US2508063A - Farm light - Google Patents

Description

H. R. GROSS FARM LIGHT May 16, 1950 2 Sheets-Sheet 1 HZ/ ear 17.

Filed Dec. 28, 1949 y 1950 H. R. GROSS 2,508,063

FARM LIGHT I Filed Dec. 28, 1949 2 Sheets-Sheet 2 IN I 'ENTOR.

This invention is concerned generally with a Fig. 4 is a fragmentary view taken along the spotlight and more specifically with a portable line 4-4 of Fig. 2; spotlight for operation from a commercial power Fig. 5 is a fragmentary sectional view taken line to give a focused beam of great intensity. along the line 55 of Fig. 2;

The necessity for a small portable light p- Fig. 6 is a perspective view of a filament and erable from a commercial power line and capable ts mount; .of projecting an intense beam over an extended Fig. '7 is a perspective view of a modification distance for intermittent periods arises frequently 0f the structure shown in Fig. 6; in farms and suburban homes. Emergency situ- Fig. 8 is a perspective view of the intermediate ations involving repair jobs, assistance in livefilament pp rt; stock birth, veterinary treatment of livestock, and Fig. 9 is a per pective view similar to Fig. 8 investigation of noises caused by straying liveshowing a ot mod ficat and stock, prowlers and other sources are constantly ig. 10 is a fra y p p ve V ShOW- arising and require the use of such a light. ng a connection at one end of the filament to a A lamp is herein provided for intermittent n S pp emergency operation from a commercial power AS Seen n S- a Spotlight embodying the Patented May 1% 1950 UNITED STATES PATENT OFFICE] FARM LIGHT Henry R. Gross, Chicago, 111.

Application December 28, 1949, Serial No. 135,493

6 Claims. (01.176-34) line to produce an intense circular beam. The present inv ntion comprises e r lly a housing lamp is rugged, lightweight and portable, and i l2, a handle i4 secured to the housing, a supportwell balanced for hand operation. The filament 111g Stand 6 also Secured to the housing, and a of the lamp is constructed and arranged to apbulb 0f the Sealed beam yp having a proximate the focal point of a parabolic reflector parabolic reflector 20 and Clear glass lens A and support is provided f the fil t to lens of stippled glass or the like is undesirable as tect the filament and to maintain the filament in i 1S f h thereby- The bulb proper position substantially free from sagging as 15 mounted Wlthm a housmg by means structure which may be conventional, including a supporting flange 24 extending inwardly of the housing 12 and a mounting ring 26 securable over the edge of the housing and rim of the bulb to hold the bulb in position. The ring 26 may be a split ring and may have a flange 28 fitting within a cooperating groove in the housing l2 when the ring is drawn together by suitable structure '30 which is in turn covered by an auxiliary as it softens and expands with heat and vibrates due to inductive forces set up by alternating current in the coils of the filament. Plug-in electrical connections for the light bulb to prevent a shock to the operator are adapted to withstand heat and to occupy a minimum of 30 space. All of these features contribute to produce a portable spotlight of high intensity for intermittent emergency operation.

Objects of the invention are the provision of housmg an emergency spotlight of high power of light 5 The stand, l6 comprises a circularportion of Weight, of instant portability, and of great heavy w1re having a central upstanding arm 35 ruggedness for repeated relatively short periods Fermmated by an eye A bifurcated bracket 38 of Operation from a commercial power Source; of is secured to the underside of the housing as by a rivets placed through it and a complementary filamfmt f3Onentr ated about the focal pomt. of 40 plate 40 on the inner surface of the housing. The a focusing reflector, and of means for supporting th fil nt to t ct a t 1 1 h ck eye 36 of the support fits between the arms of the 8 am 9 1 gams plysm S 0 bifurcated bracket 38. A threaded bolt 42 is and to maintain it 1n proper position substanpassed through the bracket and eye and a wing tially free from sagging as it softens and expands nut 44 acts to clamp the bracket against the eye due to heatmg- 45 to secure the spotlight in any desirable position, other and further ObJects and advantages of the arms of the bracket being sufficiently resilient the present invention will be apparent from the t n Such clamping f ow description When taken n conjunc- The handle i4 is angularly disposed relative tiOn Wit e p y g drawings in Whiehi to the axis of the housing to provide a convenient 1 s a p p v v w of a portable p hand grip and is preferably made of wood or lamp embodying my invention; heat insulating plastic material to prevent heat Fig. 2 is a side view mostly in cross section from the filament from being transferred to the taken along the line 22 of Fig. 1; operators hand. The handle is'hollow and has a Fig. 3 is a sectional view taken along the line lower portion or grip 46 angularly disposed rela- 22 of Fig. 1; tive to an upper or securing portion 48 which has an inner face 50 generally conforming in shape to the exterior surface of the housing I2. A gasket 52 of asbestos is placed between the face 50 and the outer surface of the housing I2 and the handle I4 is secured to the housing by means such as screws or rivets 54. An asbestos pad 56 is cemented or otherwise secured over the washers 54 on the inner face of the rear of the housing I2 further to prevent heat transfer to the handle I4. The butt of the handle is apertured to receive a drop cord 58 which may be of any convenient length. As seen in Fig. 3, the handle I4 comprises a body portion 60 of substantially channel shape and a cover 62 secured thereto by any desirable means such as screws. A transversely extending wall 64 is secured within the body portion 60 and a second transverse wall 66 projects from the cover 62 to abut against the wall 64. Complementary semicircular openings in the walls provide a circular opening through which the conductors 68 of the drop cord 58 extend. A clip I secured about the conductors prevents their being pulled back through the aperture formed in the transverse walls. One of the conductors 68 is connected to a switch I2 carried within the handle I4 while the second conductor is spliced by means of a coupling I4 to an asbestos covered wire I6 leading to a socket 18. A second asbestos covered wire 80 interconnects the switch 12 and the socket I8.

Filament leads or supporting rods 82 extend from the rear of the bulb or lamp I8 along with a seal 84 in a conventional manner. To provide for ready replacement of the bulb while precluding the possibility of shock to the operator, I have presented a plug and socket connection illustrated in Figs. 2 and 4. A metal cap 86 is clamped about the base of the bulb and carries an insulating block 88 which may be of heat resistant Bakelite, ceramic or other material. A pair of upright prongs 90 is carried by the block 88 in transverse relation to the axis of the bulb I8. The filament leads 82 may be integral with or soldered or otherwise secured to leads 9| connected to the upper ends of the prongs and the lower ends of the prongs are received by apertures in the socket I8 which is connected to the lead wires 76 and 80. The transverse arrangement of the prongs makes it possible to have a considerably shorter axial length of housing than would be possible with an axially extending plug and socket connection.

The filament leads 82 provide a main support for the filament and consist of horizontally arranged bars or rods, the extremities 92 of which are bent toward one another. The bars or rods may be solid or hollow and are flattened and bent over at the.end to clamp the filament 94 rigidly at the terminal ends or extremities of the incandescent portions thereof (Fig. The wire of the filament has a length on the order of two to three feet and is kinked and coiled throughout its length with the exception of the central portion which is kinked only to reduce this overall length to something on the order of an inch or less. The size of the kinks or small coils is so minute as to preclude showing them in detail in the drawings. The filament wire itself is made as short as possible to insure the greatest possible ruggedness and to allow over-voltage operation for the production of an intense light beam. The filament is clamped substantially along the axes of the large coils as may be seen in Fig. 10. As noted previously, the filament is then bent back upon itself to form a V-shape. The V is sufficiently narrow to approach the focal point of the reflector. The V preferably is mounted in an axial plane of the parabolic reflector in order to present the smallest possible projected area to interfere with light rays reflected from the reflecting surface 20 toward the front of the bulb. The V-shape of the filament allows the light to be concentrated about the focal point of the parabolic reflector and thus to approximate the desirable point source of light. Other filament shapes such as straight, circular, N'- shaped or U-shaped were found to give light beams which were diffused or contained dark spots or presented a flat beam of light rather than the desirable circular beam.

The apex 96 of the V-shapedfilament is supported, as seen in Fig. 6, by a resilient wire support 98. A block I00 of glass, ceramic or other heat resisting insulating material is supported by legs I02 fused therein and extending to the filament leads 82. The filament leads are rather rigid thus maintaining the block I00 and the extremities of the filament in fixed position. The support 98 previously alluded to comprises (Fig. 6) a resilient wire embedded in the block I00 and extending therefrom at an angle to the axis of the parabolic reflector. The support 98 is bent back toward the axis of the reflector and is provided with a U-shaped loop I04 through which the apex of the V-shaped filament passes loosely. The filament is looped over the 100p I04 at its apex in order that the wire at the apex may move back and forth through the loop I04 in a limited movement longitudinally of the filament to compensate for uneven expansion and contraction of the legs of the filament with changes in temperature and also to space the legs sufficiently far apart that they cannot contact one another in response to a physical shock to the spotlight. Such contacting would present a lessened end-to-end resistance of the filament and result in a higher current which would burn out the filament. The resilient support 98 is initially set to cause a slight pull on the apex of the filament along the axis of the reflector so that as the filament lengthens when heated the support will spring slightly outwardly to keep the filament substantially taut and free from sagging in an axial plane of the reflector to maintain the light rays in proper focus. The support is sufficiently rigid to prevent permanent displacement of the filament from its initial position, but due to its resiliency allows the filament to move slightly when a physical shock is applied so that there is less danger of breakage than would occur if all strains had to be taken up by each individual leg of the filament. Although it is preferred that the support should have an initial set so as to move axially and keep the filament taut, this is not absolutely necessary as the U-shaped portion I04 is sufficiently deep and the sides are arranged at a sufficiently sharp angle to prevent displacement or disengagement of the filament therefrom when heated.

An additional advantage which is derived from the loose sliding contact between the apex of the filament and the U-shaped portion of the support is that it avoids a hot spot that would be caused by a rigid connection which would materially shorten the life of the filament.

A modification of the filament support is shown in Fig. '7. In this figure the filament leads or supports 8211 along with the filament 94a, insulating block I00a, and supporting legs I 020 [0 may be identical with those previously disclosed.

The intermediate filament support "a is embedded in the insulating block 100a and extends at right angles to the block for a short distance from whence it extends parallel to the ax s of the parabolic reflector and is then turned back at right angles to the axis to be terminated in a U-shaped portion lMa about which the apex 96a of the filament is loosely looped. An advantage to the form of support shown in Fig. 7 is that thermal expanion of the elongated sect on of the support does not tend to introduce a force tending to move the apex of the filament away from the axis of the reflector and the filament is maintained substantially free from sagging in an axial plane of the reflector.

A further modification of the filament support is shown in Fig. 8 wherein parts which are identical with those previously shown are omitted with the exception of an ins lating block lllflb and supporting legs I021) fused therein and extending therefrom. The support 98b in this case is symmetrical about the axis of the parabola and is provided with a U-shaped portion Hill) havin'z transverse extensions from both arms of the U integrally connected with longitud nal po tions I 06 parallel to the axis of the reflector which are turned in toward one another at their ends and then extend into the block lDUb wherein they are fused or otherwise suitably secured. The filament is supported by this support in the same fashi n as by the supports previously disclo ed and the support is less subject to a transverse vibration.

Fig. 9 shows another modification of the filament intermediate support. and a ain identical parts are omitted with the exception of an i sulating block H100 and supporting 1891s 1020 therefor. In this modification a thin strin I08 of material which may conveniently be metal is provided with a bifurcated free end H0. The bifurcated end presents a slot which is sufficiently deep to prevent disengagement of the filament therefrom when supported in a manner similar to that shown'in preceding figures. and the extremity of the slot is preferably rounded rather than V-shaped to prevent pinching or possible cutting of the filament. Although the slot provided by the bifurcated end H is sufiicienty deep to prevent disengagement of the heat d filament therefrom, it is preferred that the stri I08 should have a suitable coefiicient of thermal expansion to keep a slightly axial tension on the filament at all times to maintain .the filament substantially free from sagging. The coefficient of thermal expansion of the strip I08 may be different from that of the filament as the primary change of dimension of the strip occurs along the, axis of the reflector while the expansion of the filament acts to alter the length and cross section along paths which are not parallel to the axis of the reflector.

It is apparent that I have herein disclosed a portable light for operation from a commercial power line to throw a substantially circular focused beam of high intensity light a great distance. Structure has been provided for handoperating the light and for supporting the light in any desirable position. The filament has been reduced in size to approximate as nearly as possible the desired point source of light for the parabolic reflector used and a unique support has been provided to support the filament rigidly at its terminal ends and to support it intermediate its ends to protect it against physical shock and to maintain it substantially in its iniof the filament as it is heated.

Obviously the'invention is not limited to the specific details of construction disclosed herein but is capable of other modifications and changes without departing from the spirit and scope of the appended claims.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

1. A portable spotlight for operation from a substantially 110 to 120 voltpower line comprising a focusing reflector for producing a long beam having substantially parallel rays, a filament of suitable length and resistance for operation from said power line comprisin a plurality of filament portions angularly disposed relative to one another, a pair'of spaced rigid supports disposed substantially in a common plane containing the focal axis of said reflector, inwardly offset end portions on said supports substantially in said common plane for rigidly supporting the terminal extremities of said filament portions in said common plane, and means for supporting the filament in said common plane intermediate the end supports and substantially at a junction between adjacent angularly disposed portions, the plurality of supporting means cooperating to support said filament substantially free from sagging substantially in said common plane containing the focal axis and substantially free from vibration.

2. A portable spotlight for operation from a substantially 110 to 120 volt power line comprising a focusing reflector for producing a long beam having substantially parallel rays, a filament of suitable length and resistance for operation from said power line comprising a pair of filament portions adapted to become incandescent and arranged in substantially a V-shape, a pair of spaced rigid supports disposed substantially ina common plane containing the focal axis of said reflector, inwardly directed end portions on said supports substantially in said common plane for rigidly supporting the terminal extremities of said filament portions in said common plane, and means for supporting the substantially V-shaped filament substantially at the apex thereof and with said apex substantially on the focal axis of said reflector, the plurality of supportin means supporting said filament substantially free from vibration and substantially in said common plane containing the focal axis of said reflector.

3. A portable spotlight comprising a reflector for producing a relatively long beam of substantially parallel rays, a pair of rigid filament supports substantially parallel to and symmetrically disposed about the focal axis of said reflector substantially in a common plane containing said focal axis, the filament contacting ends of said filament supports extending toward one another in confronting spaced relation substantially in said common plane, a filament comprising an extremely fine filamentary wire of substantial length for operation from a substantially volt to volt power line, said filament wire being formed in relatively minute coils and again coiled in relatively larger coiled portions, the axes of the relatively larger coiled portions extending in substantially straight lines and interconnected by bight means, the terminal ends of said filament being clampingly engaged substantially along the axes of said larger coiled portions and supported by the inturned confronting ends of.

said filament supports, and a support substantially in said common plane for supporting said filament intermediate the terminal ends thereof to maintain the intermediate supported position of said filament substantially constant in said common plane.

4. A portable spotlight comprising a reflector for producing a relativel long beam of substantially parallel rays, a pair of rigid filament supports substantially parallel to and symmetrically disposed about the focal axis of said reflector in a common plane containing the focal axis of the reflector, a filament comprising an extremely fine filamentary wire of substantial length for operation from a commercial power line, said filament wire having portions angularly disposed relative to one another to form substantially a V-shape, means for rigidly supporting the terminal ends of said filament by said filament supports, and additional filament supporting and guiding means having sloping sides arranged at a sharp acute angle and interconnected by a bight portion for supporting said filament substantially at the apex thereof with said apex substantially on the focal axis of said reflector, said supporting and guiding means being constructed and arranged initially to apply tension to said filament substantially axially of said reflector and said sloping sides being adapted to guide said filament to its position on said focal axis to maintain said filament substantially in said common plane containin the focal axis of the reflector.

5. A portable spotlight for operation from a substantially 110 volt to 120 volt power line comprising a focusing reflector for producing a long beam having substantially parallel rays, a filament of suitable operative length and resistance for operation from a substantially 110 volt to 120 volt power line, said filament comprising a fine wire kinked into relatively minute coils and the so kinked filament coiled into larger coils and thus to compact the filament to desired length with the axes of the larger coils of adjacent portions of said filament angularly disposed relative to one another to form a substantially V-shaped filament concentrated substantially about the focal point of said reflector, a pair of spaced rigid supports disposed substantially in a common focal plane of said reflector, said supports having inwardly directed portions formed with reversely bent ends clampingly engaging substantially the ends of the filament while crushing some coils thereof to provide a rigid mechanical support and good electrical connection for said filament, and filament supporting means for supporting said substantially v-shaped filament substantially at the apex thereof with the apex on the focal axis of said reflector for maintaining all portions of said filament sub stantially free from sagging about the focal point of said reflector under all operatin conditions and temperatures whereby to maintain said long beam properly focused.

6. A portable spotlight for operation from a substantially volt to volt power line comprising a focusing reflector for producing a long beam having substantially parallel rays, a filament of suitable operative length and resistance for operation from a substantially 110 volt to 120 volt power line, said filament comprising a fine wire kinked into relatively minute coils and the so kinked filament coiled into larger coils and thus to compact the filament to desired length with the axes of the larger coils of adja cent portions of said filament angular disposed relative to one another to form a substantially V-shaped filament concentrated substantially about the focal point of said reflector, a pair of spaced rigid supports disposed substantially in a common focal plane of said reflector, said supports having inwardly directed portions formed with reversely bent ends clampingly engaging substantially the ends of the filament while crushing some coils thereof to provide a rigid mechanical support and good electrical connection for said filament, and filament supporting and guiding means including spaced side surfaces arranged at a sharp acute angle and connected by a bight portion for supporting said substantially V-shaped filament substantially at the apex thereof with the apex on the focal axis of said reflector for maintaining all portions of said filament substantially free from sagging about the focal point of said reflector under all operating conditions and temperatures whereby to maintain said long beam properly focused.

HENRY R. GROSS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,826,025 Rose Oct. 6, 1931 2,135,263 Sisson Nov. 1. 1938 2,245,782 Holloway June 17, 1941 2,366,292 Smith Jan. 2, 1945 2,436,259 Keiifer Feb. 17, 1948

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