GB2216247A - Electrically powered unit with integrally formed battery - Google Patents

Description

16247 ELECTRICALLY POWERED UNIT WITH INTEGRALLY FORMED BATTERY The

invention pertains to electrically.5 powered units which include an integrally formed rechargeable battery therein. More particularly, the invention pertains to electrically powered units which have a housing, a portion of which is used as part of the containment housing for a rechargeable battery.

Electrically powered units such as flashlights, emergency lights and the like have long been known. These electrically powered units have in the past included individual replaceable batteries. As the stored energy in the batteries was used up, they were replaced with fresh batteries as needed.

More recently, electrically powered units have become available which include rechargeable batteries. Such units can take the form of flashlights, portable radios, or the like. Known electrical units which incorporate rechargeable batteries have utilized batteries, analogous to the disposable batteries, which are formed as individual products completely apart from the electrically powered unit in question. These rechargeable batteries are then installed in the respective electrically powered unit during the manufacturing process and are not intended to be readily removed.

Notwithstanding the convenience and usefulness of rechargeable electrical units, it has been found that the cost of such individually formed rechargeable batteries can represent a substantial ,-pxjrtion of the cost to manufacture the electrical unit.:-!-=- - addition, since the rechargeable batteries are 2 formed as individual units, each must have its own housing, usually sealed, to contain the electrodes, electrolyte and separator.

There is a need for electrically powered units which provide the convenience of rechargeable batteries but with reduced cost.

According to the present invention, an electrically powered unit comprises: a housing defining a region therein; a battery integrally formed within at least part of said region; and means carried by the housing for executing a predetermined function, the said means being couplable to the battery for selective energization thereof.

It will therefore be seen that a rechargeable battery is provided which is integrally formed within at least part of the region def ined by the housing. For example, the battery may be contained within a volume formed in part by the housing and formed in part by a cover member. 20 The housing may also carry circuitry for recharging the battery as well as for providing electrical energy to a selected load. The selected load can be one or more electrical lights. The electrical unit can be configured so as to have a manually operable control member, such as a three-positioned switch. Rigid electrical coupling conductors can be provided adjacent an exterior surface of the housing so that the unit can be easily coupled to' an exterior source of electrical energy. This electrical energy can be used for the purpose of recharging the integrally formed battery.

The electrical circuitry can also include a photodetector. The photodetector can be used to sense 3 ambient light in the vicinity of the housing for the purpose of energizing one of the electrical lights. The electrical circuitry can also include a sensor to detect the absence of electrial energy from the S exterior source. In response to the detected absence of the electrical energy supplied by the exterior source, the unit can energize a selected one of the electrical light bulbs.

The invention may be carried into practice in lo various ways but two electrically powered units embodying the invention will now be described by way of example with reference to the accompanying drawings, in which:

Figure 1 is a perspective view of a combined emergency and night light in accordance with the present invention; Figure 2 is a perspective view, partly broken away illustrating the control switch and relationship of the light bulbs to the housing of the unit of Figure 1; Figure 3 is an end view, partly broken away, of Figure 2; Figure 4 is a top plan view of the housing of the unit of Figure 1; Figure 5 is a sectional view taken along plane 5-5 of Figure 4; Figure 6 is a sectional view taken along plane 6-6 of Figure 4; Figure 7 is a sectional view taken along plane 7-7 of Figure 4; Figure 8 is a schematic diagram of an electrical control circuit usable with the unit of Figure 1; 4 Figure 9 is a side plan view of a stand alone battery in accordance with the present invention; Figure 10 is an end plan view of the stand alone battery of Figure 9; Figure 11 is a top plan view of the stand alone battery of Figure 9; Figure 12 is sectional view taken along plane 12-12 of Figure 9; Figure 13 is a sectional view taken along jo plane 13-13 of Figure 9; Figure 14 is a sectional view taken along plane 14-14 of Figure 9; and Figure 15 is a sectional view taken along plane 15-15 of Figure 9.

With respect to Figure 1, an electrical unit which can in a preferred embodiment take the form of a power fail/night light includes a housing 12 which can be moulded of a thermoplastic material. Carried by the housing 12 is a lens 14.

The housing 12 includes an aperture 16 through which a photosensor 16a can sense ambient light for the purpose of automatically switching the unit on and off when in the night light mode. The housing 12 includes an aperture 18 through which extends a portion of a three-position manually operable switch 20. The switch 20 can be used to turn the unit 10 off or to select and operating mode.

The unit 10 is illustrated in Figure 1, plugged into a standard alternating current power socket generally indicated at 22. When plugged into such a power socket, the unit 10 can not only recharge an integrally formed battery contained within the housing 12 but can also detect the absence of electrical power at the socket 22. In response to the detected absence of electrical power at the socket 22, the unit 10 can switch on a higher illumination electric light to automatically provide emergency illumination.

In Figure 2, the lens 14 has been partly broken away disclosing a curved moulded reflector member 26 which is positioned between the housing 12 and the lens 14. A relatively high level of illumination bulb 28 is removeably positioned in a socket 30. The socket 30 is generally centrally located with respect to the reflector 26. The bulb 28 is used to provide a relatively high level of illumination in the absence of externally supplied electrical energy. Such a loss can come about due to the unit 10 having been unplugged from the socket 22, in which event it can function as a flashlight, or due to failure of electrical power at the socket 22.

A relatively low illumination, long life, nonreplaceable bulb 32 extends through an opening 34 in the reflector 36. The bulb 32 is used to provide a relatively low level of illumination when the unit 10 is used as a night light.

Figure 3, further illustrates the interrelationship of the various components of the unit 10: A set of prongs 36 extends outwardly from an exterior surface 12a of the moulded housing 12. The prongs 36 are of a conventional variety and are intended to slidably engage the conductors of the alternating current socket 22.

The prongs 36 are electrically coupled to circuitry on a printed circuit board 38 carried by the housing 12. The printed circuit board 38 also provides 6 contacts for the socket 30.

The housing 12 defines an interior region 40. The region 40 includes a rechargeable, integrally formed, battery 42.

-5 The battery 42, best seen in Figure 4, is formed in an end region of the housing 12. The housing 12 has a boundary wall 44 which bounds the battery 42 on three sides with wall members 44a, 44b, and 44c. The housing 12 also has a bottom wall 46. The bottom wall 46, in a region 48, provides a lower boundary for the battery 42. A flange 50 moulded into the housing 12 provides a somewhat U-shaped interior wall for the battery 42 which extends between the two elongated sides 44a and 44b of the housing 12.

Hence, the housing 12 forms a casing or containment housing for the battery 42 bounding that battery along four edges 44a, 44b and 44c, 50 and a bottom surface in region 48. The battery 42 is closed by an upper member 52. The upper member 52 is a moulded elongated plastic member which forms the cover for the battery 42.

The cover member 52 can be ultrasonically welded to the four battery containing sides, previously noted, formed by the housing 12. Hence, the battery 42 is formed within a region 54 defined by portions of the housing 12, except for the cover 52 which is affixed thereto.

The cover 52 includes an integrally formed vent 56. The vent 56 includes a cylindrical port 58 which extends into the region 54. The port 58 is covered with a slidable valve cap 60. The cap 60 is slidable along the cylindrical port 58 in response to pressure due to gases generated within the cavity 54.

7 As the cap 60 moves away from the cylindrical port 52 in response to internal pressure in the volume 54, the seal provided by the cap 60 is broken and the pressure can be released from the closed chamber 54.

once the pressure has been released, the cap stops moving. In response to the pressure in the chamber 54 dropping subsequently, the cap 60 will be forced by atmospheric pressure back toward the battery 42 thereby resealing the port 58. A restraining member 62 which is integrally formed on the reflector 26 limits the degree of movement of the cap 60.

The pressure relief valve 56 functions to relieve pressure in the region 54 when that pressure exceeds 69 to 83 kPa.

The battery 42 is provided with first and second exterior contacts, or terminals, 66a and 66b. The contacts 66a and 66b are used to couple exterior circuitry on the printed circuit board 38 to the battery 42 for the purpose of recharging same or withdrawing electrical energy therefrom.

The battery 42 is a sealed lead-acid battery of the recombination type. Such batteries, as is known in the art, utilize spaced apart lead electrodes and an acid electrolyte.

With respect to Figure 5, a section taken along plane 5-5 of Figure 4, the structure of the battery 42 includes an exterior negative electrode 70 which functions as the anode. The electrode 70 is a conventional negative electrode formed with a lead grid. The spaces in the grid are filled with sponge lead.

The electrode 70 is folded or bent so as to form a continuously curved member having a generally U- shaped cross section. While the sponge lead in the grid of the electrode 70 may crack during the folding operation, the grid members themselves tend to be very ductile and easily folded thereby providing reliable electrical continuity within the cell. Located adjacent the folded electrode 70 is a separator layer 72 formed of nonwoven glass fibre of a commercially available type. The separator 72 in addition to separating the electrode 70 from a second, centrally located essentially planar electrode 74 also absorbs substantially all of the electrolyte present in the cell.

The electrode 74 forms a positive electrode for the cell. The electrode 74 is formed as a cast lead grid filled with lead dioxide.

The electrolyte used with the cell of the battery 42 is dilute sulphuric acid with a specific gravity on the order of 1.32 at 15.550C.

The electrodes 70 and 74 preferably utilized with the battery 42 contain conventionally available lead alloy with about.1% by weight calcium. The electrodes 70 and 74 contain lead of a purity of less than 99.9% by weight. As a result of the alloy utilized in the electrodes 72 and 74 they are substantially self-supporting.

Figure 6, a section taken along plane 6-6 of Figure 4, and Figure 7 illustrate the interrelationship between the negative electrode 70 and the associated terminal 66a.

A tab 70a which is cast with the grid of the electrode 70 is attached to the terminal 66a in a region 70b. The terminal 66a can be formed of tinned copper or tinned brass. Alternatively,the terminal 9 66a could be brass or copper with a layer of tin plate thereon. Preferably the thichness of the plating will be on the order of.0076mm thick. An end 66c of the terminal 66a slidably engages the end 70b of the lead tab 70a (best illustrated in Figure 7). The region 66c of the terminal 66a is then re-flow soldered to the lead end region 70b.

For the purpose of providing a seal between the interior region 54 and the exterior region and for providing mechanical support, the regions 50a are filled with an epoxy material.

Figure 8 is a schematic of an electrical circuit 38a usable with the unit 10. The circuitry 38a includes the electrical connection prongs 36 which extend from the rear surface 12a of the housing 12. The circuitry 38a can be mounted on and supported by the printed circuit board 38.

The circuitry 38a includes an automatic.night light activating section 90. The circuitry in section 90 includes first, second and third resistors 92a, 92b and 92c. The night light activating circuitry also includes the photosensor 16a and a silicon controlled rectifier (SCR) 94.

The photosensor 16a is located behind the optical port 16 of the housing 12. In the presence of ambient light, the photosensor 16a conducts with the result that little or no voltage appears on a gate input line 94a of the SCR 94.

Assuming that the three-position switch 20 is set in the upper or night light activating position, as the level of ambient light decreases, the sensor 16a conducts less and less. This permits the voltage on the line 94a to increase. When the voltage on the trigger input line 94a of the SCR 94 gets high enough, SCR 94 conducts. Current will then flow through the night light bulb 32 which will provide continuous illumination until the light incident on the port 16 again increases. With an increase in incident light, the photosensor 16a will again start to conduct thereby blocking conduction of the SCR 94.

A capacitor 94b eliminates flickering of the light 32 in response to reflections therefrom onto the sensor 16a.

A second section 96 of the circuitry 38a provides electrical energy from the prongs 36 to recharge the battery 42. This recharging section of the circuitry 38a includes first and second rectifier diodes 98a and 98b along with current limiting resistors 100. So long as the unit 10 is coupled to an alternating current power socket, the recharging circuitry 96 will continuously attempt to recharge the battery 42 independently of the position of the switch 20, provided power is available at the prongs 36.

A final section 102 of the circuitry 38a senses the absence of applied current and voltage, via the prongs 36. In such absence of applied current and voltage, the power fail indicator light 28 is energized provided that the switch 20 is in one of its positions other than the off position.

The power-fail detection circuitry 102 includes switching transistors 104a and 104b along with resistors 106a, 106b and 106c. So long as current and voltage are applied to the circuitry 38a through the prongs 36, transistor 104a will be turned off. With transistor 104a turned off, transistor 104b will be turned off with the result that the light 28 also will be turned off.

The transistor 104a will immediately start to conduct, due to the potential and current from the battery 42, in the absence of applied electrical energy to the prongs 36, assuming that the switch 20 is not in the off position. The current flowing through the transistor 104a, via the resistor 106c will then cause the transistor 104b to conduct. The emergency light 28 will then be turned on. The light 28 will continue to conduct until applied electrical energy is restored through the prongs 36, until the switch 20 is moved to the off position, or until the battery 42 becomes discharged to about.6 volts.

Figure 9 illustrates an alternative battery structure 120. The battery includes a self-contained housing 122 which can be moulded of a selected thermoplastic material. The housing 122 has an elongated generally rectangular cross section (best illustrated in Figure 12). The housing 122 includes 20 first and second elongated side members 124a and 124b which in turn are joined by curved, elongated end members 126a and 126b integrally formed therewith. The housing 122 is closed by a bottom 128 integrally formed therewith. A top member or cover 130 is ultrasonically 25 welded at a seam 132 to the housing 122. The housing 122 defines an interior region 132 therein. The top member or cover 13 0 carries a vent 136 as well as spaced apart first and second, positive and negative, terminals 138a and 138b. The cover 130 includes an upper portion 132a which defines an interior region 140. The region 140 can be filled with an epoxy material 142. The epoxy material 142 provides a seal between the exterior environment and the 12 interior region 132 of the battery 120. In addition the epoxy material 142 provides physical stability and strength for the terminals 138a and 138b.

Figures 12-15 illustrate the interior structure of the battery 120. That structure is similar to the interior structure of the battery 42 previously discussed. The battery 120 includes a folded or curved negative electrode 150 formed, as in the case of the battery 42, of a cast lead grid loaded with sponge lead. The negative electrode 150 forms the anode for the battery 120 at the terminal 138a. A second, essentially planar positive electrode 152 is also provided. The electrode 152, forms a substantially planar cathode for the battery 120. The electrode 152 is coupled to the terminal 138b and is formed as a cast lead grid. The electrode 152, is filled with lead dioxide.

The electrodes 150 and 152 are separated by a glass fibre separator 154.

The vent 136 is formed with a cylindrical port 136a with an interior surface 136b defining a fluid flow pathway in fluid flow communication with the interior region 132 of the battery 120. A slidable cap 136c resealably closes the vent 136. The vent 136 operates in a fashion analogous to the vent 56 of the battery 42.

With respect to Figures 14 and 15, the electrode 152 carries an integrally cast contacting tab 160. The contacting tab 160 is formed with a shaped end region 162 of the terminal 138b. The end 164 and the region 162 are reflow soldered together. Reflow soldering provides a physically strong joint therebetween without the necessity of any other 13 attaching or attachment elements.

Similarly, the electrodes 150 carries an integrally cast tab 170 with an end region 172 reflow soldered to an adjacent end region 174 of the terminal 138a.

The terminal 138a and 138b can be tin plated brass or copper. Alternatively, the terminals 138a and 138b can be formed as tinned brass or copper.

The separator 154 as well as the electrodes 150 and 152 receive an electrolyte, such as sulphuric acid of the type noted previously with a specific gravity 1.32 at 15.550C.

It will be understood that while an elongated housing 122 is illustrated, having a general-ly rectangular cross section, the battery can be formed with housings of a variety of shapes which include electrodes of substantially self supporting lead having a purity by weight of less than 99.9% lead.

Battery 42 in an exemplary embodiment having physical dimensions on the order of 76mm x 44.5mm x 12.7mm can provide 1. 6 ampere hours of current at a nominal 2 volt rating.

The battery 120 having physical dimension on the order of 89mm x 38mm x 16mm can provide 1.5 ampere hours of current at a nominal 2 volt rating.

a- 14

Claims (10)

1. An electrically powered unit comprising: C a housing defining a region therein; a battery integrally formed within at least part of said region; and means carried by the housing for executing a predetermined function, the said means being couplable to the battery for selective energization thereof.

2. An electrically powered unit as claimed in claim 1 in which the battery has a case a portion of which is formed by the housing.

3. An electrically powered unit as claimed in claim 1 or claim 2 in which the battery includes a folded electrode having a generally U-shaped cross section.

4. An electrically powered unit as claimed in claim 1 or claim 2 or claim 3 in which the integrally formed battery is rechargeable.

5. An electrically powered unit as claimed in claim 4 which includes means for selectively recharging the battery.

6. An electrically powered unit as claimed in claim 5 which is rechargeable from an exterior energy source and which includes first and second rigid conducting members, carried by the housing, for coupling to the exterior energy source.

7. An electrically powered unit as claimed in any preceding claim in which the battery is enclosed in part by a section of the housing and in part by a selectively shaped cover member affixed to the said section thereby defining a battery containing volume.

8. An electrically powered unit as claimed in claim 7 which includes means, carried by the battery, f or venting the battery containing volume in response to a detected predetermined pressure therein.

9. An electrically powered unit as claimed in claim 8 in which the venting means is reclosable in response to a selected drop in the said volume pressure.

10. An electrically powered unit substantially as described herein with reference to Figures 1 to 8 or to Figures 9 to 15 of the accompanying drawings.

Published 1989 at The Patent Offtee, State House, 66 71 High Holborn, London WC1111. 4TP. Parther copies may be obtained from The Patent O:Mce. Sales Branch, St Mary Oray, Orpington, Kent BRB 3RD. Printed by Multiplex Whniques ltd, St Mary Cray, Kent, Con- 1/87