The invention relates to a housing, especially of plastic for an electronic circuit, especially an antenna amplifier for use in an automotive vehicle according to features of the preamble of patent claim 1.
Electronic circuits which include electronic components arranged on a printed circuit board are usually protected by a housing of plastic for better isolation from mechanical effects of the interior. In order to be able to arrange the printed circuit board in the housing, the housing can be comprised of two identical or different halves although more than two parts can be conceivable as well. After the mounting of the printed circuit board in one of the housing parts, at least a further housing part can be connected detachably or nondetachably therewith. If the connection is a nondetachable connection, the housing parts can be joined, for example, by an adhesive. This has however the disadvantage that in the case of a failure, a housing must be destroyed to afford access to the arranged circuit board and its components.
A screw connection of the two housing parts, for example, is conceivable for a detachable connection thereof. This however has the drawback that to connect the two housing parts, a tool as well as additional fasteners are required. This increases the numbered parts which are necessary and, in conjunction therewith, the cost of mounting or assembly. In addition, snap connections are known for connecting the housing parts together and can include detent hooks on one housing part which can engage in openings or recesses in the other housing part. These can have however the disadvantage that they may not be able to connect the two housing parts sufficiently strongly together so that, in spite of the connection of the housing part by snap fasteners, the two housing parts can move relative to one another and can lead to undesired noise generated by the relative movement of the housing parts. Furthermore, the reliability of any seal between the two housing parts cannot be guaranteed so that especially it is possible for moisture or water sprayed onto the housing to penetrate into the interior. There is also the danger with such snap connections that two parts will not sufficiently lock together or will not lock together at all so that while optically one might have the impression that the two housing parts are connected together, in operation and especially in the case of vibration, the two housing parts can become detached from one another.
It is the object of the invention, therefore, to provide a housing of at least two parts to receive a printed circuit board with electronic components thereon, especially an antenna amplifier for an automotive vehicle in which the at least two housing parts are connected together by a snap connection more reliably and effectively.
This object is achieved with the features of patent claim 1.
According to the invention, it is provided that at least one snap connection is so configured that after the parts are locked together, they remain under a prestress, for which purpose on the one housing part an elastically yieldable snap part is arranged and on at least a further housing part, there is a part which effectively cooperates with that snap part to provide the elastic connection. The elastically yieldable snap part is so formed that it, after the assembly of the at least two parts, first forms a connection with the corresponding parts when a mechanical effect, especially a pressure application has been applied or produced. These snap connections for joining the at least two housing parts together have the advantage that they can be mounted or connected without additional components in that they are namely provided on the at least two housing parts and assembled by pressing the snap part. The snap part then engages forceably or indexes with the corresponding part of the other housing part and connects the two housing parts reliably and effectively together. Through the pressure application to the snap part, the entire snap connection after assembly remains under a certain prestress so that the at least two housing parts reliably bear against one another and can no longer move relative to one another.
A further advantage of the invention resides in that, after pressure applications to the snap part on the one housing part during its engagement with the corresponding part, a sound (clock) can be heard which serves as a signal to the mounting individual that the snap connection has been engaged in a reliable and proper manner. The same applies also for automated assembly of the at least two housing halves. The prestress under which the at least two housing parts remain has, in addition, the advantage that it can survive permanently harsh environmental conditions as may prevail in an automotive vehicle releasably without the development of noise from relative movement of the at least two housing parts. It is still another advantage of the snap connection according to the invention that the at least two housing parts can be separated from one another by release of the snap connection to enable replacement of the electronic device found in the housing, for example in the case of a defect.
An embodiment of the housing according to the invention which, however, should not be considered limiting of the invention is described in the following with reference to the Figures. They show:
The housing parts shown in
In an especially advantageous way, the at least two housing parts 1, 2 can be made in an injection molding process for synthetic resins or plastics which can produce, by a corresponding shaping of the mold, all of the structural configurations of the two housing parts 1, 2 in a single fabrication step. This applies especially to the snap parts 3, 4 which are provided on manufacture of the two housing parts. This eliminates the need for machining operations in an especially advantageous way.
The snap part 3 for example on the housing part 2 need not be located in a setback region 41. Within this setback region, a detent hook 42 can be provided which can engage in the recess 32 of the angled lug 31. By a corresponding shape of the lug 31 and its arrangement within the housing part 1, especially because of the slits 33, the lug 31 can be deflected out of the plane of the surface of the housing part 1. The dimensions and the especially positions of the lugs with respect to the detent hooks 42 are such that upon closure of the two housing parts 1, 2 about the film hinge 5 (or other assembly techniques) there is no immediate engagement of the lug 31 with the respective detent hook 42.
This engagement or locking is in an especially advantageous way first brought about by mechanical application of pressure to the lug 31 for which purpose a projection 35 is provided. The lug 31 is thus pressed over the detent hook 42 and can snap onto the latter, i.e. lock with it. As a result the snap connection remains under prestress and stresses the two housing parts 1, 2 against one another. To simplify the application of pressure to the lugs 31, the projections 35 are provided by means of which the lugs 31 can with the hand (thumb or index finger) or with a tool, possibly in an automated process, be pressed. Of especial advantage is the prestress which is obtained by snap connection according to the invention especially with the lug 31 and the detent hook 42.
Number | Date | Country | Kind |
---|---|---|---|
102 47 631.4 | Oct 2002 | DE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
---|---|---|---|---|
PCT/EP03/11260 | 10/10/2003 | WO | 3/1/2005 |