Abstract:
An end connector for connecting the ends of an expansible watch band to a watch case. The end connector is inserted between the endmost top and bottom links or the band and is engageable with the staples providing an interconnection therebetween.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates generally to expansible bands, and is concerned in particular with an improved end connector for connecting the ends of such bands to watch cases or the like. 
     2. Description of the Prior Art 
     The conventional expansible watch band typically includes a row of top links overlying a row of bottom links, with each bottom link being connected to two adjacent top links by pairs of U-shaped staples. Springs housed in the links cooperate with the staples to yieldably contract the band. 
     A number of end connectors have been developed for use with such bands. For example, and as disclosed in copending application Ser. No. 164,093 filed on Mar. 4, 1988, now U.S. Pat. No. 4,805,271 an end connector has been provided with a flat shank received between the top and bottom links, the shank having a tab which is bent out of the plane of the shank and into an interengaged position protruding between two adjacent bottom links. The drawback with this arrangement is that the integrity of the connection depends to a large extent on the accuracy with which the tab is bent. Improper bending can produce a faulty connection, which in turn can result in loss of the watch and band. 
     Another type of end connector is disclosed in my copending application Ser. No. 185,920 filed on Apr. 25, 1988, now U.S. Pat. No. 4,837,901. This connector is again provided with a flat shank adapted to be received between the endmost top and bottom links of the band. The shank has contoured side edges which enable the connector to be manipulated in the plane of the shank into an interlocked position between the staples interconnecting the endmost top and bottom links. The drawback here, however, is that the connector can be disengaged by reverse manipulation of the shank. To prevent this from occurring, an additional element is employed to block reverse manipulation once the end connector is in place. Typically, the additional element comprises a cover which is snapped into place over the endmost top link. Because this cover member is exposed, its decorative appearance must match that of the band top links. Thus, each band requires its own specially configured end connector, a factor which complicates inventory tracking while contributing unnecessarily to manufacturing costs. 
     SUMMARY OF THE INVENTION 
     The objective of the present invention is to provide a still further improved end connector of the type having a generally planar shank adapted to be inserted between the endmost top and bottom links of the band. The shank has specially contoured side edges which accommodate manipulation of the connector in the plane of the shank into an interlocked position between the endmost pairs of staples. The same contoured side edges do not, however, permit the end connector to become disengaged by reverse manipulation of the shank. This advantage is achieved without employing additional specially configured and costly retainer elements. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a partial top plan view of a watch band connected to a by means of an end connector in accordance with the present invention; 
     FIG. 2 is a cross elevational view, on an enlarged scale, taken along line 2--2 of FIG. 1; 
     FIG. 3 is a sectional view, with portions broken away, taken along line 3--3 of FIG. 2; 
     FIG. 4 is a greatly enlarged bottom view of the end connector of the, present invention illustrated in a fully interlocked position between the staple pairs interconnecting the endmost top and bottom links of the band; 
     FIG. 5 is a side view of the end connector; 
     FIGS. 6-9 are schematic illustrations indicating sequential sters in the positioning of the end connector; 
     FIG. 10 is an enlarged view of a portion of FIG. 9; 
     FIG. 11 is a side view looking in the direction of the arrows line 11--11 in FIG. 10; and 
     FIG. 12 is a schematic illustration of the final step required to shift the end connector into its interlocked position. 
    
    
     DETAILED DESCRIPTION OF INVENTION 
     Referring initially to FIGS. 1-5, a conventional expansible watch band 10 is shown connected to a watch 12. The watch band has a row of top links 14 overlying a row of bottom links 16. The links have a somewhat box-like structure, with the top links 14 typically being covered by decorative top shells 18. Each bottom link 16 is connected to two adjacent top links 14 by first and second pairs 20a, 20a&#39; and 20b, 20b&#39; of U-shaped staples. As can be best seen in FIG. 4, the staple pairs are separated from each other by a first distance d 1  measured in the direction of the band width &#34;W&#34;. The staples have legs 22 (FIG. 2) protruding into the ends of the links connected thereby. Leaf springs 24 are housed in the links. The springs 24 act on the staple legs 22 to yieldably contract the band in the direction of the band length &#34;L&#34;, and to yieldably urge the staples of each pair apart and against the side walls of each link, to thereby occupy a maximum second distance d.sub. 2 measured in the direction &#34;L&#34;. 
     The end connector of the present invention is generally indicated at 26 and comprises a generally planar shank 28 having its inner end received in an end of the band 10 between the rows of top and bottom links 14, 16, and having its outer end defined typically by a partially cylindrical hook 30 which protrudes beyond the end of the band. The hook 30 is configured to engage a spring bar 32 or the like extending between spaced lugs formed integrally with the watch case. One of the lugs is shown at 34 in FIG. 3. 
     First and second sides 36a, 36b extend between the inner and outer connector ends. First and second ears 38a, 38b respectively protrude laterally beyond the first and second sides 36a, 36b at the inner end of the shank. The width w 1  of the shank measured at the ears 36a, 36b is greater than the first distance d 1 . The difference between the width w 2  of the shank measured between the sides 36a, 36b and the first distance d 1  is less than the distance d 3  that each ear 38a, 38b protrudes beyond its respective side. 
     A notch 40 is located in the first side 36a between the inner and outer ends of the connector. The notch 40 is defined by inner and outer edges 42, 44 extending laterally from the first side 36a towards the second side 36b, and by a bottom edge 46 extending from the inner edge 42 to the outer edge 44. The distance d 4  measured between the inner and outer edges 42, 44 in the direction &#34;L&#34; is less than the distance d 2 . 
     The diagonal distance d 5  across the notch 40 measured from the junction of the first side 36a and the inner edge 42 to the junction of the bottom edge 46 with the outer edge 44 is greater than the distance d 2 . The length of the inner edge 42 is less than that of the outer edge 44, with the result that the junction of the bottom and outer edges defines an acute angle at the maximum depth of the notch 40. The width w 3  of the shank measured from the maximum depth of the notch 40 to a reference line extending in the direction L from the tip of ear 38b is less than the first distance d 1 . 
     The manner of inserting and interlocking the end connector 26 into the end of the band 10 will now be described with reference to FIGS. 6-12. Beginning with FIG. 6, the end connector 26 is inserted into the end of the band in the direction of arrow &#34;A&#34; between the endmost top and bottom links in order to position the staple pair 20a, 20a&#39; within the notch 40, with the staple 20a&#39; being located at the maximum depth of the notch as defined by the junction of the bottom and outer edges 46, 44. 
     As shown in FIG. 7, the end connector is then pivoted about staple 20a&#39; in the direction of arrow &#34;B&#34;. As can be seen in FIG. 8, because the diagonal distance d 5  is greater than the distance d 2 , the inner edge 42 moves in behind the staple 20a, with the result that the staples 20a, 20a&#39; are captured between the inner and outer notch edges 42, 44. As pivotal motion continues in the direction B, and because the distance d 4  is less than the distance d 2 , the staples 20a, 20a&#39; are gradually urged towards one another against the resilient force acting on their respective legs 22 by the springs 24. Also because the width w 3  is less than distance d 1 , the connector ear 38b moves in an arc within and past the staples 20b, 20b&#39;. At the end of the pivotal motion in the direction B, as illustrated in FIGS. 9-11, the staples 20a, 20a&#39; are confined within the notch 40 between the inner and outer edges 42, 44, and the connector side 36b is spaced inwardly from the staples 20b, 20b&#39;. 
     As illustrated in FIG. 12, the connector is then shifted laterally in the direction C, bringing the side 36b against or in close proximity to the staples 20b, 20b&#39;, and thus allowing the staples 20a, 20a&#39; to escape from the confines of notch 40. 
     When this happens, and as can best be seen in FIG. 4, the staples 20, 20a&#39; snap back under the resilient force of the springs 24 acting on their respective legs 22 to their original positions occupying distances d 2 , which as previously mentioned, is greater than the distance d 4  measured between the inner and outer notch edges. Thus, the connector becomes captured between at least one of the staples 20a, 20a&#39; bearing on side 36a, and by both of the staples 20b, 20b&#39; bearing on the opposite side 36b. This effectively prevents any subsequent lateral shifting of the connector in a direction opposite to direction C, and thus results in the end connector being securely interlocked within the end of the band. This result is achieved without having to employ additional elements, such as covers or the like. 
     In the event that it becomes necessary to remove the end connector, e.g., as a preliminary step to removing one or more end links when shortening the length of the band, a tool (not shown) must be employed to squeeze the staples 20a, 20a&#39; together so that they can reenter the notch 40 as the connector is shifted laterally in a direction opposite to direction C. The sequence illustrated in FIGS. 6-8 is then reversed. 
     In the embodiment herein illustrated, the end connector is completely hidden from view from above. This is advantageous in that the same connector can be used with bands having different top shell designs. Of course, if desired, this advantage can be relinquished by having a portion of the end connector take the place of the endmost top link and shell.