US2618454A - Lamp guiding and mounting means - Google Patents

Description

1952 T. B. FARRINGTON 2,618,454

LAMP GUIDING AND MOUNTING MEANS Filed Aug. 21, 1946 4 Sheets-Sheet l INVENTOR THAYER B. EARRING-TON A T TORNE YJ Nov. 18, 1952 T. a. FARRINGTON LAMP GUIDING AND MOUNTING MEANS 4 Sheets-Sheet 2 Filed Aug. 21, 1946 ,wvzslvron THAYER B. fhRR/ ero/v ATTORNEYS IN ME N 7' 0/? TH: YER 2S. PARKING-TON ATTORNEY-5 4 Sheets-Sheet 3 Q! a a 4,

T. B. FARRINGTQTJ LAMP GUIDING AND MOUNTING MEANS Nov. 18, 1952 Flled Aug 21, 1946 Nov. 18, 1952 "r. B. FARRINGTON LAMP GUIDING AND MOUNTING MEANS 4 Sheets-Sheet 4 Filed Aug. 21, 1946 pllllllll' //V VEN TOR THAYER :5. Sam/warm ATTGRNETJ Patented Nov. 18, 1952 LAMP GUIDING AND MOUNTING MEANS Thayer B. Farrington, Cleveland Heights, Ohio, assignor to The Thompson Electric Company, Cleveland, Ohio, a corporation of Ohio Application August 21, 1946, Serial No. 692,023

6 Claims.

This invention relates to improvements in lamp guiding and mounting means.

An object of the present invention is to provide a lamp in an elevated position with a novel, generally vertical, hollow track leading upwardly to a position adjacent the lamp, there being a novel carriage movable up and down on the track for the purpose of carrying the lamp upwardly to an elevated position when in use, or for carrying the lamp downwardly for repairs and maintenance when such is required.

Another object of the present invention is to provide such a hollow track as a means for housing the operating cable by which the lamp is raised and lowered.

Another object of the invention is to provide novel means whereby the hollow track houses the electrical conductors which energize the lamp.

Still another novel feature of the invention is the utilization of the hollow track as a housing means for both the operating cable for raising and lowering the lamp and for the electrical conductors for energizing the same, together with means for maintaining a separation between the cable and conductors. This phase of the invention may combine the hollow track with a hollow arm for supporting the lamp, wherein the operating cable and electrical conductors pass through the hollow arm, and partition means in the arm separates the cable from the conductors. Thus, the cable and conductors may be separated all the way through the track and through the arm to the lamp itself.

Another object of the present invention is to provide a carriage for guiding the lamp upwardly and downwardly and novel means mounting the carriage on the track.

Still another object of the present invention is to provide novel carriage mounting means on the guiding track wherein a roller on the carriage bears against the track to yieldingly support the carriage for limited movement toward and away from the track supporting structure, while other rollers yieldingly engage the sides of the track to support the carriage for limited movement laterally, and flanges on these last named rollers engage behind laterally projecting portions of the track so as to positively hold the carriage on the track.

Other objects and advantages of my invention include the combination of a hollow track of box beam section permitting light gauge metal to be utilized for the formation of a structurally strong track, which at the same time, provides laterally projecting hollow portions fulfilling the double purpose of housing electrical conductors and providing guiding portions for the carriage.

Other objects and advantages of the present invention will be apparent from the accompany- 2 ing drawings and description, and the essential features thereof will be summarized in the appended claims.

In the drawings,

Fig. l is a side elevational view of one form of my device;

Fig. 2 is a front elevational view, enlarged, of the carriage portion of Fig. 1 taken in the position of the line 22 of Fig. 1;

Fig. 3 is a side elevational view, enlarged, of the carriage portion of Fig. 1;

Figs. 4 and 5 are transverse sectional views taken along similarly numbered lines of Fig. 2;

Fig. 6 is a fragmental sectional view taken along the line 6-6 of Fig. 5;

Fig. 7 is a sectional view taken along the line 1--1 of Fig. 3;

Fig. 8 is a sectional view taken along the line 8--8 of Fig. 3 and showing a supporting insulator for the electrical conductors;

Fig. 9 is a side elevational view of a modified form, this view being taken in the same relative position as Fig. 3;

Fig. 10 is a front elevational view of the device of Fig. 9 taken from the left-hand side of Fig. 9;

Figs. 11 and 12 are transverse sectional views taken along similarly numbered lines of Fig. 10;

Fig. 13 'is a sectional view taken along the line |3--l3 of Fig. 9; while Fig. 14 is a sectional view similar to Fig. 13, but taken at a point where a supporting insulator for electrical conductors is inserted.

The present invention has for its purpose the provision of a generally vertical track for guiding a lamp to an elevated operating position from a lowered position where the lamp is accessible for repairs and maintenance. Such lamps have previously been guided by cables which permit a certain amount of lamp movement in high wind and which are a little diificult to operate if the guiding cable becomes coated with ice in the winter. Vertical tracks have been used for the guiding of such lamps, but the present invention overcomes certain difiiculties of these prior devices by providing a track which is cheap to construct, but nevertheless, strong and efiicient for the purpose intended, and which provides a continuous closed passageway from top to bottom for housing a lamp operating cable or electrical conductors, or both. The invention also provides novel means for mounting the lamp supporting carriage on the vertical track so that the same may be readily removed from the track, if necessary, and so that the carriage will traverse the track under all conditions of icy weather, corrosion, and like obstructions.

In the form shown in Figs. 1 to 8 inclusive, a lamp supporting fixture l 5 similar to that shown in my Patent No. 2,303,626, granted December 1, 1942, is indicated as supporting one or more lamps within the globe I6. Preferably, two such lamps on opposite sides of the fixture are provided, as shown in said patent. Those skilled in this art will understand that the globe It might be red in the case of lamps mounted on high structures for airplane warnings. The lamps carried by the fixture it are supported from above by the fixture stem ii a which is analogous to the stem 35 of my said patent. A canopy I? is supported by means of hollow arm it on the supporting structure l9 which may be a high building, a stack, tower, or similar structure. Housed in this canopy are electrical contacts, a pair of which are fixed, as indicated at 29, for cooperation with mating contacts carried by the fixture stem I50, all as fully disclosed in Fig. 2 of my above-mentioned patent. It will be understood that electrical conductors 2| and 22 pass through the hollow arm 18 for connection with the, fixed contacts 2d, and other electrical conductors lead from the mating contacts downwardly through the. stem Ida and fixture to energize the lamps within the globes It, all as shown in the above patent, and the details of which form no part of the present invention.

A guiding track 23 is fixed in a generally vertical position on the supporting structure I9. Obviously, if this supporting structure is a wall having a batter or a stack tapering toward the top, the track 23 will not be absolutely vertical, but nevertheless, it will extend in a generally vertical direction. The construction of this track is clearly shown in Figs. 4, 5, 7 and 8. It is essentially a continuous box beam from top to bottom having the general form of the letter 1. One flange member against the wall of the supporting structure comprises a platen and legs 25 of the outer beam structure secured to the supporting structure [9 by bolts or other securing means 26. The legs 25 are portions of a continuous sheet of metal which is bent outwardly at right angles to the plate 26 providing the web portions 21. The outer portion of this sheet forms a rectangular head which includes the laterally projecting hollow flanges 28 and the outermost track face 29 which is generally parallel to the plate 24'. This track is formed out of relatively light metal sheets, say of fourteen or sixteen gauge, which, when bent to the form shownand bolted in position, provides a very strong track, structurally speaking,

but one requiring a relatively small amount of metal. ihis track is provided in suitable lengths which are so constructed with slip joints at their meeting ends, as indicated at 30 in Figs. 1 and 3, that any length desired may be assembled and the surfaces 2?, 2B and 29 will be substantially in line and smooth throughout the length of the track. The details of this construction will be more clearly apparent in Figs. 3 and 7 where the portions 23 of the lower track section have been cut away from the web portions 21 sufiiciently to permit the end portions 28 and 27- to be bent inwardly, substantially the thickness of the metal rom which the track is formed. These contiguous end portions then slide into each other, as indicated in Figs. 3 and '7, to provide a continuous track with slip joints allowing a certain amount of expansion and contraction as the temperature changes.

Partition means 3! is preferably provided inside the track for the purpose of positively separating the electrical conductors from the lamp operating cable as will later appear. This comprises a strip of metal bent U form in section, as viewed in -i, 5 and 7, with the cross piece 310 of the U flat against the inside of the portion 29 of the track, and the legs 3th engaging the inner faces of the web portions 2?. Preferably, deformations 32 of half conical form are struck out from the legs filb at spaced points therealong in position to engage the walls of the hollow flanges 28, as clearly shown in Figs, 4 and 5. The member 3| is thus held against outward movement by its portion Sla and is held against inward movement by the projections 32.

A carriage indicated generally at 33 rides up and down on the track 23 and is connected with the lamp by a pair of rods 34 which are analogous to the rods 5! shown in my above-mentioned patent. These rods are held by set screws or the like in suitable openings in the fixture at their outer ends, and they enter into sockets 35 formed in bosses 35 on the face of the carriage. As clearly ShOWn in Figs. 5 and 6, short sleeve portions 3? embrace the rods 34, and these are held in place by inner set screws 38 passing into the sleeve 37 and the outer set screws 38 which pass through the sleeve and into the rods 3%. As shown in Fig. 6, the sockets 35 may be slightly tapered, as shown at 35, so as to permit the adjustment of the rods 32, at an angle to hold the lamp horizontal in case the track 23' is not exactly vertical as in the case of sloping structures mentioned above.

The base structure of the carriage comprises a base plate 58 on which is mounted a wide flat roller 4! adapted to engage the outer face 29 of the track over the wide flat surface thereof, so as to give a broad flat bearing against the track. This roller ll is yieldably mounted in the carriage for movement toward and away from the supporting structure It. To this end, the roller is mount 7 ed on a shaft :12, the opposite ends of which extend through slotted openings 43 in the boss 33 which is integral with the base plate 43. These slotted openings are at right angles to the track face 29, and plungers id extend lengthwise of each slot, bearing gainst shaft 32 at one end, and yieldingly held at the opposite end by a helical spring t5 mounted in a, cup 46, which is threaded into the boss 35, as clearly shown in Fig. 5. The roller Q! is thus firmly held against the surface 29, but may yieldingly move to accommodate itself to inequalities in the surface, coatings of ice, corrosion, or the like.

Other rollers are provided to yieldingly hold the carriage against lateral movement with respect to the track, and preferably, these comprise an upper pair 41 and a lower pair 48. Since these rollers are the same, one pair only will be described. Each roller 27' has a main roller portion 41a which bears against the outer flange edge 23 of the track, that is to say, the surface parallel to the web 21. Each roller has a flange portionflb which engages against the track surface 28a which is that portion of the track flange spaced inwardly from and parallel to the surface 29. Thus, the flange head of the track is squeezed between the roller 4! and the flanges 41b of the rollers M and similar flanges 48b of the rollers 48. The rollers 41'! are mounted for yielding movement toward and away from the track in a lateral direction. To this end, each roller is rotatably mounted in an arm 49, and these arms are pivotally mounted on a pin 59 which is mounted on the base -38. The movement of each arm 49 is controlled by a link 5| which is, pivotally mounted on the end 52a of the roller shaft 52. Each of these links extends laterally inwardly and is; flanged at Ma to provide an opening for receiving a pin 53 which in turn is freely held in an opening 54 of a projection 55 integral with the base plate 40. Opposite ends of pin 53 are embraced by short helical springs 56 held in place by nuts 51. Thus, the springs 56 yieldingly hold the flanges 5|a of links 5| inwardly so as to permit yielding movement of rollers 41 laterally away from the track upon compression of springs 56. The parts controlling rollers 48 have been given similar reference characters. It results from this construction that the rollers 41 and 48 may accommodate themselves to inequalities of the track flanges 28, or to accomulations of ice, corrosion, or the like.

Obviously, the carriage 33 may be removed from the track by spreading the rollers 41 and 48 sufficiently for the flanges 41b and 48b to clear the track.

The hollow track not only provides a strong structure with a minimum amount of metal, but it also provides a continuous closed passageway from bottom to top of the supporting structure. The bolted connection of flanges 25 with plate 24 prevents the entrance of water and moisture at the back of the track, and means are provided at the top and bottom to prevent the entrance of moisture to the hollow portion of the track. I therefore utilize the hollow passageway of the track for the guidance and protection of the lamp operating cable and the electrical conductors 2| and 22. Reference will be had first to the operating cable. My above-mentioned patent shows a latching means for holding the stem |5a in its raised position, and the present invention contemplates the use of such latching mechanism. The operating cable 58 is attached to the upper end of stem l5a, as shown in my above-mentioned patent. It then passes upwardly around pulley 59 mounted on shaft 69 in the hollow arm 8, thence through the hollow arm to the mounting connection 6| and over pulley 62 which is rotatably mounted therein on shaft 63. As cable 58 leaves pulley 62, it is in position to pass downwardly through the mid portion of the web of the hollow track, as clearly shown in the various views.

The electrical conductors 2| and 22, previously described, pass through the hollow arm l8 and the fixture 6| to a point directly over the hollow portions of flanges 23 of the track, as clearly shown in Figs. 4, 5 and 7. These conductors are housed in the opposite ends of the track flange and are separated from each other and from the operating cable 58 by means of the U-shaped member 3 I, previously described. To comply with the code relating to such matters in some places, means is provided at spaced points along the track for supporting and insulating the conductors 2| and 22. One such supporting and insulating device is shown in Figs. 3 and 8. These are preferably provided in short track sections which are fitted between longer track sections by utilizing structures similar to that shown in Fig. 7. Such special sections will have a special U- shaped member 64 fitting between the track web portions 21 and supporting a bracket 65 having a down turned flange or lip 65a which extends through a suitable slotted opening in the member 64 and may be welded thereto, if desired. Riveted on the bracket 65 is a sheet of insulating material 65 having openings 61 at its opposite ends for receiving and holding the conductors 2| and 22. The conductors fit tightly in the opening 61 so that the weight of the conductors is supported as required by code regulations in some places. At the same time, the insulator member 66 maintains the conductors in a separated position.

Preferably, I form the hollow arm I8 and the fixture 6| according to the teachings of United States Patent No. 2,403,355, granted July 2, 1946, to Thayer B. Farrington, Wade T. Keller and Robert K. Farrington, to which reference may be had for greater detailed description, if desired. The arm I8 is shorter than the arm 6 shown in the last mentioned patent, but it is provided with a partition |8a in all respects similar to the partition ||Ba of the last mentioned patent. Likewise, the shrouding 68 around pulley 59 and the shrouding 59 around the pulley 62 may be arranged according to the teachings of the last mentioned patent, so as to provide a continuous separation throughout the arm |8 and the fixture 6| between the operating cable 58 and the electrical conductors 2| and 22. The bottom plate 65a is arranged with suitable openings, one corresponding to the hollow space between the walls 21 of the track web portion, and one corresponding to the hollow flange portion housed by the walls 28 and 29 of the track. These connections are so arranged that water and moisture cannot enter the top of the track, but instead, are protected by the fixture 6|. In this fashion, the electrical conductors 2| and 22 are provided with their own passageway continuously from the hood I! through arm l8, fixture 6| and track 23, clear to the base of the supporting structure l9. In like manner, the operating cable 58 is provided with its own separate passageway through the same parts to the base of the supporting structure.

At the base of the supporting structure, I have shown a small enclosure 19 which may house the electrical connections for conductors 2| and 22 and which need not be shown. It also houses support means forthe lower end of the operating cable 58. Any suitable connection at this point for holding the cable 53 and for providing means for attaching additional cable thereto when necessary to lower the lamp, would be satisfactory. In fact, the cable 58 might be wound upon a suitable reel at the bottom of track 23, if desired. I prefer, however, to utilize the construction shown in the copending application of Wade T. Keller and Thayer B. Farrington, Serial No. 514,058, filed December 13, 1943, wherein a link 33 attached to the bottom of the operating cable is normally held by a hook 34, as shown in said application, and connector means is provided for attaching an extra length of cable, when necessary, for lowering the lamp.

It is believed that the operation of the above described device will now be apparent. The lamps are normally held in raised position by means of the latch, not shown, and with the lamp energized by proper connection with the contacts 2B. When it is desired to lower the lamp for any purpose, cable 58 (or extra cable attached thereto, if desired) is given a slight pull to disconnect the type of latch referred to in my prior patent, after which the stem |5a is disconnected and the fixture l5 carrying the lamps may be lowered, guided by the rods 34 connected with the carriage 33 which is guided by the track 23. The lamps may thus be lowered to any point desired and returned to the upper latched and energized position when repairs or maintenance operations are completed. The carriage will ride smoothly on the track 23 being clamped thereto in two difierent planes, as described in connection with the rollers 41, 47 and 48. The carriage may be removed from the track, if desired, by spreading the rollers 41 and t8.

Throughout this description and the following description and in the attached claims, I have used the word cable to refer to the member 58. Those familiar with this art will appreciate that flexible chain, rope, or other flexible tension members may be used for this purpose. I therefore use the word cable throughout the specification and claims as a short term for any such flexible tension member.

In Figs. 9 to 14 inclusive, I have shown a modification of the device already described, and only sufiicient explanation will be given for a complete understanding of the differences between the first and second forms.

Inthis second form, the track i is of hollow box beam construction from top to bottom of the supporting structure 16, but is of diamond head construction, as clearly shown in Figs. 11 to 14 inclusive. The diamond head of the track 11 is connected by web portions 18 with flanges l9, turned outwardly to receive the bolts 88 which secure the flanges 79 to a plate I06 and to the supporting structure it. This, again, gives a water-tight'construction as in the first form. The vertically movable carriage in this case comprises a base plate 8| having upstanding bosses 82 in which are mounted rods 83' which are analogous to the rods 34 of the first mentioned form and carrying the fixture IE3 at their outer ends. Here again, roller means is provided for yielding motion toward and away from the supporting structure It. This roller 84 is clearly shown in Figs. 9 and 11 as having a V-shaped periphery complementary to the ridge 71a of the diamond head track. This roller is rotatably supported by a shaft 35, the opposite ends of which extend through bosses 86. integral with the plate 8!. These bosses have slotted openings 81 extending at. right angles to the track, and plungers 8S bear against the ends of shaft 85 pressed by springs 89 which are held in cups 99 threaded into the bosses 85. Thus, the roller 84 is yieldingly held by movement toward and. away from .the track.

Roller means is also provided permitting yielding movement. of'the carriage laterally of the track. I have shown an upper pair of such rollers 9| and a lower pair of rollers 92. They are all supported in a similar manner and therefore, one onlyneed be described; For instance, each roller 9! has a shaft 93 carried by an arm 94 which is. pivota ly mounted on the base plate at 95. A link 96 pivotally connected to arm 94' at the axis of shaft 93 extends inwardly toward a bracket 9.! on the base plate 8 I. The bracket has a flange 96a by which it is mounted on a pin 98 held in the bracket 91. A spring 99 held by nut Hi0 threaded on pin 98 holds the spring 99 in compression so that roller 9i may move laterally, as shown by the dot-dash position of Fig. 10, and the pair of rollers 9| are yieldingly held toward the track by the springs 99. Similar springs 99 urge the pair of rollers 92 yieldingly toward the track. As clearly shown in Figs. 9, 11 and 12, the rollers 9| and 92 have V-shaped peripheries which are complementary to the ridges 11b of the diamond head track. The flanges. Ma and 92a nearer th supporting structure here perform the same function as that performed by the flanges 41b and 48b of the firstdescribed modification. In other words, the carriage is held on the track by the action of roller 84 and the flanges Sid and 92a. 7

The track of this second modification is of continuousform, as in the case of the first modification, the trackb'eing'made in sections which have slip joint connections with each other, as illustrated in Figs. 9 and 13; Here, the web portions 118' have been cut away from the diamond headportions TI and bent inwardly by the thickness of the metal so that the upper end of one track. section is a sliding fit in the lower end .of' the section above it, and the surfaces of the track alongtwhich the rollers move are smooth and practically uninterrupted.

Here, as in the first described modification, means is provided at spaced'portions along the track, as shown in Fig. 14 for supporting and insulating the conductors 2| and 22 from each other. These are analogous to the conductors 2! and 22 previously described, and are connected to the energizing contacts 20 in. exactly the same manner. The construction in Fig. 14 comprises a bracket member l0! welded or otherwise: secured to the diamond head trackv portion 11-. A bracket [02 extends through a slotted opening in bracket [BI and is provided with. a down-turned lip H33 by which it is held. in place. Riveted or otherwise secured to the bracket I02 is a sheet of insulating material H14 provided with end openings I95 which grip the conductors 21' and 22. The cable 53' extends through the hollow portion of the track between the web portions 78,, and the brackets HII maintain a practical separation between the cable 58 and the conductors 2| and 22' throughout the length of the track.

The upper and lower ends of the track of. Figs. Ste 14. may be closed by the housings 6i and H3 respectively, as in the case of the first described modification, so that no moisture getsinside. the

track.

Itwill be noted that in the form of my device shown in Figs. 9 to 14 inclusive, the plate I06 secured to the supporting structure it has been given a special form. 'A central rib [96a is formed running vertically of the track and of just sufiicient width to fit between the webs 18 of the outer track member when the same. is properly assembled. Preferably, also, edge flanges I061) are turned upwardly at an angle to the plate [05, these flanges being so spaced: from the rib l-llfia that the flange 19 of the outer track member will nest between the rib 106a and one of the flanges 36b, as clearly shown in Fig. 12. This construction serves to strengthen the plate I and stifien thesame, while at the same time, providing accurate spacing for the webs l8 and flanges 19 of the outer track member;

Obviously, this: improvement could be applied to plate of the first described form, if desired.

In operation, the second modification, like: the first, provides free movement of the carriage up and down on the track controlled by cable 58" and the carriage may be removed from. the track by, spreading the pairs of rollers 91 and 92. This form of carriage will y-ieldingly ride' over any ice or corrosion, or uneven surfaces on the track without danger of the carriage leaving the track unintentionally.

What I claim is:

1. In combination, a supporting structure; an arm in elevated fixed relation to said structure, a lamp and carriage assembly dependent from said arm, a. cable passing over said arm and attached to said; assembly' for raising. and lowering the same, electrical means for energizing said lamp when elevated, a hollow track extending downwardly from said arm, said track having a web portion secured to said structure and an enlarged head portion outwardlyfrom said web portion, said head portion having a flat outer face and two nd faces at right angles to said outer face and inner face portions adjacent said end faces and substantially para lel to said outer face, roller means on said carriage engaging said outer face and yieldably movable toward and away from the same, a pair of rollers engaging said two end faces respectively and yieldingly mounted on said carriage for movement toward and away from the same, said last named rollers having flanges engaging said inner face portions, and said cable extending through the hollow of said track.

2. In combination, a supporting structure, an arm in elevated fixed relation to said structure, a lamp and carriage assembly dependent from said arm, a cable passing over said arm and attached to said assembly for raising and lowering the same, electrical means for energizing said lamp when elevated, a hollow track extending downwardly from said arm, said track having a web portion secured to said structure and an enlarged head portion outwardly from said web portion, said head portion being of generally diamond shape with a diagonal thereof parallel to said web portion, said head portion providing an outer ridge and two lateral ridges extending along said track, roller means on said carriage and having a V-shape groove engaging said outer ridge, said roller means having a yieldable mounting on said carriage for movement toward and away from said track, other rollers on said carriage and having V-shape grooves engaging said lateral ridges, said last named rollers having yieldable mountings on said carriage for movement toward and away from said track, and said cable extending through the hollow of said track.

3. In combination with a vertical support, a generally vertical track having a web portion secured to said support and having an enlarged head portion spaced from said support, a carriage adapted to traverse said track, roller means rotatably mounted on said carriage on axes parallel to said web portion and adapted to engage opposite sides of said head portion, said roller means having mounting parts arranged for movement of said roller means toward and away from said head portion and the plane of said web portion in a vertical plane at right angles to said web portion, said roller means yieldingly engaging said track, said roller means including roller parts engaged on the support side of said head portion, whereby to hold said carriage on said track, said movement of said roller means away from said head portion being sufficient to permit said last named roller parts laterally to clear said head portion.

4. A hollow track for the purpose described comprising a base structure, a sheet of metal bent to provide spaced web portions extending away from said base, each of said web portions having a flange bent outwardly therefrom adjacent said base and secured thereto, a head portion joining said web portions at the side of said track away from said base, said head portion being of generally diamond shape in section and having one of its diagonals parallel to said web portions, elongated flexible members extending one through said diamond head portion and one be- 10 tween said web portions, and partition means inside said tracl: separating said flexible members.

5. In combination with a vertical support, a generally vertical track having a web portion secured to said support and having an enlarged head portion spaced from said support, a carriage adapted to traverse said track, rotatable roller means on axes parallel to said web portion and on opposite lateral sides of said track, pivoted means on said carriage attached to said roller means and arranged for movement of said roller means generally in a vertical plane at right angles to said web portion toward and away from said head portion and from the plane of said web portion, yieldable means forcing said roller means into engagement with said track, said roller means including roller parts engaged on the support side of said head portion and holding said carriage on said track, said movement of said roller means away from said head portion being suiiicient to clear said roller parts from said head portion whereby said carriage may be removed from said track intermediate the ends of the latter.

6. In an organization comprising a supporting structure and electrical contacts in an elevated position on said structure and an electrical lamp mounted on a carriage and providing an assembly for movement between a lowered position for servicing and a raised position with said lamp in electrical communication with said contacts; the combination of a generally vertical hollow track having a web portion secured to said support and having an enlarged head portion spaced from said support, a carriage adapted to traverse said track, roller means rotatably mounted on said carriage on axes parallel to said web portion and adapted to engage opposite sides of said head portion, said roller means having mounting parts arranged for movement of said roller means toward and away from said head portion and the plane of said web portion in a vertical plane at right angles to said web portion, said roller means yieldingly engaging said track, said roller means including roller parts engaged on the support side of said head portion, whereby to hold said carriage on said track, said movement of said roller means away from said head portion being sufficient to permit said last named roller parts laterally to clear said head portion, a cable connected with said lamp and carriage assembly for raising and lowering said lamp, a pulley having a fixed mounting near the top of said track, said cable passing over said pulley and down through the hollow of said track, electrical conductors connected with said contacts for supplying energy thereto, said conductors extending from said contacts downwardly through the hollow of said track, and partition means inside of the hollow of said track separating said cable from said electrical conductors.

THAYER B. FARRINGTON.

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

UNITED STATES PATENTS Number Name Date 304,795 Butz Sept. 9, 1884 426,558 Dithridge Apr. 29, 1890 547,246 Drake Oct. 1, 1895 939,039 Lawrence Nov. 2, 1909 2,364,155 Martineau Dec. 5, 1944

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