GB2198830A

GB2198830A - Flat pocket-type torch with a concave mirror reflector

Info

Publication number: GB2198830A
Application number: GB08629909A
Authority: GB
Inventors: Knut Otto Sassmannshausen
Original assignee: Individual
Current assignee: Individual
Priority date: 1985-06-27
Filing date: 1986-12-15
Publication date: 1988-06-22
Anticipated expiration: 2006-12-15
Also published as: DE3523005A1; GB8629909D0; GB2198830B; DE3523005C2

Abstract

The invention relates to a flat pocket lamp having a concave mirror reflector and cells arranged juxtaposed for the purpose of power supply. A way is indicated in which the quantity of light which is collected by the narrow concave mirror reflectors of such flat pocket lamps can be substantially increased.

Description

FIAT POCKET-TYPE TORCH WITh A CONCAVE MIRROR REFLECTOR The invention relates to a flat pocket-type torch with a concave mirror reflector and, more particularly, to such a torch having, as a current supply, either a single battery or a plurality of mutually adjacent cells or batteries. Both cells and batteries will usually be referred to hereinafter as batteries in accordance with common usage.

Battery-operated torches with batteries arranged in a row one behind the other have also often been referred to commonly as pocket torches although they are not usually able to be stuck into a jacket or coat pocket because they, and especially their heads, are too large for doing so.

Actual pocket or pocket-size tnrches however, are made so flat, as a rule, so that they can comfortably and conveniently fit into a jacket or coat pocket or into a handbag or pocketbook. In order to achieve this flat construction, the batteries or cells supplying the current in such pocket torches are usually arranged adjacent one another instead of behind one another. Tlie cells are often combined by the battery manufacturer into a flat unit within which the cells are arranged adjacent one another. A typical example thereof is tlie conventional flät battery 3 R 12. A flat and complete arrangement of -- - ( R 6 ) ( R 14 ) v:ne cells can also be aclteved by arranging A cells, C cells or.

( R 20 even D cells adjacent one another instead of behind one another.

(R6) Especially in the case of the small A cells, a very flat and small housing can thereby be produced which permits it to be stuck very conveniently into a pocket.

As a rule, the light source with a concave mirror reflector is then arranged at the head of such a pocket torch Because the body in which these batteries are received must be clearly kept as flat as possible, very limited space is available in such a flat pocket-type torch for a concave mirror ref lec- tor which is usually narrow and long.

In heretofore known pocket torches available in the market place, elongated and simultaneously narrow concave mirrcr reflectors are provided at the heads of the pocket-type torches by simply slicing off a relatively large round concave mirror reflector at the sides thereof. There thus remained from an otherwise circular reflector surrounding the axis of the concave mirror reflector, only two reflector fins or flanges which receive only a very small part of the light emitted from the light source and can direct a relatively small beam in axial direction.

It accordingly an object of the invention to provide a flat pocket-type torch with a concave mirror reflector having a battery or cells disposed adjacent one another for supplying current, with which a considerably greater part of the light emitted from a light source is received and formed into a beam without having to increase the size of the concave mirror reflector.

It is an other object of the invention to provice such a flat pocket-type torch which is economical manufacturable and meets all requirements in practical operation.

With the foregoing an other objects in view, there is provided according to the invention, a flat pocket-type torch with a light source and at least one battery for supplying current to the light source includes a concave mirror reflector for reflecting light from the light source, the concave mirror reflector being formed with a light outlet opening of such cross sectional shape as to have a longitudinal axis and an axis perpendicular to and smaller than the longitudinal axis, the concave mirror reflector having a radially inner and a radially outer reflector section of different focus distances, the radially inner reflector section having a smaller expansion perpendicularly to the axis of the concave mirror reflector and substantially concentrically surrounding the axis of the concave mirror reflector, the radially outer reflector section having a larger expansion perpendicularly to the axis of the concave mirror reflector and formed of to reflector strips.

It is emphasised that all of the following features of the invention are optional.

In accordance with another feature of the invention, the inner reflector section located nearest to the axis of the concave mirror reflector has a focal distance smaller than the focal distance of the outer reflector section located furthest from tie axis of the concave mirror reflector.

In accordance with a further feature of the invention, the inner reflector section and the outer reflector section are mutually separated by a dividing plane disposed perpendicularly to the axis of the concave mirror reflector substantially at the level of the focal space of the concave mirror reflector.

In accordance with an additional feature of the invention, inner reflector section has an outer dimension perpendicular to the axis of the concave mirror reflector corresponds substantially to the thickness of the flat pocket-type torch.

In accordance with an added feature of the invention, the light source is disposed in a focal space of one of the reflector sections.

In accordance with yet another feature of the invention, the concave mirror reflector has a narrow side which is at least as wide as the diameter of the battery and at most as wide as three times the width of thé battery.

In accordance with yet a further feature of the invention, the concave mirror reflector has an elongated side which is at least twice as long as the diameter of the battery and at most five times as long as the diameter of the battery.

In accordance with yet an additional feature of the invention, the inner reflector section is disposed so as to receive light emitted from the light source within an angular range of at least 150 and to beam it in the direction of the axis of the concave mirror reflector.

In accordance with again another mode of the invention, the outer reflector section is disposed so as to receive light emitted from the light source within an angular range of at least 120 and to beam it in the direction of the axis of the 'concave mirror reflector.

In accordance with again a further mode -of the invention, there is provided, a connecting part located between the inner and the outer reflector sections, the connecting part being so disposed as to avoid any impingement thereon of light directly emitted from said light source.

In accordance with again an additional mode of the invention, the inner reflector section and the outer reflector section have mutually coinciding focal points.

In accordance with again an added mode of the invention, the concave mirror reflector with the inner and outer reflector sections thereof is of unipartite construction In accordance with still another feature of the invention, the light outlet opening is substantially rectangular.

In accordance with still a further feature of the invention# the light outlet opening is elongated.

In accordance with still an additional feature of the invention, the light outlet opening is substantially of oval shape.

In accordance with a concomitant feature of the invention, the concave mirror reflector is substantially rectangular, and wherein the axis of the concave mirror reflector, a middle line of the long sides of the substantially rectangular concave mirror reflector and a switch for the torch are all intersected by a theoretical claim.

-Thus, the inner reflector section is disposed in the form of a closed ring around the light source. The greatest diameter of this reflector section is only insignificantly smaller than the thickness of the flat pocket-type torch) per se, in accordance with the invention. Additionally, two reflector strips are provided as outer reflector sections. Whereas, in accordance witll the invention, the inner reflector section receives almost all of the light rays emitted around the light source and forms a light beam, the outer reflector section receives only a narrow strip of the light emitted from the light source and forms it into a beam.

The inner reflector section has a relatively small parameter or focal distance so that, in spite of the narrowness of the flat pocket-type torch1 as great a part as possible of the light emitted from the light source is received by this reflector section and can be fed to the beam.

Consequently, two reflector strips are provided at the outside and form parts of the concave mirror reflector, the two reflector strips having a considerably larger parameter or focal distance than the inner reflector strip.

In accordance with the invention, the reflector section which concentrically encloses the focal space of the concave mirror reflector extends from the vertex region of the concave mirror reflector to a plane which is disposed perpendicularly to the concave mirror-axis and intersects the focal space. The focal space is often referred to as the focal point, although, in a mathematical sense, this is not quite correct. In the production of concave mirror reflectors, undesired and often even desired deviations from the ideal shape of a conical section occur so that one cannot speak about a focal point in the mathematical sel)se. Accordingly, the term focal space has been selected instead.

By arranging the light source at least in one of the focal spaces of the reflector sections, assurance is provided that at least part of the light accumulated by the reflector sections will be directed nearly parallel to the axial direction.

The limitations placed upon the size i.e. the width and the length of the sides of the concave mirror reflector with respect to the width or diameter of the battery assures that a sensible relationship exists between the ability to handle such a flat pocket-size torch and the light accumulating properties and capabilities thereof.

As a result of the specific angular range of the emitted light received by the respective inner and outer reflector sections, assurance is provided that the approximately parallel light beam will have adequate light intensity. Due to the specific disposition of the connecting part between the inner and the outer reflector sections, the surface of the connecting part is in the shadow of the inner reflector part. No disturbing stray or scattered light thus occurs.

Because of the coincidence ofwthe focal spaces of both, the inner and the outer reflector sections, a single beam of very great intensity is transmitted by both reflector sections, tiy constructing the concave mirror reflector according to the invention as a unipartite structure with both, inner and outer reflector sections, the concave mirror reflector can be produced economically and with great precision.

Due to the fact that the outer reflector section or sections have a greater focal distance or length than the inner reflector section or sections, in accordance with the invention, reinforcement of the center of the beam and, thus, a longer range of the beam is afforded.

Other features which are considered as characteristic for the invention are set forth in the appended claims.

Although the invention is illustrated and described herein as embodied in flat pocket-type torch vith a concave mirror reflector, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.

The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the.following description of specific embodiments when read in connection with the accompanying drawing, in which: FIG. 1 is a side elevational view of the flat pocket-size torch according to the invention; FIG. 2 is a top plan view of the flat pocket-size torch showing the concave reflector mirror forming part of the invention; FIG. 3 is an enlarged longitudinal sectional view of the concave reflector mirror; FIG. 4 is a top plan view of the concave reflector mirror of FIG. 3.

Referring now to the drawing and first, particularly to FIGS. 1 and 2 thereof, there is shown a flat pocket-size torch 30 with a light head 40 in which an elongated concave reflector mirror 10 is arranged. Additionally shown is a battery holder 42 in which a flat battery 3 R 12 is received. Also illustrated in FIG. 1 are a switch 44 and a closure cap for the flat pocket-size torch.

Obviously other embodiments of the battery holder are possible, such as a battery holder in which two A-cells or two C-cells or two D-cells may be disposed adjacent one another In FIG. 2, the concave reflector mirror 10 is shown as having an inner reflector section l2 and an outer reflector section 14. Further shown is a connecting part 38 located between both of the reflector sections 12 and 14. The width 28 of the flat pocket-type torch is also indicated in FIG. 2.

In the longitudinal sectional view of FIG. 3, there is shown a concave mirror reflector 10. An incandescent lamp 50 providing a light source 32 is installed on the longitudinal axis 20 of the concave reflector mirror 10. Readily apparent in FIG. 3 is an inner reflector section 12 of the concave mirror reflector 10, the inner reflector section 12 extending annularly around the incandescent lamp 50. This inner reflector section 12 receives and reflects light generated by the light source 32 and emitted within an angular range OC . In accordance with the invention, the range of the angle oC is at least 150, is advantageously at least 200 and is preferably 250. An outer reflector section 14 of the concave mirror reflector 10 part ly surrounds the incandescent lamp 50.The size of the parameter or focal distance of the inner reflector section 12 is represented by the double-headed arrow 16. In contrast, the parameter or focal distance of the outer reflector section 14 is represented by the double-headed arrow 18. It is very clearly apparent that, in accordance with the invention, the parameter or focal distance 18 is greater than the focal distance 16.

S. photometric dividing pla.fi 26 which extends perpendicularly to the axis 20 of the concave mirror reflector 10 separates the two reflector sections 12 and 14 from one another. Obviously, the dividing plane 26 is purely theoretical. It is readily apparent that this dividing plane 26 passes through the light source 32. It is furthermore clear from FIG. 3 that a connect ing part 38 between the two reflector sections 12 and 14.is so shaped and disposed that it cannot receive any light directly emanating from the light source 32.

An angle / is shown in FIG. 3 within which the outer reflector section 14 receives and has focussed thereon light emitted by the light source 32. The angle is at least 12" to at least 180, preferably.

FIG. 4 is a top plan view of the concave mirror reflector 10 of FIG. 3. Shown in detail are the encircling inner reflector section 12 and the outer reflector section 14 constructed only as arcuate reflector strips 22 and 24. Additionally, visible in FIG. 4 is the connecting part 38 between the inner reflector section 12 and the outer reflector section 14.

The concave mirror reflector 10 has a narrow side 34 and an elongated side 36. In accordance with the invention, the inner reflector section 12 encircling the light source 32 has a smaller parameter or focal distance than that of the outer reflector section 14 of which only two reflector strips 22 and 24 could be formed due to the rectangular shape of the flat pocket-type torch. The concave mirror reflector 10 at one end of the fiat pocket-type torch could also , for example, be arranged in an embodiment wherein it is rotated tlmrough an angle of 900 so that tile light beam emerges at tlre side of the flat pocket-type torch1 without departing thereby from the basic concept of the invention.

It is also within the scope of the invention to provide the interior surfaces of the concave mirror reflector i.e. the radially inner and/or radially outer reflector sections, with a multiplicity of spherical segments or dimplings,

Claims

CLAIMS: 1. Flat pocket-type torch. with a light source and at least one battery for supplying current to the light source comprising a concave mirror reflector for reflecting light from the light source, said concave mirror reflector being formed with a light outlet opening of such cross sectional shape as to have a longitudinal axis and an axis perpendicular to and smallerthan said longitudinal axis, said concave mirror reflector having a radially inner and a radially outer reflector section of different focal distances1 said radially inner reflector section having a smaller expansion perpendicularly to the axis of said concave mirror reflector and substantially concentrically surrounding the axis of said concave mirror reflector, said radially outer reflector section having a larger expansion perpendicularly to the axis of said concave mirror reflector and formed of two reflector strips
2. Flat pocket-type torch according to claim 1, wherein said inner reflector section located nearest to the axis of said concave mirror reflector has å focal distance smaller than the focal distance of said outer reflector section located fartliest from tile axis of said concave mirror reflector.
3. Flat pocket-type torch according to claim 1, wherein said inner reflector section and said outer reflector section are mutually separated by a dividing plane disposed perpendicularly to the axis of said concave mirror reflector substantially at the level of the focal space of said concave mirror reflector.
4. Flat pocket-type torch according to claim 1, wherein said inner reflector section has an outer dimension perpendicular to the axis of said concave mirror reflector corresponds substantially to the thickness of the flat pocket-type flashlight.
5. Flat pocket-type torch according to claim 1, wherein said light source is disposed in a focal space of one of said reflector sections.
6. Flat pocket-type torch according to claim 1, wherein said concave mirror reflector has a narrow side which is at least as wide as the diameter of the battery and at most as wide as three times the width of the battery.
7. Flat pocket-type torch according to claim 1, wherein said concave mirror reflector has an elongated side which is at least twice as long as. the diameter of the battery and at most five times as long as the diameter of the battery.
8. Flat pocket-type torch according to claim 1, wherein said inner reflector section is disposed so as to receive light emitted from said light source within an angular range of at least 150 and to beam it in the direction of the axis of said concave mirror reflector.
9. Flat pocket-type torch according to claim 1, wherein said outer reflector section is disposed so as to receive light emitted from said light source within an angular range of at least 120 and to beam it in the direction of the axis of said concave mirror reflector.
10. Flat pocket-type torch according to claim 1, including a connecting part located between said inner and said outer reflector sections, said connecting part being so disposed as to avoid any impingement thereon of light directly emitted from said light source.
11. Flat pocket-type torch according claim 1, wherein said inner reflector section and said outer reflector section have mutually coinciding focal points.
12. Flat pocket-type torch according to claim 1, wherein said concave mirror reflector with said inner and outer reflector sections thereof is of unipartite construction.
13. Flat pocket-type torch according.to claim 1, wherein said light outlet opening is substantially rectangular.
14. Flat pocket-type torch according to claim 1, wherein said light outlet opening is elongated.
15. Flat pocket-type torch according to claim 1, wherein said light outlet opening is substantially of oval shape.
16. Flat pocket-type torch '' according to claim 7 wherein said concave mirror reflector is substantially rectangular, and wherein the axis of said concave mirror reflector, a middle line of the long sides of the substantially rectangular concave mirror reflector and a switch for the flashlight are all intersected. by a theoretical plane.
17. Flat pocket type torch according to claim 1 wherein the interior surfaces of the concave mirror reflector i.e. the radially inner and/or radially outer reflector sections are provided with a multiplicity of spherical segments or dimplings.
18. Flat pocket type torch according to claim 17, wherein each of these spherical segments or dimplings is having an extension along the surface of said mirror reflector, said extension forming an aperture angle with the Light center of the light source, said aperture angle being smaller with the outer reflector sections, than with the inner reflector sections.
19. A flat pocket type torch substantially as herein described with reference to and as illustrated in the accompanying drawings.

Amendments to the claims have been filed as follows CLAIMS : 1. Flat pocket-type torch with a light source and at least one battery for supplying current to the light source comprising a concave mirror reflector for reflecting light from tulle light source, said concave mirror reflector being formed with a light outlet opening of such cross sectional shape as to have a longitudinal axis and an axis perpendicular to and snialler than said longitudinal axis, said concave mirror reflector having a radially inner and a radially outer reflector section of different focal distances, said radially inner reflector section having a smaller expansion perpendicularly to the axis of- said concave mirror reflector and substantially concentrically surrounding the axis of said concave mirror reflector, said radially outer reflector section having a larger expansion perpeJzdicularly to the axis of said concave mirror reflector and formed of t;.o reflector strips extending forwardly of the light source.