US2434986A - Adjustable lamp - Google Patents

Description

Jan. 27, 1948. I BREMER 2,434,986

ADJUSTABLE LAMP Filed June'll, 1945 2 Sheets-Sheet 1 IN V EN TOR.

Patented Jan. 27, 1948 UNITED STATES PATENT OFFICE ADJUSTABLE Harry E. Bremer, Milwaukee, Wis. Application' June .11, 1945, Serial No. 5987186 8 Claims. 1

This inventionrelates toimprovements in adjustable lamps.

Adjustable lamps which can be mounted in various positions and adjusted to various angles are very useful in providing proper illumination for lathes, milling machines, drafting boards, home work shops, typewriters, and for othersimilar purposes. Heretofore such lamps have been troublesome to adjust and have not been constructed to maintain themselves properly in' certain positions of adjustment. Furthermore, most adjustable lamps have an open construction wherein the Wiring is exposed at the joint and subjected to strains during use. This is a hazard in' factories where sparks from short circuits are likely to cause trouble.

It is a general object of the present invention to provide an improved lamp which can be mounted in any desired position, and in which the jointed'supporting arms maybe quickly moved to various angular relationships and maintained in a desired position regardless of the mounted position of the lamp or the particular condition of adjustment.

A more specific object of the invention is to provide a lamp" having a base and having a sup; porting post so connected to said base that the post may be maintained in a vertical position with respect to the'floor regardlessof the plane'of' support for the base; The post includes a freely swivelling portion which supports the jointed extension arms of the lamp; By thusmainta'ining the post in a vertical position regardless of the position of thebase, gravity'will not cause the extension portion of the lamp toundesirably float toa new position on the swivel.

A further object of the invention is to provide a lamp having a plurality of pivotally connectedsections in which there is an improve'd'joint between the sections which permits adjustment without loosening of a nut or bolt, the joints bein so constructed as to maintain the sectionsina desired angular relationship without the necessity of retightening the joints, once the proper tension at the joint has been obtained;

A further object of the invention is to provide alamp in which all Of the wiring is concealed and. protected by substantially water proof joint forming members to eliminate any hazard from short circuits.

A further object of the invention isto-provide an adjustable lamp in whichthe relatively mov- 2 purposes, and in which the construction is suchas to eliminate wobbling of portions of the lamp 7 during use.

able parts maintain a desired condition"of'tightness while being freely movablefor adjustment A further object of the invention is to provide merals designateflthe same parts in all of the views:

Fig. I is' a side elevationalview of the lamp, the dot: and dash lines indicating an angular mounting for the base sucli as might be used when the lamp is mounted onan angularly disposed drafting board;

Fig. 2' is a fragn'ientary view illustrating the lower portion of the lamp and indicating the base mounted on a vertical wall or support; I

Fig; 3 is a rear view of the lower portion of the lamp assembly;

Fig. 4 is a fragmentary cross-sectional view through the joint at the upper end of Fig. 3;

Fig. 5 is a view taken approximately on the line 5'-5 of Fig. 4, part of the facing ringbeing broken away;

Fig. 6 is a view partially in vertical section of a the lower portion of the lamp showing the interior of the base from one side;

Fig. 7 is a similar view showing the interior of the base from theopposite side F g. 8' is a sectional view taken on the lined-=8 Fig. 9 is a fragmentary sectional view taken on the line 9- -9-'of Fig. 8.

Referring: more particularly to the" drawing,

the lamp comprises a hollow base member H! which isadapted to be connected by screws or the like to a suitable support. The upper portion of the chamber H within the baseis'semi-circular as at l-2 to rotatablyhouse an adjustment wheel The wheel 13 has a threaded [3 (see Fig. '7). central opening l4" (see Fig. 8) for receiving the inner end of a bolt l5'which bolt extends throughan opening [6 in the base member and loosely throughan opening ll in atoothed disc l8; The teeth IS on the disc l'8 extend in a circle and'are loosened to permit disengagement of the teeth I9 from the teeth 20, then the adjustment wheel may be swung to an angular position as shown by dot and dash lines in Fig. 7. During such swinging movement the head of the bolt rotates in the hole N5 of the casing and the bolt rotates within the toothed disc l8. When a desired position of adjustment has been obtained, then the bolt |5 may be tightened to cause engagement of the teeth with one another as in Fig. 8. When in this condition, no amount of weight can cause rotation of the adjustment wheel I3 because the toothed disc |8 has lower winged extensions 24 (see Fig. 6)

4 the threaded outer end 44 of the stud 43 to maintain the parts in assembled position and to aid in creating a proper tension at the joint.

When the hand nut 5| is tightened slightly it will cause the rim portion 48 to bear against the copper ring 40 and will tend to compress the rubber ring 38 slightly. A slight amount of tightening of the nut 5| will cause some compression of the ring 38 and will cause the parts to hold a position such as the position of Fig. 1 against the force of gravity, The majority of required changes in adjustment at the knee joint may then be made without touching the nut 5|.

which fit the casing and which maintain the disc I8 against rotation.

Rotatable in the tubular boss 22 is a tubular However, if for certain work the extension arms are almost in alignment and extended out at right angles,

then, of course, gravity will act more strongly on the tubular boss 22. Just below the shoulder the swivel fitting 25 has a portion 25' of reduced diameter or annularly recessed; This portion of reduced diameter is engaged by the inner end of a screw 21, as shown in Fig. 9. The screw 21 serves to lock a cap 28 over the annular shoulder 26 and around the boss 22. The inner end of the screw 21 so engages in the reduced diameter portion 26 of the swivel member as to permit rotating movement while preventing relative longitudinal movement between the parts.

The upper end of the swivel fitting 25 is threaded as at 29 for insertion in a threaded opening 30 of a tubular part 3| which projects downwardly from a circular member 32 (see Fig. 4), the latter forming part ofthe first knee joint. A setscrew 33 serves to lock the threaded extension 29 of the swivel fitting in a desired position in the member 3|. The members 25, 28, and 3| form a swivelling supporting post for the jointed extension arms and lamp proper.

It is apparent that with the above construction all portions of the lamp connected to the part 3| may swivel with the swivel fitting 25 within the tubular boss 22. Due to the construction just described there is a firm support at the swivel notwithstanding the fact that there nay be considerable strain thereon when the lamp is in the position shown in Fig. 1. The annular shoulder 25 in conjunction with the cap 28 effectively prevent all wobbling action. Whenever required, swivelling movement is limited by engagement of the stop projection 34' with the lug 35 (see Fig. 9).

The circular part 32 (see Fig. 4) has a rim 36,

which is recessed as at 31 to receive a ring'33 of resilient material such as rubberor synthetic rubber, The portion of the rim 36 on the'inner side of the rubber ring is shorter than the portion on the outer side as indicated at 39 and a thin-washer 40 of copper or other suitable material is secured to the outer face of the rubber ring 38 and has its inner edge portion overlapping the annular rim part 39. Within the-part 32 isa chamber 4| and within the chamber is a boss 42 having a stud 43 projecting therefrom, The outer end of the stud is threaded as at 44. i

A cooperating circular joint forming member 45 has a rim portion 45 surrounding an internal chamber 41. The rim portion has its engaging end of reduced diameter as at 48 to fit within the outer part of the rim 36 of the member 32.

The circular member 45 is formed with an apertured center cup 49 for receiving a ballbearing set 50, and the stud 43 is adapted to project through the center cup and through the ballbearing set when the parts are in the assembled positionotFig. 4. A hand nut 5| is threaded on the joints and it may be necessary to tighten the nut 5| a little further in order to cause the extension arms of the lamp to hold a desired position of adjustment. However, for most normal adjustments there isno need for'changing the tension by manipulating the nut 5|. a

When an adjustment at a joint is made by partially rotating the member 45 relative to the member 32, the rotation will be against the face of the copper Washer 40. Because of the use of the ballbearing set 50, which acts as a thrust bearing against the part 50' of which the hub portion 52 of the nut 5| bears after the nut is tightened, rotation of the joint portion 45 will never cause loosening or further tightening of the nut 5|. This is due to the fact that the part 50' of the ballbearing set will remain fixed while the shell and other part of the ballbearing set is rotating with the member 45 around said part 50'. Thus, any number of angular adjustments may be made without manipulating the nut and without effecting the tension at the joint.

The circular joint member 45 is formed with an outwardly projecting tubular extension 53 which receives the end of a tubular extension arm 54, the other end of the arm is rigidly connected to a tubular extension 55 projecting radially outwardly from a joint member 56 which corresponds in all respects with the joint member 32 heretofore described. A cooperating joint member 51 is rotatable relative to the joint member 56 and the member 51 is constructed in an identical manner to the member 45 heretofore described. The nut for adjusting the tension at the second joint is indicated'by'the numeralifland operates in the same manner as the nut 5|.

Projecting radially outwardly from the joint member 51 is a tubular extension 59-to which the inner end of a second tubular extension arm 60 is rigidly connected. The other end of the arm 60 supports a lamp and shade unit 6| in the usual manner, and there is a ball and socket joint 62 between the outer end of the arm 60 and the lamp unit. The lamp unit includes the usual socket member 53 and there is the usual lamp bulb within the shade screwed into the socket 63.

A suitable electric cord 64 which is connectable with a source of current extends into a recess 65 in the lower portion of the base H] (see Fig. 8), upwardly and into the open end of the adjustment wheel l3, into the lower end of the tubular swivel fitting 25, and out of the upper end of the latter. The cord then extends into the tubular extension 3| of the joint member 32, through an openin 32' in the rim of said joint member (see Fig. 4), across to the interior chamber 41 of the joint member 45, and out through the tubular extension 53, as shown in Fig. l. The

cord then extends through the tubular arm 54,

ta nish t e iillhllle it 55 ac ss to the sh n th 19 st member 51 th o h e ene es as t rou h the u ul rel sh the tubula bal and eeke o n 2 and in o h lam s lset- It a pa n tha ll pa d ns f th e ec ric o tl t cor W t e am a e il re iab y .e neeale and pr c at h oints from wate or oth pn i i s- It is also ap ar nt tha the k ee J nt ar s we: s pieted ad us ments m y be ma wi h u lnpe ine an str i upon th outl t .cord- .In us .o 'the lam i it i de ired to av e am s p orted on a o izon a ob ec p l s a fia t e. th the bas m mb r H s wed or 9.. ,d t he table While the posit on shown in idlllipe i F g.- 1 h w r suppo t g o assembly 66 is adjusted in the slot 23 of the base mber i9 75. t at it lqpl the pper end of the slot to maintain the post in a vertical position. Assuming that there is proper tension at the two knee joints, any desired adjustment of the extension arms 54 and 69 may be made by merely pulling or pushing on the arms. If, however, the tension is not correct for the purpose of holding the arms in a particular adjusted position, this may be taken care of by manipulation of the nuts 5| and 58.

If the lamp is to be supported on an inclined surface such as a drafting board, as indicated by dot and dash lines in Fig. '1. then it is necessary to lopsen't-he screw [5- (see Fig. 8) until the teeth of the disc 18 are disengaged from the teethof the adjustment wheel 13. *The wheel may then be rotated slightly so as to maintain the lower supporting post assembly 66 in a vertical position inspite of the angular position of the base memberin', "I-he supporting post assembly may be loclged in a desired position by retightening of the screw '3. If the supportin post assembly 66 were left in its former position it would be'perpendicular to the plane 61 (see Fig. 1) of the drafting board or other inclined surface, and the weight of the extension arms and lamp would cause the lamp to undesirably float on the swivel connection at the top of the base member I. However, by always maintaining the supporting post assembly 66 in a vertical position regardless of the position of the base it], then there can be no undesired swivelling, and the lamp will hold itself in any swivelled position in which it is left.

If it is desired to mount the base on a vertical surface, such as a side-wall, then the base is screwed or bolted to said surface as shown in Fig. 2, and the supporting post assembly 66 is readjusted to bring it to the lower end of the slot 23 of the base member II], as is shown in Fig. 2. Thus, the supporting post assembly 66 is still maintained in a vertical position.

Various changes and modifications may be made without departing from the spirit of the invention, and all of such changes are contemplated as may come within the scope of the claims.

What I claim is;

1. In an adjustable lamp, a base having an internal chamber and having an elongated slot in one of its walls communicating with said chamber, a member rotatable on a horizontal axis in said chamber of the base and having a relatively short extension projecting through and movable in said slot upon rotation of said rotatable member, elongated lamp supporting means, means forming a swivel joint close to said base connecting said elongated lamp supporting means to said extension, said swivel joint having a cylindrical pivot member to provide for rotation along a sina eax s and rorl oh ns thespian ah e membe in a sele ed p s tion o rotation to mai ta the axis r said eljpint in adesired esit en in said s ot w th respec to he plane o h b se s tha undesi e swiv ling wi l no be aus d b ravity a t n on h relativ ly long mp suppo n means- 2- Inap ad u abl mp a base member haw ing an in rna c am er r i ed with a semicula o all por on, s id wa l port o vn an el ng t d s t xtending erip e al y thereof, a wheel rotatable on a horizontal axis aid h mber of th ba and fitt ng-the cu va ur f the op wall thereof, sa d wheel ha ing looking D JQ I i l on an end 'fi lfilf and havin a: elati el shor e t sion pro ect g f om its noiph r-y thr u h said slot, o ated lamp supportin m ans, eans fo m n a swivel joint close to said base connectin said elon ated lamp Slipportin means to said extension, said swivel joint having a cylindrical pivot member to provide for rotat o along a sin le axis only complementary locking projections in connection with the base member cooperable with the projections of said wheel, and means for releasably holding said locking projections in engagement with one an other to maintain the wheel in a selected position of rotation and maintain the axis of said swivel joint in a desired position with respect to the plane of the base so that undesired swivel: ing will not be caused by gravity acting on the relatively long lamp supporting means. a

3. In an adjustable lamp, a base member have, ing an internal chamber provided with a semi! cylindrical top wall portion, said wall portion having an elongated slot extending peripherally thereof, a wheel rotatable on a horizontal axis in said chamber of the base and fitting the curvature of the top wall thereof, said wheel having teeth on an end thereof and having a relatively short extension projecting from its periphery through said slot, elongated lamp. supporting means, meansforming a swivel joint close to said base connecting said elongating 1amp supporting means to said extension, said swivel joint having a cylindrical pivot member to provide for rotation along a single axis only, a toothed disc supported in said chamber of the base and having a common axis with said wheel and being cooperable with the teeth of said wheel, means preventing rotation of said toothed disc, and means for releasably holding the teeth of the wheel in engagement with the teeth of the disc to lock the wheel in a selected position of rotation and maintain the axis of said swivel joint in a desired position with respect to the plane of the base so that undesired swiveling will not be caused by ravity acting on the relatively long lamp supporting means.

4. In an adjustable lamp, a base member having a tubular extension projecting therefrom, a swivel fitting freely rotatable in said tubular extension and having an intermediately located annular shoulder rotatably seated on the end of said tubular extension, a cap through which said swivel fitting extends having an inwardly projecting annular flange engaging the upper surface of said shoulder, and elongated lamp supporting means connected to said swivel fitting outwardly of said cap.

5. In a lamp, a base member, a tubular lamp support projecting from said base and having a joint member at its outer end, a second tubular lamp support having a joint member at its inner end, said joint members having complementary flat surfaces for frictional engagement, -means connecting said two'joint members for relative pivotal movement, and means-including an adjustment nut for adjusting'the friction between said joint members to maintain the latter in a selected position of pivotal movementwhlie per mitting forced adjustable movement without ma nipulation of said nut, said means including mechanism for preventing transmission of rotating movement from-the second tubular lamp support to said adjustment nut while efiecting such forced adjustable movement. 7 r a 6. In alamp, a base, a tubular lamp support projecting from said base and having a joint member at its outer end, a second tubular lamp support having a joint member at its inner end,-

said joint members having complementary flat surfaces for frictional engagement, a stud projecting from one of said joint members and forming an axis for rotation of the other joint member thereon, a nut threaded onthe outer end of said stud, and a ball bearing set surrounding said stud and positioned between and contacting said nut and last mentioned joint member only to prevent transmission of rotating movement from said last-mentioned joint member to said nut.

'7. In a lamp, a base, a lamp support projecting from said base and having a joint member at its outer end, asecond lamp support having a joint member at its inner end, said joint members having complementary fiat surfaces for frictional engagement, a stud" projecting from one ,of said joint members and forming an axis for rotation of the other joint member thereon, a nut threaded on the outer end of said stud, a thrust bearing surrounding said stud and positioned between and contacting said nut and said last-mentioned joint member only to prevent transmission of ro- V tating movement from said last-mentioned joint member to said nut, and a resiliently mounted friction ring between said two joint members."

8. In an adjustable lamp, a base member, a relatively short post'projecting from said base and having a joint member at its outer end, a relatiyely long lamp supporting member having 'a joint memberat its inner end, means connecting saidtwo joint members for relative pivotal movemerit to form a first joint, said 'joint including mechanism fo'r" maintaining said joint members in a predetermined position of angular adjustment against the force of gravity, means located between said first joint and said post forming a freely rotatab1e swivel joint connecting said first joint to said postjmeans for adjustably varying the position of the axisof said swivel joint and said post withrespect to said base and for locking thefparts in said position to maintain said axis in a vertical position regardless of the plane of support for the base so that'undesired swiveling will not be caused by gravity acting on the relativel long lamp supporting member. V HARRY E. BREMER. REFERENCES CITED' The following references are of record in the fileof this patent:

' UNITED STATES PATENTS Nun ben Name 7 Date 476,188 Connor May 31, 1892 912,493 Sanders Feb. 16, 1909 980,580 Williams Jan. 3, 1911 986,445 Dekle Mar. 14, 1911 1,112,503 Wambsgans Oct. 6, 1914 1,693,925 Holt Dec. 4, 1928 1,697,710 Bostroem Jan. 1, 1929 1,853,153 Skeel Apr. 12, 1932 1,930,993 Blodgett Oct. 17, 1933 2,093,330. Lundborg e Sept, 14, 1937 2,202,195 Drachman et a1 May 28, 1940 2,331,382 Eubanks Oct. 12, 1943 2,382,679 Tollman Aug. 14, 1945 2,395,178 Flori Feb; 19, 1946 FOREIGN PATENTS Number 1 Country Date Great Britain Dec. 31, 1928

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