GB2112562A - Device for fixing a battery in a watch - Google Patents

Abstract

The battery strap member comprises a ring (2) which is applied to the battery (4) and two fixing lugs (6). Each lug comprises notches (8, 10, 12) which co-operate with a slot 24 in the insulating substrate (20a). The notches form three bayonet-type closure systems which define three battery heights. The device thus makes it possible to use a single strap member for a watch which accepts batteries of three different thicknesses, while all being of the same diameter. <IMAGE>

Description

SPECIFICATION Device for fixing a battery in a watch The present invention concerns a device for fixing a battery in a watch. The term "battery" is used in accordance with common usage to comprehend a single cell.

It is well known that electronic watches invariably use as an electrical power supply source, batteries which have to be fixed to the watch, in most cases to the movement of the watch. In addition, the battery must be electrically connected to the various electronic or electrical - mechanical components of the watch.

lin most cases, the battery fixing is achieved by means of a device which is referred to as a strap member which holds the battery to a plate of the watch and which in addition frequently forms one of the two electrical connections.

US patent No 2 985 705 discloses a battery fixing strap in the form of a small bar which is provided with two curved lugs which terminate with two latching elements co-operable with bores machined in a support plate. By moving the lugstowards each other, the latching elements can be inserted into the bores. When the lugs are released, the resiliency thereof causes them to move apart, thereby locking the strap in place and therefore holding the battery to support plate.

However, such a battery strap can only be used effectively to fix in position batteries which are all not just of the same diameter but also of the same thickness. Now, it is a well known fact that the batteries which are currently in use may be of various different thicknesses, with the same voltage and with the same diameter. For example, in the case of lithium - type batteries, the general thicknesses may range from 1.6 to 2.6 mm. In the case of silver oxide - type batteries, the thickness of the battery may vary for example from 1.6 to 3.6 mm. It will be clear that the resiliency of the strap member can accommodate small differences in thickness.

However, the differences in thickness referred to above are too great for just the resiliency of the strap member sufficing to accommodate such differences, while ensuring that the battery is efficiently and reliably fixed in place, throughout the service life of the battery.

To overcome that problem, a first object of the present invention is to provide a device forfixing a battery in a watch, which permits batteries of differentthicknessesto be secured in place.

Asecond object of the invention is to provide such a device which makes it possible to accommodate such differentthicknesses, by virtue of the very structure of the battery strap member and not by excessive resilient deformation thereof.

A third object of the invention isto provide such a device which further permits a battery to be set in position and removed easily, in particular without requiring screws.

Fourth object of the invention is to provide such a device which does not result in a substantial increase in the diameter of the thickness of the assembly formed by the battery and the battery fixing system.

The device according to the invention is defined in claim 1 below.

The strap member comprises a plurality of latching elements which are disposed at different heights, thereby permitting batteries of different thicknesses to be fixed in place.

in a first embodiment, each lug is provided on its edges with machinings forming the different latching elements. The support element which is for example the printed circuit of the watch is provided with the same number of slots as there are lugs. That assembly forms as many bayonet -typefixing systems, as there are machinings on each lug. To give the latching action, the whole of the strap member simply has to be rotated about the axis of the battery.

It will be appreciated that in this way the device does not have any fixing screw and that the bayonet type closure system does not result in any substantial increase in the outside diameter of the battery.

Thisis a particularly attractive consideration in the case of a watch which is fitted with a lithium - type battery, the diameter of which is very close to the diameter of the watch movement.

In another embodiment, the lugs are provided on their face which directed towards the battery or on the external face, with a plurality of projections which can co-operate with the edge of a bore provided in the support plate. Resilient deformation of the lugs causes the strap member to be latched to the support plate. This is then a closure arrangement which operates by a resilient clip action. Each projection on a lug defines one battery height.

The invention will be described in more detail with reference to the accompanying drawings, in which: Figure 1 is a plan view of a strap member mounted on a battery.

Figure 2 is a view in vertical section taken along line ll-ll in Figure 1,showing a first embodimentof the strap member, Figure 3 shows a detail view of the strap member shown in Figure 2, more particularly illustrating the notches in the lugs of the strap member, forming a part of the bayonet - type fixing system.

Figures 4a to 4c show the different positions of fixing batteries using the strap member shown in Figures 2 and 3, Figure 5 shows an elevationatand sectional view of half of a second embodiment of the strap member for fixing a battery, by means of a clipping action, and Figure 6 shows third embodiment of the battery strap member, which fixes the battery in place by clipping, in a--situation where the battery is partially recessed into a housing.

Referring to Figures 1 to 4, a first embodiment of the battery fixing device wherein the strap member is fixed by a bayonet - type system will now be described. Figures 1 and 2 show the form of the strap member which comprises a ring 2 of conducting-material. The outside diameter of the ring 2 is substantially equal to the outside diameter of the battery 2. The ring 2 is therefore applied to the periphery of the substantially flat face 4a of the battery 4. Incidentally, it will be noted that this form of strap member permits all the useful information which may appear on the face 4a of the battery to be read. The ring 2 forms the support portion of the strap member. As can best be seen from Figure 2, the ring 2 is not flat but has a fold along its diameter X,X'.The strap member further comprises two fixing lugs 6 and 6' which are substantially perpendicular to the ring 2 and therefore substantially parallel to the axis of symmetry of the battery 4. As is best visible in Figure 3, each lug 6 or 6' is in the form of a tongue portion, of which the edges 6a and 6b (in regard to the lug 6) are provided with notches. The edge 6a has a single notch 8. It is defined by a lower edge 8a which is perpendicular to the height of the battery and the distance of which from the ring 2 is equal to h1. The edge 6b is provided with two notches 10 and 12 which communicate with each other.The notch 12 is defined downwardly by an edge 12a and the notch 10 is defined downwardly by an edge 1 0a. It will be appreciated that the notch 10 is deeper than the notch 12, so that the edges 1 0a and 12a are thus disposed in a stair- like configuration.

The edge 1 Oa is disposed at a distance h2 from the ring 2 while the edge 1 2a is disposed at a distance h3 from the ring 2. The difference between the heights h1 and h3 is for example 1 mm.

It will be appreciated that the fixing lug 6' is provided with the same systems of notches on its edges 6'a and 6'b. As will be described hereinafter, these three notches which are provided on the two fixing lugs thus define three fixing depths, that is to say, three thicknesses of battery, which are compati blewiththis type of strap member.

The strap member or more precisely the ring 2 further comprises projections as indicated at 14 which project outwardly from the ring to permitthe battery to be set in position or removed easily, even when the movement is encased. In addition, two holding lugs 16 and 16' (only the lug 16 can be seen in Figure 2) complete the action of holding the battery 4 in place within the strap member. In fact, the strap member is fixed to the support plate only by the two lugs 6 and 6' and the two holding lugs 16 prevent the strap member from possibly becoming loosened, by rotation thereof about an axis which does not coincide with the axis of the battery.

Figure 4 shows that, in the embodiment envisaged, the plate to which the strap member is secured is formed by the printed circuit 20. The printed circuit 20 is fixed to the frame support structure 22 of the watch, the face 22a of which faces towards the dial.

The printed circuit 20 is provided with two slots 24, only one of which can be seen in Figure 4 and which is of sufficient width to permit all the lugs 6 or 6' to bsinserted. In addition, the height of each notch is greater than the thickness of the printed circuit 24.

As is wen known, the printed circuit in its proper sense comprises a rigid insulating substrate 20a and conductortracks as indicated at20b.

The operation of setting the battery in position and swing it in place by means of the strap member is sry simple. The battery is set in position and the battery strap member is placed onthe upper face 4a of the battery, the strap member being centered relative to the battery by the fixing lugs 6 and 6' and also by the positioning lugs 16 and 16'.

In this way, the lugs 6 and 6' are inserted into the slots 24. By applying a light pressuretothe ring in line with the points of origin of the lugs 6 and 6', the ring is subjected to slight deformation by virtue of a folding motion thereof and, by means of the projections 14, the strap member is turned about its axis in the appropriate direction, thereby ensuring that one of the edges 26 of the insulating substrate 20a of the printed circuit which defines the slot 24 enters the notch corresponding to the required battery thickness (being the notch 8 in the situation shown in Figure 4a).

Figures 4a, 4b and 4c correspond to the different battery thicknesses h1, h2 and h3. In addition, by virtue of the folding movement and resilient deformation ofthe ring 2, the edge of the notch (edge shown in Figure 4a) is firmly applied against the printed circuit or more precisely the conductor track 20b. This therefore results in an excellent electrical contact.

Figure 5 is a view in a simplified form of a second embodiment of the invention wherein the strap member is fixed in place by clipping. The strap member also comprises a ring as indicated at 28, which bears against the upper face 4a of the battery, two fixing lugs of which only one (as indicated at 30) is shown in Figure 5, and two positioning lugs (not shown) which are similar to the- positioning lugs 16 and 16' in Figure 1. The essential difference lies in the machinings which define the different positions for latching of the strap member to the support plate.

The machinings are provided on the inside flat surface 30a of each fixing lug, instead of being at the edges of the fixing lugs. The machiningsessentially comprise three projections 32a, 32b and32cwhich are provided on the inside face 30a and which separate or define three grooves 34a, 34b and 34c at the bottom. In fact, the groove 34a is defined only by the projection disposed below it. as indicated at 32a.

There is no upper limit The grooves co-operate with the edge of slots such as at 24' which are provided in the insulating substrate 20' of the printed circuit of the watch, as was already the case in the first embodiment It will be appreciated however that it is the edge 24'a which is parallel to the length of the stot, that co-operates with a groovy Thus, the upper edges of the projections which define each groove downwardly are disposed at different distances hi, h2 and h3 from the ring 28, whereby batteries of different thicknesses corresponding to different distances can be fixed in place.

Figure 6 shows a second embodiment whereinthe battery 4' is for example a silver oxide battery. As is well known, that means that the diameter of the battery is relatively small relative to the movement of the watch and consequently the battery is partially received in a housing provided in the movement.

Figure 6 diagrammatically shows a plate 40 of the movement, whichfacestowards the dial of the watch, a portion 42 of the insulating substrate of the printed circuit, with a conductor track 42', and a part 44 of the movement, which forms a housing or recess 46 into which the battery 4' is fitted. This embodiment is very close to that shown in Figure 5, but the grooves and projections are provided on the outside face 30b of each of the fixing lugs, with only the lug 30 being shown in Figure 6. The different projections, which are similar to the projections shown in Figure 5, define different battery fixing depths. The projections are indicated in Figure 6 by the same references as in Figure 5, but with the addition of the prime.It will be appreciated that in this case the heights h1, h2 and h3 of the different grooves are less than the total height H of the batteries since the strap member is latched in position at the level of the printed circuit, that is to say for example, half way up the height of the battery.

It will be apparent from the foregoing description of the various embodiments of the invention that the particular form of the strap member and the machinings on the support plate, which may be formed by different parts of the watch, effectively provide the possibility of using the same strap member to fix batteries of different thicknesses. In addition, fixing or removing such batteries is very easy since there is no screw to be undone. In addition, the different latching positions correspond to staggering of the different thicknesses that are possible in regard to the battery, but it is clear that intermediate values in respect of such thicknesses could be accommodated by resilient deformation of the strap member.

Moreover, it would not be a departure from the invention for the strap member to act solely as a mechanical fixing means, with the electricalconnec- tion being produced by other members. Finally, in the embodiments described, the battery has only two fixing lugs. More generally, the device comprises n fixing lugs (n 2) and each lug comprises p machinings (p 5 2). This therefore defines heights of battery, which can be used with the fixing device according to the invention.

Claims (1)

1. 7. A device for fixing a battery in an electronic watch, of the type comprising a strap member and a support element to which the battery is fixed, the strap member comprising a support portion which abuts a face of the battery and a plurality n of fixing lugs which are directed substantially in the direction of the height of said battery and are connected to the support portion, each lug comprising towards its distal end a pluralitypofshaped formations forming p tatching elements which are displaced in the direction of the said height, and wherein the support element has a plurality n of locking portions co-operating with a formation of one of the lugs to fix the strap- member to the support element and to apply the support portion against the face of the battery.

   2. A device according to claim 1, wherein the support portion of the strap member is in the form of a ring which bears against the periphery of the face of the battery.

   3. A device according to claim 2, wherein the ring has a fold disposed along a diameter of the ring.

   4. A device according to claim 2 or 3, wherein the strap memberfurthercomprises at least one lug for holding the battery, the holding lug being bent over with respect to the ring and being disposed on the same side with respect to the ring as the fixing lugs.

   5. A device according to any of claims 1 to 4, wherein each fixing lug is defined by two edges, each of the p shaped formations of each fixing lug comprises a notch which opens at one of the said edges, and wherein each of the said n locking portions of the support element comprises a cutout portion which is at least partially defined by an edge to permit one of the fixing lugs to be introduced, each notch being greater in height than the thickness of the edge of the cut - out portions to permit the introduction of the edge into each notch, the cut-out portions and notches forming p bayonet - type systems for securing the strap member to the support element.

   6. A device according to any of claims 1 to 5, wherein the fixing lug is defined by an internal face which is directed towards the battery and an external face, each of the p formations of the fixing lugs comprises a projection provided on one of the said faces, two successive projections being separated by a groove, and wherein each said locking portion of the support element comprises a cut - out portion to permit one of the lugs to be introduced, each cut out portion being at least partially defined by an edge, each groove being greater in height than the thickness of the edge of said cut - out portions to permit co - operation of the edge and projections, the projections and cut - out portions forming p systems for securing the strap member to the support element by a resilient clip action.

   7. A device according to any of claims 1 to 6, wherein the support element is the printed circuit of the watch.