US2862529A

US2862529A - Apparatus for feeding filamentary particles

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Publication number: US2862529A
Application number: US562442A
Authority: US
Inventors: Rosenblatt Alexander; Donald H Pfefferle
Original assignee: Sylvania Electric Products Inc
Current assignee: GTE Sylvania Inc
Priority date: 1956-01-31
Filing date: 1956-01-31
Publication date: 1958-12-02
Anticipated expiration: 1975-12-02

Description

A. ROSENBLATT ETAL 2,862,529

APPARATUS FOR FEEDING FILAMENTARY PARTICLES Filed Jan. 51, 1956 5 Sheets-Sheet 1 INVENTORS ALEM/VDEK AflSf/VEZATT DONALD H PFEFFERLE Dec. 2, 1958 A. ROSENBLATT ET AL' 2,862,529

APPARATUS FOR FEEDING FILAMENTARY PARTICLES 3 Sheets-Sheet 2 Filed Jan. 31, 1956' INVENTORS ALfXANDEl? R05 E/VBL47 7 [MN/4L0 H PFEFFERLE Dec. 2, 1958 A. ROSENBLQTT ET AL APPARATUS FOR FEEDING FILAMENTARY PARTICLES 3 Sheets-Sheet 5 Filed Jan. 51, 1956 INVENTORS ALEXA/V05? RflJE/VELATT DONALD H. PFZFFERLE @464 ATTORNEY United States Patent 2,862,529 MPMtA-TUS FQR FEEDING FILAMEN-TARY "PARTIQLES .AlexanderrRosenblatt and Donald Pfefierle, Williams- ;port, ,P,a assignors tosylvania Electric ;Products Inc., .SalemQMaea, a. corporation. (ifs-Massachusetts This invention elates-,toithe-manufacture of fiashilamps andsmore particularly to theintroductionnofaicombustible 1 1 1 3 int mfl-ash mpzbul .ln the manufacture of hash :lamps, filamentary par- ;ticles of a combustible metal material, -;such as .shredded ,afoiltforz-example are introduced into the; lamp bulb. .The

;sh.re,dde.d :foil may :be formed by feeding a .sheet of the .eomhustible ;metal1material :into a suitable .cutting .ma- -:.chine, :sueh as :the .maehiue shown .in 1U. S. Patent j2;69.9;83;1;for;example. T;The shredded foilzprodncedby zthe :cutting :machinezis then ffedQto the lamp :bulb. .A

method for introducing shredded foil into lamp bulbs disclosedinethe no pcndingyapplication of Bennett et al, Serial No. 1192;224nfi1e32l:Qcotb.er;26, 195.0?11OW .U.:S. Patent-2,272,103.

An. object 10f it-his invention zisrto; introducexfilamentary particles l-into iflashtlamp .bulbs.

Ano her-cobieet of thisiinventionis to provideapparatus gfQI. Efeeding filamentary :particles jinto flash damp :bulbs.

Affurther ;obj,ectiis:to-;p1:ovide, apparatus for :automatipally g feeding filamentary particles to lamp 'iblilbs married :to:-;loading.-position by.a. conveyor.

These and otherobjects, advantages and featuresare ;attained,,in accordancewith the;pri-nciples ofonriinvention, by reciprocating 'a :nozzle, preferably rotatable, into .andnut: of;-a:l.ampzbulb carried :by an indexing conveyor. The reciprocatingestroke :of the nozzle is synchr.onized -,with :the :indexing ;of the bulb-carrying conveyorl'so that tthe forward stroke -.:of IhCTIlOZZIG ;oc.curs:after :a :bulb :has been; carried :hy the;conv.eyor into register .with: the: nozzle,

and-the return stroke occurs aftera charge of filamentary partiales,:.sueh as shredded foil, forexample, has :been deliveredito the bulb :through the nozzle. A pneumatic vsystem employed-toicarrya charge of shreddedifoil from .a supply thereof :to the nozzle is :actuated intermittently :and is synchronized withrt-he reciprocationof the nozzle to provide ;for the :delivery of a charge .of shredded foil .to the;no z-zle when thetnozzlegis-in .deliveryposition with vrespect to' a bulb.

This invention is further characterized by the provision :ofa -pair .of reciprocating nozzles, preferably ro- ;tatable,-to whichshreddedzfoil isfedfrom a:common sup- -ply,ifor alternately delivering a charge .-of shredded foil :to1a bulb ontone conveyonand then to;another bul.b.on ranothertconveyor. .Thus the outputtof alsingle foil'shreddingimachine isemployedto provide achargeof shredded foilttoibulbs-carried-on two separateconveyors.

:In the vspecificenibodiment of the sinvention 'shown in the accompanying drawings,

Figure 1.:is a plan :view of apparatusfor introducing a quantity of shredded foil into llamp bulbs, and includes also iaeportion .of apparatus which may :be employed to v.shred foil and a portionof the conveyors :which carry bulbs into foilefilling position.

Figure 2 isa sideelevational view, partly in sectiou,.o-f :the apparatus er Figure 1.

Figure 3 is a fragmentary detail, partly in section, and .on $311 enlarged :scale, illustrating the means employed to c.onvey..a quantity-of shredded foil to the nozzle which delivers it to.a flash lamp bulb.

.Referring now to. the drawings, particularly Figure :1 thereof, that portion of afoil shreddingapparatus shown ttherein is designated-by the generalreferenee numeral .10. The foilshredding apparatus dthmaybe-ofthettype -show-n anddescr-ibed inUrS. Patent .'2,69 9,-8-31 for example. Shredded foil, asitdrops awayifrom-thezcutters .of .the foil .shredding apparatus, is -drawn into =venturi .assemblies 112 .and 14 through 'venturi feeding -.tubes :16 \and .18. respectively. .Theventuri assembliesxare mounted .on brackets .20 attached 1 tothe tableiZ-Z on which'ther foil shredding apparatus :ltlris disposed.

:Referring now ato Figure -3, .the -venturi assembly :14 ,-comprisesabody'member 24:having abore 26 extending -.therethrough, one end of the borebeing fitted'with an outlet pipe 28, and-the otherend of'the borebeing 'pro- \videdwitha nozzle 30' to which arplug 32. is' attachedy the 111 48 32 in turnbeing connectedtoa source "of gas, such gas airtfor example, under pressurethrough flexible tubing 54. Thus :fiSlOlI-lS ShI'ddCd by the foil shredding appa- :ratus.-10;.the flow .of-gas'under pressure through Lfiex'ibIe '-.t-ubing34,:.plug3-2:and nozzle '3ilzdrawsthe shredded foil .through't-he venturi feeding tube 1-8 of venturi '14, into the bore261and1discharge it :through theoutlet pipe'28. ,The venturieassernbly :12 is of similar construction and -;operatestin-the same :mannerras venturi assembly 14.

"Thesshredde'difoil.discharged from outlet pipe 28 '(Fig. 3.) ris'rreceived :by funnel *36 of 'venturi assembly' d and is discharged through :outlet pipe 40 thereof "by the ad- :missiOJl of cgas,s:such.as'air for :example, under pressure into the venturi assembly 38 through fiexible tubing 42,

--;plug .414. andnozzle :46. Venturi assembly 48 (Fig; 2) is of asimilar ;constrnctio-n and operates f in the same manner ;as Venturirassem'bly 38, except that its outlet pipe-411s much :longer rtha-n :outlet :pipe 40 -of venturi assembly 38 lfOlil'BfiSOIlSiWhiGh will beapparent from-the description ibelowtoff the;remainder of the apparatus orthis invention.

rThe shredded:foil dischargedfrom outlet pipe ill-(Fig. .:'3).-.is received by funnel .50 mounted on one end emolplowzshaftx52zofamotori54. The otheren'dof shaft El is zprovidediwithsa nozzle56 which is attached thereto "by ameans of a.'chuck 53. The chuck 58 is prcvided'with san O.ring seal 60' held':in place by aretaining ring 62-and mm 56.4. The force exerted by the gas entering the ven- :tufLSS-throug'h flexible tubing '42 is-sufiicient to drive the eshreddedifoil through the hollow shaft 52 and the nozzle 5'6 :into the :bulb 1. Similarly, shredded foil is *fed to "bulb .(:Fig. 2-) from venturi'48 and the venturi outlet pipe 41. Venturis 38 and 48 are-supported from their respective associated motors 'Sdby means of arms 55 :depending from the motors, and clamps 57 extending laterally frorn thelowerends of the arms 55 and attached to the 'outlet'pipes dll and 41 respectively of the ventur'is 38 and 48.

Referring-now'to Figures 1 and 2, bulb 1 is supported by a 'bu'lbholder.66 attached to an endless chain conveyor 68; and bulb 3 is supported by a bulb holder'70 attachedto an endless chain'convey'or'72.

Conveyors

68 and 7 2 are provided with a plurality of bulb holders 6'6 and 70=respectively for carrying bulbs'into position above and 'in register with the apparatus just described toreceive a charge of shredded foil therefrom. Each of the bulb-conveyors is provided with a bulb orienting device, designated generallyby the reference numeral 71, which is mounted on a pedestal 73which supports idler shaft 75 of

conveyors

68 and 72. The bulb orienting device '7=1 comprises a pair of jaws 77 which are opened and closed about the neck of a bulb by the motion transmitted thereto'by-suitable means from a roller79 which rides-on a bar cam .81 attached to lift shaft 76.

"The apparatus for reciprocating the nozzle 56 into and out of the bulb 1 to deliver a charge of shredded foil thereto will now be described. Delivery is effected when the nozzle 56, venturi 38 and venturi 14 are in the relative position in which they are shown in Figure 3. The

- mechanism for advancing the nozzle 56 and its associated parts into delivery position is shown in Figure 2. The motor 54, which is connected to the nozzle 56 by the chuck 58, and which is connected to the venturi 38 by arm and clamp 57, is mounted on clamp 74 attached to the upper end of lift shaft 76. Lift shaft 76, which ex- -tends through and is supported by lift shaft housing 78 mounted on table 80, has a clamp 82 attached to the lower end thereof. In order to prevent the lift shaft from rotatmg, the clamp 82 attached to the lower end of the lift shaft is provided with a slotted slide 84 which rides up and down on a guide bar 86 attached to and depending from the lift shaft housing 78. A link 88, depending from link pin 90 which is mounted in and projects laterally from clamp 82, connects the lift shaft clamp 82 to one end of a cam arm 92. Cam arm 92 is pivotallymounted intermediate its ends on shaft 94 which is supported in Similar apparatus, operating in a similar manner, is provided for delivering a charge of shredded foil to the bulb 3. Cam shaft 102 on which cam is mounted, and stub shaft 103 on which a earn 105 similar to cam 100 15 mounted, are driven by a common drive (not shown) .unounted on the table 80, the casting 107 for housing a portion of this drive being mounted on top of table 80 as shown in Fig. 2.

The means for energizing the motors 54, to effect rotation of the nozzles 56 will now be described, reference being made particularly to the right hand side of Figure 2. Wire 106, from a source of electrical energy not shown, 18 connected to a screw 108 disposed in housing 110 of insulating material mounted on table 80. The housing 110 is provided with a bore within which a spring 112 is disposed. One end of spring 112 is connected to screw 108 and the other end thereof is attached to one end of an electrically conducting rod 114 mounted in housing cover 116 which is slidably disposed on housing 110. A wire 118, attached to the other end of rod 114,

. extends through aperture 120 in housing cover 116 and is connected to motor 54. A bracket 122, attached to both the housing cover 116 and a cap 124 slidably disbe described,'reference being made particularly to Figures 1 and 2. Air from a source not shown is admitted into the system through feed line 126 into filter 128. Four separate feed lines run from filter 128 to four separate pressure regulators 130. A feed line 132 connects each of the pressure regulators to an air valve 134, the several air valves being attached to a mounting plate 136 supported by a pair of standards 138, one of which is shown in Figures 1 and 2. Each of the air valves 134 is provided with a mercury switch 140 depending therefrom, the roller 142 of which rides on cam 144. The cams 144 are mounted on shaft 146 which is supported in bearing housings 148 mounted on standards 138; Feed lines 150 extending from air valves 134 are clamped to support bar 154 which is attached to table 80 by bolt 81. Flexible tubes 34, depending from

venturis

12 and 14, are con- 4, nected to the termini of two of the feed lines 150 at support bar 154. Similarly, flexible tubes 42, depending from venturis 38 and 48, are connected to the termini of the other two feed lines 150 at support bar 154.

The operation of the shredded foil feeding apparatus will now be described, reference being made initially to Figure 2. The reciprocating nozzle 56 of the shredded foil feeding assembly illustrated at the right hand side of Figure 2 is shown in the advanced or delivery position, i. e., the tip thereof has been moved inside the bulb 1 to deliver a charge of shredded foil 5; whereas the nozzle 56a of the shredded foil feeding assembly illustrated at the left hand side of Figure 2 is shown in the retracted position, awaiting its turn to advance and deliver a quantity of shredded foil to bulb 3.

Advancement of the nozzle 56 from its retracted position to its advanced position is effected by the cam 100 on cam shaft 102, through cam follower 98, earn arm 92, link 88, link pin 90, clamp 82 and lift shaft 76. As the lift shaft 76 moves upwardly, it carries with it the motor 54, the nozzle 56 which is attached to the hollow motor shaft 52, and the venturi 38 which is supported from the motor 54 by arm 55 and clamp 57. When the upward stroke of the lift shaft 76 has been completechthe nozzle 56 is disposed inside bulb 1 (Fig. 3) and the funnel 36 of venturi 38 is in alignment with the outlet pipe 28 of venturi 14. With the apparatus so disposed, the-nozzle 56 is ready to receive a charge of shredded foil from the foil shredding apparatus 10 (Fig. 1) and deliver it into the bulb 1.

Actuation of the pneumatic system for supplying air under pressure to the

venturis

12, 14, 38 and 48 is synchronized with the reciprocation of the lift shafts 76 so that a blast of air is admitted to the shredded foil feeding system intermittently, i. e., when a nozzle 56 is in position inside a bulb. Referring now to Figure 2, the two right hand air valves 134 are shown in the open position, having been actuated by the rotation of the shaft 146, through their respective cams 144, rollers 142 and mercury switches 140. Air from these two valves flows to the

venturis

14 and 38 throughthe two feed lines 150 and flexible utbes 34 and 42 respectively. Air flowing through the venturi 14 draws shredded foil from the foil shredding apparatus 10 (Fig. 1) through feeding tube 18 and discharges it through outlet pipe 28 into funnel 36 of venturi 38 (Fig. 3). Similarly, air flowing through the venturi 38 draws the shredded foil through funnel 36 and discharges it through outlet pipe 40 and into funnel 50 on one end of the hollow motor shaft 52 with suflicient force to drive it through the shaft 52 and nozzle 56 into the bulb 1. Rotation of the nozzle 56, which is preferably provided with a delivery opening 53 in the side wall thereof like the nozzle shown in the copending application of Bennett et al. referred to above, effects a satisfactory distribution of the shredded foil within the bulb 1.

The air valves 134 (Fig. 2) which were opened to admit air to the

venturis

14 and 38, are now closed by the further rotation of shaft 146 on which the cams 144 associated therewith are mounted, thereby terminating the flow of shredded foil to the nozzle 56. The return stroke of the lift shaft 76 (Fig. 2), to withdraw the nozzle 56 from the bulb 1 to which a charge of shredded foil 5 has been delivered, is effected by the further rotation of shaft 102 on which cam 100 is mounted. The conveyor 68 indexes one station, carrying away the bulb which has been provided with a charge of shredded foil and bringing another bulb into loading position.

While the nozzle 56 and its associated mechanism is returning to its rest position, the nozzle 56a (Fig. 2) and its associated mechanism is advancing from the rest position to effect delivery of a charge of shredded foil to bulb 3. Since the mechanisms employed and their mode of 'operation are the same as those associated with nozzle 56, a detailed description thereof is believed to be unnecessary. 1

Frornthe foregoing, it is apparent that, in accordance with tlieprin'eiples ofthisint/e'ntion; not only is automatic apparatus'provided' for deliveringa charge'ot shredded foil to'fiash lamp bulbs'asftheyare advanced by a conveyortoa'loading station, but maximum utilization of the output of a foil shredding machine is obtained by synchronizingtwo foil feeding mechanisms therewith and with t'wo"bulb conveyors'whereby shredded'foil is being fed'to' a bulbon'o'ne conveyor by'one foil feeding mechanism while the other foir feeding" mechanism 'is re-' turning to its'rest'positio'n afteifhavingjust' delivered a charge ofishrtedddfdilto a bulb'on another conveyor.

WhatweeIaini is: I 7 p 1. Appara'tii's'for providing'lampbulbs with a filling of filamentary particles comprising: a nozzle through which-filamentary particles may be' dischar ed; a conveyordisposed in operative relationship with respect to said nozzle"f"or"carrying lam -bulbs sequentially into reg ister with said nozzle; means for reciprocating said nozzle into and out of a lamp bulb in register th'erewith on said conveyor; meansfor'causing a flow of filamentary particles throughv said nozzle when saidnozzle is in the advanced position of itsreciprocating. stroke; and means for rotating said nozzle when said nozzle is in the advancedlposition of its reciprocating stroke to efiect adistribution within the lampbulb of the filamentary par- I ticles flowing from said nozzle.

2. Apparatus for providing lamp bulbs with a filling of filamentary particles comprising: a nozzle through which filamentary particles may be discharged; a conveyor disposed in operative relationship with respect to said nozzle for carrying lamp bulbs sequentially into register with said nozzle; means for reciprocating said nozzle into and out of a lamp bulb in register therewith on said conveyor; pneumatic means for causing a flow of filamentary particles through said nozzle when said nozzle is in the advanced position of its reciprocating stroke; and means for rotating said nozzle when said nozzle is in the advanced position of its reciprocating stroke to efiect a distribution within the lamp bulb of the filamentary particles flowing from said nozzle.

3. Apparatus for providing lamp bulbs with a filling of filamentary particles comprising: a reciprocable nozzle through which filamentary particles may be discharged; a conveyor disposed in operative relationship with respect to said nozzle for carrying lamp bulbs sequentially into register with said nozzle; a reciprocable venturi assembly, the outlet of which is in axial alignment with said nozzle; means for synchronously reciprocating said venturi assembly and said nozzle whereby said nozzle is moved into and out of a lamp bulb in register therewith on said conveyor; means, in communication with a source of filamentary particles, for introducing filamentary particles into said venturi assembly; means for actuating said venturi assembly to efiect a flow of filamentary particles therethrough and through said nozzle into a lamp bulb when said nozzle is in the advanced position of its reciprocating stroke; and means for rotating said nozzle when said nozzle is in the advanced position of its reciprocating stroke to effect a distribution Within the lamp bulb of the filamentary particles flowing from said nozzle.

4. Apparatus for providing lamp bulbs with a filling of shredded foil comprising: a reciprocable nozzle through which shredded foil may be discharged; a conveyor disposed in operative relationship with respect to said nozzle for carrying lamp bulbs sequentially into register with said nozzle; a stationary venturi assembly in communication with a supply of shredded foil; a reciprocable venturi assembly movable into foil-receiving relationship with respect to said stationary venturi, and said reciprocable venturi assembly having an outlet in axial alignment with said nozzle; means for synchronously reciprocating said nozzle and said reciprocable venturi whereby said nozzle is moved into and out of a lamp bulb in register therewith on said conveyor; and said reciprocable venturi is moved into and out of foil-receiving relationship with respect" tosaid-stationaryyenturi; and'meansfor effecting a flow of shredded foil from asupply thereof through said stationary venturi assembly, said reciprocable venturi assembly and said nozzle into a lamp bulb when said nozzle and said'reciprocable venturi assembly are in the advanced position of their reciprocating stroke.

5. Apparatus for providing lamp bulbs with a filling of shredded 'foil comprising: a reciprocable nozzle through whichshredded foil may be discharged; a con veyor disposed in operative relationship with respect to said nozzle for carrying lamp bulbs sequentially into register with said nozzle; a stationary venturi assembly in communication with a supply of shredded foil; a reciprocable venturi assembly mov'ableinto foil-receiving relationship with respect to said stationary venturi; and said reciprocable venturi assembly having an outlet in axial alignment With-saidnozz'le'; means for syn= chronously reci rocating said nozzle and said reciprocable venturi whereby said' nozzle is moved into and out of 'a lamp bulb in register'therewith on said conveyor, and said reciprocable venturi is moved into and out of foilreceiv-ing relationship with respect to said stationary venturi; means for etfe'cting a flow of shredded foil from a supply thereof through said stationary venturi assembly, said reciprocable venturi: assembly and said nozzle into a lamp bulb when said nozzle and said reciprocable venturi assembly are in the advanced position of their reciprocatingstroke;; and means: forrotating said nozzle when said nozzle is in the advanced position of its reciprocating stroke to efiect a distribution within the lamp bulb of the shredded foil flowing from said nozzle.

6. Apparatus for providing lamp bulbs with a filling of filamentary particles comprising: a pair of nozzles through which filamentary particles may be discharged; a pair of conveyors, each of which is disposed in operative relationship with respect to one of said pair of nozzles, for carrying lamp bulbs sequentially into register therewith; means for alternately reciprocating said pair of nozzles into and out of lamp bulbs in register therewith on said conveyors; and means for causing a flow of filamentary particles alternately through one and then the other of said pair of nozzles when said nozzles are in the advanced position of their reciprocating strokes.

'7. Apparatus for providing lamp bulbs with a filling of filamentary particles comprising: a pair of nozzles through which filamentary particles may be discharged; a pair of conveyors, each of which is disposed in operative relationship with respect to one of said pair of I nozzles, for carrying lamp bulbs sequentially into register therewith; means for alternately reciprocating said pair of nozzles into and out of lamp bulbs in register therewith on said conveyors; means for causing a flow of filamentary particles alternately through one and then the other of said pair of nozzles when said nozzles are in the advanced position of their reciprocating strokes; and means for rotating said nozzles when said nozzles are in the advanced position of their reciprocating strokes to effect a distribution within the lamp bulbs of the filamentary particles flowing from said nozzles.

8. Apparatus for providing lamp bulbs with a filling of filamentary particles comprising: a pair of reciprocable nozzles through which filamentary particles may be discharged; a pair of conveyors, each of which is disposed in operative relationship with respect to one of said pair of nozzles, for carrying lamp bulbs sequentially into register therewith; a pair of reciprocable venturi assemblies the outlet of each being in axial alignment with one of said pair of nozzles; means for alternately reciprccating each venturi assembly and the nozzle in cooperative relationship with respect thereto whereby the said nozzles are moved into and out of lamp bulbs in register therewith on said conveyors; means, in communication with a source of filamentary particles, for alternately introducing filamentary particles first into one 7 andthen into the other of said pair of'venturi assemblies; and means for actuating saidrpair of venturi assemblies alternately to effect a flow of filamentary particles therethrough and through the nozzles in cooperative relationship with respect thereto into the lamp bulbs when said nozzles are in the advanced position of their reciprocating strokes.

9. Apparatus for providing lamp bulbs with a filling of filamentary particles comprising: a pair of reciprocable nozzles through which filamentary particles may be discharged; a pair of conveyors, each of which is disposed in operative relationship with respect to one of said pair of nozzles, for carrying lamp bulbs sequentially into register therewith; a pair of reciprocable venturi assemblies the outlet of each being in axial alignment with one of said pair of nozzles; means for alternately reciprocating each venturi assembly and the nozzle in cooperative relationship with respect thereto whereby the said nozzles are moved into and out of lamp bulbs in register therewith on said conveyors; means, in communication with a source of filamentary particles, for alternately introducing filamentary particles first into one and then into the other of said pair of venturi assemblies; means for actuating said pair of venturi assemblies alternately to effect a flow of filamentary particles therethrough and through the nozzles in cooperative relationship with respect thereto into the lamp bulbs when said nozzles are in the advanced position of their reciprocating strokes; and means for rotating said nozzles when 'said nozzles are in the advancedrposition of their reciprocating strokes to effect a distribution within the lamp bulbsof the filamentary particles flowing from said nozzles.

10. Apparatus for providing a lamp bulb with a filling of filamentary particles comprising: a nozzle through which filamentary particles may be discharged; a conveyor disposed in operative relationship with respect to said nozzle forcarrying lamp bulbs sequentially into register with said nozzle; means for effecting relative displacement of said conveyor and said nozzle whereby said nozzle is disposed in a lamp bulb in register therewith on said conveyor; means for causing a flow of filamentary particles through said nozzle; and means for rotating said nozzle, when it is disposed in a lamp bulb, to effect a distribution within the lamp bulb of the filamentary particles flowing from said nozzle.

References Cited in the file of this patent UNITED STATES PATENTS 833,637 Sheffield Oct. 16," 1906 1,859,562 Huston May 24, 1932 2,273,735 Raymer Feb. 17, 1942 2,347,046 Geiger Apr. 18, 1944 2,547,606 Staller Apr. 3, 1951 FOREIGN PATENTS 7 239,948 Great Britain Sept. 24, 1925