Foldable and portable telephone

Abstract: The invention provides an opening and closing device for a portable telephone wherein a receiver section can be opened by one touch by depressing a push-button while holding the portable telephone with one hand and can be stopped freely at any angle from a predetermined opening angle and besides, also when the receiver section is in a closed condition, the closed condition of the receiver section can be kept stably. To this end, between a mounting portion of a transmitter section and a mounting portion of a receiver section which are connected for pivotal motion into and from a twofold condition by means of a hinge shaft, a torsion spring wound around the hinge shaft is interposed resiliently, and arresting means for arresting an end portion of the torsion spring by the mounting portion of the receiver section only within a range of the angle of the receiver section greater than a predetermined open angle is interposed between the mounting portion of the transmitter section and the mounting portion of the receiver section. A cam mechanism is provided between the mounting portion of the transmitter section and the mounting portion of the receiver section, and a push-button is mounted for manual operation in an axial direction on the mounting portion of the transmitter section. By a manual depressing operation of the push-button, the cam mechanism pivots the receiver section to a position at which the arresting means arrests the end portion of the torsion spring. Locking means for arresting the mounting portion of the receiver section and canceling the arresting condition thereof by depression of the push-button may be provided on the mounting portion of the receiver section, and/or a friction mechanism for stopping the receiver section freely at any position from the predetermined open angle may be provided.

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to an opening and closing device suitable for use with a portable telephone wherein a transmitter section and a receiver section are folded in a twofolded condition when the portable telephone is carried but are opened when the portable telephone is to be used. 2. Description of the Related Art Conventionally, as an opening and closing device for mounting a receiver section of a twofold portable telephone for opening and closing movement on a transmitter section, an opening and closing device of the free stopping type having a friction function is known. However, as portable telephones are popularized, a demand for higher convenience increases, and an opening and closing device which is constructed so that the receiver section can be opened relative to the transmitter section by one touch only by one hand is demanded. In WO-A-93/18592 a hinge assembly for hingedly connecting a cover and a housing, such as a keypad cover and a housing of a portable radiotelephone, is disclosed. The hinge assembly comprises a hollow hinge arm being coupled to the cover and a hinge pin being affixed to the housing. The hinge pin is axially extending inside the hinge arm. The hinge pin comprises cams, and the inner walls of the hinge arm comprise cam followers corresponding to the cams. Cams and cam followers form a locking means by which the cover can be held locked with respect to the housing optionally in a closed or in an opened position. The EP-A-0 588 210 discloses a portable radio telephone set according to the preamble of claim 1, the portable radio telephone comprising a receiver section ("display section") and a transmitter section ("operating section") being rotatably connected via a mounting portion having a hinge shaft, a torsion spring and a hollow flange. Further there is provided a locking means for locking the receiver section and the transmitter section in optionally a closed (folded) or an opened condition with respect to each other. At one end of the shaft/flange, there is provided a push button for releasing the locking means, such that, when the push button is depressed, the receiver section is freely rotatable with respect to the transmitter section. SUMMARY OF THE INVENTION It is an object of the present invention to provide an opening and closing device for a portable telephone wherein a receiver section can be opened by one touch by depressing a push-button while holding the portable telephone with one hand and, also when the receiver section is in a closed condition, the closed condition of the receiver section can be kept stably. It is another object of the present invention to provide an opening and closing device for a portable telephone wherein a receiver section can be opened with respect to a transmitter section by one touch using one hand and the opening and closing device itself can stably lock the receiver section in its closed condition. It is a further object of the present invention to provide an opening and closing device for a portable telephone wherein a receiver section can be opened with respect to a transmitter section by one touch using one hand and the opening and closing device itself can stably lock the receiver section in its closed condition and besides the receiver section can be stopped freely at any angle from a predetermined opening angle. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view of a potable telephone embodying the present invention; Fig. 2 is an exploded perspective view of an opening and closing device of the portable telephone according to the present invention; Fig. 3 is a horizontal sectional view of the opening and closing device of the portable telephone according to the present invention when a receiver section is closed; - Fig. 4 is a sectional view illustrating a positional relationship of various components when the receiver section is closed; Fig. 5 is a sectional view illustrating the positions of various components when a locked condition of the receiver section by locking means is canceled; Fig. 6 is a perspective view illustrating the positional relationship between a rotor and a stator when the receiver section is closed; Fig. 7 is a perspective view illustrating the positional relationship between the rotor and the stator when the receiver section is opened and a friction function begins to operate; and Fig. 8 is an exploded perspective view of the opening and closing device of the portable telephone according to the present invention as viewed in the opposite direction to that of Fig. 2. DESCRIPTION OF THE PREFERRED EMBODIMENT The drawings show an embodiment of the present invention. Referring to Fig. 1, a transmitter section 1 carries an manual operation portion 1a including a plurality of manually operable buttons and a microphone portion 1b. A first mounting portion 2, a second mounting portion 3 and a third mounting portion 4 each having a tubular portion are mounted in a predetermined spaced relationship from each other in this order from the left side at an end portion of the transmitter section 1. The second mounting portion 3 has the greatest length among the first, second and third mounting portions 2, 3 and 4. The mounting portions 2 to 4 may alternatively be formed integrally with the transmitter section 1. Still referring to Fig. 1, reference numeral 5 denotes a receiver section on which a display portion 5a and a loudspeaker portion 5b are provided. A fourth mounting portion 6 and a fifth mounting portion 7 each similarly having a tubular portion are provided at an end portion of the receiver section 5 and individually fitted between adjacent ones of the mounting portions 2 to 4 of the transmitter section 1 side, and the fourth mounting portion 6 side is connected for pivotal motion to the first mounting portion 2 and the second mounting portion 3 by means of a hinge shaft 8 as seen in Fig. 2 and so forth. Though not shown sufficiently, the fifth mounting portion 7 is connected for pivotal motion between the second mounting portion 3 and the third mounting portion 4 by way of a hinge pin 9 shown in Figs. 3 to 5 which is coaxial with the hinge shaft 8. The opening and closing device according to the present invention is provided on the hinge shaft 8 side and will be described in detail below. A tubular stator 10 is accommodated in the inside of the second mounting portion 3. The stator 10 has a pair of first convex portions 10a and an arresting groove 10b provided in an axial direction at an end face thereof, and the hinge shaft 8 extends coaxially in an inner hollow portion of the stator 10. The stator 10 has an arresting rib 10c provided on an outer periphery thereof and fitted in an engaging groove 3a formed on an inner periphery of the second mounting portion 3 so that the stator 10 may not be rotated relative to the second mounting portion 3. However, the stator 10 may alternatively be formed integrally with the second mounting portion 3. The hinge shaft 8 is securely mounted at an end portion thereof to a mounting wall 3b provided in the second mounting portion 3 by means of a mounting screw 12. A rotor 13 is accommodated in the fourth mounting portion 6 of the receiver section 5 side which contacts with an end face of the second mounting portion 3. The hinge shaft 8 extends coaxially in an inner hollow portion of the rotor 13, and the rotor 13 is held in position by a flange portion 8a of the hinge shaft 8. The rotor 13 has a pair of arresting projections 13a formed to extend outwardly from an outer periphery thereof. The arresting projections 13a of the rotor 13 are engaged with a pair of first engaging grooves 6a provided on an inner periphery of the fourth mounting portion 6 to secure the rotor 13 to the fourth mounting portion 6. The hinge shaft 8 is accommodated in the stator 10 while a torsion spring 14 is wound spirally around the hinge shaft 8. The torsion spring 14 is arrested at a first end portion 14a thereof by an arresting hole 10d provided in the stator 10 and at the other, a second end portion 14b thereof with an arresting portion 13b provided arcuately in a concave condition on the other end face of the rotor 13. The arresting portion 13b has an inclined portion 13c provided at an end thereof such that it is inclined in a direction to rewind the torsion spring 14. As particularly seen in Figs. 4 and 5, arresting means 15 for the torsion spring 14 is formed from the arresting portion 13b provided on the rotor 13 and having the inclined portion 13c, and the arresting groove 10b provided on the stator 10 side. The rotor 13 further has a pair of second convex portions 13d provided on an end face thereof adjacent to the arresting means 15. The second convex portions 13d of the rotor 13 are opposed to the first convex portions 10a provided on the end face of the stator 10. A friction mechanism 23 is formed from the first convex portions 10a and the second convex portions 13d. Subsequently, locking means 22 will be described. A locking member 17 having a larger diameter than that of the rotor 13 is accommodated in the fourth mounting portion 6 remote from the end portion in which the rotor 13 is fitted. The locking member 17 has a pair of arresting projections 17a formed on an outer periphery thereof. The arresting projections 17a of the locking member 17 are held in engagement with a pair of second engaging grooves 6b of the fourth mounting portion 6 of the receiver section 5 side in such a manner as to allow the locking member 17 to slidably move in an axial direction in and with respect to the fourth mounting portion 6. The hinge shaft 8 extends coaxially in an inner hollow portion of the locking member 17. A compression spring 18 is interposed between a pressure receiving plate 17b of the locking member 17 and the flange portion 8a of the hinge shaft 8 to normally urge the locking member 17 to slidably move in one direction. The first mounting portion 2 has a pair of locking grooves 2a which are aligned with the arresting projections 17a of the locking member 17 at a predetermined position of the first mounting portion 2 (at a closing position of the receiver section 5). A push-button 21 is accommodated for sliding movement in an axial direction in the inside of the first mounting portion 2. The push-button 21 includes a first push-button 19 and a second push-button 20 disposed in an overlapping relationship with each other in their axial direction. The first push-button 19 has an outer diameter substantially equal to that of the rotor 13 and has a pair of arresting projections 19a provided on an outer periphery thereof. The arresting projections 19a of the first push-button 19 are held in engagement with a pair of engaging grooves 2b of the first mounting portion 2. The hinge shaft 8 extends coaxially through the first push-button 19. An E-snap ring 24 is fitted on the hinge shaft 8 adjacent to an end of the first push-button 19 so that the first push-button 19 may not come off the hinge shaft 8, and a pressing cam portion 19b extends in an axial direction from the other end of the first push-button 19. The pressing cam portion 19b extends through an arcuate recess 17c formed on the locking member 17 until it is opposed to an inclined portion 16a of a pressure receiving cam portion 16. The pressing cam portion 19b and the pressure receiving cam portion 16 form a cam mechanism 25. The second push-button 20 has a pair of arresting projections 20a formed on an outer periphery thereof. The arresting projections 20a of the second push-button 20 are engaged with a pair of arresting grooves 2c, which are each closed at an end thereof, provided on the first mounting portion 2 so that the second push-button 20 can slidably move in an axial direction with respect to the first mounting portion 2 but cannot come off the first mounting portion 2. The first push-button 19 and the second push-button 20 may alternatively be combined into an integral unitary member. Accordingly, in a condition wherein the receiver section 5 is closed, as seen in Figs. 3 and 4, the second end portion 14b of the torsion spring 14 is not arrested by the arresting portion 13b of the rotor 13 but is pushed by an end edge of the arresting portion 13b until it is accommodated in a somewhat compressed condition in the arresting groove 10b of the stator 10. Further, the second convex portions 13d of the rotor 13 are accommodated in a pair of recessed portions 10e provided on the end face of the stator 10. Furthermore, the locking member 17 urged in the leftward direction by the compression spring 18 in Figs. 3 and 4 is in a condition wherein the arresting projections 17a provided on the outer periphery thereof are held in engagement with both of the second engaging grooves 6b provided on the fourth mounting portion 6 of the receiver section 5 side and the locking grooves 2a of the first mounting portion 2 of the transmitter section 1 side. Meanwhile, also the first push-button 19 is urged in the leftward direction in Figs. 3 and 4 by the locking member 17 until it extends outwardly from the end portion of the first mounting portion 2. Further, the pressing cam portion 19b of the first push-button 19 extends through the arcuate recess 17c of the locking member 17 until it is opposed in a somewhat spaced relationship to the inclined portion 16a of the pressure receiving cam portion 16. If the first push-button 19 is depressed in the rightward direction in this condition, then the depressing force is transmitted to the locking member 17 by way of the second push-button 20 so that the locking member 17 is slidably moved in the rightward direction in Figs. 3 and 4 against the urging force of the compression spring 18. Consequently, the engagement between the arresting projections 17a of the locking member 17 and the locking grooves 2a of the first mounting portion 2 of the transmitter section 1 side is canceled first, and then the pressing cam portion 19b is brought into contact with and presses the inclined portion 16a of the pressure receiving cam portion 16. As a result, the rotor 13 is rotated in the counterclockwise direction to open the receiver section 5 a little as seen in Fig. 6. Consequently, the arresting portion 13b of the rotor 13 comes to the position of the arresting groove 10b of the stator 10 as seen in Fig. 5, whereupon an end portion of the torsion spring 14 in a wound in condition and in a compressed condition is moved in the leftward direction in Fig. 5 and is arrested by the arresting portion 13b. As a result, the rotor 13 is acted upon by an urging force to rotate it in the counterclockwise direction so that the receiver section 5 in a somewhat open condition in such a manner as described above is further opened automatically by the urging force of the torsion spring 14. In this instance, since the torsion spring 14 is in a compressed condition and is arrested at the second end portion 14b thereof by the arresting portion 13b, it will not come off the arresting portion 13b irrespective of the presence of the inclined portion 13c. After the receiver section 5 is opened to a certain open angle with respect to the transmitter section 1, the torque of the torsion spring 14 becomes weak and the second convex portions 13d of the rotor 13 are contacted with the first convex portions 10a of the stator 10 as seen in Fig. 7. Consequently, the receiver section 5 can thereafter be stopped freely at any position within a predetermined open angle range by the friction action between the second convex portions 13d and the first convex portions 10a. As the open receiver section 5 is pivoted in a closing direction, the torsion spring 14 is wound in until a predetermined closed angle is reached. However, after the predetermined closed angle is reached, the resistance of the torsion spring 14 to be wound in increases so that the second end portion 14b thereof finally slips on and is disengaged from the inclined portion 13c of the arresting portion 13b. Then, the second end portion 14b of the torsion spring 14 is pressed (compressed) in an axial direction by an edge portion of the inclined portion 13c of the arresting portion 13b until it is arrested in a wound in condition by the arresting groove 10b of the stator 10. Consequently, in a closed angle after then, the torque of the torsion spring 14 will not act upon the rotor 13, that is, upon the receiver section 5. When the receiver section 5 is closed to 0 degree, the condition shown in Fig. 3 is reached. In this condition, the arresting projections 17a of the locking member 17 which are normally urged to slidably move in the leftward direction in Fig. 3 are engaged with the locking grooves 2a provided on the first mounting portion 2 of the transmitter section 1 side by the compression spring 18. Consequently, the receiver section 5 is locked to the transmitter section 1 in a twofold condition.

Claims: An opening and closing device for a portable telephone, comprising: a transmitter section (1); a receiver section (5) connected at a mounting portion (6, 7) thereof to a mounting portion (2, 3, 4) of said transmitter section (1) for pivotal movement into and from a twofold condition by means of a hinge shaft (8) on said mounting portion (2, 3, 4) of said transmitter section (1); a torsion spring (14) wound around said hinge shaft (8) and interposed resiliently between said mounting portion (6) of said receiver section (5) and said mounting portion (3) of said transmitter section (1); arresting means (15) interposed between said mounting portion (3) of said transmitter section (1) and said mounting portion (6) of said receiver section (5) for arresting an end portion (14b) of said torsion spring (14) at an angle of said receiver section (5) greater than a predetermined open angle; and a push-button (21) mounted for manual operation in an axial direction at an end portion of said mounting portion (2) of said transmitter section (1), characterised in that the opening and closing device further comprises a cam mechanism (25) provided between said mounting portion (2) of said transmitter section (1) and said mounting portion (6) of said receiver section (5); said push-button (21) being provided for operating said cam mechanism (25), said cam mechanism (25) pivoting, by a manual depressing operation of said push-button (21), said receiver section (5) to a position at which said arresting means (15) and said end portion (14b) of said torsion spring (14) are engaged with each other. An opening and closing device for a portable telephone according to claim 1, further comprising locking means (22) for arresting said mounting portion (6) of said receiver section (5) and canceling the arresting condition thereof by depression of said push-button (21). An opening and closing device for a portable telephone according to claim 2, further comprising a friction mechanism (23) for stopping said receiver section (5) freely at any position from the predetermined open angle. An opening and closing device for a portable telephone according to any one of claims 1 to 3, wherein said arresting means (15) includes an arresting portion (13b) provided on an end face of a rotor (13) accommodated in said mounting portion (6) of said receiver section (5) for arresting the end portion (14b) of said torsion spring (14), an inclined portion (13c) provided in a rewiring direction of said torsion spring (14) with respect to said arresting portion (13b), and an arresting groove (10b) positioned in an axial direction of said torsion spring (14) on said mounting portion (3) of said transmitter section (1) for arresting the end portion (14b) of said torsion spring (14) released from arresting by said arresting portion (13b). An opening and closing device for a portable telephone according to any one of claims 1 to 3, wherein said cam mechanism (25) includes a pressing cam portion (19b) provided projectingly on an end face of said push-button (21), and a pressure receiving cam portion (16) having an inclined portion (16a) provided projectingly at a position of an end face of a rotor (13) opposing to said pressing cam portion (19b), said rotor (13) being accommodated in said mounting portion (6) of said receiver section (5). An opening and closing device for a portable telephone according to claim 2, wherein said locking means (22) includes a locking member (17) accommodated for sliding movement in said mounting portion (6) of said receiver section (5) and normally urged to slidably move in one direction by a compression spring (18), said hinge shaft (8) extending through said locking member (17), and a locking groove (2a) provided in an axial direction with respect to the end face of said mounting portion (2) of said transmitter section (1) for allowing back and forth movement of said locking member (17) into and from said mounting portion (6) of said receiver section (5). An opening and closing device for a portable telephone according to claim 3, wherein said friction mechanism (23) includes a first convex portion (10a) provided on the end face of said mounting portion (3) of said transmitter section (1), and a second convex portion (13d) provided on the end face of said mounting portion (6) of said receiver section (5) in such a manner as to contact under pressure with said first convex portion (10a) within a predetermined open angle range of said receiver section (5).

Inventors: NAGAI MICHIO, OHTSUKA YOSHIHIRO, NAGAI, MICHIO, OHTSUKA, YOSHIHIRO, NAGAI, MICHIO, C/O NEC CORPORATION
Applicants: KATO ELECTRIC & MACHINARY CO, NIPPON ELECTRIC CO, KATOH ELECTRICAL MACHINERY CO. LTD., NEC CORPORATION
Application year: 1995
Main classification: H04M1
IPC codes: E05F1, H04M1, F16C11, H04Q7