box lock joint, I employ Va pivot pin with an upper spherical end in reference to its position when the sides of the box are closed on the bar, as indicated at 39 and with a right angular lower end as indicated at 3|. o

In the preferred method the inner faces of the sides of the boxare plain. At the time of assembling the levers the box is again heated to soften the metal and the levers are assembled as shown in Figs. 2 and 3 before the metal of the box has had a chance to cool and then as the sides of the box are closed against the bar as indicated in Figs. 4 and 5 the ends of the pin make their own seats in the plain inner faces of the heat nitely control the amount of projection of the rounded end of the pivot pin from the upper side of the bar and the depth of the seat in the upper side of the box made by this end of the pivot pin.

In the operation of closing the sides of the box upon the bar, they` have been brought into a proper working contact with the bar and easingup operations are not required. Because of the parallel engagement between the lower end of the pivot pin and the lower side of the box and also because of the fact that this end seats in a shallow recess in the lower side of the box relative wabbling of the sides or levers is prevented substantially as eifectively as if both ends of the pivot pin were right angular. Pivot pins having both ends rounded or right angular could be used but I prefer to use pivot pins having one end rounded or at least of reduced diameter and the other end right angular to control the position of the pin. The construction is such that either lever may move on the pivot, but it is obvious that the ends or intermediate portions of the pivot pin could be of rectangular or other non-circular cross section to hold the pivot pin from rotation in either lever. The final position of the pivot pin might be controlled or predetermined in other ways or by other means but I prefer to control its position by the shape of its lower end as this appears to me now to be the simplest way.

While I have shown and described a preferred form of my invention as applied to forceps and with great particularity, it is to be understood that I reserve the right to all such uses and changes in method and in construction as fall within the principles of the invention disclosed and the scope of the appended claims. v

I claim:

1. The method of assembling a pivot pin with .a box lock of pivoted levers in which the sides of the box have inner plain faces, which consists in assembling a pivot pin of less length than the thickness of the box with the inner element of the box lock, spreading the sides of the box, heating the box to soften the metal, passing the lever provided with the inner element into the box to position the pivot pin within the box and in closing the sides of the box against the inner element and embedding the ends of the pivot pin therein while the metal of the box is still soft.

2. The method of pivotally connecting the elements of a box lock of pivoted levers which consists in providing a pivot pin of less length than the height of the box, assembling the pivot pin with the inner element of the box lock, spreading the sides of the box, heating the box to soften the metal, passing the lever provided with the inner element into the box to position the pivot pin within the box and in closing the sides of the box While the metal of the box is still soft against the inner element.

3. rThe method of pivotally connecting the elements of a box lock of pivoted levers which consists in providing the inner element of the box lock with a pivot pin hole, providing a pivot pin of less length than the height of the box with a rounded end and a `right angular end and of a diameter to tightly fit in the pivot pin hole, inserting the pivot pin into the hole with its right angular end ush with one face of the inner element, spreading the sides of the box, heating the box to soften the metal, passing the lever provided with the inner element and the pivot pin into the box to position the pivot pin within the box and closing the sides of the box while the metal is still soft against the inner element.

4. The method of assembling a pivot pin with the box lock of pivoted levers which consists in spreading the sides of the box of the one lever to receive the other lever, providing the inner element of the box lock with a pivot pin hole, providing a pivot pin having ends of diierent cross sectional areas and of a diameter to frictionally fit in said hole, inserting the pivot pin in said hole, heating the box to soften the metal, assembling said levers by passing the lever provided with the inner element into said box to position the pivot pin inside of said box and closing the sides of said box against the inner element while the metal of the box is still soft.

5. In a box lock pivot construction, the combination with the intertting box and inner element of the pivot construction, the inner face of one of the sides of the box being provided with a recess, of a pivot pin associated with the inner element and seated in said recess in the inner face of a side of the box.

6. In a -box lock pivot construction, the combination with the interiitting box and inner element of the pivot construction, the inner face of one of the sides of the box being provided with a recess, of a pivot pin extending through the inner velement of the pivot construction and having one of its ends seated in said recess in said side of the box of the pivot construction and having its other end seated against the inner face of the other side ofthe box of the pivot construction.

7. In a box lock pivot construction, the combination with the interfitting box and inner element of the pivot construction, the inner faces of both sides of said box being provided with recesses alined transversely of said box, of va pivot pin extending through the inner element of the pivot construction and having its ends inner element of the pivot construction and having a, rounded endseated in said recess and a right angular end seated on the inner face of the other side of the box of the pivot construction.

FRANK J. GRUBEL.

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