Rechargeable type small electric appliance

Abstract: A rechargeable type small electric appliance including a rechargeable battery (5) supplied by a charging circuit (6), both within a casing (1), having a battery outlet covered by a lid (14) is described. Means are provided for preventing operation of the charging circuit whilst it is open. In one embodiment this is by relative positioning of the power supply socket (124) and the lid (14) so as to prevent simultaneous charging and opening of the lid, whilst in other embodiments it is by physical integration of the power supply socket and the lid, or location of a power supply switch which must be "OFF" in order to remove the lid.

Description: The present invention generally relates to electric appliances and more particularly, to a small electric appliance incorporating a rechargeable battery, in which the rechargeable battery is removable therefrom. Of recent years, in small electric appliances such as an electric shaver, etc., rechargeable batteries, which can be used repetitively, are mainly employed in place of dry cells. However, rechargeable batteries, for example, Ni-Cd (nickel-cadmium) batteries contain harmful substances such as cadmium. Therefore, from a standpoint of prevention of environmental pollution, it is not desirable to discard the Ni-Cd batteries together with the electric appliances anywhere. Thus, when the electric appliances incorporating the Ni-Cd batteries are discarded, the Ni-Cd batteries are required to be removed from the electric appliances so as to be collected for their safe disposal. The known electric appliances have a risk that if an operator inadvertently removes the rechargeable battery from the known electric appliances when the rechargeable battery is being charged by connecting the rechargeable battery to an external power source, the operator may receive an electric shock. Furthermore, in the known electric appliances, if the rechargeable battery is removed from the known electric appliances by cutting the lead wires when not only electric power of the rechargeable battery has not yet vanished but a power source switch of the known electric appliances is in an ON state, there is such a danger as generation of sparks from cut portions of the lead wires. An object of the present invention is to provide a rechargeable type small electric appliance in which a safety countermeasure is taken such that electric current is not applied to a load side of the electric appliance even if charging of the electric appliance is performed inadvertently after the rechargeable battery has been removed from the electric appliance. The present invention therefore provides a rechargeable type small electric appliance as set out in claim 1, claim 4 or claim 5. Embodiments of the present invention will now be described by way of example with reference to the accompanying drawings, in which: Fig. 1 is a front elevational view of a rechargeable type small electric appliance which is not an embodiment of the invention but is useful for understanding embodiment of the present invention; Fig. 2 is a perspective view showing a state in which a lid has been removed from the electric appliance of Fig. 1; Figs. 3 and 4 are views similar to Figs. 1 and 2 particularly showing 1 st and 2 nd embodiments of the present invention, respectively; Figs. 5a and 5b are fragmentary front elevational views showing a nonchargeable state and a chargeable state of a rechargeable type small electric appliance according to a 3 rd embodiment of the present invention, respectively; Fig. 5c is a fragmentary front elevational view showing a state in which a lid has been removed from the electric appliance of Fig. 5a; Figs. 6a, 6b and 6c are views similar to Figs. 5a, 5b and 5c, respectively, particularly showing a 4 th embodiment of the present invention; and Fig. 7 is a fragmentary front elevational view of a rechargeable type small electric appliance according to a 5 th embodiment of the present invention. Before the description of the present invention proceeds, it is to be noted that like parts are designated by like reference numerals throughout several views of the accompanying drawings. A chargeable type electric shaving being a rechargeable type small electric appliance to which the present invention may be applied is described with reference to the accompanying figures. Figs. 1 and 2 show a rechargeable type electric shaver K23 which is not an embodiment of the invention but is useful for understanding the present invention. In the electric shaver K23, the battery outlet 13 is provided at the bottom of the casing 1, The peripheral portions 4b project from the wiring board 4 towards the battery outlet 13 so as to be snapped off from the wiring bard 4 and the rechargeable battery 5 is mounted on the peripheral portions 4b. Meanwhile, the charging pins 28 mounted on the wiring board 4 project towards the battery outlet 13. The lid 14 is detachably mounted on the battery outlet 13. The lid 14 has a lug inlet 124 for receiving a plug 123 of the power source cord 52 and the window 84 for visually inspecting presence of the rechargeable battery 5. Furthermore, the engageable claws 118 capable of elastic deformation are provided on the lid 14 and are detachably engaged with the mouth edge of the battery outlet 13 such that the battery outlet 13 is kept closed by the lid 14. When the battery outlet 13 is being closed by the lid 14, the charging pins 28 are projected into the plug inlet 124. By the above described arrangement of the electric shaver K23, when the plug 123 of the power source cord 52 is inserted into the plug inlet 124, the charging pins 28 are fitted into the plug 123 and thus, the plug 123 prevents the lid 14 from being removed from the casing 1. Hence, at this time, the rechargeable battery 5 cannot be removed from the wiring board 4, so that it is not possible for the operator to receive an electric shock. On the other hand, when the plug 123 has been drawn from the plug inlet 124, the lid 14 can be removed from the casing 1 and thus, the rechargeable battery 5 can be removed from the wiring board 4. Fig. 3 shows a rechargeable type electric shaver K24 according to a 1 st embodiment of the present invention. The electric shaver K24 is generally similar to the electric shaver K23, but differs in that in the electric shaver K24, the lid 14 is provided with the charging plug 3 having the retractable plug blades. By this arrangement of the electric shaver K24, since the charging plug 3 is inserted into the socket outlet 120 at the time of charging of the electric shaver K24 the lid 14 cannot be removed from the casing 1 and thus, the rechargeable battery is not removed from the wiring board 4 inadvertently. On the contrary, when the electric shaver K24 is not being charged, the lid 14 can be removed from the casing 1 such that the rechargeable battery 14 can be removed from the wiring board 4. Fig. 4 shows a rechargeable type electric shaver K25 according to a 2 nd embodiment of the present invention. The electric shaver K25 is generally similar to the electric, shaver K23. In the electric shaver K23, the charging pins 28 are provided on the casing 1. On the other hand, in the electric shaver K25, the charging pins 28 are provided in the plug inlet 124 of the lid 14 such that one end of each of the charging pins 28 is inserted into each of pin holes 131 of the wiring board 4 when the lid 14 is mounted on the battery outlet 13. Figs. 5a, 5b and 5c show a rechargeable type electric shaver K26 according to a 3 rd embodiment of the present invention. In the electric shaver K26, the battery outlet 13 is formed at one side face of the casing 1 and the plug inlet 124 is formed at the bottom face of the casing 1. The lid 14 is detachably mounted on the battery outlet 13. A lid locking means is provided between the lid 14 and the plug inlet 124. When the plug 123 of the power source cord 52 is inserted into the plug inlet 124, the lid locking means locks the lid 14 so as to prevent the lid 14 from being removed from the casing 1. Meanwhile, when the plug 123 has been drawn from the plug inlet 124, the lid locking means allows the lid 14 to be removed from the casing 1. The lid locking means includes a guide groove 125 formed, between the battery outlet 13 and the plug inlet 124, on the casing 1 and a first lock piece 126 having an L-shaped cross section. The first lock piece 126 is vertically movably incorporated in the guide groove 125. One end 126a of the first lock piece 126 is projected into the plug inlet 124. Meanwhile, as shown in Fig. 5a , only when the first lock means 126 has been lifted, the other end 126b of the first lock means 126 is projected into the battery outlet 13 so as be brought into engagement with a recess 127 of the lid 14. Furthermore, there is provided a charging preventing means for preventing the plug 123 from being inserted into the plug inlet 124 when the lid 14 has been removed from the casing 1. The charging preventing means includes a guide groove 128 formed, between the battery outlet 13 and the plug inlet 124, on the casing 1 and a second lock piece 129 having an L-shaped cross section. The second lock piece 129 is horizontally slidably incorporated in the guide groove 128 through a spring 130 such that one end 129a of the second lock piece 129 closes or opens, upon horizontal slide of the second lock piece 129, an upper end opening of the guide groove 125 confronting the battery outlet 13. Therefore, as shown in Fig. 5a , when the plug 123 of the power source cord 52 is not being inserted into the plug inlet 124, namely when the electric shaver K26 is not being charged, the first lock piece 126 descends in the guide groove 125 by its own weight or by a downward urging force of a spring and the second lock piece 129 is depressed into the guide groove 128 against an urging force of the spring 130 by the lid 14. Thus, at this time, the lid 14 can be removed from the battery outlet 13. However, when the plug 123 of the power source cord 52 has been inserted into the plug inlet 124 as shown in Fig. 5b , the first lock piece 126 is lifted by the plug 123 so as to bring the other end 126b of the first lock piece 126 into engagement with the recess 127 of the lid 14. Hence, the lid 14 cannot be removed from the battery outlet 13. When the lid 14 has been removed from the battery outlet 13 in the state of Fig.5a in order to take the rechargeable battery 5 out of the casing 1, the second lock piece 129 is projected into the battery outlet 13 by the urging force of the spring 130 as shown in Fig. 8c so as to close the guide groove 125 such that ascent of the first lock piece 126 is prevented. Therefore, at this time, even if the operator tries to insert the plug 123 of the power source cord 52 into the plug inlet 124, the end 126a of the first lock piece 126 prevents insertion of the plug 123 into the plug inlet 124. Consequently, since charging of the electric shaver K26 cannot be performed, such an erroneous operation can be prevented that the electric shaver K26 is charged at the time of removal of the rechargeable battery 5 from the battery outlet 13, thereby resulting in safe charging of the electric shaver K26. Figs. 6a, 6b and 6c show a rechargeable type electric shaver K27 according to a 4 th embodiment of the present invention. The electric shaver K27 is a modification of the electric shaver K26. In the electric shaver K27, the first lock piece 126 is incorporated between the battery outlet 13 and the plug inlet 124 of the casing 1 in the same manner as the electric shaver K26. However, the electric shaver K27 is different, in construction of the charging preventing means, from the electric shaver K26. Namely, in the electric shaver K27, the second lock piece 129 has a substantially U-shaped cross section and is horizontally slidably incorporated, through the spring 130, in the guide groove 128 formed between the battery outlet 13 and the plug inlet 124 of the casing 1. Furthermore, the ends 129a and 129b of the second lock piece 129 are arranged to retractably project into the battery outlet 13 and the plug inlet 124, respectively. Thus, when the plug 123 of the power source cord 52 is not being inserted into the plug inlet 124 as shown in Fig. 6a, namely when the electric shaver K27 is not being charged, the first lock piece 126 descends in the guide groove 125 and the second lock piece 129 is depressed into the guide groove 128 against the urging force of the spring 130 by the lid 14. Hence, at this time, the lid 14 can be removed from the battery outlet 13. However, when the plug 123 of the power source cord 52 has been inserted into the plug inlet 124 as shown in Fig. 6b, the first lock piece 126 is lifted by the plug 123 so as to bring the end 126b of the first lock piece 126 into engagement with the recess 127. Therefore, the lid 14 cannot be removed from the battery outlet 13. When the lid 14 has been removed from the battery outlet 13 in the state of Fig. 6a in order to take the rechargeable battery 5 out of the casing 1, the ends 129a and 129b of the second lock piece 129 are, respectively, projected into the battery outlet 13 and the plug inlet 124 by the urging force of the spring 130 as shown in Fig. 9c such that the plug inlet 124 is closed by the end 129b. Hence, at this time, the plug 123 of the power source cord 52 cannot be inserted into the plug inlet 124 such that the electric shaver K27 cannot be charged. Fig. 7 shows a rechargeable type electric shaver K28 according to a 5 th embodiment of the present invention. In the electric shaver K28, the battery outlet 13 is formed at the side face of the casing 1, while the plug inlet 124 is formed at the bottom face of the casing 1. When the lid 14 is slidably moved on the outer peripheral surface of the casing 1 perpendicularly in the direction of the arrow R from a state in which the lid 14 closes the battery outlet 13, the battery outlet 13 is opened and at the same time, the plug inlet 124 is closed by the lid 14. It is so arranged that once the lid 14 has been slid in the direction of the arrow R as described above, the lid 14 cannot be returned to the original position in the direction opposite to the direction of the arrow R. Therefore, when the battery outlet 13 is opened and the plug inlet 124 is closed by the lid 14 by sliding the lid 14 towards the plug inlet 124, the rechargeable battery 5 can be removed from the wiring board 4 but such an undesirable phenomenon does not take place that the operator receives an electric shock through inadvertent charging of the electric shaver K28. It is needless to say that the slits 106 for the plug blades 105 of the charging plug 3 in the electric shaver K22 may also be closed by the lid 14 in place of the plug inlet 124. In the electric shavers K23 to K28, the rechargeable battery 5 is directly mounted on the wiring board 4 but may also be gripped between ribs projecting from the inner face of the casing 1 in a known manner. In the rechargeable type small electric appliance according to the 1st to 4 th embodiments of the present invention, since the battery outlet 13 to be closed by the lid 14 is provided on the casing 1, the rechargeable battery 5 can be easily taken out of the battery outlet 13 by opening the lid 14 and removing the rechargeable battery 5 from the wiring board 4 without unreasonably destroying the casing 1 at random. Furthermore, since the lid 14 cannot be removed from the battery outlet 13 at the time of charging of the electric appliance, such an accident can be prevented that the operator receives an electric shock by taking the rechargeable battery 5 out of the casing 1 while the electric appliance is being connected to the external power source, thereby resulting in safe removal of the electric appliance.

Claims: A rechargeable type small electric appliance comprising: a rechargeable battery (5) which is fixed to a substrate (4) having a charging circuit (6); a casing (1) for accommodating said substrate (4); a cover (14) for opening and closing a portion of said casing (1), which is detachably mounted on said casing (1); a connector (123) which is connectable to an external power source for charging said rechargeable battery (5) and is connected to said charging circuit (6) of said substrate (4); and a charging preventing means comprising a connector obstruction means (126, 129, 130) movable, on removal of said cover (14) from said casing to expose said substrate (4), from a withdrawn position to one obstruction position in which it is arranged to obstruct the connection of the connector (123) to the charging circuit (6). An appliance according to claim 1, wherein said connector obstruction means comprises a first locking piece (126) movable between a withdrawn position and an obstruction position in which it is arranged to obstruct the connection of the connector (123) to the charging circuit (6) and a second locking piece (129,130) movable, on removal of said cover (14) from said casing to expose said substrate (4), from a withdrawn position to an obstruction position in which it is arranged to obstruct movement of the first locking piece (126) from the obstruction position of the first locking piece to the withdrawn position. An appliance according to claim 1, wherein said connector obstruction means comprises a locking piece (128, 130) which is held in said withdrawn position by said cover (14) and is movable to said obstruction position on removal of said cover (14). A rechargeable type small electric appliance comprising: a rechargeable battery (5) which is fixed to a substrate (4) having a charging circuit (6); a casing (1) for accommodating said substrate (4); a cover (14) for opening and closing a portion of said casing (1), which is detachably mounted on said casing (1); a connector (123) which is connectable to an external power source for charging said rechargeable battery (5) and is connected to said charging circuit (6) of said substrate (4); and a charge preventing means formed by terminals (3,28)in or on said cover, said terminals (3,28) being arranged such as to interconnect said charging circuit (6) and said connector (123) when said cover (14) is on said casing (1) and arranged to be disconnected from said charging circuit (6) when said cover (14) has been removed from said casing (1) so as to expose said substrate (4) thereby to disconnect said connector (124) from said charging circuit (6). A rechargeable type small electric appliance comprising: a rechargeable battery (5) which is fixed to a substrate (4) having a charging circuit (6); a casing (1) for accommodating said substrate (4); a cover (14) for opening and closing a portion of said casing (1), which is detachably mounted on said casing (1); a connector (123) which is connectable to an external power source for charging said rechargeable battery (5) and is connected to said charging circuit (6) of said substrate (4); and a charging preventing means comprising means for providing movement of said cover (14) between a first position in which said cover (14) covers said battery (5) with said portion being closed, and a second position in which said portion is open and said cover interposes between said connector (123) and said charging circuit (6).

Inventors: CHIYAJO MASANOBU, KUROKI TOSHIO, SAKATA EIJI, CHIYAJO, MASANOBU, KUROKI, TOSHIO, SAKATA, EIJI
Applicants: HITACHI MAXELL, KYUSHU HITACHI MAXELL, LTD.
Application year: 1989
Main classification: H01M2
IPC codes: H05K1, H01M2, B26B19, H01M10, H05K3