Expansible Mechanism

Abstract

An expansible mechanism suitable for use as an expanding fastening device for a wrist watch strap or band and for recording personal identification information is described. The information-bearing panels of the mechanism are serially interconnected through end hinges so that they can be folded over into a concertina-like configuration for retraction into a housing. A displaceable detent tongue within the housing normally engages a lug on a longer one of the panels to retain all the panels in their retracted positions within the housing. A release stud on the housing is effective to displace the detent tongue to allow the panels to be automatically extended through an open end of the housing under the action of a compression spring within the housing, shoulders being provided at the open end of the housing to prevent the bodily movement of the longer panel completely out of the housing. Holder-adaptors are optionally provided for alternatively fastening the mechanism to a key ring or for clipping it in a person's pocket.

Description

BACKGROUND OF THE INVENTION

The present invention relates to expansible mechanisms and more particularly to expansible mechanisms especially suitable for use as expansible fastening devices for wrist watch straps and bands as well as for the recording of personal identification data.

Various expansible mechanisms have heretofore been suggested for use as wrist watch fasteners but such previously proposed mechanisms have presented various disadvantages. For instance, some of the known mechansims have been relatively bulky and they were not, therefore, particularly aesthetically attractive for use on watch straps or bands. Other known expansible watch-strap fasteners have proved to be somewhat unreliable in their operation in that they have not always provided a sufficiently positive locking of the mechanism components.

Accordingly, it is a principal object of this invention to provide an expansible mechanism which is relatively compact and simple in its construction and which is reliable in use providing a positive locking action of its individual components in their non-expanded positions.

Another object of this invention is to provide an expansible mechanism which is especially suited for use as an expansible fastening device in a watch strap or band.

Yet another object of this invention is to provide an expansible mechanism which also has utility for recording personal identification information or the like.

Other objects of the invention will become apparent as the description herein proceeds.

SUMMARY OF THE INVENTION

In its broad scope, the present invention provides an expansible mechanism including a hollow housing having an open forward end and defined by top and bottom walls retained in mutually spaced apart disposition by spaced apart side walls, a first panel having side edges and forward and rearward ends and slidingly disposed within said housing for movement between a rearward retracted position essentially within said housing and an extended forward position in which it projects forwardly from said housing through said open end thereof, co-operating first detent means on said panel and said housing for preventing movement of said rearward end of said panel out of said housing, spring means within said housing and engaging said panel normally to urge said panel into said extended position thereof, co-operating second detent means on said panel and said housing releasably to retain said panel in said retracted position thereof within said housing against the action of said spring means, and a manually operable detent release member extending from within said housing and operatively associated with said second detent means to permit movement of said panel from said retracted position thereof into said extended position thereof under the action of said spring means on operation of said detent release member.

Although the invention is not restricted to the provision of any particular number of panels in an expansible mechanism in accordance therewith, mechanisms particularly useful as expansible watch strap fastening devices are provided when an odd number of such panels is provided in such a mechanism.

One important advantage presented by the mechanisms of this invention results from the fact that personal identification information, such as the wearer's name, address, allergies, blood type, etc., can be recorded on the panels of the mechanism so as to be readily available in the event that the wearer is involved in a personal emergency. For example, if a mechanism in accordance with this invention is utilized as a watch strap fastening device, it is possible for a swimmer to be assured of positive personal identification without requiring that person to wear a separate identification bracelet.

In addition to being utilizable as watch strap fastening devices per se, the mechanisms of this invention are also readily securable by the use of very simple adaptor-holders to existing watch straps for the purpose of providing an identification device for the wearer.

By the use of an alternative type of adaptor-holder, the mechanisms of this invention can also easily be secured to a key ring or clipped onto a person's pocket. Other features and advantages of the invention will become apparent as the description herein proceeds.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described merely by way of illustration with reference to the accompanying drawings in which:

Fig. 1 is an enlarged perspective view of one embodiment of an expansible mechanism in accordance with this invention showing that mechanism in exploded disposition together with an adaptor-holder by the use of which the mechanism can be used as an expansible fastening device in a wrist watch band, the two ends of the latter being shown fragmentarily;

FIG. 2 is an exploded perspective view of the expansible mechanism of FIG. 1;

FIG. 3 is a perspective view of an upper part of the housing of the expansible mechanism of FIGS. 1 and 2 when viewed as indicated by the arrows 3--3 of FIG. 2;

FIG. 4 is an even more enlarged perspective view of a compression spring included in the expansible mechanism shown in FIGS. 1 and 2;

FIG. 5 is an enlarged plan view of the expansible mechanism of FIGS. 1 and 2 with the upper part of the housing thereof removed to reveal its internal construction;

FIG. 6 is a transverse section through the expansible mechanism of FIGS. 1 and 2 when taken as indicated by the arrows 6-6 of FIG. 5, also showing the top part of the housing in its assembled position but with certain other components omitted for the sake of clarity;

FIG. 7 is a longitudinal sectional view through the expansible mechanism of FIGS. 1 and 2 when taken as indicated by the arrows 7--7 of FIG. 6;

FIG. 8 is an even more enlarged perspective view of three panels included in an alternative embodiment of an expansible mechanism in accordance with this invention, such panels being shown in their folded configuration;

FIG. 9 is a perspective view showing the securement of the expansible mechanism of FIGS. 1 and 2 in a holder by means of which the mechanism can then be mounted on a flexible watch strap which is shown fragmentarily;

FIG. 10 is an elevational view taken as indicated by the arrows 10--10 of FIG. 9;

FIG. 11 is a rear perspective view of a holder for the expansible mechanism of FIGS. 1 and 2 intended for clipping onto the edge of a pocket or for attachment to a key ring;

FIG. 12 is a front elevation of the mechanism of FIGS. 1 and 2 disposed in the holder shown in FIG. 11 and showing that holder attached to a key ring;

FIG. 13 is a side elevation of the mechanism and holder shown in FIG. 11 illustrating the manner in which the holder functions to retain the mechanism clipped onto the edge of a pocket;

FIG. 14 is a fragmentary perspective view showing an alternative construction for two panels used in an expansible mechanism in accordance with this invention;

FIG. 15 is a fragmentary sectional view through the panels shown in FIG. 14 when taken as indicated by the arrows 15--15 of that figure;

FIG. 16 is a plan view from below of one of the panels shown in FIG. 14; and

FIG. 17 is a fragmentary and sectional exploded view of the panels shown in FIG. 14.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The expansible mechanism generally indicated at 10 in FIG. 1 of the accompanying drawings includes a housing generally indicated at 12 and formed from an upper part generally indicated at 13 and a lower part generally indicated at 14.

The upper part 13 of the housing 12 includes a flat web 15 constituting the upper wall of the housing 10 and integrally formed downwardly extending side flanges 16 and 17. The right hand or forward end of the upper part 13 as viewed in FIGS. 1 and 2 is open while the opposite or rearward end is closed by an end flange 18 as shown in FIG. 3.

A notch 20 is formed in the side flange 16 at its rearward end while a short slot 21 extends into the flange 17 from its rearward end as will be readily understood by reference to FIG. 3. A generally central open notch 22 is also formed in the end flange 18. The purposes of the notches 20 and 22 and of the slot 21 will be more readily understood as the description herein proceeds. It is also to be noted that the forward end corners 23 and 24 of the flanges 16 and 17 respectively are bent slightly inwardly.

The lower part 14 of the housing 12 includes a flat web 25 intergrally formed with upstanding side flanges 26 and 27. Both ends of the lower part 14 are essentially open but a generally central upstanding lug 28 is formed at the rearward end of the web 25 while the forward end of the web 25 curves slightly upwardly as indicated at 29 and as particularly shown in FIG. 7.

A short slot 31 is formed in the rearward end of the flange 27 for alignment with the aforementioned slot 21 in the flange 17 of the upper part 13 when the upper and lower parts 13 and 14 respectively are assembled with their side flanges in contiguous surface abutment as particularly shown in FIG. 6. A somewhat longer slot 32 is formed in the opposite flange 26 in alignment with the slot 31 while the flange 27 is cut away as indicated at 33 forwardly of the aforementioned slot 31 for a purpose yet to be explained.

The flanges 26 and 27 are integrally formed at their forward ends with respective tongues generally indicated at 35 and which are folded rearwardly but slightly inwardly spaced apart from the inner surfaces of the respective ones of the flanges 26 and 27 as well as from the top surface of the web 25. Each tongue 35 has a notched undersurface (FIG. 7) to provide an abutment shoulder 36 between a lower edge 37 spaced apart upwardly from the top surface of the web 25 and an edge 39 spaced apart upwardly from the edge 37 effectively to provide a guide slot 38.

The mechanism 10 also includes an internal dividing wall generally indicated at 40 comprising a web 41 with upstanding side flanges 42 and 43 and short downwardly extending end lugs 44 and 45 generally equidistant from respective side edges of the web 41 at the rearward end thereof. The web 41 is slightly narrower than the web 25 of the lower part 14 of the housing 12 so that the side flanges 42 and 43 of the dividing wall 40 are disposed in contiguous inner surface abutment with the side flanges 26 and 27 respectively of the lower part 14 when it is disposed in that part.

Referring further to the internal dividing wall 40, it will be seen from FIG. 2 that the web 41 thereof is formed with a generally centrally disposed and longitudinally extending slot 47 while an open ended slot 48 and a shorter open ended slot 49 are formed in the rearward ends of the side flanges 42 and 43 respectively. Forwardly of the slot 49, the flange 43 is cut away and deformed inwardly to provide a somewhat narrower tongue 50 which can be resiliently flexed outwardly in a manner yet to be described. The dividing wall 40 is formed of a metal having an adequate degree of springiness normally to bias the tongue 50 inwardly to the position actually shown in FIGS. 2 and 5 but to permit its resilient deformation outwardly from that position.

The manner in which the dividing wall 40 is supported in the lower part 14 of the housing 12 with the web 41 thereof spaced upwardly from the web 25 of the lower part 14 of that housing will now be described with particular reference to FIG. 7. For this purpose, the forward ends of the flanges 42 and 43 of the dividing wall 40 are inserted between respective ones of the side flanges 26 and 27 and the tongues 35 with the rearward end of the web 41 raised above the lower part 14 until the forward edge of the web 41 is supported on the upturned forward edge 29 of the web 25. The dividing wall 40 is then pivoted downwardly until the lugs 44 and 45 on the rearward edge of the web 41 engage the top surface of the web 25, at which time the upstanding lug 28 engages the rearward edge of the web 41 of the dividing wall 40 thereby preventing relative rearward movement of that wall. Frictional engagement between the flanges 42 and 43 of the dividing wall 40 and respective ones of the flanges 26 and 27 of the lower part 14 serves to retain those components in their assembled dispositions. Referring further to FIG. 7, it will be seen that the web 41 of the dividing wall 40 and the web 25 of the lower part 14 together define a compartment 52 in which a compression spring 53 is disposed in a manner yet to be described. For the sake of clarity, the spring 53 is not shown in FIGS. 6 and 7.

From FIGS. 2 and 4 it will be seen that the spring 53 comprises a generally planar section 54 in the form of a W with an additional leg 55 provided at its forward end. Generally centrally, the leg 55 extends upwardly and rearwardly as at 56 to a forwardly facing hook portion 57 from which the spring then extends forwardly as indicated at 58. The rearward end leg of the W-shaped section 54 of the spring 53 is identified by the legend 59. The generally planar W-shaped section 54 of the spring 53 is movably housed in the compartment 52 with the leg 59 thereof abutting the aforementioned lugs 28, 44 and 45. The upward extension 56 of the spring 53 passes freely through the aforementioned slot 47 in the web 41 of the dividing wall 40.

It is also to be noted that, with the lower part 14 of the housing 12 and the dividing wall 40 in their hereinbefore described assembled dispositions, the slots 31, 32, 48 and 49 are all transversely aligned.

Referring further to the upper part 13 of the housing 12, the manner in which that particular part is secured to the lower part 14 containing the dividng wall 40 will now be explained. For the purpose of such assembly, the forward end of the lower part 14 is angularly inserted into the forward end of the upper part 13 between the side flanges 16 and 17 respectively thereof until the inturned forward corners 23 and 24 of the flanges 16 and 17 engage the forward ends of the flanges 26 and 27 respectively of the lower part 14. The upper and lower parts 13 and 14 respectively are then pivotally moved together until the end flange 18 of the upper part 13 engages the rearward end of the housing, frictional engagement of the side flanges 16 and 17 of the upper part 13 with the side flanges 26 and 27 respectively of the lower part 14 serving to retain the two parts in their assembled disposition. It is to be noted that, in such an assembled disposition, the notch 20 in the side flange 16 of the upper part 13 reveals the slot 32 in the side flange 26 of the lower part 14 while the slot 21 in the side flange 17 becomes aligned with the slot 31 in the flange 27. The notch 22 in the end flange 18 receives the lug 28 of the lower part 14.

Prior to such assembling of the upper and lower parts 13 and 14 respectively, a generally planar and manually operable detent release member or arm generally indicated at 60 is disposed in the aforementioned aligned slots 32, 48, 49 and 31 so as to be retained therein by the end flange 18 of the upper part 13 of the housing 12. The arm 60 is formed at one end with a relatively narrow end section 61 which is freely received in the aligned slots 49 and 31 and, at its opposite end, with a somewhat wider end section 62 which is received in the aligned slots 32 and 48 and which is bent downwardly to form a release stud 63. Within the housing 12, the arm 60 is formed with two forwardly extending lugs 64 and 65. The lug 64 is adapted to abut the inner surface of the flange 42 of the internal dividing wall 40 so as to retain the arm 60 within the housing while the lug 65 engages the aforementioned tongue 50 so that, on the application of finger pressure to the stud 63, the tongue 50 is displaced outwardly from its normal position. When such manual pressure is released, the tongue 50 resiliently returns to the position shown in FIG. 5. It is to be noted that the arm 60 is omitted from FIGS. 6 and 7 for the sake of clarity.

The expansible mechanism 10 is shown in FIGS. 1 and 2 of the accompanying drawings as also including three planar members or panels generally indicated at 66, 67 and 68 but the use of a different number of such panels is equally within the scope of this invention. The first panel 66 is slidingly mounted in the housing 12 as shown in FIG. 1 between the upper part 13 and the dividing wall 40 and is formed at its rearward end with transversely outwardly extending lugs 69 and 70 and, generally centrally along its rearward edge, with an open ended forwardly extending slot 71. The forward end of the slot 71 receives the hook 57 of the spring 53 so that the spring 53 is operative to urge the panel 66 forwardly through the forward open end of the housing 12. In the extended position of the panel 66 as shown in FIG. 1, the lugs 69 and 70 are received in respective ones of the guide slots 38, forward movement of the panel 66 completely out of the housing 12 then being prevented by abutment of the lugs 69 and 70 with respective ones of the shoulders 36.

When the panel 66 is moved rearwardly into the housing 12, the lug 70 engages the aforementioned tongue 50 formed in the side flange 43 of the dividing wall 40 and that tongue 50 is then operative to retain the panel 66 in such a retracted position until the tongue is depressed by manual pressure on the release stud 63 at which time the spring 53 urges the panel 66 automatically into its extended position shown in FIG. 1.

At its forward end, the panel 66 is integrally formed with a central hinge sleeve 72 for interdisposition between spaced apart hinge sleeves 73 and 74 formed on the rearward edge of the second panel 67 so that the two panels 66 and 67 can be hingedly interconnected by a hinge pin 75. Similarly, the forward edge of the central panel 67 is pivotally interconnected to the rearward edge of the third panel 68 by a hinge pin 76. In this way, the panels 66, 67 and 68 can be folded in concertina fashion from their extended positions shown in FIG. 1 into the folded positions shown in FIG. 8 in which positions they can be manually pushed rearwardly through the open forward end of the housng 12 as indicated by the arrow A in FIG. 5. It should perhaps be explained at this juncture that the panel 66 is longer than either of the panels 67 and 68 since part of the panel 66 is retained at all times within the housing 12.

The expansible mechanism 10 is illustrated in FIG. 1 as being suitable for use as an expansion fastening device for a wrist watch band and, for such a purpose, the third panel 68 is shown in that figure as usefully being integrally formed with a pair of spaced apart hinge sleeves 77 and 78 for connection by a hinge pin 79 to a central hinge sleeve 80 formed on one end 81 of a watch band while a central hinge sleeve (not shown) can be provided on the flange 18 of the upper part 13 of the housing 12 for pivotal connection by a hinge pin 82 to the opposite end 83 of the watch band. Alternatively and as shown in FIG. 1, the strap end 83 can be pivotally connected by the pin 82 to a central hinge sleeve 84 formed on an adaptor-holder generally indicated at 85 and formed with spring metal side flanges 86 and 87 between which the housing 12 of the mechanism 10 can be removably retained.

If the mechanism 10 is also to be used as an identification device, information such as the owner's address, telephone number, blood type, allergies, etc., can be recorded, for example, by engraving on the faces of the panels 66, 67 and 68 as indicated at 88 and 89. Yet another possibility within the scope of this invention is to secure a record-bearing sheet 90, such as a monthly calendar, removably to one of the panels 66, 67 and 68 using a pressure sensitive adhesive coating on the back surface of such a sheet. Another possibility is for the owner's name to be engraved on the top surface of the web 15 of the top part 13 as indicated at 91.

It is to be noted that the end panel generally indicated at 92 in FIG. 8 differs from the previously described end panel 68 in that the former is not provided with a hinge sleeve on its forward end, as is required only when the mechanism is to be used as an expansible fastening device. Instead, the panel 92 has an integrally formed depending end flange 93 which closes the open forward end of the housing 12 when the panels are retracted into that housing. The structure illustrated in FIG. 8 also differs from that shown in the preceding figures in that the pivotal connection between the panels 67 and 92 is designed so as to urge the panel 92 in its released state to adopt the upwardly sloping position shown in FIG. 8. With such a pivot structure, the panels 66, 67 and 92 tend automatically to unfold into their extended linear configuration as they move forwardly out of the housing 12 under the action of the spring 53.

Having completed the description herein of the structure of the mechanism 10 shown in FIGS. 1 to 8 of the accompanying drawings, the manner of operation of that mechanism will briefly be summarized. Assuming that the panels 66, 67 and 68 thereof are in their extended positions as shown in FIG. 1 of the drawings with the outer panel 68 pivotally connected to the watch band end 81 and with the housing 12 held by the adaptor 85 which is in turn pivotally connected to the watch band end 83, the information recorded on the panels 66, 67 and 68 is readily visible and the watch band is expanded to allow its removal from the wearer's wrist.

When the wearer desires to fasten the watch band about his wrist, he simply folds the panels 66, 67 and 68 in a concertina-like manner into a position corresponding to that shown in FIG. 8. He then pushes rearwardly on the folded panels against the action of the spring 53 until the lug 70 of the panel 66 is engaged by the tongue 50, such engagement then serving positively to prevent accidental extension of the panels 66, 67 and 68 from within the housing 12. When the wearer wishes to release the mechanism 10, he simply presses on the release stud 63 to cause the lug 65 to depress the tongue 50 so allowing the panels 66, 67 and 68 to move forwardly through the open forward end of the housing 12 into their extended positions in which they can then be unfolded into their linear extended positions as shown in FIG. 1.

Referring now to FIGS. 9 and 10 of the drawings, there is shown therein generally at 95 a holder-adaptor by means of which the mechanism 10 can be secured to a flexible wrist strap generally indicated at 96, for example, a conventional nylon wrist watch strap. The adaptor 95 includes a base web 97 integrally formed with upstanding spring metal side flanges 98 and 99 between which the housing 12 of the mechanism 10 can be releasably but positively held. Ears 101 and 102 are integrally formed with each of the side flanges 98 and 99 and conventional spring expanding pins 103 and 104 are retained in aligned holes formed in the ears 101 and 102. The holder 95 can then be secured on the watch strap 96 by passing the latter downwardly between the pin 103 and the flange 99, below the base web 97 and upwardly between the pin 104 and the flange 98.

It will now be understood that the mechanism 10 can be secured to watch straps of different widths without modification or adjustment of the mechanism simply by the use of different sized adaptors.

Another form of holder-adaptor for use with the expansible mechanism 10 is illustrated generally at 105 in FIGS. 11, 12 and 13 of the accompanying drawings. The adaptor 105 is generally similar to the holder 95 in that it comprises a base web 106 and spring metal side flanges 107 and 108 for retaining the housing 12 of the mechanism 10 therebetween as shown in FIGS. 12 and 13 but as omitted from FIG. 11. For attachment to a key ring 110, the base web 106 of the adaptor 105 is provided with a transversely extending tongue 111 including an opening 112 through which the key ring 110 may be attached as shown in FIG. 12.

The base web 106 is also integrally formed with a spring tab 114 which is spaced apart slightly rearwardly from the rear surface of the base web 106 so that the adaptor can be clipped over the edge of a person's pocket as actually shown in FIG. 13.

Referring now to FIGS. 14 to 17 of the accompanying drawings, there is shown therein an alternative construction for the panels provided in an expansible mechanism in accordance with this invention. The arrangement illustrated in FIG. 14 comprises two panels generally indicated at 119 and 120, the former corresponding to the panel 66 of the mechanism hereinbefore described with reference to the preceding figures of the drawings.

The panel 119 is integrally provided at its rearward or left-hand end by a metal stamping operation on a single sheet of metal with upstanding lugs 121 and 122 which are disposed transversely outwardly of the side edges of the panel. The lugs 121 and 122 are provided for the same purpose as were the lugs 69 and 70 on the panel 66 on the mechanism 10. It will of course be understood, however, that guide slots wider than the slots 38 will need to be provided within the mechanism for slidingly accommodating the lugs 121 and 122.

A generally central notch 123 is cut from the rear end of the panel 119 to receive the hook portion 57 of the compression spring 53 provided within the housing of the mechanism.

At its forward end, the panel 119 is integrally formed with upstanding ears 125 and 126 which are disposed outwardly of respective side edges of the panel, openings 127 being provided in the ears 125 and 126 for a purpose yet to be explained. Immediately transversely inwardly of the ears 125 and 126, the material of the panel 119 is upset to provide forwardly and downwardly extending lugs 130 and 131 respectively. At its rearward end, the panel 120 is upset to provide rearwardly and upwardly extending tongues 132 and 133 which are integrally formed with outwardly projecting pivot pins 135 which in turn are freely received in respective ones of the openings 127 in the ears 125 and 126 respectively.

With the construction shown in FIGS. 14 to 17, the panel 120 can be moved between the open position shown in FIG. 14 and a closed position in which the top surface of the panel 120 is disposed in co-extensive opposition to the top surface of the panel 119. In the open position, the undersurfaces of the tongues 132 and 133 abut the top surfaces of respective ones of the lugs 130 and 131 to prevent pivoting of the panel 120 downwardly beyond the open position shown in FIG. 14 thereby ensuring that the top surfaces of the panels 119 and 120 are arrested in a generally coplanar mutual disposition.

One particularly important advantage of the structure shown in FIGS. 14 to 17 is that it can be manufactured relatively inexpensively by a metal stamping operation.

The versatility of the expansible mechanisms of this invention will now be appreciated. It will be noted, for example, that such a mechanism can be used as an expanding fastening device for a wrist watch band as well as for personal identification purposes. For the latter purpose, the mechanism can be secured on an existing wrist watch strap as shown in FIGS. 9 and 10 or it can have the dual function of identification and watch strap fastening device. For indentification purposes, the mechanism of this invention can alternatively be secured to a person's key ring or clipped in his pocket.

Yet another important advantage of the mechanism of this invention is that it can be constructed so that its assembly involves neither the use of any screws, nuts, bolts or similar fastening members nor the bending or deformation of any lugs for the purpose of retaining the several components in their assembled dispositions. This results in a substantial reduction in the manufacturing cost of the mechanism.

It should perhaps further be stressed that the invention is not restricted to the specific embodiments hereinbefore particularly described and that numerous modifications and variations can be made in the described structures without departing from the scope of the invention. It is, for example, possible to construct a mechanism of this invention with one or more panels although the use of a plurality of such panels is advantageous, an odd number of panels generally being indicated when the mechanism is to be used as a fastening device in the manner already described herein.

Numerous other applications and modifications of the structures described will be apparent to the reader.

Claims

What is claimed is:

1. An expansible mechanism including a hollow housing having an open forward end and defined by top and bottom walls retained in mutually spaced apart disposition by spaced apart side walls; a first panel having lugs projecting from its side and having side edges and forward and rearward ends and slidingly disposed within said housing for movement between a rearward retracted position essentially within said housing and an extended forward position in which it projects forwardly from said housing through said open end thereof; co-operating first detent means in said housing for preventing movement of said rearward end of said panel out of said housing; spring means within said housing and engaging said panel normally to urge said panel into said entended position thereof; co-operating second detent means in said housing releasably to retain said panel in said retracted position thereof within said housing against the action of said spring means; and a manually operable detent release member extending from within said housing and operatively associated with said second detent means to permit movement of said panel from said retracted position thereof into said extended position thereof under the action of said spring means upon operation of said detent release member, said second detent means comprising a resiliently displaceable abutment extending inwardly from a side wall of said housing for engagement with one of said lugs projecting from said first panel for releasably retaining that panel in said retracted position thereof and in which said manually operable detent release member comprises an arm slidingly and transversely mounted in said housing for engagement with said displaceable abutment whereby, on manual inward movement of said detent release arm, that arm is effective to displace said displaceable abutment for disengagement thereof from said lug in turn to permit forward movement of said first panel into said extended position thereof under the action of said spring means.

2. An expansible mechanism as claimed in claim 1 which additionally comprises a plurality of panels pivotally and serially end-interconnected to said first panel for movement between a linear extended configuration outside said housing and a concertina-folded configuration for bodily movement of said panels in said folded configuration thereof into and out of said housing through said open forward end thereof.

3. An expansible mechanism as claimed in claim 2 which includes an odd number of said panels so that a non-connected end of a terminal one of said panels is disposed in general proximity to said open forward end of said housing when said panels are retracted into said housing in said folded configuration thereof.

4. An expansible mechanism as claimed in claim 3 in which said non-connected end of said terminal one of said panels is provided with a first coupling means for securement to a first elongated band end and in which said housing is provided generally at its rearward end with a second coupling means for securement to a second elongated band end whereby said expansible mechanism is operative to function as an expansible fastening device for interconnecting such first and second elongated band ends.

5. An expansible mechanism as claimed in claim 3 in which at least one of said panels has visible information recorded thereon for inspection when said panels are extended from within said housing.

6. An expansible mechanism as claimed in claim 3 in which at least one of said panels has a record-carrying sheet removably bonded thereto for inspection when said panels are extended from within said housing.

7. An expansible mechanism as claimed in claim 2 in which said first detent means comprises lugs transversely projecting from said side edges of said first panel in proximity to said rearward end thereof and abutments in said housing in general proximity to said open forward end thereof for engagement of said abutments by respective ones of said lugs thereby to prevent movement of said rearward end of said first panel forwardly out of said housing.

8. An expansible mechanism as claimed in claim 7 in which said housing has a multipartite structure including upper and lower parts constituting respective ones of said top and bottom walls, each of said upper and lower parts including side edge flanges for engagement with the corresponding side edge flanges of the other of said parts to constitute said side walls of said housing.

9. An expansible mechanism as claimed in claim 8 in which said housing also includes an internal dividing wall in spaced apart disposition relative to each of said top and bottom walls of said housing so as to define a first compartment for accommodating said spring means and a second compartment for accommodating said panels, in which said spring means comprises a compression spring with a first end thereof engaging an abutment at the rearward end of said housing and with a second end thereof extending through an elongated slot in said internal dividng wall for engagement with said first panel.

10. An expansible mechanism as claimed in claim 9 in which said internal dividing wall is integrally formed with side edge flanges for contiguous surface abutment with said side edge flanges of said lower part of said housing, in which said internal dividing wall and said bottom wall of said housing are integrally formed with transversely spaced apart lugs for abutment by said first end of said compression spring, and in which said side edge flanges of said lower part of said housing are integrally formed at said open forward end of said housing with longitudinally extending tongues folded back so as to grip respective ones of said side edge flanges of said internal dividing wall and to constitute said abutments for engagement by said lugs provided on said first panel for preventing forward movement of said rearward end of said first panel out of said housing.

11. An expansible mechanism as claimed in claim 11 in which said resiliently displaceable abutment comprises a section of one of said side edge flanges of said internal dividing wall.

12. An expansible mechanism as claimed in claim 11 in which said arm constituting said manually operable detent release member is slidingly disposed in aligned openings in said side edge flanges of both said internal dividing wall and said lower section of said housing and in which said upper section of said housing is formed with a rearward end flange closing said openings in the assembled housing.

13. An expansible mechanism as claimed in claim 2 which comprises two said panels, said first panel having a generally planar top surface and being formed on said side edges thereof generally at said forward end thereof with transversely spaced apart upstanding ears, the second panel of said two panels also having a generally planar top surface and being provided at a rearward end thereof with spaced apart rearwardly and upwardly sloping tongues provided with transversely outwardly porjecting pivot pins freely received in openings in respective ones of said ears thereby pivotally to interconnect said first and second panels for movement between said linear extended configuration thereof and said folded configuration thereof, and forwardly and downwardly sloping lugs being provided in said first panel at said forward end thereof for abutment by respective ones of said tongues when said panels are in said linear extended configuration thereof with said first and second panels in mutual edge abutment, whereby said panels can be pivoted into said folded configuration thereof with said planar top surfaces thereof in mutual surface opposition and whereby said abutment of said tongues with said lugs restricts relative pivoting movement of said panels angularly past said linear extended configuration thereof.

14. An expansible mechanism as claimed in claim 13 in which said lugs and said ears are integrally formed with said first panel and in which said tongues and said pivot pins are integrally formed with said second panel.

15. An expansible mechanism as claimed in claim 1 in which said housing is releasably secured in a holder including a perforated extension for attachment to a key ring.

16. An expansible mechanism as claimed in claim 1 in which said housing is releasably secured in a holder including a folded spring clip for gripping attachment with the edge of a pocket in the manner of a pen clip.

17. An expansible mechanism as claimed in claim 1 in which said housing is releasably secured in a holder including spaced apart and generally parallel slots for receiving a flexible watch strap.

18. An expansible mechanism as claimed in claim 17 in which said holder comprises spaced apart upstanding spring side flanges for gripping said side walls of said housing.