Abstract:
A housing is shaped and sized to conform to the user&#39;s ear in the manner of a hearing aid. Within the housing is a position-responsive switch and a second generator responsive to the switch. An arm extends from the switch exteriorly of the housing to allow easy adjustment of the switch&#39;s position relative to the housing. In use, the housing is positioned behind the user&#39;s ear and the switch adjusted so that the sound generator is off. Should the user&#39;s head nod, the sound generator will be actuated, alerting the user by both bone conducted and atmospherically conducted sound, to prevent his falling asleep.

Description:
BACKGROUND OF THE INVENTION 
     In French application No. 76 39723 filed Dec. 31, 1976, a device controlled by the inclination of the head of a driver and preventing his falling asleep has been described. The device comprises essentially a detector of the changes of the head positions and an audible warning. The embodiment shows a detector placed on the ear and an alarm positioned in a relatively large box. This device, in use, has proven itself impractical, fragile and of insufficient sensitivity. For example, the shape of the envelope of the detector-interrupter requires precise positioning on the ear and its necessary displacement for establishing (or breaking) the circuit of the alarm renders it troublesome to the user who has little tolerance for it. 
     SUMMARY OF THE INVENTION 
     To overcome these and other disadvantages, the inventor has perfected a device of the type mentioned above comprising a head position detector, a warning emitter, and a battery, characterized in that these three miniaturized elements are held in a prosthetic device of the type which is contoured to the ear such that the position of the detector may be adjusted within the very interior of the prosthesis. To do this, the detector comprises a small mercury ampule mounted in a rocker adapted to be pivoted around an interior axis of the prosthesis by means of a finger passing through a slit provided in the end of the prosthesis. The slit is arcuate and at least one of its edges is notched to form a curved rack in which the finger of the rocker or a projection provided for this purpose on the finger penetrates. It is thus possible to place the prosthesis on the ear in a normal position such that it is of little annoyance, and then to cause an adjustment with the finger extending to the exterior, to bring the mercury ampule to a position such that an abnormal inclination of the head causes a sufficient displacement of the mercury in the ampule to close the supply contact of the alarm. This adjustment of the position of the mercury ampule makes it possible for each driver to adapt the device to his morphology and/or his posture. 
     The mercury ampule thus serves as an automatic breaker or switch in normal usage. It can likewise serve to switch out of service, on the condition that it is properly positioned in the arrangement box, without which the alarm might be unintentionally set off and the battery uselessly wasted. 
     According to the invention, a second switch or interrupter operated exclusively manually is placed in series with the ampule. Thus, when not in use, the current can be cut, whatever the position of the prosthesis in the arrangement box, and whatever the position of the mercury ampule. 
     Since the battery must be removeable from the prosthesis for its periodic replacement, it is placed in a support which is maneuverable from the exterior, and this movement is utilized in part to open or close the circuit. The support is pivoted in a passage provided in the thickness of the prosthesis to assume one of three positions. In a first position it is completely embedded and the battery powers the apparatus. In a second semi-embedded position, the battery no longer powers the apparatus but cannot be removed. In a third position the support is almost completely removed from the prosthesis and the battery can be removed or inserted in place. The battery support is generally shaped in the form of a short thick cylinder whose hollow portion is occupied by the battery. This cylinder comprises a large slot or opening over a portion of its periphery placed in the prosthesis and a gripping finger on its external periphery. One of its faces comprises a head adapted to be embedded in the hollows provided in the thickness of the wall of the prosthesis to maintain the support in the embedded or semi-embedded position. 
     The possible movement of the battery maneuvered by means of the finger of its support makes it possible to rest it or not against two contact springs. One of the springs is positioned laterally and makes contact across the opening of the battery support, and the other spring is attached at the end of the prosthesis and makes contact with the corresponding face of the battery. The lateral spring is in the general form of a &#34;V&#34;, one of its arms being fitted in an opening provided in the lateral wall facing the opening of the battery support, the other arm being directed towards this opening with a free end bent in a fashion so as to go through it and to laterally rest on the battery. The spring placed at the end has a general shape of a plate which is half-slotted lengthwise in a manner so as to define two tongues (or fingers) of unequal width. The narrower of the tongues is folded towards the interior with a rounded attachment bent at a right angle to bear against the face of the battery and to make contact. 
     The prosthesis of the type contoured to the ear is formed of two molded elements comprising complimentary hollows, and which are substantially symmetrical in a fashion so as to define a receptical extending from the narrowest to the widest portion of the prosthesis and constituting a container for the detector of the inclination of the head of the wearer, a container for the battery and its contacts, and a container for the alarm. 
     The miniaturization of the apparatus has involved a minute study of the prosthesis elements which exhibit numerous original characteristics which can practically only be described by the drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     One embodiment of the invention is illustrated in the annexed drawings in which: 
     FIG. 1 is an exterior and perspective view of the device ready for use, 
     FIG. 2 is a schematic and perspective blown-up view of the apparatus assembly (in the alarm position). 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The device is positioned in a prosthesis of the type whose contour matches the ear. In FIG. 2, the external corners of this prosthesis have been shown in continuous dashed lines for clarity of the drawing, but it is well understood that the exterior corners are rounded, as this may otherwise be seen in FIG. 1. 
     The prosthesis is formed of two hollowed molded elements 1 and 30 which are complimentary, substantially of the same volume, constituting a container for the apparatus placed therein. 
     Interiorly the housing is divided essentially into three zones A, B, C to hold the mercury ampule 53, the battery 60 and the alarm 73. 
     Element 1 comprises walls 2 (called end wall) 3 and 4 (called lateral walls) and 5 (called lower wall). The end 2 has, from left to right in FIG. 2, a planar surface 6 ending in a rounded portion 7 with a spindle 8 at its center. Beyond this rounded portion 7 is a slit 9, slightly curved, whose edge 10 furtherest spaced from the spindle comprises notches 11 defining a curved rack. 
     Beyond this zone A, is zone B with at this position the wall 3 having a height of approximately one half of elsewhere and with two internal projections or bulges 12 and 14. The projection 12 is rounded and comprises at its center an axle portion 13 extending to the normal level of the wall. The projection 14 is angular with two small depressions 15 and 15&#39;. Opposite this wall 3, the wall 4 is of normal height but is reinforced at 16 until approximately half its height, with an axial portion 17 which extends to the level of the walls. Another projection 16&#39; faces the projection 14, with an axial portion 18. The projections 16 and 16&#39; act as shoulders to define a housing for spring 69 which will be discussed below. 
     Zone C begins after this projection 14, with a projection 19, 19&#39; facing it. The molding is adapted such that the housing formed by the elements 1 and 30 is parallelpipedic. On the base 2 five depressions 20 are provided for the positioning of the feet 74 of the warning means or alarm 73. 
     The element 1 comprises small mortises 21 in the upper faces of the walls 3 and 4, and the element 30 has small corresponding cooperating tenons 31. 
     Element 30 is of a generally similar form to element 1, but symmetrical with respect to their common plane. It comprises walls 32, 33 and 34 with an additional wall 39 provided with a tubular stub 40. The base 32 also comprises a surface 36 ending in a rounded portion 37 whose center is occupied by a spindle 38 (whose height extends to the common level of the elements 1 and 30). 
     In zone B wall 33 is approximately half as high as elsewhere and comprises a projection 42 (with an spindle portion 43) symmetrical to 12 (and 13) of the element 1. Base 32 comprises small heads 41 for the attachment of the spring 66. 
     Zone C of element 30 is symmetrical to that of the element 1. It can be bored with small orifices in this zone C. 
     Other details of manufacture will appear from examination of the drawings. Thus, at zone B one clearly sees that the walls 3 and 33 define between them a passage 52. 
     It is seen that one places the ampule 53 at A, the battery 60 in B, and the alarm in C in the receptacle. 
     An ampule of known type is fixed in a rocker comprising two elements 44 and 54 of which one end 45 (and 55) is narrower or rounded with a mortice head and an orifice 47 for the passage of the axial portion 8. The other end 48 of the plate 49 is offset at a right angle in the direction of the other element 54. On the other face of the plate 49 a finger 50 is provided comprising a projection 51. After mounting, this finger passes into the slot 9 and the protrusion 51 lodges itself in notch 11 of the edge 10. Element 54 has the same general form with a rounded end 55 and a tenon head 56 which extends into the mortice 46. The opening or orifice 57 permits the spindle portion 38 to pass in such a manner that the rocker assembly of the ampule can pivot slightly around two half spindles 8, 38 which face one another and constitute a single spindle after assembly. The end 58 of the plate 59 is bent in a right angle towards the other element 44. The ends 48 and 58 bear against one another, and the ampule 53 is held between the two elements 45 and 54, pivotable around the spindles 8 and 38, between the walls of the elements 1 and 30 and blockable in the selected position with the assistance of a finger 50, accessible from the exterior of the apparatus. To assure good protection of the ampule it is embedded in a layer of foam material (not shown in the drawings) upon closure of the rocker. 
     Battery 60 is mounted in a support 61 of thickness substantially equal to that of the battery and adapted to fit into the passage 52. This support 61 surrounds the battery except at 62 and comprises a curved face 63 for holding the battery. Hole 64 is bored with the thickness of the support for the passage of the half-spindles 13 and 43. Lug 65 is provided opposite this hole. 
     Still in zone B, is attached interiorly on the base 32, a spring 66, by pressing the pipe 41 into the holes 66&#39;. This spring 66 comprises a tongue 67 which is directed towards the interior. Tongue 67 further comprises an attachment 68 bent at a right angle towards battery 60. Spring 69 is attached along wall 4 on the reinforcement or backing means 16 and 16&#39;. End 70 is placed between the wall 4 and the spindles 17 and 18. This spring has the general shape of a &#34;V&#34; whose bottom end rests against the projection 19&#39; and whose free end 71 is bent towards the battery 60. 
     Battery 60 is placed in its support 61 and the support is fitted on the spindle 13, 43 of which each of the two portions penetrates into the hole 64 on their respective sides. When one presses on the support 61 and when one makes it pass into the passage 52, the battery 60 makes contact, at its end, with the attachment 68 of spring 66, and then laterally with the end 71 of the spring 69 (across the passage 62). On one of the two faces, the support 61 comprises a protuberance 72 (in a broken line in the figure) which can penetrate into one of the two depressions 15, 15&#39;. When the contact is made between the battery and the two springs 66 and 69, the protuberance 72 is lodged in the depression 15. By pulling on the lug 65, one pivots the support 61 until the moment when the protuberance 72 reaches the depression 15&#39;, and at this moment the contact is interrupted, but the battery cannot fall. This maneuver makes it possible to open or close the circuit. When necessary, by continuing to pull on the lug 65, and as a result by continuing to pivot the support 61 around the spindle 13, 43 in a fashion so as to completely disengage the battery, the battery can be replaced. 
     In the zone C, an alarm or warning device (buzzer) 73 is positioned such that its feet 74 penetrate into the depressions 20 or 35. So as to not complicate the drawings the electrical connections of conventional design have not been shown. 
     After assembly has been completed, the apparatus is provided with a conventional clip 75 for its good attachment to the ear. 
     Other embodiments are possible without going beyond the scope of the invention. Preferably the prosthesis has a shape such that it is fitted over the mastoid bone. 
     The operation of the device can be explained as follows: When the driver inclines his head, the alarm is automatically set off, it emits vibrations and a sound. The vibrations are transmitted by &#34;bone conduction&#34; (because the prosthesis is fitted on the mastoid bone) and the sound is transmitted atmospherically. To improve this atmospheric transmission, one can extend the clip by a canule (hearing tube) ending in a small sphere introduced in the ear hole.