Extensible link band

This disclosure relates to a link band, in particular a watch wrist band, a bracelet or the like which includes a plurality of links defined by opposite longitudinal edges, opposite transverse edges, and opposite upper and lower surfaces; adjacent links being articulately interconnected by projections received in recesses, the connection between an end of a projection and an associated recess having an axis of rotation located contiguous adjacent longitudinal edges and upper surfaces of adjacent links, and the articulating connections being such as to absorb longitudinal forces imparted to the link band when in use and to also lock adjacent links together against unlocking movement of the links perpendicular to a longitudinal plane of the link band.

The present invention is directed to an extensible or articulated link 
band, particularly a watch wrist band or a bracelet, but also usable as a 
belt. The link band consists of a plurality of individual links joined in 
an articulating manner and being provided at opposite longitudinal edges 
with mutally engaging articulating connection means in the form of 
connecting elements which in the assembled or interlocked state form a 
joint connection holding the links tightly together along longitudinal 
sides or edges thereof. 
Such link bands assembled from individual links provide the appearance of a 
uniformly closed band if the individual links are properly shaped and 
joined together tightly enough when the band assumes a flat position. 
However, when used as a watch band, they must usually be bent more or less 
as, for example, when being placed around the wrist of the user. This 
bending and inward or inside direction is desirable, but bending in an 
outward or outside direction though desirable should also be limited. 
Due to the latter conditions or desires associated with link bands, a 
number of requirements is placed on the articulating connections of 
associated adjacent links which are not only difficult to meet but also 
are generally somewhat in conflict. For example, in an known embodiment of 
a link band, the links are articulately joined together such as to retain 
an essentially uniform practically trivial or minuscule spacing between 
adjacent links for most any conditions of bending. In such a band, 
however, when in the curved or bent state, the links due to their design 
assume a mutual position in which they abut each other like steps or 
stairs in the manner of roof shingles or tiles with the height of the 
steps increasing with the bending. 
In other link bands the gap or spacing between two adjacent links changes 
as the band is bent and in order that the band also be somewhat outwardly 
bendable, this gap must also be present to some degree when the band lies 
flat. Thus, this gap generally increases mainly in the sense of increasing 
band curvature and thus decreases as the curvature of the band decreases. 
In order that such a gap does not become excessive in appearance, ribs or 
projections which project transversely of longitudinal edges of one or 
more adjacent ribs are provided to underlie the gap and, therefore, block 
the interior of the band to one's view, thus rendering the gap less 
visible though it is still present. Even with the latter solution, the gap 
between adjacent links remains more or less visible in part because the 
view blocking projections or ribs must be located as close as possible to 
the outside of the band, while a minimum material thickness must be 
preserved for band integrity and strength. Obviously, a further difficulty 
is that such wrist bands are relatively thick to provide strength at the 
articulating joints or elements, but as the thickness of the bands or the 
links associated therewith is reduced, the available space for 
interconnecting adjacent links and for closing or hiding the gap 
therebetween becomes a more difficult problem. 
It is a primary object of the present invention to avoid the latter-noted 
shortcomings and difficulties in previously known designs of link bands 
and to create a link band such that the interconnected links and 
particularly the connecting elements thereof not only offer an extensively 
step-free outside surface appearance in all bent positions of the 
individual links relative to each other, but also is free of any 
significant gaps between the individual links. 
A link band of the latter type can be achieved by this invention because 
the axis of rotation of the articulating connection of adjacent links lies 
approximately at or in the outer surface of the link band and in the area 
of the gap defined by the longitudinal edges of adjacent links, while at 
the same time those portions of the links which form articulating bearing 
pins and bearing sleeves are located remote from the axis of rotation. In 
order to employ bands which are generally thin, the elements forming the 
articulating connection may be divided or categorized into groups of 
elements and in such cases, one or several of the elements making up a 
group will absorb the bands longitudinal forces while others function to 
secure the links against movement or forces perpendicularly to the plane 
of the band. The group of elements absorbing the longitudinal forces can 
appropriately comprise the elements acting as the articulating connections 
(bearing bins and bearing sleeves) or consists of such comparable 
elements. 
A wide variety of designs can be implemented due to the construction of the 
present invention. For example, one or several projection means, such as 
lips, tenons, projections and/or shoulders can be provided along 
longitudinal edges or sides of adjoining links with corresponding recesses 
being formed on the other sides of these links which are mutually and 
alternatingly arranged for mating engagement in a comb-like fashion. These 
projection means and associated recesses secure the position of the links 
perpendicularly to the plane of the band and are located as close as 
possible to the other side of the band. The projection means furthermore 
can be provided with cylindrical surfaces or segments as surfaces acting 
as bearing sleeves which, when the links are lined up one against the 
other, will engage behind cylindrical surfaces or cylindrical surface 
segments--arranged coaxially with the axis of pivot motion or of rotation 
of the links and acting as bearing pivots--the recesses of the neighboring 
links. The projection means and recesses may be of such a design that the 
links are connected by hooking one into the other, namely, one projection 
within one recess. This connection also permits ready detachment of 
adjacent links even with the same being locked together by an appropriate 
locking element which appropriately is formed as an integral homogeneous 
part of the individual links of the link band. Though preferably integral, 
such locking element may, of course, be a separate element. 
With the above and other objects in view that will hereinafter appear, the 
nature of the invention will be more clearly understood by reference to 
the following detailed description, the appended claims and the several 
views illustrated in the accompanying drawings.

Reference is first made to a novel link band (FIG. 1, FIG. 1a and FIG. 1b) 
which may be, for example, a watch wrist band, a bracelet, or belt or the 
like and is formed of a pair of mutually joined links 11, 12 of which the 
link 11 comprises recess means or recesses 111, 112 along a longitudinal 
side or edge 115, then are penetrated by or received projections 121, 122 
located along an adjoining longitudinal side or edge 125 of a neighboring 
link 12. The link 11 also includes projections 113, 114 which are received 
in recesses 123, 124, respectively, of the link 12 when, of course, the 
links 11, 12 are adjacent and interlocked with each other, as is shown in 
FIGS. 1, 1b and 1a. The latter effects a comb-like interconnection or 
meshing of the projection means and link means which in effect results in 
an articulating connection, as in the form of a hinge, and also secures 
the position of the links 11, 12 perpendicular to the plane of the overall 
band. 
The links 11, 12 push against each other along their longitudinal sides or 
edges 115, 125. In order to absorb these tension forces in the 
longitudinal direction of the link band, the projections 121, 122 are 
provided with means in the form of end portions, arms or attachments 126, 
127, respectively, which rests or seat behind respective offsets 116, 117 
of the respective recesses 111 and 112 of the link 11. The parts of the 
two links engaging in the manner thus described are designed as 
cylindrical surfaces 119, 129, and the same are concentric to the axis of 
rotation or the pivot axis of the links which is located in the area of 
the gap (unnumbered) between the two longitudinal edges 115, 125 near 
their upper surfaces thereof, as is best indicated by the radius R in FIG. 
1b. Thus, the axis of rotation lies at the end of the lead line associated 
with the arrow R remote from the head of the arrow thereof which in FIG. 
1b) is shown terminating just at the gap between the longitudinal edges 
115, 125 of the respective links 11, 12. The angled arms or attachments 
126, 127 form bearing pins or bearing portions which impart the pivoting 
capability to the links 11, 12 and also permit some outward bending of the 
link band to a moderate degree, as is evident in FIG. 1a. The outward 
bending of the links 11, 12 relative to eah other is limited by abutment 
surface means in the form of heels 130, 131 which abut one another in the 
manner best illustrated in FIG. 1a as they contact cooperative abutment 
surface means or heels 140, 141, respectively, of the projection means 
121, 122. Thus, when the links 11, 12 are pivoted relative to each other, 
the cylindrical surfaces 129 (FIG. 1b) act as bearing sleeves which move 
over the cylindrical surfaces 119 acting as the bearing pins. 
When the links 11, 12 are in their lined-up position (common single plane), 
they are secured by releasable locking means consisting of an integral 
locking shoe or terminal locking end portion 128 formed as an integral 
extension of the projection 121. The integral extension or locking shoe 
128 is flexible and deflectable due to its inherent elasticity and, thus, 
the locking shoe or arm 128 can be pressed back into the recess 124 in 
which it is located when the links are hooked together. In the latched 
state, the locking shoe 128 presses in the manner of a ratchet pawl or 
tooth behind a similar protruding pawl or tooth 118 of the projection 114 
of the link 11. The locking shoe or element 128 further functions as means 
for blocking ones' view into the interior of the link band through the gap 
between the longitudinal edges 115, 125 by, of course, spanning the gap 
therebetween. However, the links 11, 12 can be slightly parted across the 
gaps 115, 125 when the locking shoe 128 is pressed back from the lower 
side of the band into the recess 124 using an appropriate tool that can be 
inserted into a depression 120 of the projection 114. 
Reference is now made to the link band of FIG. 2 which corresponds 
generally to that of the link band of FIG. 1 with identical elements being 
similarly numbered but being in the 200 rather than the 100 series. The 
articulating connecting or connection means and the manner in which the 
same are secured in position are achieved by projection means or 
projections 221, 222 of the link 22 and like projections 213, 214 of the 
link 21. The projection 221, 222 are received in respective recesses 211, 
212 of the link 21, while portions or projections 226, 227 of the 
projections 221, 222 have cylindrical surfaces or segments 229 which 
engage and mate with cylindrical surfaces or segments 219 of heels or 
surfaces 216, 217, and thus seat themselves into the recesses 211, 212, 
respectively. In this case, a locking element 218 is carried by the 
projection on lip 214 or the link 21 and is received in the recess 224 of 
the link 22 and in spanning relationship to the gap between the 
longitudinal edges 215,225 with the locking element 218 acting as a view 
blocking means. In the latched state, the locking element or shoe 218 
rests against a pawl 228 of the link 22. 
Reference is now made to FIG. 3 of the drawings in which is illustrated 
links 31, 32 having longitudinal edges 315, 325 between which is a gap 
(unnumbered). The link 32 includes a projection 321 received in the recess 
311 of the link 31, whereas the latter link 31 includes projections or 
shoulders 313, 314 received in recesses 323, 324, respectively, of the 
link 32. The projections 321 of the link 32 tapers or converges toward its 
free end, as is best illustrated in FIG. 3a and includes an essentially 
rectangular opening 326 into which enters a tongue or cleat 316 provided 
at the lower side (unnumbered) of the link 31. The cleat 316 is provided 
at the side thereof facing away from the longitudinal edges 315, 325 with 
a cylindrical surface 319 acting as a bearing surface or pin with a 
cylindrical surface 329 of the side wall of the opening 326 cooperating 
with the surface 319 and acting as a bearing sleeve. In this matter, the 
mutual mobility of the links 31, 32 and the absorption of the tensile 
forces in the longitudinal direction are ensured by the cooperative 
cylindrical surfaces or segments 319, 329. Preferably, a tongue 318 is 
bent from its dotted position shown in FIG. 3a to its solid outline 
position in this same figure to lock the tongue or projection 321 within 
the recess 311 and also to function to limit the pivoting movement of the 
link 32 in an outward direction relative to the link 31, as is readily 
apparent from FIG. 3a. 
Reference is now made to the embodiment of the invention shown in FIG. 4 
which corresponds generally to that shown in FIG. 3, except for the 
locking means 418 which is an integral locking element of the link 41 
housed within a recess 411 of the latter and disposed with its axis 
generally parallel to that of the transverse edges (unnumbered) of the 
links 41, 42. In this case, the links 41, 42 are articulated in the same 
manner as in the structure of the links 31, 32, namely, by interconnected 
shoulders or projections 421, 413, 414 and associated respective recesses 
411, 423, 424. Again, the tensions in the longitudinal direction of the 
link band are absorbed in the same manner using an opening 426 of a 
rectangular configuration in a cleat, projection or tongue 416 and the 
latters respective cylindrical surfaces 419 and 429. The locking arm 418 
is provided with an angled rim or flange 412 (FIG. 4a) functioning as the 
locking element which underlies a ledge 428 of the projection 421 in the 
manner illustrated in FIG. 4 and in FIG. 4a. However, the locking arm 418 
can be deflected to the left, as viewed in FIGS. 4 and 4a to move the rim 
412 from beneath the ledge 428 and permit relative outward pivoting of the 
links 41, 42 to permit the same to be easily separated, if so desired. 
Reference is now made to FIGS. 5 and 6 of the drawings which illustrate 
another embodiment of the invention particularly adapted to be 
manufactured by a stamping or punching operation(s). For the sake of 
clarity, only a single link is shown, but it is to be understood that a 
link band is composed of a plurality of such identically formed and 
interconnected links. In this embodiment of the invention, the 
articulating connection is implemented by projection means which penetrate 
recess means of adjoining links, as in the manner heretofore described. To 
the latter end, the illustrated link 51 is provided along longitudinal 
sides or edges 511 or 512 with projection means 513 and 514 on one side 
and 515 and 516 on the other side with two recess means 517 and 518 on the 
one side and 519 and 520 on the other. Using these projection means and 
recess means, the links can be hooked up in the manner readily apparent 
from FIGS. 5 and 6 with, obviously, the projection means 521, 522 of one 
link, the link shown, being received in recesses corresponding to those of 
the recesses 519, 520 of another nonillustrated link, and so on. 
In order to absorb the longitudinal tension, extensions or projections of 
the projecting means are indicated at 521, 522 and these extensions of the 
projection means 513, 514 seat behind surfaces or heels 527, 529 of the 
respective recesses 519, 520. The extensions or projections 521, 522 can 
displace mutually in the recesses 519, 520, respectively, on their 
associated support surfaces when the links pivot thereby effecting an 
operation corresponding to the embodiment of FIGS. 1 or 2. Again, the 
manner of mutually locking the link 51 to an identical link corresponds to 
the embodiment of FIG. 1 in that an arm 523 forming an integral 
homogeneous portion of the projecting means 522 is provided at its free 
end with a locking shoe or locking terminal end 524. The locking arm 523 
is elastic and deflectable so that the locking shoe 524 can be forced back 
into a recess 517 of an associated adjoining link when two such identical 
links are hooked together. When the hooks are inserted, the locking shoe 
first slides over the projection means 515 and in the hook-up state rests 
by its front face against the side surface of this extension. By placing a 
tool in a depression 525 at the top side of the locking shoe 524 on the 
one hand and into a depression 526 in the side wall of the recess 520 on 
the other, the locking means can be released whereby adjoining interlocked 
links can be again separated. 
Although only a preferred embodiment of the invention has been specifically 
illustrated and described herein, it is to be understood that minor 
variations may be made in the apparatus without departing from the spirit 
and scope of the invention, as defined in the appended claims.