US2507701A

US2507701A - Spring bar

Info

Publication number: US2507701A
Application number: US679507A
Authority: US
Inventors: Jacob S Feiner; Lawrence L Stone
Original assignee: CHARLES B GREENBERG
Current assignee: CHARLES B GREENBERG
Priority date: 1946-06-26
Filing date: 1946-06-26
Publication date: 1950-05-16
Anticipated expiration: 1967-05-16

Description

May 116, 1950 J. 5. FEINER ET AL SPRING BAR Filed June 26, 1946 INVENTORS JACOB S. ffl/VER ZA WRENCE 1.. STONZ- A TTORNEX Patented May 16, 1950 its s'rAss SPRING BAR Application June 26, 1946, Serial No. 619,507

3 Claims. 1

This invention relates to spring bars for wrist watches, bracelets and other items of jewelry, and more particularly, spring bars of the type having a hollow tube, a trunnion slidably received at one or both ends of the tube and a compression spring within the tube forcing the trunnion or trunnions outwardly.

One object of the invention is to provide a spring bar of the type described having component parts, more particularly, trunnions, which are facilelyand quickly assembled in position. In spring bar-s heretofore made the trunnions are not symmetrical so that each trunnion is required to be handled separately and examined carefully in order that its prop-er end be inserted in the tube. An allied object of the invention is to provide a spring oar construction in which the trunnions are symmetrical so that either end may be inserted in the tube indiscriminately without examination. Ihis lends itself to simple, accurate and fast assembly, which may be automatic or semi-automatic, the improved trunnions being dumped into a hopper and individually fed from the mouth thereof.

A. further object of the invention is to provide a spring bar of the type described having a structure, particularly, that of the trunnion, which will eliminatewobble and play of the parts and reduce stress repetition, fatigue and consequent failure. An allied object is to provide a trunnion having an increased bearing surface in the form of a double bearing surface comprising two widely spaced-apartbearing surfaces separated by a central recessed portion. A further object is to provide a trunnion having double bearing surfaces separated by a central annular recess adapted to cooperate with one or more identatic-ns on the tube inwardly projected into the annular recess to retain the trunnion within the tube.

For the attainment of the foregoing and such other objects of invention as may appear or be pointed out herein we have shown several embodiments of our invention in the accompanying drawing, wherein:

Figure l is a top view of one form of improved spring bar, showing fragmentary portion of the jewelry item to which it is applied;

Figure 2 is a top view of the improved trunnion used in the spring bar of Figure 1;

Figure 3 is a top view,partially sectionalized, of a portion of a second form of spring bar, employing the improved trunnion of Figure 2;

Figure dis a top view-partially'sectionalized,

of a portion of a third form of improved spring bar;

Figure 5 is a top view of the improved trunnion used in the spring bar ofFigure 4;

Figure 6 is a top view,'partially sectionalized, showing a fourth form of improved springbar, showing a portion of the jewelry item towhich it is applied; and

Figure '7 is a tcpview of the improved trunnion used in the spring'bar of Figure 6.

The type of spring bar to which this invention relates includes a tube, such as I, Figure 1, which is to be removably secured'between a pair of spaced supportingeiements, such as the spaced lugs 9, projecting from the wrist watch 8 or other item of jewelry. Spaced lugs 9 are provided with aligned openings i on their inner, opposing faces. As shownin Figure 1, openings i do not extend through to the outer faces of the lugs; this form of spring bar connection, referred to as blind," is preferred because an opening on the outer faces of the lugs would mar their appearance and interfere with any design engraved thereon. In some cases, known as through connections, apertures, such as '5; Figure '6, extend through the lugs.

The spring bar is further provided with a reduced stein projecting outwardly at each end of its tube and adapted to be received within the openings (I, Figure l, 6, Figure 6) of the lugs. At least one of the stems is an integral part of an element known as a trunnion which is slidably retained within the tube and spring pressed to project its stem outwardly of the encasing tube. The trunnion permits the spring bartobe inserted in, and removed from, itssecured position between the lugs, by forcing the trunnion inwardly against the spring toengage its stem, or to free its stem from engagement, in the lug opening. In some cases one of the stems is formed out of the tube material or may be fixedly secured at one end. of the tube. In other cases, a trunnion is provided at each end of the tube. This is the form illustrated in the drawing. Also, the invention applies equally to blind connections, Figure l, or through connections, Figure 6.

In Figure 1, trunnion I0, one at each end of tube i, shown inFigure 2, has a central portion comprising a pair of intermediate cylindrical portions ll, l2, separated by a central annular recess l3, presenting bearing surfaces slidably engaged with the interior surface of tube I. The trunnions Ill, [0 areurged outwardly by a helical compression spring 5 within the tube but are retained withinthe tube against the force of the spring by one or more projections 4 formed by indenting the tube material inwardly. Indentations 4 project into the annular recess I3 of the trunnions and are abutted by the spring-pressed trunnions at the annular shoulder defining the inner wall of cylindrical portions I I, I2 and one wall of annular recess I3. Projecting outwardly of cylindrical portions II, I2 and centrally located on the longitudinal axis L-L, Figure 2, of the spring bar are reduced stems I5, I4, respectively. One of the stems, such as the stem I4 of the trunnion at the right end of the tube, Figure 1, is received in the opening 'I of the supporting lug 9. The indentations 4 are positioned at a predetermined distance from the ends of the tube so that a stem, such as the stem I4 of the right trunnion, will project outwardly beyond the tube a predetermined extent so that it may be readily fitted into the opening I, the spring bar being then held securely between the

spaced lugs

9, 9 by the compressive force of spring 5, and so that the spring bar may be removed from the lugs by forcing the trunnion into the tube, against the outward urgency of the compression spring, to clear the stem from engagement with opening I.

The dimension of the cylindrical portion, such as the cylindrical portion I2 of the trunnion at the right end of the tube, Figure 1, and the said predetermined position of indentations 4 are such that a predetermined part of the cylindrical portion, designated I2 in Figure 1, extends beyond the end of the tube. It is required that the cylindrical portion extend beyond the end of the tube so that the outer wall of the cylindrical portion may abut the inner wall of supporting lug 9 at a point beyond the end of the tube, to enable a blade or other instrument to be forced between the abutting walls. The distance of outward extension I2 of the cylindrical por tion is such that the trunnion may be forced into the tube a sufficient distance-limited by the abutment of the blade or instrument with the end of the tube-to enable the stem to be cleared from the opening I.

The trunnion of the improved spring bar, such as the trunnion I0, Figure 2, is made symmetrical about a plane SS transversely disposed, i. e., normally to the longitudinal axis L-L of the trunnion, at a central point thereof. By reason of the symmetrical formation of trunnion I0, its stems i4, I5 are identically dimensioned and equidistanced from the plane of symmetry S-S, and its cylindrical portions II, I2 are likewise identically dimensioned and equi-distanced from S-S; finally, annular recess I3 is centrally divided by the plane of symmetry SS. As a result of the said symmetrical formation of trunnion I9, either end may be indiscriminately inserted in the tube of the spring bar. For example, one trunnion I is inserted into the tube, Figure 1, at the right thereof with stem I and cylindrical portion Ii foremost so stem I 4 and an extent I2 of cylindrical portion I2 project beyond the tube. It is immaterial which end of the trunnion is inserted in the tube; the trunnion could as well have been inserted with stem I4 and cylindrical portion I2 foremost, as is shown in connection with the trunnion at the left of the tube, in which case stem I5 and extent II of cylindrical portion II project beyond the tube. Irrespective of which end of the trunnion is inserted in the tube, the stem (whether stem I4 at the right, Figure '1, or stem I5 at the left) projecting from the tube will be identically dimensioned and will project the same distance beyond the tube; like- 4 wise, the extent of cylindrical portion (whether I2 at the right, Figure 1, or I I at the left) projecting from the tube will be the same.

The helical spring 5 of the improved spring bar is such that the diameter of its central, inner space is sufficiently large to enable the stern I4, I5 of the trunnion to be received therein, as shown in Figure 1, so that either end of the trunnion may be inserted in the tube and the inserted stem will be received in the inner space of the spring. The retaining projections 4 may be indented in the tube wall after the trunnion or trunnions have been inserted in the tube, or the tube may be first indented and the trunnion or trunnions subsequently inserted, the tube material having sufiicient yieldability or resilience to permit the leading cylindrical portion lI, I2 to be forced inwardly beyond the projections 4.

The improved symmetrical trunnion III of Figure 2 may be used in a second type of spring bar shown in Figure 3 wherein the end of the tube I6 is crimped or spun over at I! to be received within the annular recess I3 of the trunnion to retain it within the tube against the urgency of compression spring 5 and with stem I5 as well as one cylindrical portion II entirely beyond the end of the tube. The parts are designed so that the stem and the cylindrical portion will be disposed at predetermined positions from the end of the tube. By reason of the symmetrical formation of the trunnion either end may be inserted in the tube so that at all times a stem (whether stem I4 or I5) and a cylindrical portion (whether I2 or II) will be disposed at the said predetermined positions.

A third type of spring bar is shown in Figure 4 wherein the trunnion 20 has a central cylindrical portion 23 on both sides of which are annularly recessed or reduced portions 2i, 22, and reduced

stems

24, 25 extending from annularly reduced portions 2i, 22. Central cylindrical portion 23 is in slidable engagement with the inner surface of tube I6, and the trunnion retained within the tube by crimping or spinning the end I! of the tube over the central cylindrical portion 23 of the trunnion, the inwardly turned end I! being received in the annular space provided by annularly reducing portions 2|, 22. The reduced portions 2|, 22 thus enables the end of the tube to be crimped over, and also provides a part projecting beyond the end of the tube, which projecting part functions in inserting and removing the spring bar as more fully explained with reference to projecting part I 2 Figure 1.

Trunnion 28, Figures 4 and 5, is symmetrical about central transverse plane SS, Figure 5, so that either end of the trunnion may be indiscriminately inserted in the tube and there will, at all times, project from the end of the tube a stem (whether 24 or 25) of identical dimension and disposed at the same predetermined distance from the end of the tube, and a predetermined extent of a reduced portion (whether 22 or ZI).

The type of spring bar illustrated in Figure 1, Figure 3, and Figure 4 may be used in either the blind connection (described above with reference to Figure 1)by reason of the projected portion of the trunnion (such as portion I2 Figure 1, the cylindrical portion I I, Figure 3, or the extended portion of RI, Figure 4)-or in the through connection (described below with reference to Figure 6). The fourth type of spring bar shown in Figure 6 employing the improved trunnion 30 shown in Figure '7 can be used only with 76 the through connection (as shown in Figure 6) as it can be removed only by forcing the trunnion into the tube by applying a force at the end of the stem, such as 34, exposed at the outer face of supporting lug 9. Trunnion 30 has a central cylindrical portion 33 and reduced

stems

34, 35 on each side thereof and is retained within the tube l6 by crimped end I! thereof. Trunnion 30 is symmetrical about central transverse plane S-S so that either end of the trunion may be indiscriminately inserted in the tube to project a stem (whether 34 or 35) of identical dimensions beyond the end of the tube.

A troublesome objection to spring bars as heretofore made is the wobble and play of theparts,

particularly at the trunnion, which causes stress repetition, fatigue and consequent wear and failure and loosening of the spring bar. We have overcome this objection by providing a spring bar, see Figure 1, in which trunnion ID has increased bearing surface at the spaced cylindrical portions ll, l2; the provision of spaced bearing surfaces, one at cylindrical portion H and the other at cylindrical portion 12, reduces wobble and play and at the same time utilizes the central recess I3 for retaining the trunnion within the tube, by the indented projections 4, as already described.

We claim:

1. An improved trunnion for use in a spring bar of the type having a tube, an inwardly extending stop on the tube and a trunnion at at least one end of said tube, said improved trunnion comprising a central portion annularly recessed to present a pair of spaced intermediate cylindrical portions, at least one of the said cylindrical portions being adapted for slidable engagement with the interior surface of the tube and adapted to engage said stop, said central recessed portion being proportioned for receiving therein said stop, and a reduced stem extending outwardly from each of said cylindrical portions, said stems, cylindrical portions and annular recess being symmetrical about a central transverse plane through the improved trunnion, whereby either end of the improved trunnion may be inserted in the said tube to present a stern of predetermined dimensions projecting a predetermined extent outwardly of the tube.

2. A spring bar of the class described comprising a tube, a trunnion at at least one end thereof, and a compression spring within the tube bearing against the trunnion and urging it outwardly, said trunnion having a central portion annularly recessed to present a pair of spaced intermediate cylindrical portions and a 05 reduced stem extending outwardly from each of said cylindrical portions, projections indented inwardly of the tube material and received within the said annular recess of the trunnion to retain the same within the tube against the urgency of said compression spring, said projections being disposed relative to the end of the tube such that the said stem will project a predetermined distance beyond the tube and a predetermined extent of the cylindrical portion will project beyond the tube, said trunnion being symmetrical about a central transverse plane whereby either end of the trunnion may be inserted in the tube to project a stem at the said predetermined distance, and to project the said predetermined extent of a cylindrical portion, beyond the end of the tube.

3. A spring bar of the class described comprising a tube, a trunnion at at least one end thereof, and a compression spring within the tube bearing against the trunnion and urging it outwardly, said trunnion having a central portion annularly recessed to present a pair of spaced cylindrical portions and a reduced stem extending outwardly from each of said cylindrical portions, projections indented inwardly of the tube material and received within the said annular recess of the trunnion to retain thesame within the tube against the urgency of said compression spring, said projections being disposed relative to the end of the tube such that the said stem will project a predetermined distance beyond the tube, the said cylindrical portions presenting double bearing surfaces slidably engaged with the interior surface of the tube, and spaced apart to increase the effective bearing surface of the trunnion, said trunnion being symmetrical about a central transverse plane.

JACOB S. FEINER. LAWRENCE L. STONE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,194,484 Depollier Aug. 15, 1916 1,744,685 Nittel Jan. 21, 1930 1,745,565 Wittman Feb. 4, 1930 2,063,733 Greenberg Dec. 8, 1936 2,157,408 Greenberg May 9, 1939 2,392,092 Konikofi Jan. 1, 1946 FOREIGN PATENTS Number Country Date 125,540 Switzerland July '7, 1928 130,728 Switzerland Mar. 1, 1929