US 3617658 A
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United States Patent  Inventors Wolfgang Griiger,
Stuttgart-Zuffenhausen; Heinz fisterBerlimbiinter, Schwanck, Berlin, all of Germany  Appl. No. 9,461
 Filed Sept. 12,1969
 Patented Nov. 2, 1971  Assignee International Standard Electric Corporation New York, N.Y.
 Priority May 29, 1969  Germany  SNAP-TOGETHER TELEPHONE SUBSET 4 Claims, 1 Drawing Fig.
 US. Cl 179/179  Int. Cl H04m 1/02  Field of Search 179/179  References Cited UNITED STATES PATENTS 3,133,163 5/1964 Persson et a1 179/179 2,495,164 l/l950 Erickson 179/179 X Primary Examiner-Kathleen H. Claffy Assistant ExaminerThomas W. Brown Attorneys-C. Cornell Remsen, Jr., Walter J. Baum, Percy P.
Lantzy, J. Warren Whitesel and Delbert P. Warner ABSTRACT: The baseplate and the cover of the subset are connected in such a way to one another that projections are arranged on the front side of the cover, for engaging correspondingly shaped slots provided in the baseplate, and in that on the rear side of the cover there is provided a recess which is engaged by a flexible hook-shaped projection provided on the baseplate.
The present invention relates to the housing of a telephone subset composed of a cover portion and of a baseplate.
In conventional types of embodiments of telephone subsets the baseplate, on which mostly all switching elements or, at least, only with the exception of the dial switch, all remaining mechanical and electrical components are arranged, is mounted to the cover of the subset with the aid of two screws. These screws are arranged near the front and rear edges of the subset and are made undetachable with the aid of threads in the baseplate, safety washers, springs, and the like. Besides this expenditure, it is still necessary to provide in the cover of the subset thread-type inserts by which the die-cast tool is rendered more expensive. Since various institutions, such as the postal authorities, require the subsets to be capable of being sealed, the screwheads are mostly arranged in a countersunk fashion, so that the space above the screwhead can be sealed with a casting resin, or the like. In order to avoid the disadvantage of the time-consuming sealing, as well as of the troublesome removal of the sealing compound which is necessary under certain circumstances, one'type of embodiment has already become known in which the borehole, instead of with a sealing compound, is closed with a prefabricated sealing disk. The latter, however, can only be removed in the destructed state, and it cannot be excluded that, in so doing, the edges of the borehole in the baseplate are damaged.
it is the object of the present invention to avoid the aforementioned disadvantages, in other words, to provide a connection between the baseplate and the cover of the subset doing without screws, disks, threaded inserts, and the like, but still providing the possibility of sealing the subsets. According to the invention this is accomplished in that to the front wall of the cover of the subset, there are die-cast two straps extending beyond the lower edge of the cover in the form of ring-sectorlike flaps which, when hinging the cover, engage correspondingly shaped receptacles of the baseplate projecting on three upwardly extending walls, and in that in the rear wall of the cover of the subset there is provided at least one recess which is engaged by a flexible, hook-shaped projection of the baseplate when the cover is pressed into position.
it is appropriate for the slots to extend through the receptacles of the baseplate, because in that case the flaps may be longer and, consequently, the holding arrangement is rendered still more reliable.
The requirement for being capable of being sealed is met by the inventive housing in that directly behind the flexible projection in the baseplate, there is provided a borehole and, in alignment therewith, and in the cover of the subset, above the recess, there is provided an abutment for receiving a latching pm.
This type of embodiment provides for a substantial reduction in Lcosts for the housing of the subset. This is so because, on one hand, there may be completely omitted the connecting screws and the expenditure required for the holding arrangement thereof; and, on the other hand, various steps of operation may be omitted, such as the insertion of the screws, and the screwing together of the parts. The placing in position of the cover of the telephone subset is effected in the most simple way and requires a minimum of time and skill.
The invention will now be described with reference to the accompanying drawing, showing the baseplate with the cover of the telephone subset as hinged thereto, in a longitudinal sectional representation. in this drawing there are only shown those parts which are important for enabling a better understanding of the invention, i.e. all internal constructions have been omitted.
The baseplate of the telephone subset is indicated by the reference numeral 1. and the cover of the subset by the reference numeral 2. Both parts are made from a plastics material. To the front wall of the cover 2 there are shaped vertical straps 4 projecting over the bottom edge of the cover in the shape of flap projections or tongues 6 which, when looked at from the side, are designed to correspond to the sha e of a ring sector. Appropriately, two such flaps are die-cast t ereto,
but it is equally well possible to provide more such flaps.
The projections 6, when positioning the cover 2 on the baseplate l, are inserted in corresponding receptacles which are shaped to the inside of the baseplate. The receptacles are formed by walls 10 which are pulled upwards, and surround the slot 3 on three sides. The rear side is left free in order to facilitate the insertion of the flaps. The front wall 10 is arched, and the curvature corresponds to that of the projection 6. The slot 3 may be closed on the outside of the baseplate but, for die-cast technical reasons it may also be appropriate, to provide it in the shape of an open recess.
After the cover 2, by inserting the flaps 6 into the receptacles of the baseplate l, is hinged thereto, this condition is illustrated in the drawing-the cover is swiveled also with the rear side against the baseplate 1 until it becomes engaged. To this end the rear side of the cover 2 contains a recess 7 into which there fits a hook-shaped flexible projection 5 of the baseplate 1, which is die-cast to the rear side wall thereof. it is also possible to arrange several such recesses and fitting projections, but in order to obtain a reliable holding arrangement, it is sufficient to provide one such engaging device, because the cover itself is anyway fixed in position by a step-shaped rim extending along the top edge of the baseplate 1.
It is of advantage to provide an embodiment in which the size of the projection 5 corresponds somewhat to the surface area of a finger top, so that the pressing in of the projection, when loosening the cover 2, is possible in a particularly easy way.
Directly behind the projection 5, the baseplate 1 is provided with a borehole 8 which, in the cover 2 of the telephone subset, above the recess 7, is opposed by an abutment 9, e.g. a blind hole, in an aligned fashion. In cases where the subset is to be sealed, a latching pin is inserted at this point which, in the closed condition of the housing, makes it impossible to press-in the projection 5. The head of the latching pin is designed in such a way that the pin can only be removed by an authorized person.
The portion of the projection 5 which is visible in the closed state is either designed in the way as shown in the drawing, i.e. the vertical surface is restricted on both sides and at the bottom edge, by rim strap portions, with the edges thereof following the contours of the cover 2, or else the outer surface of the projection 5 is adapted to the contours of the cover, and the straps are provided as a reinforcement on the inside.
What is claimed is:
l. A housing for a telephone subset which is composed of a cover and of a baseplate, characterized in that to the front wall of the cover of the housing there are die-cast two straps extending beyond the bottom edge of the cover in the form of ring-sectorlike projections, said straps engaging cor respondingly shaped recesses provided in the baseplate to hinge the cover to the baseplate, said baseplate including walls extending upwardly on three sides, and at least one recess provided in the rear wall of the cover of the subset which is engaged by a flexible hook-shaped projection provided on the baseplate when the cover is pressed into position to close the housing.
2. A housing according to claim 1, characterized in that the recesses provided in the baseplate extend through said baseplate.
3. A housing according to claim 1, characterized in that directly behind said flexible projection in said baseplate, there is provided a borehole and, in alignment therewith and in the cover of the housing, above the recess, an abutment for receiving a latching pin.
4. A housing according to claim 1, characterized in that the portion of said projection which is visible in the closed state of the housing is adapted to the contours of the cover of the housing, or is provided with a finger portion.
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