US2388474A - Inspection light - Google Patents

Description

Nov. 6,1945. 6. ELLIS INSPECTION LIGHT Filed Jan. 7, 1943 INVENTOR Greer Ellis BY Fl ATTORNEYS Patented Nov. 6, 1945 INSPECTION LIGHT Greer Ellis, Chicago, Ill

bymelne alaslignor, ligaments, to Joseph L. Switzerand Robert 0. Switzer- Application January 1, 194:, Serial at. 411,545

2Clalml.

This invention relates to inspection lights and mountings therefor. More particularly, this invention relates to an ultraviolet inspection light and a mounting which permits the convenient use of the light either as a fixed and focused 5 light or as a portable spot-light.

, Inspection lights made according to this invention are especially useful in inspecting articles according to the methods disclosed in U. 3. Patents Nos. 2,259,400 and 2,267,999. As these methi ods are usually practiced, articles carrying fluorescent indications of flaws and defects are inspected under filtered ultraviolet light in inspection booths which are substantially closed in order to shut out visible light. As may be apprel ciated, the working conditions in such booths are not the best. The difiiculty of ventilating such closed booths makes it desirable to use as few inspection lights as possible, not only for economy in equipment, but also to reduce heat costly delay and confusion is almost certain to arise in production inspection.

In certain types of fluorescent inspection, as where both large and small objects are'examined, it is desirable to have a fixed light to permit small objects to be picked up in the hands for examination and a portable spot-light to permit large, heavy objects to be examined. In order to avoid the use of two lamps, use of a demountable spotlight was indicated. Demountable spot-lights available to the prior art, usually mounted by means of a spring or screw clamp, were very unsatisfactory; two hands were required to mount and demount the lights if a screw clamp was employed or if the spring clamp was strong enough to hold the light rigid; spring clamp lights also tended to fatigue the operator's hands; remounting the lights was difficult and confusing in the absence of visible light; if the clamp was fixed to the light, as was usually the case, the clamp tended to become tangled with the light cord.

By far the greatest objection to demountable lights, however, was that entirely too much time was required to refocus the light after it had been remounted. Table lamps on portable stands were not satisfactory; the lamps were clumsy, requiring two hands for manipulation, and also cluttered up the inspection table. As a result of the foregoing disadvantages, there was a tendency to use both a fixed light and a portable light,

both of which were constantly operated to avoid time lost in waiting for the light to warm up and in waiting for the light to cool down before restarting the light. The disadvantages of using two constantly operating lights were less than the disadvantages of the demountable portable lights known to the prior art.

It is the object of this invention to provide an ultraviolet inspection light and mounting therefor which will permit the convenient use of the light both as a fixed inspection light and as a portable spot-light. More specifically. it is the object of this invention to provide an inspection light which may be'instantly, and with one hand, demounted or remounted and which, when remounted, will be automatically and securely refocused. It is also an object of this invention to provide an inspection light which may be conveniently manipulated without entangling the light cord.

It is a further object of this invention to provide an inspection light in which the light bulb support will insure that the bulb is in proper focus and, at the same time, protect the bulb from sudden shocks.

Other and still further objects and advantages of my invention will be apparent from the following specification, claims, and drawing, in which:

Fig. l is an elevation, partly in section and partly diagrammatic, of an inspection light and mounting made according to my invention.

F18. 2 is a developed plan, partly in section, taken along the line 2-2 of Fig. 1.

The embodiment of my inspection light and mounting disclosed in the drawing employs a universal mounting II and a light 30, the mounting ill permitting the light ill to be aimed or focused at substantially any spot within the booth in which the unit is employed. The mounting I 0 is comprised of a bracket ll, fixed to the wall of the booth, which bracket carries a bracket arm I! pivotal on a vertical axis. The bracket arm I: may be locked in any position to which it may be swung by the locking thumb bolt l3, the lower vertical pivot for the bracket arm. The bracket arm I! terminates in a boss is having a vertical serrated surface which mates with the similarly serrated surface of the boss IS on the stud arm It. The mating serrated surfaces of the bosses I4 and it are held in locking engagement by the thumb bolt II which, when the bosses are disengaged, serves as a horizontal pivot permitting the stud arm It to swing in a vertical lane. The stud arm l6 terminates in a cylindrical stud sleeve II in which the stud II is received.

' and comprises a lower cylindrical staff portion 2| and an upper, square, index stall portion 22, the two staff portions being separated by a central flange 2!. The cylindrical staff portion 2! is preferably shorter than the stud sleeve I8 and the end of the stall portion 2| is tapped to receive the thumb bolt 24, which carries a suitable lock washer. As is apparent from the drawing, the cylindrical staff portion 2| is rotatable in the sleeve l8 and may be locked in any rotated position by tightening on the thumb bolt 24 to lock the sleeve between the flange 23 and the lock washer carried by the bolt.

The light II comprises an open-ended shell 3|, preferably of a streamlined shape. Within the apex or closed end of the shell I I, a short axiallyextending ring fitting 22 is secured. The fitting 32 supports a socket is in which a mercury-arc bulb and reflector unit 34 is carried, the bulb unit 34 being provided with a suitable filter I4) to filter out visible light and pass ultraviolet light emitted by the bulb unit 24. The open end of the shell II is covered by a suitably secured, removable hood II, the forward end of the hood 5 being provided with an open grille 3i, comprised of one or more suitably supported concentric rings in this instance. A plurality of axiallyextending centering spring leaves 31, preferably three, are secured at one end to the inner wall of the hood. For the major portion of their length these centering leaves 31 are spaced inwardly of the hood wall and are centered about the longitudinal axis of the hood and shell, the free ends of the centering leaves being slightly outwardly flared so that the leaves will engage, and be slightly sprung by, the rim of the bulb unit 34. A plurality of ventilating openings 38 are located adjacent the apex of the shell 3| to permit the passage of cooling currents of air around the bulb unit 34, the open grille 38 and the openings 38 constituting the necessary entrance and exit for such currents. A lead-in opening 39 is also provided near the apex of the shell 3|.

The shell 3| is supported by a hollow pistolgrip handle 4| secured to the shell 3| by bolts or other suitable means, the handle being positioned upon the shell so that the light as a whole will be conveniently balanced when held in' the hand. The shell 3| may be spaced from the handle 40 by resilient washers 4|, as shown. Although the handle 40 is largely hollow, the butt of the handle is made solid to provide walls for a square index socket 42 in which the index staff 22 of the stud 20 will be slidably received. A light-cord passage 43 is also provided through the butt of the handle 40 forwardly of the index socket 42. The back of the handle is preferably extended to serve as a guard over the lead-in opening a.

Electric current for operating the light is obtained from any suitable source through the autotransformer SI and spring reel 52 mounted in or on the wall of the booth. From the spring reel I2, the light-cord ill is led up through the passage 43 in the butt of the handle 40, through the lead-in opening 38 in the shell 3| and thence to the socket 32 through the ring fitting 32.

To use the above described embodiment of my invention as a fixed light. the light is focused by means of the universal mounting Ill. Focusing is usually accomplished by swinging the bracket arm l2 in the bracket ll until the vertical plane a,ssa,474

point on the inspection table. with the thumb bolt l'l loosened, the stud arm I6 is pivoted until the lamp is focused on the desired point; the thumb bolts l2 and H are then tightened to lock the mounting in its adjusted position. The stud 20 is usually locked in the sleeve II. By loosening the thumb bolt 24, however, it is possible to obtain a sort of vernier adjustment between the fixed angles of adjustment permitted by the serrations of the bosses l4 and II. By making the stud 20 pivotal in the sleeve II, it is possible to swing the mounting ll close to the wall on which it is mounted. It is also possible to focus the light on a point immediately beneath the mounting by swinsina the stud arm I! to a substantially vertical position and then reversing the stud 2| in the sleeve l8.

To use my light as a portable spot-light, the handle 40 is grasped and the light 30 is simply lifted off the stud 20. Such additional lengths of light-cord ill as may be required will be paid off by the spring reel 52, which is preferably of the ratchet type so that there will be no pull on the cord III to distract the operator while manipulating the light. The well-balanced shell on the pistol-grip handle obviously allows the light to be easily manipulated with one hand, leaving the operator's other hand free at all times, even during demounting and remounting. Because the cord is is led in through the butt of the handle and because there is no protuberance below the handle in this preferred embodiment, the possibility of the cord's becoming entangled is reduced to a minimum. Although rough usage of the light is not recommended, the single fitting 32, which is slightly resilient, and the resilient centering leaves 31 protect the bulb unit 34 against sudden shocks which might otherwise crack the electrodes within the bulb. The resilient washers 4| also absorb some physical shocks.

To remount the light, the handle 40 is simply placed on the stud 20 so that the index staff 22 slides into the index socket 42. Thus, the light is automatically refocused when remounted. If the spring reel is of the ratchet typ a slight pull on the cord 50 will release the pawl and cause the reel to take up excess cord. The capacity of the reel is preferably such that a slight amount of slack will always be provided to permit the handle. to be lifted off the index staff 22. By having the cord lead-in passage 43 forward of the index socket 42, there is no tendency for the cord ill to become entangled with the mounting it.

While the foregoing is a description of a preferred embodiment of my invention, it should be apparent that my invention may be modified by those skilled in the art. For example, the switch for the lighting circuit -is indicated in the drawing as being located on the line side of the transformer II; the type and location of this switch is obviously a matter of choice. For instance, the lighting switch could be a toggle switch located forwardly of the pistol-grip handle 40 to be worked by the operator's trigger-finger; such a switch permitting instant control of the light would afford no advantage in the embodiment disclosed because mercury vapor lights require several minutes to warm up. Also, the close sliding fit between the index stafl 22 and the index socket 42, as shown, usually provides an amply secure connection between the mounting II and the light 30; to obtain a more secure connection, the inof the bracket arm is aligned with the desired dexing staff 22 may be provided with a spring aseaua currencewould be quite remote in actual practice;

in order to eliminate this remote possibility, the

indexing staff and socket may be made with an unbalanced or irregular section, as, for example, by providing a flat on an otherwise circular section; any non-circular cross-section on a projection slidably received in a mating socket will usually sufllce, the term non-circular cross-section" being understood to include the cross-section of a plurality of pins, whose total cross-section isnon-circular, as well as the cross-section of a single projection or stud. Further, the indexing stafl 22' and/or the socket 42 may be tapered to aid in remounting the light. The specific universal mounting I0 is preferred because the several locldng thumb-bolts are readily accessible though not likely to interfere with the mounting or demounting of the light; obviously, within the scope of this invention, other universal mountings may be employed.

While this disclosure has been directed to the use of my light as a source of filtered ultraviolet light, my light may also be used as a source of visible light. It should be apparent, therefore,

that my invention is not limited to the specific use or embodiment disclosed but by the appended claims.

What is claimed is: 1. A- demountable light comprising a bracket, a bracket arm. a first pivot connecting said bracketand bracket arm, means for locking said bracket arm with respect to said bracket, a stud arm, a second pivot connecting said stud'arm to said bracket arm, said first and second pivots lying in perpendicular planes to permit said stud arm to be moved substantially universally with respect to said bracket, means for locking said stud arm with respect to said bracket arm, a sleeve in said stud arm, a stud rotatably received in said sleeve, an index stafl portion of said stud extending from said sleeve, said stafl portion having a non-circular cross-section, means for locking said stud in said sleeve, an electric inspection light, a handle secured to said inspection light, said handle having in the butt thereof an index socket in which said index staff is slidably received, said socket having a non-circular cross-section mating with said index staff, said handle having a light-cord passage therethrough and normally located beyond said stud arm, and a light-cord passing through said passage to electrically connect said inspection light to a source of electrical energy.

2. In a mounting for a demountable light, a bracket, a sleeve, means connecting said bracket and said sleeve permitting universal angular movement of said sleeve with respect to said bracket, means to lock said sleeve with respect to said bracket, a stud rotatable in said sleeve and receivable in either end thereof, means to lock said stud in said sleeve, and a stall portion of said stud extending beyond said sleeve, said stafl portion having at least one non-circular cross-section. GREER. ELLIS.

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