Abstract:
Door chime assembly includes a chime base having a rear plate and at least one resonance chamber secured to said rear plate, a tone bar within the chamber and a striking means mounted on the plate for striking the tone bar. The chime base is molded in a single piece and employs at least one living hinge which permits folding of parts of the assembly to form the resonance chamber. The tone bar is mounted on dowels in the chamber of a length which prevents the tone bar from falling off the dowels during transit.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a door chime assembly, and more particularly to a one-piece door chime assembly having one or more resonance chambers with portions which are foldable to provide such chambers. 
     2. Background and Objects of the Invention 
     Door chimes are well known in the art and typically include a chime base holding one or more tone bars and a striking means to strike the tone bars, which vibrate with a predetermined tone. Conventional chime bases also include one or more sound or resonance chambers which amplify the tone bar vibration. Conventional door chime bases, particularly the sound or resonance chambers, are typically made of several component parts, which require handling and assembly. Even for chime bases made by injection molding, a separate piece is necessary to enclose each sound chamber. These extra pieces add to the amount of handling required to assemble each door chime. 
     In addition to the problem of increased handling, a further problem of conventional door chimes is that the tone bars become misaligned or loose when shipped or mishandled. Conventional solutions to this problem have included tightening the tone bars with rubber bands as well as using cardboard inserts to wedge the bars in place during transit which bands or inserts must be removed before the chime assembly is placed in operation. Although ostensibly solving the problem, these solutions further increase the amount of handling required and require actions on the part of the purchaser to remove the retaining devices. 
     One object of the invention is to reduce the number of component parts required to assemble a door chime, particularly by reducing the number of component parts in the door chime base. 
     Another object of the invention is to reduce the amount of handling required by molding the entire chime base from a single piece of material, the parts of which may be easily folded to provide the resonance chambers. 
     A further object of the invention is to facilitate the shipping of door chimes, particularly the securing of the tone bars, by eliminating the special packaging requirements necessary to secure conventional tone bars in place during transit. 
     SUMMARY OF THE INVENTION 
     In accordance with the preferred embodiment of the invention, a door chime assembly includes a door chime base having one or more sound or resonance chambers, each of which encloses a tone bar, and wherein the entire chime base is made of a single piece of plastic material, and includes one or more living hinges to connect the component base parts and to form the sound chamber structures. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other objects and advantages of the present invention will be apparent from the following detailed description of the presently preferred embodiments thereof, which description should be considered in conjunction with the accompanying drawings in which: 
     FIG. 1 is a top view, partly in section, of an assembled door chime base, tone bars and striking means of the claimed invention; 
     FIG. 2 is an end elevation view, partly in section, of the assembled door chime shown in FIG. 1; 
     FIG. 3 is a top view of the door chime embodiment of FIGS. 1 and 2 unassembled; and 
     FIG. 4 is an end elevation view, partly in section, of the unassembled door chime base embodiment shown in FIG. 3. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     With reference to FIGS. 1-4, the preferred embodiment of the door chime assembly 1 of the invention includes a base portion 2 which is illustrated in FIGS. 1 and 2 in an assembled state without a decorative cover. Door chime base portion 2 includes a rear plate 3 having mounting holes 4 to secure said base 2, and hence, said assembly 1, to a wall. Base portion 2 also includes a pair of resonance chambers 5 and 5a, forming an integral part with said rear plate 3. A conventional solenoid, or strike means 6 is secured to said rear plate 3 adjacent said resonance chambers 5 and 5a. In the embodiment shown in FIGS. 1-4, a pair of opposed resonance chambers 5 and 5a are shown with said solenoid means 6 secured between them. 
     Although not required in accordance with principles of the invention, it is conventional to provide the door chime assembly 1 with two chime bars 9 and 9a, two of which are struck by a first electromagnetically movable rod when a first door button, e.g. a front door button, is operated and one of which is struck by a second electromagnetically movable rod when a second door button, e.g., a back door button is operated. Each strike rod is movable by separate, electrically energizable solenoids. Solenoid means 6 includes one or more strike rods 7 and 7a, each situated within an electrically energizable solenoid 8 (only one of which is schematically shown in FIG. 1), which when energized causes said strike rod 7 or 7a to move longitudinally of its axis and strike a tone bar 9 or 9a, as shown in FIGS. 1 and 2, causing the respective tone bar 9 or 9a to vibrate at a predetermined tone. Conventional chimes typically place said resonance chambers 5 and 5a around or in close proximity to the tone bars 9 and 9a to amplify the sound. Strike rods 7 and 7a pass through one or more openings or slots 10 and 10a along inner walls 11 and 11a of said resonance chambers 5 and 5a, where said inner walls 11 and 11a face said solenoid means 6. When struck by said strike rod 7 or 7a, tone bar 9 or 9a vibrates within said resonance chamber 5 at said predetermined tone. 
     As shown in FIGS. 1 and 2, each resonance chamber 5 and 5a, in addition to inner walls 11 and 11a, includes outer walls 12 and 12a, top wall 13 and 13a, a bottom wall 14 and 14a (portions of the plate 3), a front wall 15 and 15a and a back wall 16 and 16a, where the front walls and back walls being integral with the respective walls 11 and 11a. As shown in FIGS. 3 and 4, instead of the resonance chambers 5 and 5a being made of several separate components as in conventional chimes, each requiring handling and assembly, each of the walls is, preferably, attached to one another, forming a simple-to-assemble one-piece door chime base portion 2. 
     Outer walls 12 and 12a and top walls 13 and 13a are connected to said bottom walls 14 and 14a, i.e. the rear plate 3, by line or living hinges 17 and 17a, which form a flexible bridge of material between said outer walls 12 and 12a and rear plate 3 (bottom walls 14 and 14a ), pivotably joining said outer walls 12 and 12a to rear plate 3 along the junctures 18 and 18a between them, as shown in FIG. 3. Living hinges 17 and 17a are preferably made of the same material as said door chime base portion 2, but are sufficiently thinned so that the living hinges 17 and 17a bend, allowing the outer walls 12, 12a, and 13, 13a to fold over and contact inner walls 11 and 11a, respectively. Although other plastics can be used, suitable materials for both base 2 and living hinges 17 and 17a include polypropylene and compositions of polypropylene including up to 20% of talc. By sealing the junctures 18 and 18a with living hinges 17 and 17a, resonating air within said resonance chambers 5 and 5a is restricted along the junctures, thereby preserving the tonal resonance with the chambers 5 and 5a. Since conventional resonance chambers are made of several separate pieces each requiring individual handling, one advantage of using living hinges is that the entire door chime base portion 2 may be uniformly made by straight injection molding into a single piece, as shown in FIGS. 3 and 4, which may be then easily assembled, as shown in FIGS. 1 and 2, thereby greatly reducing the handling process. It should nonetheless be understood that line or living hinges 17 and 17a can attach the above walls across junctures 18 and 18a with a plurality of short hinge sections along the junctures. 
     Attached to said top walls 13 and 13a are a pair of clasp means comprising straps 19 and 19a, which are preferably secured to said top walls 13 and 13a, respectively, by living hinges 20 and 20a, which allow the straps 19 and 19a to also be injection molded as a component part of the one-piece chime base portion 2 described above. The straps 19 and 19a, shown bent back in FIG. 3, include slotted portions 21 and 21a, respectively, which upon closing of the resonance chambers 5 and 5a, as shown in FIGS. 1 and 2, engage one of a pair of corresponding projections 22 and 22a secured along the exterior of the inner side walls 11 and 11a of the resonance chambers 5 and 5a. When engaged, the clasp means 19 and 22, or 19a and 22a, firmly secures said resonance chambers 5 and 5a in place. It should be understood that other clasp means may be employed to secure said chambers 5 and 5a. 
     Tone bars 9 and 9a rest within said tone resonance chambers 5 and 5a, respectively, on a pair of dowel supports 23, which have pins 24 and 24a passing through holes 9b in said bars 9 and 9a. Preferably, the length of said dowel support 23 is so selected that upon assembly said tone bars 9 and 9a are centrally and securely situated within said tone resonance chambers 5 and 5a, respectively. To permit relatively free vibration of stricken tone bars 9 and 9a rubber grommets 25 are interposed between the pins 24 and 24a and the tone bars 9 and 9a. The grommets 25 preferably also extend slightly outwards beyond the faces of the tone bars 9 and 9a to further cushion the bars 9 and 9a from the dowel supports 23 and 23a and wedge members 26 and 26a affixed to the inside surfaces of said inner side walls 11 and 11a. Wedge members 26 and 26a have a sufficient thickness to engage said grommets 25 and thereby prevent said tone bars 9 and 9a from falling off the pins 24 and 24a during transit and handling of the chime assembly. 
     A decorative cover (not shown) may overlie the door chime assembly 1 to cover the solenoid means 6 and chambers 5 and 5a with a more aesthetic front. The decorative cover should include a plurality of holes or slots to transmit the resonating sounds produced therein and alert persons adjacent the place where the chime assembly is installed. 
     As mentioned in the background and objects section, an advantage of the invention is to reduce the number of component parts necessary to construct a door chime assembly. In the above embodiment as illustrated in FIGS. 1-4, the entire door chime base portion, including rear support 3, resonance chambers 5 and 5a, clasps 19 and 19a, and living hinges 17, 17a, 20 and 20a, is made of one piece, eliminating a variety of separate component parts and reducing the amount of handling and assembly required, particularly in constructing or adding the tone resonance chambers 5 and 5a. A further benefit of the foregoing construction is that the tone bars 9 and 9a are prevented from falling off the pins 24 and 24a and thus, do not become loose or misaligned during shipping. 
     It should be understood that although a pair of resonance chambers 5 and 5a are illustrated and described, the invention may utilize a single chamber or more than two chambers. It should also be understood that it is not necessary that all resonance chambers have a tone bar therein. A combination of &#34;empty&#34; chamber and a chamber with a tone bar may thus be employed if it is desired to use the structure of the invention with only a single tone bar. 
     Although a preferred embodiment of the present invention has been described and illustrated, it will be apparent to those skilled in the art that various modifications may be made without departing from the principles of the invention.