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 and the lid 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 power source switch of the known electric appliances is an ON state, there is such a danger as generation of sparks from cut portions of the lead wires. CH-A-484530 discloses a battery arrangement for an electrical appliance in which a battery holder is slidable in a casing either to expose the battery for replacement or to expose terminals. The present invention therefore provides a rechargeable type small electric appliance (K26) comprising: a rechargeable battery; a casing which is formed, at a portion of its outer surface, with a battery outlet for receiving said rechargeable battery; said rechargeable battery being detachably accommodated in said casing; a cover which is detachably mounted on said battery outlet; a connector which is connectable to an external power source for charging said rechargeable battery; and a locking means which is capable of locking said cover when said connector can be connected to said external power source. 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 side elevational view showing a chargeable state of a rechargeable type small electric appliance which is not an embodiment of the invention, but is useful in understanding 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; Fig. 3 is a circuit diagram of the electric appliance of Fig. 1; Figs. 4c and 4b are fragmentary front elevational views showing a nonchargeable state and a chargeable state of a rechargeable type small electric appliance according to a first embodiment of the present invention, respectively; Fig. 4c is a fragmentary front elevational view showing a state in which a lid has been removed from the electric appliance of Fig. 5a; Figs. 5a, 5b and 5c are views similar to Figs. 4a, 4b and 4c, respectively, particularly showing a second 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 shaver 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 to 3 show a rechargeable type electric shaver K22 which is not an embodiment of the present invention but is useful in understanding the present invention. The shaving blade unit 2 is provided at the upper portion of the casing 1, while the charging plug 3 is provided at the bottom portion of the casing 1. The charging plug 3 has a pair of retractable plug blades 105. The plug blades 105 retractably project from a pair of slits 106 formed on the side face 1A of the casing 1, respectively. In the vicinity of the slits 106, the battery outlet 13 opens at the side face 1A, the front face 1B and a rear face 1C. The pattern 18 corresponding to a circuit shown in Fig. 3 is formed on the wiring board 4. Furthermore, the rechargeable battery 5, the transformer 6, a switch 111, etc. are mounted on the wiring board 4. At least the rechargeable battery 5 is so provided on the wiring board 4 as to confront the battery outlet 13. The rechargeable battery 5 is detachably mounted on the wiring board 4. For example, the peripheral portions 4b of the joints between the negative terminal 8 and the lead piece 10 and between the positive terminal 9 and the lead piece 11 are snapped off from the wiring board 4 along the snap line 33. The lid 14 having an U-shaped cross section is detachably mounted on the battery outlet 13 so as to be opened in the direction of the arrow Q identical with the direction of projection of the plug blades 105. The lid 14 has a nonslip portion 110 for preventing slip of a finger and a predetermined number of engageable claws 118 capable of elastic deformation. Through utilization of elasticity, the engageable claws 118 are detachably engageable with a mouth edge of the battery outlet 13 of the casing 1. The engageable claws 118 are brought into engagement with the mouth edge of the battery outlet 13 such that the battery outlet 13 is kept closed by the lid 14. Meanwhile, when the lid 14 is pulled in the direction of the arrow Q by gripping the nonslip portion 110 with a hand, the engageable claws 118 are disengaged from the mouth edge of the battery outlet 13 and thus, the lid 14 is removed from the casing 1. Meanwhile, the window 84 is provided on the lid 14 so as to enable the operator to visually inspect presence of the rechargeable battery 5 from outside of the lid 14. When the electric shaver K22 is charged, the plug blades 105 are projected as shown in Fig. 1 and are inserted into a socket outlet 120 on a wall or a socket outlet provided at one end of a power source cord. In this charging state, the socket outlet 120 is disposed adjacent to the lid 14 in the direction of the arrow Q for opening the lid 14 and thus, the socket outlet 120 prevents the lid 14 from being removed from the casing 1. Therefore, the rechargeable battery 5 is not removed from the wiring board 4 inadvertently at the time of charging of the electric shaver K22, thereby resulting in safe charging of the electric shaver K22. On the contrary, when the electric shaver K22 is not being charged, the lid 14 can be removed from the casing 1, so that the rechargeable battery 5 can be removed from the wiring board 4 by snapping off the peripheral portions 4b from the wiring board 4. The plug blades 105 of the charging plug 3 are retractably displaced by sliding a knob of the charging plug 3 in the direction of the arrow Q and in the direction opposite to the direction of the arrow Q but may also be retractably displaced through their rotational operation. Figs. 4a, 4b and 4c show a rechargeable type electric shaver K26 according to a first 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. 4b, 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. 4b, 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. 4b, 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. 4a 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. 4c 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. 5a, 5b and 5c show a rechargeable type electric shaver K27 according to a second 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. 5a, 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. 5b, 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. 5a 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. 5c 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. In the electric shavers K26 and K27, 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 or second 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 (K26) comprising: a rechargeable battery (5); a casing (1) which is formed, at a portion of its outer surface, with a battery outlet (13) for receiving said rechargeable battery (5); said rechargeable battery (5) being detachably accommodated in said casing (1); a cover (14) which is detachably mounted on said battery outlet (13); a connector (124) which is connectable to an external power source (123) for charging said rechargeable battery (5); and a locking means (126) which is capable of locking said cover (14) when said connector (124) can be connected to said external power source (123). A rechargeable type small electric appliance (K26) as claimed in claim 1, wherein said connector is formed by a socket (124); wherein when a charging plug (123) of said external power source is inserted into said socket (124), said locking means (126) is held in engagement with said cover (14). A rechargeable type small electric appliance (K26) as claimed in claim 2, wherein said locking means (126) is mounted on said casing (1) so as to be slidably operated from outside and is slid so as to be brought out of engagement with said cover (14); said rechargeable type small electric appliance (K26) further comprising; a second locking means (29) for preventing slide of said locking means (126) when said cover (14) has been detached from said casing (1), which is provided on said casing (1). A rechargeable type small electric appliance (K26, K27) as claimed in claim 2, further comprising: a preventive means (126a, 129b) for preventing insertion of said charging plug (123) into said socket (124) when said cover (14) has been removed from said casing (1) through disengagement of said locking means (126) from said cover (14), which is provided between charging pins (28) in said socket (124) and a mouth of said socket (124). A rechargeable type small electric appliance (K26) as claimed in claim 1, wherein said connector (124) is formed by a charging plug (3) projecting retractably from said casing (10 and said locking means (126) is held in engagement with said cover (14) when said charging plug (3) projects from said casing (1).

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: H01M2, H05K1, H05K3, H01M10, B26B19