Slide assembly for a communication unit

Abstract: A communication unit has a housing part provided with means for entering information, and a slide assembly. The housing part is provided with a set of tracks along which the slide assembly is moveable relative to the housing part. The slide assembly or the housing part includes means for moving the slide assembly along the tracks on the housing part. It could be a wire spring, a motor or a gear provided spring box that moves the slide assembly. The communication unit also has means for decreasing the friction on the sliding surfaces in a communication unit having a slide. These means could be linear bearings positioned between the moving parts or internally lubricated materials used on the sliding surfaces.

Description: The invention relates to a slidable cover device which may be used in a communication unit such as a hand portable phone. Both sliding covers and pivotal flips are widely used to protect the keypad of a phone against unintended use and against dirt from the environment. US 4.845.772 describes a phone having a pivotal flip that disables the keys when the flip is closed. GB 2.235.606 discloses a phone having a slide cover carrying a microphone. International design bulletin DM/039951 and DM/039675 shows two phones having detachable slides. Magneto-rheological fluids and electro-rheological fluids used as motion controllers in dampers or shock-absorbers are well known in applications like automobile clutches, doors or lids. US 4.200.003 shows a rotary viscous damper using a magnetic fluid as the damping medium. In this case the fluid is used to control the rotation motion of a rotor. In US 5.257.681 is shown a segmented slim blade, where a magnetic field responsive fluid is used for motion control. JP-10009329 shows a spring box motion controller with the additional refinement of a completely flat version. An electro-viscous fluid is used for controlling the damping of the rotation of the rotary shaft. From US 5.736.798 a big magnetically controlled rotational damper is shown, where magnets can be moved closer to the fluid for adjustable braking action in exercise machines. An object of the invention is to provide an improved slidable cover device that may be used for a communication unit Such as a mobile phone. According to the invention there is provided a slidable cover device comprising a slide assembly mounted on a housing part provided with means for entering information, said slide assembly being movable along tracks on the housing part, wherein the slide assembly includes a cover part which at least partly covers said means for entering information in one position of said slide assembly, wherein the tracks on the housing part converge, and that the slide assembly includes wings for moving along the converging tracks, and spring means operable to bias the wings towards each other to urge them along the tracks. The spring means may be connected to the wings such that they are urged towards one another, and said wings have tracks corresponding to the tracks on the housing part. One of the wings may be fixedly attached to the cover part and the other wing may be flexibly mounted to be able to glide relative to the cover part and follow the converging tracks on the housing part. In the tracks on the housing part and in the slide assembly wings are bearings, linear bearings, where each linear bearing consists of two guide ways and a set of caged balls (manufactured by e.g. Schneeberger, Switzerland or INA, Germany) between the guide ways. Preferably the spring is biased in the locked position of the slide. When a release mechanism is released, the slide assembly is moved by the biased spring. Means for decreasing friction may be used in the form of an internally lubricated polycarbonate on the sliding surfaces on both the housing part and the slide assembly. The invention will be explained more fully below, by way of example, in connection with an embodiment thereof and with reference to the drawing, in which: Fig. 1 in perspective shows a preferred embodiment of the communication unit according to the invention. Fig. 2 shows the communication unit shown in fig. 1 with the slide in open position. Fig. 3 schematically shows components of a telephone for communication with a cellular network. Fig. 4 shows the front cover of the unit shown in fig. 1 and 2. Fig. 5 shows the slide assembly and the conical housing of the unit, with a spring as connecting the two slide wings of the slide assembly. A slidable cover device according to the invention will be described with reference to a communication unit in the form of a hand portable phone, preferably a cellular phone as shown in fig. 1 and 2. The phone is shown with a slidable cover device in closed and open positions in fig. 1 and 2, respectively. As will be seen, the phone is provided with a front cover 2 having a window frame 3 encircling the protection window of a display assembly 1. It will furthermore be seen how the phone is provided with a slide cover 5 snapped onto a slide frame 6 sliding in slide tracks 38 (see fig. 5) in the front cover 2 along a keypad area 7 and in extension thereof. A microphone 46 records the user's speech, and the analog signals formed thereby are A/D converted in an A/D converter (not shown) before the speech is encoded in an audio part 20 shown in Figure 3. The encoded speech signal is transferred to the controller 18 (physical layer processor), which e.g. supports the GSM terminal software. The controller 18 also forms the interface to the peripheral units of the apparatus, including RAM and ROM memories 17a and 17b, a SIM card 16, the display 1 and the keypad 7 (as well as data, power supply, etc.). The controller 18 communicates with the transmitter/receiver circuit 19. The audio part 20 speech-decodes the signal, which is transferred from the controller 18 to the earpiece 21 via a D/A converter (not shown). The phone is adapted for use in connection with the GSM network, but, of course, the invention may also be applied in connection with other phone networks. It could be cellular networks, various forms of cordless phone systems or in dual band phones accessing sets of these systems/networks. The controller 18 is connected to the user interface. Thus, it is the controller 18, which monitors the activity in the phone and controls the display 1 in response thereto. Therefore, it is the controller 18, which detects the occurrence of a state change event and changes the state of the phone and thus the display text. The user may cause a state change event, when he activates the keypad 7 including the navigation key 10, and these type of events are called entry events or user events. However, the network communicating with the phone may also cause a state change event. These type of events and other events beyond the user's control are called non-user events. Non user events comprise status change during call set-up, change in battery voltage, change in antenna conditions, message on reception of SMS, etc. Fig. 5 shows a preferred embodiment of the invention, where a housing part 30 has a wider portion nearest the display 1 and a narrower portion nearest the bottom end of the unit. The housing part 30 is provided with means, a keypad 7, for entering information (best shown in fig. 2). Said housing part 30 also includes a set of converging tracks, one track 31 on each long side of the housing part. Along these converging tracks 31 are a slide assembly 32 being moveable, said slide assembly includes a cover part 39, which at least partly covers said means 7 for entering information in one position of said slide assembly 32. The slide assembly 32 also includes a pair of slide wings 37 and 38, that are loosely connected to each other with a wire spring 36. The left slide wing 37 is fastened to the slide cover 39, while the right slide wing 38 is only fastened to the left slide wing through the wire spring 36. This enables the slide wings to closely follow the shape of the housing part 30. The movement of the slide assembly 32 along the housing part 30 is performed by the wire spring 36,which presses the slide wings 37 and 38 together and strives for moving the slide assembly towards the narrower end of the housing part 30. The movement starts when a slide release mechanism is initiated by pressing a push button, whereafter the wire spring 36 starts to move the slide cover into the open position where the keypad 7 may be accessed. The right slide 38 is able to glide inside the slide cover 39 during the movement to closely follow the converging tracks along the housing part 30. Also shown in fig 5. is a linear bearing 33, which is located in each of the converging tracks 31 on the housing part 30 and in a corresponding set of tracks 40 on the slide wings 37 and 38. The linear bearing 33 aims to decrease the friction, which occurs then the slide assembly 32 moves between the open position and the closed position. The linear bearing 33 includes two guideways 34 and 35, and a set of caged balls 41 between said guideways 34 and 35. To decrease the friction between the sliding surfaces on a slide assembly and a housing part an internally lubricated polycarbonate is used on the sliding surfaces. The internally lubricated polycarbonate (PC) is applied onto the sliding surfaces by moulding. In a first shot injection moulding the main part of the housing part and the slide assembly is produced by using an ABS/PC blend and in a second injection moulding the sliding surfaces are produced by using an internally lubricated polycarbonate. The internally lubricated materials could also be produced into a thin film or plate, and then these polymer pieces are placed permanently on the sliding surfaces, which has been made in the first injection moulding is this case. The friction coefficient of the internally lubricated polycarbonates can be adjusted by using different internal lubrication agents. It could be agents, like polytetrafluorethane, silicone or a combination of both. Other materials having the same effect, without affecting other desired characteristics, could also be used. Using internally lubricated polymers on the sliding surfaces also has some assembly advantages. In present solutions it is often necessary to grease the sliding surfaces as a separate work operation, but if the assembly already has the friction-decreasing means in itself this work operation could be left out. The invention is not limited to the above described and in the drawings shown examples of an embodiment but can be varied within the scope of the appended claims.

Claims: A slidable cover device comprising a housing part and a slide assembly (32) mounted on the housing part (30) provided with means (7) for entering information, said slide assembly (32) being movable along tracks (31) on the housing part, wherein the slide assembly (32) includes a cover part (39) which at least partly covers said means (7) for entering information in one position of said slide assembly, characterized in that the tracks (31) on the housing part (30) converge, and that the slide assembly (32) includes wings (37, 38) for moving along the converging tracks, and spring means (7) operable to bias the wings towards each other to urge them along the tracks. A device according to claim 1 wherein the spring means (7) is connected to the wings (37, 38) such that they are urged towards one another, and said wings have tracks (40) corresponding to the tracks(31) on the housing part. A device according to claim 2 one of the wings (37)is fixedly attached to the cover part (37), and the other wing (38) is flexibly mounted to be able to glide relative to the cover part (37) and follow the converging tracks (31) on the housing part (30). A device according to claim 2 or 3 wherein linear bearings (33) are located in the tracks (31) on the housing part (30) and the wings (37, 38), each linear bearing including two guideways (34, 35) and a set of caged balls (41) between the guideways. A communication unit with a slidable cover device as claimed in any preceding claim. A communication unit according to claim 5 including a polycarbonate lubricant on surfaces on the housing part (30) and the slide assembly (32). A communication unit according to claim 5 or 6 comprising a hand portable phone.

Inventors: HILTUNEN KARI, KAUHANIEMI ILPO, KOLEDA EUGEN, RONKKO ANTTI, HILTUNEN, KARI, KAUHANIEMI, ILPO, KOLEDA, EUGEN, RONKKO, ANTTI
Applicants: NOKIA CORP, NOKIA CORPORATION
Application year: 2000
Main classification: H04M1
IPC codes: H04M1