US1651090A - Lamp - Google Patents

Description

Nov. 29, 1927.

F. A. HART LAMP &......... 2

` Filed Feb. l, 1926 or INVENTOR 7M cmi- B Y A TTORNE Y WrTNEESEE Patent' Nov. 29, 1927.

FREDERICK A. HART, OF NEW BRITAIN, CONNECTICUT.

LAMP.

Application tiled February 1, 1926. Serial No. 85,219.

My invention relates to lamps of the sort that stand on the floor and have an 'adjustable extension arm which carries the light.

- My invention has for its principal object to provide certain improvements-in lamps of the character mentioned.

To the above and other ends my invention consists incertain features of construction and combinations andA arrangements of arts, all of which will be fully set forth erein and particularly pointed out in the claims. y

In the accompanying drawings,

Fig. 1 is an elevation on a\reduced scale of a lamp embodying my invention.

Fig. 21s a vertical central section through the upper part of the lamp stand.

Fig. 3 is a perspective view of one of the friction disks.

Fig.' 4 is a plan view in section on the y line 4.4 of Fig. 2.

Fig. 5 is a top view of one ofthe joints.

Fig. 6 is a view similar to Fig. 4 but show-v ing a preferred construction.

Fig. 7 is a view of a washer used in the construction shown in Fig. 6.

The lamp shown in the drawing is designed to stand on the floor and to hold an incandescent electric light in a suitable po- 30 sition for the use of a person-working at a desk. This particular lamp was more especially designedY for the use of persons operating typewriting and adding machines.

- The lam comprises a cast base 1 of sulficient breath and weight to keep the lamp from being easily turned over, an upright or standard 2, consistin of a piece of rather light tubing, prefera ly steel, inserted in a suitable hole in the base 1 and suitably secured in position there, as forexample, by a set screw 3. Near its upward end the vtube 2 has two diametrically opposite holes 5 made therein, these holes bein made with straight up and down sides as s own in Fig. 2. An extension arm 6 passes through these two holes 5 and has -a plece 7 pivotedl thereto on a bolt 8. This nipple is threaded as shown `at 9 and :hasa lamp socket 10 screwed on to it in the usual way, and attached to said socket there is shown in the drawing a shade and reflector 11. v Said socket 10 and reiector 11 may be of any ordinary and suit'- able sort. l

The arm 6 may consist of a piece of tubing of rectangular cross section, but I find it cheaper and just as good to employ instead a channel bar of the form shown in Fig. 2, made by making two longitudinal right-angular bends -in a strip of sheet metal, the open side being down.

The joint between the arms 6 and standard 2 is of novel and advantageous construction. It comprises a bolt' 12, inserted through holes pierced in the standard 2 and through the side walls of the arm 6, a nut 13 screwed on to the end of .said bolt and two friction disks 14, each having a hole 15 through which the bolt passes. These disks which lie fiat against the sides of the arm 6, communicate the pressure of the nut through the standard 2 to said arm so as to furnish the friction desirable for holding the arm in any position to which it may be moved while permitting it to be readily adjusted by hand up and down. It is desirable to make the standard 2 of rather light tubing and it was found that if plane disks 14 were employed the metal of the tube 2 would be spread by the pressure of the head of the bolt and the nut 13 and it was not practicable to get the desired degree of friction without distorting the tube. For that and other reasons I have made the disks 14 with shoulders, arranged to take the lateral pressure of the edges of the standard bounding the perforations 5 to prevent the spreading of the tube under the pressure of the bolt. Theseishoulders can be produced by providing up'and down ribs on the disks 14 but I find it more convenient to cut in the outer surface of each disk two grooves 16 as shown in Figs. 3 and 4, these grooves being so spaced that the edges of the holes 5 in the tube 2 just it into them. The outer walls of the grooves furnish the necessary shoulders to prevent the spreading of the tube as will be readily understood from an ins ection of Fig. 4. By this means a rather lig t steel tube isstiflened to such an extent as to furnish an entirely satisfactory degree of friction. to maintaln the .arm 6 in whatever position the user moves itl to.

In addition to stiifening the tube 2, the grooves 16 revent the disks 14 from turning when t e arm 6 is swung up or down. TheV rubbing is therefore confined to the inner surfaces of the said disks and to that part of the outer surface of the arm 6 which 1s enclosed or embraced by the said disks.

" The exterior surface of the lam may therefore be finished in any desire ornamental wayl and no visible part of the finish willbe having on its outer end screw threads to lit the ordinary lamp socket 10 and at its other end, bifurcated as shown so "as to form two cheeks which may be drawn by the nut 19 on said bolt into frictional engagement with the fiat sides of the arm 6. his piece 7 is of course provided with a hole through it for the cord 20, said cord passing out of the socket 10 throu h the piece 7 and into the upper part of t e arm 6 above the bolt 8.

The cord also asses above and back of the bolt 12, down t rough the upright standard 2, and out near the base of said standard through a suitable insulating washer 21. The tension on the cord will be suiiicient to prevent it from saggin down in the arm 6 to a point whereit wi be Visible.

The upper end of standard 2 may be finished in any suitable way. In the present instance a turned wooden plug or stopper 22 is inserted with a fairly good fit in the upper end of the tube. This plug or end piece has a saw-cut 23, indicated by dotted llines in Fig. 2, extending diametrically across it from the bottom of the plug up to about the level of the top of the tube. An axial counter-bore 24 from the top of the plug extends down deep enough to intersect the upper part of the slot 23, and a tapered wood screw 25 is screwed through 'the plug as shown. This screw has the effect of a' wedge to tighten the plug in the tube 2, this action being permitted by the saw-cut 23 without splitting the plug.

While my lamp 1s described primarily as a iioor lamp, it will of course be understood that the standard tube-may, if desired, be shortened and the lamp adapted to stand on some higher .support than the floor.

In Figs. 6 and 7 I have shown the same construction as in the other figures and as above'described, but have added two washers 26 on the bolt 12, one of said washers bein placed between the head of said bolt an the tube 2, and the other between the nut 13 and said tube. These may be round sheet metal Washers bent into cylindrical or arched form, but'with a radius of curvature a little less than that of the tube 2. This a pears in Fig. 6 where the parts are shown before the nut 13 .is tightened, and it will be seen that two opposite edges of each washer contact with the tube, but the middle part of the washer stands Aa little away from the tube. When the nut'is tightened, the washer is sprung by the pressure into about the same radius of curvature as the tube, which it embraces closely. These washers greatly stiffen the arched portions of the standard against the pressure of the bolt and enable me to employ a lighter tubing for the standard 2 than 1s practicable without them, the washers enabling the thin tubing to withstand the necessary pressure without undue distortion. By using these washers I have been able to make a satisfactory standard 2 of welded steel tubing of a thickness of only about twenty-live thousandths of an inch, and which tubing would be crushed inby the bolt 12\ and nut 13I if used without the washers.

Various changes may be made, in the details of construction and arrangements without departing from my invention.

What I claim as new and desire to secure by Letters Patent, is:

1. In a lamp, the combination of a thin tubular standard perforated on o posite sides, the metal surrounding lthe e ges 0f said perforations being yieldable, a lightsupporting arm passing through said perforations, friction disks in said perforations,

each of said disks being provided. with shoulders registering with the side edges of said perforatious to take the lateral or spreading pressure of said edges and prevent crushing or distortion of said tubular standard, and means for applying transverse pressure to said standard and through it to said friction disks andby the latter to the light-supporting arm. l

2. In a lamp, the combination of a thin tubular standard having opposite perforations, the metal surrounding the edges of said perforations being yieldable, an arm eX- tending through said perforations, friction disks in said perforations and between which said arm is mounted, said disks having shoulders registering lwith the side edges of said perforations to take the lateral or spreading pressure of said edges and prevent crushin or distortion of said tubular standard, an a bolt extending through said standard, said disks and said arm and serving both as a pivot for said arm and as means for applying pressure to produce friction between said arm and said disks. e

3. In a lamp, the combination of a thin tubular standard having longitudinal perforations on opiposite sides thereof, the metal surrounding t e edges of said perforations being yieldable, an arm passing through said perforations, friction disks in said perfora- 125 1 tions and pressing against said arm, each of said dis s being grooved, and the,v edges boundlng said perforations l ing in the l grooved parts of each disk so tat the walls of said grooves may` take the lateralA or spreading pressure of the edges bounding said perforations and prevent crushing or distortion of said tubular standard, and a pivot extending through. said standard, said disks and said arm and serving to apply pressure to produce friction between said disks and said arm.

\4. In a lamp, the combination of a thin tubular standard having two oppositely disposed perforations in its walls, said perforations having straight sides extending longitudinally of said standard and the metal of the standard through which said perforations are made being yieldable, two friction disks in said perforations and each made with two grooves to receive the straight edges of said perforations and toprevent crushing or distortion of said tubular standard, an arm between said disks and a pivot bolt for said arm arranged also to put pressure on said standard and disks to frictionally restrain said arm.

5. In a lamp, the combination of a thin tubular standard, an arm to support an electric light, said standard having oppositely disposed perforations through which said arm passes, the metal surrounding the edges of said perforations being yieldable, friction disks in said perforations and on opposite sides of said arm, said disks being provided with shoulders registering with the side edges of said perfor-ations to take the lateral or spreading pressure of said edges and prevent crushing or distortion of said tubular standard, a pivot bolt passing through said standard, disks and arm and supplying the pressure to produce the necessary friction, and a cord of insulated wire passing through said standard over said pivot bolt and along said arm to supply current to said lamp.

6. In a lamp, the combination of a thin tubular standard having opposite perforations, the metal surrounding the edges of said perforations being yieldable, an arm extending through said perforations, friction disks in said perforations and between which said arm is mounted, said disks having shoulders registering with the side edges of sald perforations to take thenlateral or spreading pressure of said edges and prevent crushing or distortion of said tubular standard, a. bolt extending through said standard, said disks and said arm and serving both as a pivot for said arm and as means for applying pressure to produce friction between said arm and said disks, and washers for said bolt arched to embrace said standard.

7. In a lamp, the combination ot' a thin tubular standard having opposite perforations, the metal surrounding the edges of said perforations being yieldable, an arm extending through said perforations, friction disks in said perforations and between which said arm is mounted, said disks having shoulders registering with the side edges of said perforations to take the lateral or spreading pressure of said edges and to prevent crushing or distortion of said tubular standard, a bolt extending through said standard, said disks and said arm' and serving both as a pivot for said arm and as means for applying pressure to produce friction between said arm and said disks, and sheet metal washers for said bolt each of said washers made in the shape of an arch having a radius of curvature less than that of said standard and sprung by the pressure of said bolt into substantial conformity to the curvature of said standard.

8. In a lamp, the combination of a thin tubular standard having oppositeiy disposed perforations, the metal surrounding the edges of said perforations being yieldable, friction disks in said perforations, a lightsupporting arm extending through said perforations between said disks, said arm consisting of a channel shaped flat bar made by forming a strip of sheet metal with an upper wall and two vertical walls to form Hat surfaces to be embraced between said disks, a pvot bolt for said arm acting also to put the necessary frictional pressure on said disks, means on said disks to prevent spreading of said standard under such pressure, and a cord running through said standard and through said Hat light-supporting arm to the electric light socket which is supported by said arm.

Signed at the borough of Manhattan, city of New York, in the county of New York and State of New York, this 28th day of January, A. D. 1926.

FREDERICK A. HART.

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