A RADIO HOUSING ASSEMBLY WITH A PLUGABLE CONTROL MODULE

Abstract: A radio housing assembly (200) is provided which includes a housing chassis (220) and a plugable control housing (100). The control housing (100) includes nest portions (112, 114, 116, and 118) for inserting electrical controls, such as a toggle switch (120), a rotary switch (130), and a volume control (130). The nest portions receive, align and center the controls while firmly securing and positioning them in place. The control module (100) also includes a flexible circuit for coupling the controls to the radio circuitry. The control module (100) is then plugged in to the housing chassis (220) which includes a corresponding chamber (222) having ridge shaped features (224) for facilitating insertion.

Description: A RADIO HOUSING ASSEMBLY WITH A PLUGGABLE CONTROL MODULE Technical Field This invention relates generally to the field of housing assemblies and more particularly to a housing assembly for a portable radio device. Background Portable radio devices are extensively used in today's communication systems. As the complexity of the communication systems increases, the portable radio devices become more user interactive in order to enable the user to activate offered features. A user interacts with the radio device knobs, switches, display devices, and variety of other control components. The control components are carried in a radio housing assembly which also carries other radio components such as main radio circuit board and an antenna. The control components activate one or more operational feature of the radio device through a movable actuation mechanism. For example, a desired channel may be selected by rotating a rotary switch, or a signaling message may be transmitted by pressing a button or toggling a switch. Conventional radio housing assemblies include a housing frame within which the control components and circuitry are positioned. The housing assembly is enclosed by a front and a back cover which engage the housing frame via screws and/or snap-on features. Generally, the control components electrically couple to the main radio circuitry by interconnection runners of a cable or a flexible circuit. In conventional radio housing assemblies, one or more of the switches and the control components are hand soldered to the interconnecting circuitry and the sub-assembly so produced is fastened to the radio frame by nuts or other laborious operations. The conventional radio housing assembly process is labor intensive and does not conform to the strict quality requirements of today's competitive world. The handling of the sub-assembly during the conventional manufacturing process tends to stress the solder joints and the flexible material causing solder joints detachments and other undesirable consequences. Therefore, with the ever increasing drive for reducing manufacturing cost and improving quality, there is a need for a radio housing assembly design which is high quality and easily manufacturable . Summary of the Invention Briefly, according to the invention, there is provided a housing assembly for a radio unit which includes a chassis for carrying radio circuitry having a plug-in portion for plugging a control module thereto. The control module includes control housing and a plurality of control pieces for controlling one or more radio functions. The control housing has a plurality of nest portions correspondingly formed to center and securely position the control pieces. The control housing is shaped to be plugged into the plug-in portion of the housing chassis. Brief Description of the Drawings FIG. 1 is an exploded view of a control module according to the present invention. FIG. 2 is a front side view of the control module of FIG. 1. FIG. 3 is an exploded view of a housing assembly according to the present invention. Detailed Description of the Preferred Embodiment Referring to FIG. 1, an exploded view of a control module 100 according to the present invention is shown. The control module 100 when assembled carries the electrical controls of a two-way portable radio device which is capable of communicating messages with other devices within a communication system. The electrical controls are means by which a user interfaces with the radio device for activating or controlling one or more radio functions. The electrical controls may comprise a rotary switch for selecting a desired frequency channel, a toggle switch or a push button switch for activating a signaling transmission, and a potentiometer for adjusting the volume of the radio device. As described later in detail, the control module 100 plugs into a radio housing chassis which also carries the radio circuitry and other radio components such as a battery. As shown in FIG. 1, the control module 100 includes a control housing 110 for receiving and positioning a plurality of electrical control pieces, such as a toggle switch 120, a rotary switch 130, and a potentiometer 140. The control housing 110 also receives a LED 150 which provide visual indication of a particular radio function. Please note that hereinafter in this specification, the toggle switch 120, the rotary switch 130, the potentiometer 140, and the LED 150 will be referred to as electrical control pieces. The electrical control pieces include actuator portions (collectively shown by the reference numeral 122), such as a toggle portion and rotary portions, which upon actuation activate or control a specific radio function. The control pieces also include control terminals or leads (collectively shown by reference numeral 119) which provide the control signal for controlling and activating the radio functions. In the preferred embodiment of the invention, the control housing 110 is made of a substantially rigid plastic material which is molded to create predefined features on each side. The control housing 110 has a front surface 117, a rear surface 115, and opposing support surfaces 111. The opposing support surfaces 111 are shaped to include plug in features comprising a keyed slot or groove 113 on each side. The grooves 113 are formed as channels for receiving narrow strips formed on an external housing chassis, thereby making the control module 100 pluggable. A plurality of nest portions 112, 114, 116, and 118 are formed on the rear surface 115 to accommodate the shapes of the electrical control pieces. The nest portions are correspondingly shaped to receive and firmly position the electrical control pieces in place. As a result, the nest portions 112, 114, 116, and 118 provide a tight and snug fit which fully captivate and retains major body portions of the control pieces and aligns them for subsequent assembly operation. Referring to FIG. 2, a front view of the control housing 110 after the insertion of the electrical controls is shown. When the control pieces are inserted into the nest portions 112, 114, 116, and 118, the actuator portions 122 of the control pieces protrude through a number openings disposed on the front surface 117 of the control module 110. As shown, a plurality of openings 119 are disposed on the front surface 117 of the control housing 110. The openings 119 are shaped to allow the electrical control pieces to be inserted into the control housing 110 and be accessed by the radio user. The openings 119 include means for centering or aligning the electrical controls once the control means are inserted into the control housing 110. The centering or aligning means may comprise a variety of arrangements, such as notch 136, or hole 134 which engage key tabs of the control pieces and prevent them from moving within the control housing 110. Referring back to FIG. 1, once the control pieces are inserted, aligned and centered by the control housing 110, a flexible circuit 170 may be soldered to the control terminals 119 in order to extend the control signals. The flexible circuit 170 carries the interconnecting runners which terminate at a contact portion 172 comprising of a series of contacts which may be coupled to the to the radio circuitry to complete the electrical connection of control pieces. It may be appreciated that the control housing 110 in addition to being a firm retainer for the control pieces, may also operate as a nest for soldering the flexible circuit 170 to the control terminals 119, thereby simplifying the assembly process. However, the flexible circuit 170 may also be presoldered to the control pieces prior to insertion. Finally, a molded plastic cover piece 160 is attached to the control housing completely enclose the control piece 110 and covers all the exposed portions of the control pieces and the control terminals, while also providing electrical insulation. Preferably, the molded cover piece 160 is a molded plastic piece which includes snap features which snap on to complementary features formed on the control housing 110. Referring to FIG. 3, an exploded view of a housing assembly 200 according to the present invention is shown. The housing assembly 200 includes a housing chassis 220 for carrying major components of the assembly. These components include the control module 100, radio circuitry disposed on a circuit board 210, a battery 240, and a front cover 230. In the preferred embodiment of the invention, the housing chassis 220 is a conductive die-cast frame made of a conductive material such as zinc. The housing chassis 220 includes a plug-in chamber 222 which is shaped to receive the pluggable control module 100. The plug-in chamber 222 is positioned on top of the housing chassis and has surrounding walls upon which a plurality of ridge shaped features are formed (only one is shown— reference numeral 224) which may be shaped to correspond to the grooves 113 of the control housing 110. The edges may be slid into grooves 113, thereby facilitating insertion of the control module 100 into the housing chassis 220. The housing chassis 220 also carries a circuit board 210 which has various radio circuitry disposed therein. During assembly, the circuit board 210 is fastened on top surface 226 of the housing chassis via complementary snap features 228 formed on the circuit board 210 and the housing chassis 220. Thereafter, the control module 100 is plugged into the plug-in chamber 222. The circuit board 210 includes the control circuits of the radio device. A receptor connector 212 is disposed on the circuit board 210 for receiving the contact portion 172 of the flexible circuit 170 so as to complete electrical connections between the radio circuitry an the electrical controls. The front cover 230 is then fastened to the housing chassis 220 to enclose the circuit board 210 and the control module 100. The front cover also includes openings for making the actuators 122 of the electrical controls accessible to the user. Thereafter, knobs 290 are engaged to the actuators 122 to facilitate user interaction. The battery 240 is engaged to the housing assembly through the opposing side 219 of the housing chassis 220 and supplies the battery power needed to operate the radio device. In another embodiment, the plug-in arrangement of the control housing may be advantageously used in order to improve electrostatic discharge (ESD) protection of the radio device. In conventional assembly designs, static charge entering via a switch shaft or the like is dissipated through discrete electronic components on interconnecting circuitry or alternatively through separate mechanical grounding pieces made specially for the discharge purpose. However, since the control housing 110 may be molded from a conductive plastic, it can be made to couple to the body of the control pieces in such a way that any static charges may be grounded by the conductive housing chassis. As such, the control housing 110 provides a conductive electrostatic discharge path through the housing chassis 220 and protects the radio device. As may be apparent from the above description, the housing assembly 200 of the present invention provides many advantages over the conventional assemblies. The electrical controls are easily inserted into the control housing 110 which, in addition to aligning and centering them, also acts as a nest for performing the flexible circuit soldering operation. After placing the cover piece 160, the control module 100 is simply plugged into the housing chassis 220 and electrically coupled to the radio circuitry. Accordingly, a single-axis and plug-in assembly process is provided which is much simpler than the torqued nuts fastener process of the prior art and greatly enhances the assembly process by eliminating the need for labor intensive operations. What is claimed is:

Claims: Claims 1. A housing assembly for a radio unit, comprising: a housing chassis for carrying radio circuitry including a plug-in portion; and a control module including: a plurality of control pieces for controlling one or more radio functions; and a control housing having a plurality of nest portions correspondingly shaped to center and securely position the control pieces, said control housing being formed to be plugged into the plug-in portion of the housing chassis. 2. The radio housing assembly of claim 1, further including an interconnection means for electrically coupling the control pieces to the radio circuitry. 3. The radio housing assembly of claim 2, further including a cover piece engaged to the control module for fully enclosing the control pieces and covering any exposed portions thereof. 4. The radio housing assembly of claim 3, wherein said interconnection means comprises a flexible circuit. 5. The radio housing assembly of claim 4, further including a front cover engaged to the housing chassis for enclosing the radio circuitry and the control module. 6. The radio housing assembly of claim 1; wherein said housing chassis comprises a conductive chassis. 7. The radio housing assembly of claim 6, wherein said control housing is made of a conductive plastic for providing a electrostatic discharge path through the conductive chassis. 8. A housing assembly for a radio unit, comprising: a housing chassis for carrying radio circuitry including a plug-in portion; and a control module including: a plurality of electrical control for controlling one or more radio functions; and a control housing having a first portion including a plurality of nest portions correspondingly shaped for receiving and positioning the electrical controls and a second portion attached to the control module for fully enclosing the electrical controls and covering any exposed portions thereof, said control housing being formed to be plugged into the plug-in portion of the housing chassis. 9. The housing assembly of claim 8, wherein the first portion and the second portion of the control housing include snap features for attaching them together. 10. The housing assembly of claim 8, wherein the electrical controls include actuator portions and wherein the first portion of the control housing includes opening for receiving the actuator portions.

Inventors: BRADFORD WILLIAM M, CHAMBERS RANDALL P, DIONISIO VITO JR, GILMORE PETER B, BRADFORD, WILLIAM, M., CHAMBERS, RANDALL, P., DIONISIO, VITO, JR., GILMORE, PETER, B.
Applicants: MOTOROLA INC, MOTOROLA, INC.
Application year: 1993
Main classification: H04B1
IPC codes: H04B1, H04Q7