US2687006A - Oscillating device activated by bimetallic element - Google Patents

Description

Aug. 24, 1954 F. M .LYoN's Filed Jan. 23, 1953 Patented Aug. 24, 1954 OSCILLATING DEVICE ACTIVATED BY BIMETALLIC ELEMENT Francis M. Lyons, Oceanside, N. Y., assignor to Einson-Freeman Co., Inc., Long Island City, 3 N. Y., a corporation of Delaware Application January 23, 1953, Serial No. 332,797

2 Claims. l

My present invention relates generally to motors, and has particular reference to a motive unit which generates oscillatory movements as the result of distortion of a bi-metallic element whose opposite surfaces are subjected to diiferent temperatures at successive intervals of time. Coordinately, my invention relates to oscillating devices in which the driving motor is of the character Y mentioned.

A general object of the inventionvis to improve 'i the efliciency of operation of a type of motive unit Ithat aifords a simplified and unusually inexpensive source of relatively minute motive power suitable for such uses as the animation of lightweight advertising displays, amusement devices, and similar items. The type of motor to which the invention relates derives its energy from an activator having a temperature appreciably different from the ambient temperature, the temperature diierential being utilized by means of the distortions of a bi-metallic element. This element is of the well-known type whose opposite surfaces have different temperature coefcients of expansion.

More particularly, the motor involves a resilient deflectable strip secured in association with the activator in such a way that one end `of the strip is anchored at a point of pivotal support while the strip extends in an adjacent relation to the activator. The strip includes as a part thereof a bi-metallic element adapted to distort upon subjection of itsopposite surfaces to the two different temperatures which are thus afforded. The

distortion is effective to initiate a swinging movement of the strip away from the activator, and it is during this swing that the bi-metallic element is afforded an opportunity to resume its normal shape, so that upon the completion of the return swing `the activator is again effective to distort the bi-metallic element and thereby repeat the operation.

ln the preferred embodiment of the invention, the source of temperature differential is an ordinary electric lamp of relatively low wattage. The heat generated by such a lamp is quite small but is nevertheless suicient for the present purpose. Where the motor is to be used for the animation of `advertising displays such as the cardboard devices commonly employed on store counters and in store windows, `the use of an electric lamp as the source of temperaturediflerential is of particular advantage because it can be utilized at the same time `to illuminate a selected part of 4the display.` It has been found, however, that the heat radiated by such `a lamp often warms up the surrounding region `to such an extent that the desired cooling-off of the loi-metallic element does not occur as quickly and reliably as it should. the smooth and eicient operation of the motor being correspondingly impaired. It is the object of the present invention to overcome this difficulty.

In accordance with my invention, an opaque heat-conductive shield is` interposed between the lamp and the bi-metallic element. The shield is heated by the lamp, and is so positioned that the lai-metallic element establishes contact with it, and is heated by it, `on each return swing. At the same time, the shield serves as a barrier to the transmission of radiant heat from the lamp -to the space in which the movements of the bi-metallic element take place.

The preferred way of achieving the objectives and advantages of the invention is illustrated in the accompanying drawing, in which- Figure l is an elevational view of the working parts of an illustrative oscillating device constructed in accordance with the present invention;

Figure 2 is a view taken at right angles to Figure l; and

Figure 3 is a perspective view of the opaque heat-conductive shield, shown by itself.

In the device shown, 20 represents an `ordinary electric lamp, having a relatively low wattage such as 6'0 watts or so, mounted in an ordinary lamp socket 2l. The socket may be secured in any suitable fashion to a supporting bracket 22 by means of which the lamp is mounted in appropriate association with a display or other oscillating device in connection with which it is to be used.

Secured to the bracket 22, by rivets 23 or any equivalent mounting expedient, is a resilient p deflectable strip which extends upwardly in adjacent relation to the lamp 20. As indicated and suggested in the aforementioned pending patent application of Brett S. Nichols, this strip may be constructed in Various ways. I have chosen to show the strip formed of a lower springy metallic element 24, an intermediate bi-metallic strip 25 of well-known distortable character, and an upper segment 26. These parts are secured together in any convenient manner and the element 25 is so shaped and positioned that it normally lies in close proximity to the lamp 20. The two metals of which the element 25 is formed are so arranged with respect to th-e lamp that the heat from the lamp will distort the elementto initiate a swinging movement of the entire deflectable strip away from the lamp.

For illustrative purposes I have shown an element 21, forming part of an advertising display device, secured to the free end of the segment 2B. The element 21 may be composed of a blank of cardboardaiorwthe like; .and mayhave anzappropriate cardboard loop- 28.?formed onuit. by means.

of which it is frictionally supported upon the free end of the segment 26. The element 21 consti;

tutesa "load which is so designed, in. relation toY the shape and disposition of -the deiiectablestrip on which it is mounted, .that an oscillation of substantial magnitude may be achieved..i.In ,the illus-v trated construction, the partsfare*intended to swing back and forth between the full-line 'and vthe dotted-line positions. More specifically;theiy center of gravity of the load is so located that when the bi-metallic element 25 is distorted undery the inuence of the lamp the center of gravity movesfpast fthe; :dead center Iv-'axis extending' ver"- ticallvthrough ".the'A point of .pivotal support;

In accordance with myinvention, there is4 in'- terposed between :the-` l'ampZil4 andthe biemetallic elementi a shield :which iszheat-conductive and which .is jheate'd by. ',the:.'lamp',;`fyet y'opaque to: `the radiantenergy emanating from'the lamp;` Where the lamp is of the ordinary shape shown, pro'- vid'ed with ia lament'and a substantially globular gla'ssriilamentenclosure,r the lshield can be conveniently formed'of a strip" of'metal'lii'v bent into the shape of ani.` inverted-U; Such shield issho-wn by' itselfinFigure 3..v It ismade vof a size'. and shapexpermitting. it .to be applied directly i to ther1a1mp,tras shown, land toretainiits position in direct.contactfwithlthe` lamp by-Lfrictional engagement..r Tcl-achieve Vthisiresult, it is satisfactory to impart to the strip 29 'a curvature'subl stantially 4equal 1to1 thatfof the lamp, and vto form the strip ofs'a Ametalfvvhich is slightly springy, the free ends of the' strip being `turnedwtoward each" other to a :slight degree-as shown... As a result, the shield 29 caribe@ applied endwis'e tosthe lamp bulb andwill .remain inthe-position shown Vas. a result of .its inherent resilience'.-

When the lamp is turned on, the bulb becomes heated. in well-known.-vfashion.y This4 heat is transferred tothe metal shield .29,'and quickly brings' about a .distortionI of ythe bi-metallic element 25.. The..parts..areso designed that the.

distortion .iseifective to move the center of .gravity past the :dead center axis,..and..as..tl1is happens the weightof.- the1..load..amplifies .the 4swinging movement that has beninitiated.. Depending upon the size, shape, resilience, and other characteristics of the deflectable strip and of the load itself, the swinging movements will reachlan` extreme .position shown indotted lines at which4 thestress upon theelement 24. issuicientto impartv a ,returning...impulse.. Affecting. this .result is theretarding action of the additionalspring 30 which'may be.` provided near thepivotal support, as shown. As the partstend to resume their initial positions, the center of. gravity returns` across the deadcenter axis and becomes ede'ctive to' complete the return swing., In the meantime, the 'bi-metallic elem'ent has had an opportunity vtov return', at least partly, to its initial undistorted shape, andthe process is repeated as :theelement 25 comes again into contact with the he'atedl shield 29.

Because ofthe fact .that the shield 29 serves as a barrierto; the transmission of radiant heat from the Ylamp to the space in which the movethe air in this ambient region does not become overheated, and is always cool enough to permit the bi-metallic element 25 to cool off to the desired degree during the time that it is out of contact with the heated piece of metal 29. Because of this, the operation of the motor is uniform, emcientgfand reliable at .all times;

The motor. is unusually.;smallinisize. and has a minimum of moving parts, requiring no lubri- "cation or other attention. It will operate almost which-the oscillatory movements Iof .the-strip. maybe transmitted .to .a relatively` remote-point.. The. particular..design of the. deflectable. strip.

of the. bi-Inetallic-.element formingpart. 1of.. it, and of extraneous springs optionallyI employed,

such vas the spring. shownatBO', will depend uponA- the .nature andcharacte'ristics vof the oscillation.

that may be desired in any particular case.

In .general itY will be understood that Ythose skilled in the art will be4 enabled-to modifyithe. details herein described fand depicted without.

necessarily `departing from the. spirit and vscope ofthe. invention.. It' is intended, therefore, vthat these detailsbe considered as illustrative, not in a Alimiting sense,

Having thus described my inventionand illustrated its use what I `claim as new and. desire to' secureby. Letters Patent is:

l. An oscillating .device of the kind described,"

comprising anele'ctriclampga resilient deflect-l able` strip secured at its'lower end to a point of pivotal .support and extending upward vtherefrom in adjacent' "relation"` to said lamp, said f strip `including as. a part thereof a pi-metallic element so shaped and .positioned that the heat ofthe lamp 'is eiective to distort it and by such distortion to initiate a "swinging movement of the strip away from' the lamp, a lo'ad'carriedl by. the free end of the strip and having its center-V of gravityfso located that as the strip moves under the inuence of said distortion the center` of .gravityis carried past: the dead centeraxis. whichextends vertically. throughA said point of support; thereby amplifying the swinging movement away .from the lamp, and an opaque heatconductive' shield heated by said lamp `and xedlyl positioned.. between said lamp and said'bimetallic elementso that the latter establishes contact with and is heated by said shield on each return swing, said shield serving as a barrier to the transmission of radiant heat from the lamp to the space within which the movements of the loi-metallic. element take place.

2'.. Anoscillating device of the kind described,

comprising an electricklamp includingfa 'substantially vglobular' Afilament enclosure,l a resilient deflectable strip 'secured at its lower end to a point of pivotal support and extending up-` wardv therefrom; in` adjacent relation to saidv lamp, said strip including as 'a partv thereof a loi-metallic element sol shaped andy positioned that the heat'of the lamp is effective vto Idi'stortit and by suchdistortion toinitiate a swingingv movement -of the strip away from the lamp, a

5 load carried by the free end of the strip and having its center of gravity so located that as the strip moves under the iniiuence of said distortion the center of gravity is carried past the dead center axis which extends vertically through said point of support, thereby amplifying the swinging movement away from the` lamp, and a heat-conductive piece of metal` heated by said lamp and so positioned between said lamp and said bi-metallic element that the latter establishes contact with and is heated by said metal on each return swing, said metal being a U-shaped piece frictionally engaging around the globular lamp filament enclosure and serving as a barrier to the transmission of radiant heat from the lamp to the space within which the movements of the bi-metallic element take place.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,382,928 Whitney et a1 Aug. 14, 1945 2,561,217 Muir July 17, 1951

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