US3443084A - Disposable flashlight - Google Patents

Description

Ma 6, 1969 I f 3,443,084

DI SPOSABLE FLASHLIGHT Filed March 18, 1966 Sheet of 2 2 INVENTOR JEAN FIRMIN JAMMET BY ATTORNEYS y 6, 11969 J. F- JAMMET 3,443,084

DISPOSABLE FLASHLIGHT Filed March 18, 1966 Sheet 2 of 2 INVENTOR JE AN FIRMIN JAMMET ATTORNEYS United States Patent Ofice 3,443,084 Patented May 6, 1969 Int. Cl. i zn 7/00 US. Cl. 24010.65 14 Claims ABSTRACT OF THE DISCLOSURE A disposable flashlight of the type comprising a conventional battery having resilient terminal blades and a bulb mounted in a common sealed casing. A first terminal of the bulb is in permanent contact with one of the resilient terminal blades, and the other terminal blade is normally in open circuit condition relative to a plate member which is in permanent direct electric contact with the other terminal of the bulb. A slidable switch element is mounted on the casing and is in slidable engagement with the second terminal blade so as to be able to move it into circuit closing contact with said plate member and thus to complete the electric circuit from said battery through said bulb and illuminate said bulb. Upon exhaustion of the battery, the entire device is discarded.

This invention relates to flashlights and particularly to a type which can be manufactured cheaply and discarded or otherwise disposed of after exhaustion of its batteries.

Flashlights of this type which are extant are known to have some drawbacks.

In a known discardable type of flashlight, the moving contact of the switch is generally constituted by one terminal blade of the electric battery which when urged by a switching member comes into contact with the threaded base of the bulb. The contact area between the blade and the base is, however, very small and practically a point. Moreover, the resilience of the blade is not always sufficient in itself to insure adequate contact pressure with the bulb to maintain the closed circuit.

It should also .be kept in mind that such flashlights have to be mass produced and this implies some manufacturing tolerances. Thus, it happens frequently that the switch fails before a complete discharge of the battery and it is impossible to mend it since the flashlight casing is sealed. Thus, the useful life of the device is shortened unnecessarily.

Moreover, in such known flashlights, the terminal blade which constitutes the moving contact of the switch must be given a relatively great length. Thus, it is not possible to use the blades of standard batteries. This, of course, causes an undesirable increase in the manufacturing price of the flashlight.

An object and feature of this invention is the provision of a discardable type of flashlight which avoids such drawbacks and also has numerous advantages relating as well to the ease of its manufacture and to the lowness of its manufacturing price as well as to the reliability of its operation to the full length of the life of its batteries.

The discardable flashlight according to the present invention comprises an electric battery provided with two resilient contact blades and a bulb all contained in a common sealed casing, one of the battery blades being always in contact with one terminal of the bulb, the second blade being normally spaced apart from the second terminal of the bulb and being subjected to the action of a switch element which is accessible from outside of the casing and constituting switching means, which element is able to urge the second blade against the second contact terminal of the bulb, the said flashlight being more especially notable in that the first terminal is constituted by the central stud of the bulb and in that the second terminal comprises a metal plate that is in permanent contact with the second terminal (base) of the said bulb, the said second blade being movable into contact with an edge of the said plate when so urged by the said switching element.

The advantage of such a disposition is immediately apparent. The contact between the second blade and the plate is efl ected on substantially the whole width of said blade, and the resilience of the plate is added to that of said blade for ensuring an adequate contact pressure to establish and ma'mtain the closed circuit.

With such an arrangement, moreover, it becomes possible to use the blades of standard or conventional batteries since the edge of the plate constituting the necessary contact part can be placed in any suitable location.

Other objects, characteristics and features of the invention will become apparent from the following description as well as the accompanying drawings given as non-limitative examples and wherein:

FIGURE 1 is a partly sectional front view of a disposable flashlight according to the invention with the switch in open condition;

FIGURE 2 is a fractional sectional view similar to that of FIGURE 1 with the switch in a closed position;

FIGURE 3 is a plan view from above of the plate constituting one contact terminal of the bulb;

FIGURES 4 and 5 are sectional views of FIGURE 3 along lines 4-4 and 5-5;

FIGURES 6, 7 and 8 are views similar to FIGURES 3, 4 and 5 showing another embodiment of the plate, and FIGURE 9 is a perspective view from underneath and on an enlarged scale of the switching element.

In the example shown in the drawings, the flashlight comprises a casing 1 preferably made of plastic material disposed around the series-connected cells 2 of the battery which is provided in the conventional manner with a short positive terminal blade 3 and a longer negative terminal blade 4.

A cover 5, also of plastic material, is fastened to the casing as by welding, gluing or in any other suitable way, said cover comprising in its upper wall 6 a transparent recessed portion 7 represented as having substantially the shape of an inverted truncated cone that extends inwardly of the cover 5 and has a cylindrical, resilient tubular extension 8 provided with a large longitudinal slot 9 inside of the cover. This tube 8 serves for receiving and frictionally holding and carrying the base 10 of the bulb 11, the central contact stud 12 of which is thus placed in direct contact with the positive blade 3 of the battery which is folded into a substantially horizontal position. This blade 3 has suflicient resilience to make permanent contact with the central stud 12 of the bulb.

A metal plate 13 is permanently mounted on the tube 8, said plate being shown in detail on FIGURES 3, 4 and 5. This plate, in width, is equal substantially to the inner distance between the side plates of the cover part 5.

This plate 13 is preferably substantially rectangular and comprises a central hole 13a having two peripheral resilient lugs 14 and 15 in diametrical opposition, lug 14 frictionally engaging the outer wall of tube 8, whereas lug 15 includes a groove defining a rib 16 near its free end which passes through slot 9 and engages the threaded base 10 of the bulb with the rib 16 being positioned between two spires of the threaded base 10.

Plate 13 is reinforced and made more rigid by the provision of linear grooves 17 and 18 in its surface.

In the embodiment shown in FIGURES 6, 7 and 8, plate 13 has turned down edges or flanges 19 and 20 to provide the same rigidity as the said grooves 17 and 18 of plate 13. These flanges, moreover, have the advantage of facilitating the introduction of the plate 13 in the cover and of preventing cutting edges of plate 13 from damaging the material of the side walls of the cover 5.

It is obvious that plates 13 or 13' may be given a shape differing from the rectangular shape which has been shown without departing from the scope of the invention.

More especially, it also may be advantageous to turn down the plate edge which cooperates with negative terminal blade 4 in order to increase the contact area.

It is also possible, when the negative terminal blade 4 has a given groove defining a rib bend along its transversal section, to give a corresponding shape to the edge cooperating with the plate in order to obtain a linear contact.

As shown in FIGURES 1 and 2, the negative terminal blade 4 which in the example shown is reinforced by a central groove defining a rib 21 and which is transversely bent at 22 has a general slant toward the plate 13 and its end is normally located slightly above and away from the edge of said plate. It should be noted that the central rib 21 and the bend 22 may be provided without difliculty on a conventional terminal blade already fastened to the battery cells so that it is possible to use existing standard conventional batteries.

Terminal blade 4 is subjected to the action of a switch element 23 which has been shown in a perspective view from underneath in FIGURE 9. This switch element 23 preferably of plastic material comprises a head 24 and a lower tined prong part 25 which is capable of sliding in a substantially rectangular slit or opening 26a made in the arcuate portion 26 of the casing. Head 24 has arcuate shape in conformity with the outer surface of portion 26 of cover 5. The prong part 25 of the switching organ is slightly wider than the opening 26 and is united to the head 24 by a portion 27 of a smaller width in which the edges of opening 26a are engaged. Said lower part 25 is split at 28 in its whole or on part of its depth. Thus, the switching element 23 can be easily mounted on cover 5 by insertion of its prong part 25 through the rectangular opening 26 as by squeezing prong part 25 through the opening 26a until the narrower portion 27 arrives at the level of the edges defining opening 26a in the cover wall. Both tines of the lower prong part 25 then lie on respective sides of rib 21 provided on terminal blade 4 which promotes and guides its sliding thereover. As also shown in FIGURES 1 and 2, the lower part 25 is bevelled at its outer edge so that in the position shown on FIGURE 1 (open circuit) its surface is substantially parallel to the end of terminal blade 4 upon which it rests.

The length and location of the rectangular opening 26a in cover 5 and the location of bend 22 of blade 4 are chosen such that when the switch is moved to the position of FIGURE 2 (closed circuit), the peak of the bevelled end of part 25 which is then the only portion in contact with terminal blade 4 is situated slightly beyond the bend 22. This is an important advantage for since the peak of the bevelled end of prong part 25 has to pass to the other side of the bend 22 in order to return to the position of FIGURE 1, the switch element 26 is maintained in a stable position when it is in the circuit-closing position.

It should be noted, also, that the casing wall 26 in which the rectangular opening 261: is provided for the switching element 23 is shown preferably as inwardly curved, the head 24 of the switching organ having a corresponding shape. This facilitates hand manipulation of the element 13 by the user.

Moreover, metal contact plate 13 may serve as a reflector, in which case the wall of recess 7, in which bulb 11 is located is of transparent material. This wall may be metallized to provide a reflector, if desired.

Assembly of the components to form the disposable flashlight of this invention may, for example, be effected as follows: The prong part 25 of the switch element 23 is inserted into the rectangular opening 26a of the cover 5 until its narrower portion 27 is in register with the edges defining said opening 26a. Then, the bulb 11 is pushed into recessed portion 7 and into tubular portion 8 and then the plate 13 or 13 is mounted on the said tubular extension 8. The cover 5 is then ready to be mounted on the assembled battery in casing 1. The assembled battery is of the type presently manufactured, except that it is provided with the plastic casing 1. It exists in the state where its elements are already interconnected. The contact blades 3 and 4 are then set in form, that is to say, the blade 3 is bent horizontally and the blade 4 after formation of its rib 21 is bent at 22 to desired angle. Then, the cover 5 having been positioned, parted or adhered to the container, the stud 12 of bulb 11 rests on the blade 3 and the extremity of the portion 25 of the switch element 23 comes into contact with the forward portion of blade 4. The flashlight is then ready for use. It is to be noted that an accidental slide of the switching element cannot then be effected to cause a permanent closure of the illuminating circuit of the bulb because the elasticity of the blade 4 acting on the peak of part 25 then pushes the switch element 33 back towards the open circuit position as seen in FIG. 1. Likewise, once moved by the user to circuit-closing condition, the resiliency of blade 4 and plate 13 retain switch element 23 in this condition until the user applies suflicient force to slide the peak of pronged portion 25 across and past bend 22 in reverse direction. Thus, the flashlight will not be turned on or off accidentally during transit or in storage.

It is to be understood that the invention is in no way limited to the specific embodiments described and shown herein, which have been given as a non-limitative example. It is obvious that the particular shape given to the flashlight and the location inside said flashlight of various components may be chosen arbitrarily and changed according to the needs and to the purpose of the flashlight, all within the scope of the appended claims. There is no intention, therefore, of limitation to the exact disclosure herein made.

What is claimed is:

1. In a disposable flashlight of the type comprising a battery having resilient terminal blades and a bulb mounted in a common sealed casing with a first terminal of the bulb in permanent contact with one of the resilient terminal blades, said other terminal blade being normally in open circuit condition relative to a second terminal constituting the base of the bulb, a plate member in permanent electric contact with said second terminal of said bulb and a switch element slidably mounted on said casing and in sliding engagement with said second terminal blade for moving the latter into circuit-closing contact with said plate member to illuminate said bulb, said casing including a cover part secured thereto having an inwardly projecting cylindrical deformable longitudinally slotted tubular portion into which the base of said bulb is insertable, said plate member having an opening so as to mount it on said tubular portion, and a lug part in said opening frictionally engaging said tubular portion to retain said plate member thereon and a resilient lug part extending through the longitudinal slot in said tubular portion into electrical contact with said base of said bulb.

2. In a disposable flashlight according to claim 1, said first terminal of said bulb being the central contact stud thereof, said second terminal of said bulb being the threaded base thereof, said plate member including an integral lug engaging the threaded base, and said switching element including a bevelled portion extending inwardly through a slot in said casing for linear guidance in slidable engagement with said second terminal blade.

3. In the disposable flashlight of claim 1, said bulb being threaded, and said resilient lug having a ribbed end engageable between adjoining spires of the threads on said base.

4. In the disposable flashlight of claim 1, said firstnamed lug part being resilient to increase its frictional engagement with said tubular portion.

5. In the disposable flashlight of claim 1, said plate meitiber being resilient and having reinforcing means to increase its rigidity.

6. In the disposable flashlight of claim 5, said reinforcing means being ribs in the surface of said plate member.

7. In the disposable flashlight of claim 5, said plate member having a width equal to the inner Width of said cover part and said reinforcing means being turned-down edge flanges on said plate member to eliminate cutting edges on said plate member that engage the inner walls of said cover part.

8. In a disposable flashlight, a battery having resilient terminal blades and a bulb mounted in a common sealed casing with a first terminal of the bulb in permanent contact with one of the resilient terminal blades, said other terminal blade being normally in open circuit condition relative to a second terminal constituting the base of the bulb, a plate member in permanent electric contact with said second terminal of said bulb and a switch element slidably mounted on said casing and in sliding engagement with said second terminal blade for moving the latter into circuit-closing contact with said plate member to illuminate said bulb, said casing including a cover part secured thereto and having a transparent portion adjacent said bulb, said plate member having a width equal substantially to the inner width of said cover part, and secured within said casing adjacent said transparent portion to serve as a reflector for light emitted by said bulb.

9. In the disposable flashlight of claim 1, said other terminal blade of said battery having a bend, and said switch element having a blade-engaging portion slidable over said last-named terminal blade, said bend being so located that the said blade engaging portion must be forcibly passed it by a user to move said switch element into circuit-closing position and vice versa.

10. In the disposable flashlight of claim 9, said bladeengaging portion being bevelled at its inner extremity to rest on said other terminal blade in the circuit-open position of said; switch element and engageable with the bevel peak only with said last-named terminal blade when said switch element has been moved by the user past said bend to circuit-closing condition.

11. In a disposable flashlight of the typecomprising a battery having resilient terminal blades and a bulb mounted in a common sealed casing with a first terminal of the bulb in permanent contact with one of the resilient terminal blades, said other terminal blade being normally in open circuit condition relative to a second terminal constituting the base of the bulb, a plate member in permanent electric contact with said second terminal of said bulb and a switch element slidably mounted on said casing and in sliding engagement with said second terminal blade for moving the latter into circuit-closing contact with said plate member to illuminate said bulb, said casing having a slotted opening wherein said switch element is positioned, said switch element including a head part disposed outside of said casing, a protruding part integral therewith extending into said casing, said latter part having a narrower slotted portion engaged by the edges defining said opening to be retained thereby and guide sliding movement of said switch element, said latter part also being forked to permit its deformation for mounting of said switch element from the outside of said casing into said slotted opening.

12. In a disposable flashlight of the type comprising a battery having resilient terminal blades and a bulb mounted in a common sealed casing with a first terminal of the bulb in permanent contact with one of the resilient terminal blades, said other terminal blade being normally in open circuit condition relative to a second terminal constituting the base of the bulb, a plate member in permanent electric contact with said second terminal of said bulb and a switch element slidably mounted on said casing and in sliding engagement with said second terminal bladefor moving the latter into circuit-closing contact with said plate member to illuminate said bulb, said second terminal blade having a longitudinal reinforcement rib and said switch element having a forked prong part whose tines are guidedly slidable at opposite sides of said rib.

13. In the disposable flashlight of claim 1, said casing having a curved wall portion and said switch element having a corresponding curved head portion slidable on the outer surface of said curved wall portion.

14. In a disposable flashlight of the type comprising a battery having resilient terminal blades and a bulb mounted in a common sealed casing with a first terminal of the bulb in permanent contact with one of the resilient terminal blades, said other terminal blade being normally in open circuit condition relative to a second terminal constituting the base of the bulb, a plate member in permanent electric contact with said second terminal of said bulb and a switch element slidably mounted on said casing and in sliding engagement with said second terminal blade for moving the latter into circuit-closing contact with an edge of said plate member to illuminate said bulb, said first terminal of said bulb being the central contact stud thereof, said second terminal of said bulb being the base thereof, said plate member including an integral lug engaging the base, and said switching element including a bevelled portion extending inwardly through a slot in said casing for linear guidance in slidable engagement with said second terminal blade, said casing including a cover part secured thereto having an inwardly projecting cylindrical deformable longitudinally slotted tubular portion into which the base of said bulb is insertable, said plate member having an opening so as to mount it on said tubular portion, and a lug part in said opening frictionally engaging said tubular portion to retain said plate member thereon and a resilient lug part extending through the longitudinal slot in said tubular portion into electrical contact with said base of said bulb.

References Cited UNITED STATES PATENTS 1,866,600 7/1932 Rauch 24010.65 2,591,112 4/1952 Zwierzynski 24010.65 3,067,324 12/ 1962 Thompson 240--10.61

FOREIGN PATENTS 1,399,619 4/1965 France.

262,244 5/1964 Netherlands.

NORTON ANSHER, Primary Examiner. R. P. GREINER, Assistant Examiner.

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