Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.

Patents

  1. Advanced Patent Search
Publication numberUS2538655 A
Publication typeGrant
Publication dateJan 16, 1951
Filing dateMay 5, 1947
Priority dateMay 5, 1947
Publication numberUS 2538655 A, US 2538655A, US-A-2538655, US2538655 A, US2538655A
InventorsPreston Ralph G
Original AssigneePreston Ralph G
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Loader's extensible light fixture
US 2538655 A
Abstract  available in
Images(1)
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)

LOADER'S EXTENSIBLE LIGHT FIXTURE Filed May 5, 1947 9 /0 4 l /4 I INVENTOR.

47 M Fa 0% 6' Paar/an Z ATTORNEYS Patented Jan. 16, i951 UNITED S TAT ES PATENT '0 FF! CE 7 2,538,655 Lonnnn s 'EXTENSIBLE "LIGHT FIXTURE Ralph GrP'reston, Chicago, Ill.

Application May 5, 1941,Serial No.745;962

(cram-52) 9 Claims. 1

' This invention pertains to a device for proyiding good light where desiredat freight, express and transfer terminals, in trucks and box cars, for the loading'and unloading of freight, express and mail.

' -It is an object of the invention to provide a device which 'will enable alight to be installed as a permanent fixture where it will readily be accessible for use-at an times.

A further object is {the provision of a lighting device which can be placed inside of car door openings and in the ends of trucks without the use of dangling cords or special hangersso that if the device is forgotten and the freight car -or truck moves from the loading platform, the :light will automatically become disengaged and return to its original position without damage to the light.

These androther objects are attained by the novel construction and arrangement of parts hereinafter described and illustrated by the :ac-

companying drawings, .forming a part hereof,

and .in which:

Fig. 1 is an :elevational view :showing an :ap- I ZDlication of the :lighting :device.

- .Fig. 2 is an elevational view, partly inisecti'on, so? :a device embodying the invention.

.Fig. '3 is a sectional view taken on the :line 3--3 of Fig. 2. j

Fig. 4 :is .a sectional view taken :on the linefll of Fig. "2.

.Fig. v5 is a View showing the device man outof-ithe-way position.

Referring to Fig. .1 of the drawings, it will be seen that the entire unit is suspended from the canopy or roof [8 of :a loading dock byxmeans of a cable or chain or'swivel joint it connected with the apex of the hanger, -U -rod, or stirrup Th hanger l is attached to apiston comprising :a-ba cking plate or guide ring 5 and ,adowriwardiy facing cup leather -6. A tension coilspring Fl :has .one end secured to the piston 5, 16, while the other end thereof is secured to a similar piston comprising a backing plate 9 and an upw'ardly iacing cup leather 8. Thepiston assembly 8,:j9, is secured to a central tube :2 which extendsithrough .a hollow cylindrical casing 3 which is provided with ta cap 22, the tube 2, as well :as the hanger 4, extending through a suitable opening2 I formed in the cap 22. A coil spring H) is compressed between the piston assembly 8, 9 and the lower end of the tubular-casing 3.

Anarm l 3 is pivotallyconnectedwith the :lower end of the tube 2 'by means of a hinge -l2 :and L itsouter ;end .has a lamp socket andreflectin'g shield to for an incandescent lamp l5. Current is supplied to the lamp through a two :conducltor cord 4 9 which extends through the tube 2 around or through the hinge l2 and through the arm 4'3 to the lamp socket.

:A bracket 1 I of generally triangular shape has its lower edge secured to the arm 43 and at its upper end has a latch projection ll which when the parts are in normal position as shown in Fig. 2, projects into a-sui'table opening to formed the lower end Wall of the casings.

The tension spring i'l has suhicient strength :to slightly more than sustain the entire weight of the unit while the compression spring to has sufficient strength to maintain the latch :portion it; of the bracket ll within the opening 20, as

shown in Fig. 2, under all normal conditions of :use of the unit. The distance from the top end of the tubular casing 13 to the piston assembly 5, 6, when the light is hanging free, will .be approxinrnatelytwo and one-:halflto three times the length :or" the spring 3 when the latter isstressed merely :suificiently to sustain the weight of the fixture.

' This distance .to which the spring .1 may .be

.As shown in Fig. l, the tube 2 and the casing 3 are pulled downwardly against the tension of the spring 7, and the arm 13 is hooked beneath the door i'rame or against the'ceiling of a truck, th'e spring 1' retaining the fixture in this position. This places the lamp l5 inside the freight car or truck at the top :of the opening "through which "the truck or car is being loaded or unloaded, so

that it .does not interfere with the loading -'or unloading. operations and provides adequate illuminationJfor-theinterior of the 'vehicle.

Upon completing the loading or unloading operation, the tube 2 and casing 3 may .be pulled downwardly slightly, :to disengage the arm i=3 from contact with the vehicle, and then released. Thesspace between-the cup-leathers E and ii forms :a dashpot chamber so that :the return of the casing 3 and tube 2 to the normal position of Fig. 2 will :take place at :a controlled rate so as -.to avoid the possibility of damage to the lamp 1 5 and otherparts .from slack.

3 Should the fixture inadvertently be left in the position shown in Fig. 1, and the vehicle driven ofi, it would likely result in substantial damage to the fixture were it not for the detent latching means provided by the interengagement of the portion ll-of the latching bracket ll and the opening at the lower end of the casing 3. The spring in is compressed between the lower. end of the casing 3 and the backing plate 9 of the piston assembly 8, 9, which, it will be recalled, is rigidly secured to the tube2. Thus the spring normally maintains the latch in latching position with the arm I3 generally perpendicular to the tube 2. However, when, under the conditions named, the arm i3 is pulled away from the hanger 4 a sufficient distance such that the backing plate 5 engages the upper end cap 22, a sufiicient force may be exerted to compress spring IE! and permit relative movement of the tube 2 and casing 3 to withdraw the latching part I! or the latching bracket l I from the opening in the lower end of the tubular casing 3, so that the arm 13 may swing to the position shown in Fig. 5, and thus free itself from engagement with the vehicle. When this occurs,'the piston 5, ,6, together with the casing 3, operates as a dashpot to slow down the speed at which the spring 7 contracts.

The latch may readily be reset merely by pulling the bracket and tube 2 downwardly relative to the casing so as to compress the spring [0 sufficiently to reinsert the end portion I! of the bracket within the opening at the lower end of the casing 3.

It will be seen that there has been provided a light unit which is maintained above the work without the use of special hangers or attachments. The light unit is automatically returned .from whereverit is placed if pulled beyond a predetermined length, and requires no dangling cords, the unit being a permanent fixture. Plugs and receptacles are eliminated and the wiring ing having substantially closed ends and having centrally disposed openings in said ends, an

inverted U-shaped hanger extending into the upper end of the casing, an upper piston carried by the inner end of the hanger and positioned in the casing, an electric cord carrying tube extending longitudinally through the casing and the piston and slidably-positioned in the centrally disposed openings in the ends of the casing, a lower piston fixedly mounted on said cord carrying tube and spaced from the said upper piston, a tension spring in the casing positioned between the said piston and having the ends thereof connected to the pistons, respectively, a compression spring positioned between the lower piston and lower end of the casing, a light bulb carrying arm pivotally connected to the lower end of the said light cord carrying tube, and a projection on the light bulb carrying arm positioned for insertion into the opening in the lower end of the casing for temporarily retaining the light bulb carrying arm in an outwardly extended position. 2. In an extensible light bracket, the combination which comprises an elongated tubular casing having substantially closed ends and having centrally disposed openings in said ends, an inverted U-shaped hanger extending into the upper end of the casing, an upper piston carried by the inner end of the hanger and positioned in the casing, an electric cord carrying tube extended longitudinally through the casing and piston and slidably positioned in the centrally disposed openings in the ends of the casing, a lower piston fixedly mounted on said cord carrying tube and spaced from the said upper piston, a tension spring in the casing positioned between the said pistons and having the ends thereof connected to the pistons, respectively, a compression spring positioned between the lower piston and lower end of the casing, a light bulb carrying arm pivotally connected to the lower end of the said light cord carrying tube, and a bracket carried by the said light :bulb carrying arm, positioned to engage the side surface of the cord carrying tube and having a projection on the end thereof positioned to extend into the opening in the lower end of the casing for temporarily retaining the said light bulb carrying arm in an outwardly extended position.

3. In a loaders light fixture, the combination of a pair of'relatively telescoping members, a spring holding said members in telescoped position, a lamp-supporting arm pivotally secured to one of saidmembers, a detent means for holding said arm perpendicular to'the direction of telescoping movement of the members, said detent means including means yieldable to release the arm upon application to the arm of a predetermined force in the general direction of the telescoping movement of said members.

4. A lamp hanger, comprising a pair of telescopically movable members, a lamp-supporting arm pivotally secured to one of said members, means to hold said arm in a plane normal to the direction of telescopic movement of said telescopically movable members including locking members movable relative to each other to releas the arm for pivotal movement from said normal position, yieldable means to urge said telescopically movable members to contracted position, and means yieldable in response'to the application of a predetermined force to the arm in the direction of extension of said telescopically movablemembers to release said locking members for relative movement to inoperative position.

5. In a loaders light fixture, the combination of a pair of relatively telescoping members, means forming a dashpot between said members to damp telescopic movement thereof, a 'spring'holding said members in telescoped position, a lamp supporting arm pivotallysecured to one of said members, and means for holding said arm substantially perpendicular to the direction of telescoping movement of said telescoping members including releasable locking means and means yieldable upon the application to the arm of a predetermined force in the general direction of telescoping movement of said members to release said locking means.

6. In a loaders light fixture, the combination of a pair of relatively telescoping members,

lamp supporting arm pivotally secured to one of said members, and means for holding said arm substantially perpendicular to the direction of telescoping movement of said telescoping members including releasable locking means and means yieldable upon the application to the arm of a predetermined force in the general direction of telescoping movement of said members to release said locking means.

7. A loaders light fixture comprising, an

elongated fixture supporting member, a piston secured to the lower end of the member, an.

elongated tube extending slidably through the piston and forming a conduit for electrical conductors,-a tubular casing enclosing the piston and forming a dashpot chamber for the piston, a spring in the casing biasing the tube upward relative to the piston, a lamp carrying arm pivotally connected with the lower end of the tube, latching means on the lower end of the casing engageable with the arm normally to hold the arm generally perpendicular to the tube and releasable by downward movement of the tube relative to the casing to permit the arm to swing to a position in general alignment with the tube, a second spring biasing the tube upward relative to the casing, and means on the casing limiting downward movement of the casing relative to the piston, whereby the arm is released from the latching means by extreme extension of the tube relative to the piston.

8. A loaders light fixture comprising an elongated fixture supporting member, a piston secured to the lower end of the member, an elongated tube slidably extending through the piston and forming a conduit for electrical conductors, a tubular casing enclosing the piston and forming a dashpot chamberfor the piston,

a spring in the casing biasing the tube upward relative to the piston, a lamp carrying arm 'pivotally connected with the lower end of the tube, cooperating means on said arm and at the lower end of the casing normally holding the arm generally perpendicular to the tube, and means yieldable in response to the application of a predetermined downward force on the arm to release the cooperating means.

9. A loaders light fixture comprising, an upper member having a hanger for supporting the fixture, a lower member, means to confine said members for relative telescoping movement including means forming a dashpot between the members, means including a spring urging the members toward each other, a lamp carrying arm pivotally connected with the lower member, latching means normally holding the arm generally perpendicular to the lower member and releasable to permit the arm to swing to a position in general alignment with the lower member, and means operable by extreme outward movement of the members to release the latching means.

RALPH G. PRESTO-N.

REFERENCES CITED The'following references are of record inthe file of this patent:

UNITED STATES PATENTS Number Name Date 182,089 Warner Sept. 12, 1876 500,517 Thompson June 27, 1893 1,622,057 Senter Mar. 22, 1927 1,639,336 Gannett Aug. 16, 1927 1,802,589 Thompson Apr. 28, 1931 2,265,792 Allen l Dec. 9, 1941

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US182089 *May 6, 1876Sep 12, 1876 Improvement in suspending chandeliers
US500517 *May 24, 1892Jun 27, 1893 William d
US1622057 *May 19, 1926Mar 22, 1927Carl U SenterPortable wall bracket
US1639336 *Jun 27, 1924Aug 16, 1927Gannett Homer ELamp mounting
US1802589 *Oct 24, 1927Apr 28, 1931Thompson Allison JShock absorber for lighting units
US2265792 *Oct 26, 1940Dec 9, 1941Ward W AllenLight bracket
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2670428 *May 10, 1951Feb 23, 1954Pyle National CoLoading light
US2709561 *Dec 23, 1952May 31, 1955Shelley Robert JPermanently lubricated spring cabinet tray elevator
US2716701 *Dec 6, 1949Aug 30, 1955Rodger F BeckerSeparable suspension device for an extension lamp
US2743353 *Dec 27, 1951Apr 24, 1956American Can CoPortable light attachable to freight cars
US2796515 *Nov 7, 1955Jun 18, 1957George M WaskleExtensible vehicle lamp
US3227869 *Apr 1, 1963Jan 4, 1966Elastic Stop Nut CorpWarning light casing construction
US3239829 *Aug 21, 1962Mar 8, 1966Cline Ray VIrrigation signal lamp
US3482087 *Feb 20, 1967Dec 2, 1969Gen ElectricLuminaire
US3736417 *Jul 27, 1970May 29, 1973C WilliamsLighting fixture
US3742209 *May 28, 1971Jun 26, 1973C WilliamsLighting fixture
US4395749 *May 6, 1981Jul 26, 1983Poveromo George ABoat trailer lamp and license plate support
US5709458 *Aug 14, 1996Jan 20, 1998Metz; DonaldDock light
US7533431 *Jul 11, 2006May 19, 2009Rite-Hite Holding CorporationIlluminating dock leveler
US9255699Feb 8, 2013Feb 9, 2016Rite-Hite Holding CorporationMotion sensing dock lighting systems
US20060279860 *Jun 8, 2006Dec 14, 2006Doiron Anthony ETrailer Guide
US20080010757 *Jul 11, 2006Jan 17, 2008Al HochsteinIlluminating dock leveler
Classifications
U.S. Classification362/427, D26/29, 248/284.1, 248/592, 362/419
International ClassificationB60Q3/06, F21V21/26
Cooperative ClassificationB60Q3/06, F21V21/26
European ClassificationB60Q3/06, F21V21/26