US3761703A - Apparatus for illumination of instrument faces - Google Patents

Abstract

A lamp cartridge for insertion in the edge of a light conductive block for distributing light to an instrument or instrument panel. The cartridge includes spring clip contacts along opposite sides thereof for making resiliently biased contact with bus bars in the light block, guides for orienting the clips in relation to an opening in the light block for receiving the cartridge, and an exposed portion facilitating manual insertion or withdrawal of the cartridge with respect to the opening.

Description

United States Patent Mund et al. 1 Sept. 25, 1973 [54] APPARATUS FOR ILLUMINATION ()F 3,639,745 2/1972 Shiki 240/8.l6 X

INSTRUMENT FACES 3,610,914 10/1971 Blackwell i 1 240/2.1 3,154,251 lO/l964 Dupree et a1. 240/8.l6

Inventors: Willard Mund, Morristown;

Wolfgang Fuhr, North Haledon, both of NJ.

Assignee: U. S. Radium Corporation,

Morristown. NJ.

Filed: Dec. 23, 1971 Appl. No.: 211,344

U.S. Cl. 240/2.1, 240/1 EL Int. Cl. GOld 11/28 Field of Search 240/1 EL, 2.1, 8.16,

References Cited UNITED STATES PATENTS l/1972 Strianese 1. 240/8.16 X

Primary Examiner-Fred L. Braun AttorneyDean S. Edmonds et al.

[57] ABSTRACT A lamp cartridge for insertion in the edge ofa light con ductive block for distributing light to an instrument or instrument panel. The cartridge includes spring clip contacts along opposite sides thereof for making resiliently biased contact with bus bars in the light block, guides for orienting the clips in relation to an opening in the light block for receiving the cartridge, and an exposed portion facilitating manual insertion or withdrawal of the cartridge with respect to the opening.

5 Claims, 5 Drawing Figures PATENTED SEPZ 5 I973 INVENTORS WILLARD MUND wo BY $225M; FUHR ATTORNEYS APPARATUS FOR ILLUMINATION OF INSTRUMENT FACES BACKGROUND OF THE INVENTION The present invention concerns improvements in integrally illuminated edgelighted instruments or instrument panels; i.e. those employing light block conductors. Conventional illuminated instruments or instru ment panels of this type do not provide for ready replacement of the lighting means, usually an incandescent lamp or several such lamps. In the event of lamp failure, the instrument or panel must be disassembled in some manner in order to provide access to the lamp for its replacement. Typically, lamp replacement requires detaching the lighting assembly from the instrument mechanism, followed by further removal of pointers, dial, light conductor etc. before access is gained to the inoperative lamp. In most assemblies, the lamps are soldered to a printed circuit board or held in place by other mechanical fastening means. To disassemble an instrument or panel is time consuming, costly and normally requires instrument recalibration after reassembly. In order to avoid the above difficulties, some instruments are designed for front lamp replacement and some edgelighted panels are designed for rear surface replacement. Unfortunately, both of these solutions are mechanically limited, waste space, and front lamp replacement configuration significantly obstruct the panel presentation BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective view of an edge lighted instrument showing the lamp cartridge of the present invention in position immediately prior to its insertion into the light block of an instrument;

FIG. 2 is a front view of the instrument of FIG. 1 with portions of the light block in cross section and the lamp cartridge of the invention in position therein;

FIG. 3 is a cross section taken in the direction of arrows 3-3 of FIG. 2;

FIG. 4 is a cross section taken in the direction of arrows 4-4 of FIG. 3; and

FIG. 5 is an enlarged detail of portions of the lamp cartridge of the invention.

DESCRIPTION OF A PREFERRED EMBODIMENT Referring to the drawing, an integrally lighted instrument body has been illustrated which includes a cylindrical light conducting block 11 of Lucite, or material having similar properties. Although the application of the invention as shown and described herein is made with reference to a single instrument, it should be understood that the principles of the invention are as readily applied to edge lighted instrument panels. A face ordial 12 includesvarious indicia 13 which will transmit light from the interior of the block 11. An opaque light absorbent coating covers theface 12 the sides and rear areas of block 11 to prevent light from escaping from within the light block 11 except through the various indicia. The block 11 has a centralaxial opening 15 which receives ashaft 16 integrally connected to anouter hub 17 andpointer 18 all formed of light conducting material.Hub 17 is coated with an opaque light inhibiting medium but not theshaft 16 orpointer 18 and consequently, when the light block 11 is illuminated light will be conducted to thepointer 18.

In accordance with the present invention, the block 11 has been provided with a more or less radially directedbore 19 proceeding into side llb of the light block and whoseterminal end 19a is approximately adjacent to thecentral opening 15 in the block 11. Theoutermost end 19b of thebore 19 is of greater diameter than the diameter of theterminal end 19a and the bore includes a semicircular longitudinal groove 190 for reasons which will be explained.

As seen in FIGS. 35,parallel bus bars 20, 21 extend tangentially through the block ll in a manner such thatinner edge portions 200, 21a protrude into thegreater diameter section 19b of thebore 19 for a distance less than the internal diameter ofsection 19a. Ends of the bus bars are soldered toelectrical leads 23, 24 which provide direct current from a battery (not shown).

In combination with the foregoing aunique lamp cartridge 26 has been devised which can be readily inserted into thebore 19 and removed therefrom when lamp failure has occurred. Thecartridge 26 includes aplastic lamp holder 27 which mounts alamp 28. Thelamp 28 is a standard unbased type having twolead wires 29 and 30 (FIG. 5) which pass throughclearance holes 29a, 30a in thelamp holder 27 and are connected tospring clips 31 and 32. These clips, one at each side of theholder 27 have their ends bent over the top of the body of the holder and thus clamped to it. They havestraight sections 31a, 31b, and 32a, 32b which diverge from the lamp holder and adjoin athigh points 310, 320. At the ends furthest from thelamp 28,clips 31 and 32 haverounded shoulders 31d and 32d.Recesses 27b formed in thelamp holder 27 receive the ends 31a, 32a of theclips 31, 32 and provide clearance to permit depression of the clip.

Thelamp holder 27 includes thelongitudinal spline 27a. Acap 33 is joined to thelamp holder 27 by pressure fit of a plug portion comprising thesplit tongue 33a into arecess 27c formed in the upper end of the lamp holder. The lamp lead wires are brought up through therecess 27c alongside the downwardly extending ends 3le, 32c of the spring clips and over the tops of the clips as shown. They are pressed into tight and secure electrical contact with the clips by the tongue of the cap. The splittongue 33a fits very tightly in therecess 27c and secures the cap firmly in place while at the same time holding the lead wires in secure electrical contact with the clips. The assembly is such that if the lamp burns out, the cap can be forced off, whereupon the lamp can be readily withdrawn from the holder and can be replaced by a new one. Of course, it is understood that alternatively theends 31c, 32e of the spring clips could be soldered to thelamp wires 29 and 30 if it were desired to make the entire lamp cartridge 26 a replaceable item.

Thecap 33 has a raisedsection 33b which together with the main part of the cap forms a lip or groove 330. When thelamp cartridge 26 is to be inserted into thebore 19 of light block 11, the end of the cartridge will be held by the raisedsection 33b and thespline 27a will be aligned withgroove 19c. This will properly positionspring clip contacts 31 and 32 with respect tobus bars 20 and 21. Thecartridge 26 may be inserted into thebore 19 and theclips 31, 32 will be forced inwardly intogrooves 27b in the lamp body as thehigh points 31c, 320 of the spring clips are forced to pass by thebus bars 20 and 21. Theclips sections 31b and 32b then resiliently cam the cartridge into its fully installed position whereinbus bars 20 and 21 rest againstrounded shoulders 31d, 32d of the spring clips and againstsections 31b and 32b. Thecartridge 26 is readily removed without tools from thebore 19 by grasping the protrudingcap section 33b between thumb and forefinger, with the thumbnail ingroove 33c providing positive engagement.

in the operative position, thespring clips 31 and 32 exert a force against thebus bars 20 and 21 and prevent the cartridge from moving out of position. The spline 2711 not only insures positive location of the component parts of the cartridge with respect to the bus bars but prevents rotation of the cartridge due to vibration.

Thecartridge 26 can be fabricated from transparent components which will not cause light loss or blockage during operation. Clearance is provided around thelamp 28 insection 19a of thebore 19 so that colored filters can be used. If desired the cartridge and receiving bore can be fabricated in various lengths in order to allow the lamp to be located in its most efficient position within the lighting assembly, whether this be a light block for an instrument dial, or an edge lighted instrument panel.

It will be understood that the foregoing description relates to a particular embodiment of the invention and is therefore representative. In order to appreciate the scope of the invention, reference should be made to the appended claims.

We claim:

1. Means for illuminating an instrument face comprising:

a. a transparent light block adapted to be positioned directly behind said face;

b. a lamp-receiving recess formed in said block;

c. spaced bus conductors carried by said block and having portions thereof extending in exposed relation transversely across said recess; and

d. a lamp assembly removably inserted in said recess,

said lamp assembly comprising:

1. a lamp holder,

2. an electric lamp carried by said holder, and

3. contact members exposed on the outside of said holder and electrically connected to lightproducing means of the lamp, said contact members being resiliently mounted on said holder and including cam surfaces engaging the exposed portions of said conductors upon linear movement of said lamp assembly into said recess to electrically connect and mechanically hold said lamp assembly in said recess.

2. The illuminating means according to claim 1 wherein:

a. said lamp holder includes a cap having a section which projects from the light block when the lamp holder is fully received within said recess, said projecting section being formed so as to permit manual gripping thereof without the use of tools.

3. The illuminating means according to claim 1 wherein:

a. said contact members are flexible spring members having rounded end sections and being fixed at said rounded end sections to said lamp holder and extending freely toward the forward end of the lamp holder;

b. said recess is cylindrical in shape;

c. a groove is defined in the wall surface of the recess extending longitudinally thereof; and

d. a spline is formed on said lamp holder for recep tion in said groove, said spline aligning said spring contact members precisely in position for contact with the bus conductors when the lamp holder is inserted in the recess, said spline further preventing rotation of the lamp holder.

4. The illuminating means according to claim 1 wherein:

a. said lamp holder has a forward end and a rearward end with the forward end being adapted to be inserted into said recess first;

b. each of said contact members includes:

l.a first section diverging outwardly from said lamp holder as measured along said holder in a direction extending from said forward end toward said rearward end,

2.a second section converging inwardly toward said holder as measured along said direction, said second section being connected to said first section and forming a continuation thereof extending toward the rear end of said holder, and

Ba rounded end section located at the rearward end of the holder and forming a continuation of said second section at least one of said sections forming said cam surfaces; and

c. the exposed portion of each of said bus conductors being positioned within said recess in the path of movement of said contact members as the holder is inserted into said recess for riding along said first and second sections thereof and into seated relation at the juncture of the second section and the rounded end section.

5. Means for illuminating an instrument face comprising:

a. a transparent light block adapted to be positioned directly behind said face;

b. a lamp receiving recess formed in said block;

c. spaced bus conductors carried by said block and having portions thereof exposed within said recess; and

d. a lamp assembly removably inserted in said recess,

said lamp assembly comprising:

1. a lamp holder having a forward end and a rearward end with the forward end being adapted to be inserted into said recess first,

2. an electric lamp carried by said holder at the forward end thereof,

3. a recess formed in the rearward end of the lamp holder,

4. spring contact members exposed on the outside of said holder and electrically connected to lightproducing means of the lamp, said spring contact members being in resilient electrical contact engagement with the exposed portions of the bus conductors for conducting energizing power to the lamp and having their ends extending into the recess in the rearward end of said lamp holder,

5. wire leads extending from said lamp into the recess in the rearward end of the lamp holder and into contact with the spring contact members in said recess, and

6. a cap having a first section force fitted in the recess at the rearward end of the lamp holder against said wire leads and contact ends to hold them securely in place, and a second section projecting from the light block when the lamp holder is fully received within the lamp receiving recess formed in said block, said second section being formed so as to permit manual gripping thereof.

Claims (12)

1. Means for illuminating an instrument face comprising: a. a transparent light block adapted to be positioned directly behind said face; b. a lamp-receiving recess formed in said block; c. spaced bus conductors carried by said block and having portions thereof extending in exposed relation transversely across said recess; and d. a lamp assembly removably inserted in said recess, said lamp assembly comprising: 1. a lamp holder, 2. an electric lamp carried by said holder, and 3. contact members exposed on the outside of said holder and electrically connected to light-producing means of the lamp, said contact members being resiliently mounted on said holder and including cam surfaces engaging the exposed portions of said conductors upon linear movement of said lamp assembly into said recess to electrically connect and mechanically hold said lamp assembly in said recess.

2. an electric lamp carried by said holder, and

2. The illuminating means according to claim 1 wherein: a. said lamp holder includes a cap having a section which projects from the light block when the lamp holder is fully received within said recess, said projecting section being formed so as to permit manual gripping thereof without the use of tools.

2. an electric lamp carried by said holder at the forward end thereof,

3. The illuminating means according to claim 1 wherein: a. said contact members are flexible spring members having rounded end sections and being fixed at said rounded end sections to said lamp holder and extending freely toward the forward end of the lamp holder; b. said recess is cylindrical in shape; c. a groove is defined in the wall surface of the recess extending longitudinally thereof; and d. a spline is formed on said lamp holder for reception in said groove, said spline aligning said spring contact members precisely in position for contact with the bus conductors when the lamp holder is inserted in the recess, said spline further preventing rotation of the lamp holder.

3. a recess formed in the rearward end of the lamp holder,

3. contact members exposed on the outside of said holder and electrically connected to light-producing means of the lamp, said contact members being resiliently mounted on said holder and including cam surfaces engaging the exposed portions of said conductors upon linear movement of said lamp assembly into said recess to electrically connect and mechanically hold said lamp assembly in said recess.

4. spring contact members exposed on the outside of said holder and electrically connected to light-producing means of the lamp, said spring contact members being in resilient electrical contact engagement with the exposed portions of the bus conductors for conducting energizing power to the lamp and having their ends extending into the recess in the rearward end of said lamp holder,

4. The illuminating means according to claim 1 wherein: a. said lamp holder has a forward end and a rearward end with the forward end being adapted to be inserted into said recess first; b. each of said contact members includes: 1.a first section diverging outwardly from said lamp holder as measured along said holder in a direction extending from said forward end toward said rearward end, 2.a second section converging inwardly toward said holder as measured along said direction, said second section being connected to said first section and forming a continuatIon thereof extending toward the rear end of said holder, and 3.a rounded end section located at the rearward end of the holder and forming a continuation of said second section at least one of said sections forming said cam surfaces; and c. the exposed portion of each of said bus conductors being positioned within said recess in the path of movement of said contact members as the holder is inserted into said recess for riding along said first and second sections thereof and into seated relation at the juncture of the second section and the rounded end section.

5. Means for illuminating an instrument face comprising: a. a transparent light block adapted to be positioned directly behind said face; b. a lamp receiving recess formed in said block; c. spaced bus conductors carried by said block and having portions thereof exposed within said recess; and d. a lamp assembly removably inserted in said recess, said lamp assembly comprising:

5. wire leads extending from said lamp into the recess in the rearward end of the lamp holder and into contact with the spring contact members in said recess, and

6. a cap having a first section force fitted in the recess at the rearward end of the lamp holder against said wire leads and contact ends to hold them securely in place, and a second section projecting from the light block when the lamp holder is fully received within the lamp receiving recess formed in said block, said second section being formed so as to permit manual gripping thereof.

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