US2632378A

US2632378A - Can cooker

Info

Publication number: US2632378A
Application number: US688226A
Authority: US
Inventors: Carvallo Pierre
Original assignee: Individual
Current assignee: Individual
Priority date: 1945-08-20
Filing date: 1946-08-03
Publication date: 1953-03-24
Anticipated expiration: 1970-03-24

Description

March 24, 195s i. @Am/ALLO 2,632,378

CAN COOKER 4 Sheets-Sheet 1 Filed Aug. 3, 1946 l i ./l3 ./2

ZF' V y 30 /z INVlNTOK P IRRE CAFNALLO aY MIM* *"3" AeeNTs March 24, 1953 P, CARVALLO 2,632,378

CAN COOKER ,Fild Aug. s, 194e r 4 sheets-sheet 2 HG 29 23a 23h 23.7.

Irv/dials 73eme: Cemevoo ff.' f

l AJ 1r March 24, 1953 P, CARVALLQ 2,632,378

. CAN COOKER `4 sheets-sheet s Filed Aug. 3, 1946 ng. /z

l l nvN-roa P\ E BRE vCAR v A L.\.o

AG ENTS Patented Mar. 24, 1953 UNITED STATES QPATENT oFF-ICE ApplicationwAugust 3, 1946, SerialrNofGSlSZ In France Augustl 20,1945

` In a prior patent,V I Ahave 'described' and claimed, in connection 'with the art of 'continuously sterilizing or pasteurizing'food product containers, the use of baskets 'made oi'pe'rfora'te metal sheets oroi equivalent construction 'forming'the treating unit and .which are automaticallyfedthrough the apparatus and into. which may be introduced containers of any shape and't'ype for-the'purpose of treating the latter.

AThe present invention vprovides 'improvements relating to the construction of the means for circulating or feeding such baskets and 'to the method of `introducing containers into and extracting same from said baskets.

One object of the invention isto provide a runway or path of travel for said baskets in the form of an endless circuit wherein no handling of 'the baskets is required at any point, a mechanical device being adapted to immobili'ze said baskets during iilling and extracting operations.

Another object of the vinvention is to provide an automatic means for dischargingtr'eated containers from said baskets and alsoior 'charging into said baskets containers to be treated, said means being in the form of a ramming piston controlled bya chain 'device or apneumatic tube orequivalentmeans adjusted in timed relationship 'with the travelling of said'baskets.

A further object of the'inventionis toprovide, in connection with the treatment of metallic cans the bottoms of which are liable to be puffed, or to expand, during 'the treatment, a safety device preventing the introducing into said baskets lof an excessive number of cans.

VAnother object is to provide,moreparticularly in connection with the treatment of glass or similar fragile containers, liable to breakage in the course of treatment, .means for extractingsaid containers from said baskets in the form of a scoop or trough adapted to be irst introduced into said baskets under said containers, thento drive said containers out oi said baskets thereby avoiding any risk of jamming said containers due to vthe possible vpresence Yof fragments of broken containers vin* said'fbaskets.

A further object of the inventionis tovprovide, in an apparatus of the type described, for carrying` out .a treatmentatihigh temperatures and pressures, a .circulating path for said baskets comprising .a head Vof Watertserving as a Water 'seal andmaking it possible .to introduce and re- Vmove said baskets Yinto! and-,from an enclosure under pressure, wherein .the temperaturaofL treatment Ymay .be adj-usted with Va `high degree of accuracy -by adjusting said head of Water.

A 'further obj ect xis^'tofproviie a`ne'.pparatus of 'the type "described Y-more particularly vdesigned 'for "the treatment ^of 1fragile containers, wherein "said baskets, are p successively 'fed-through a -plurality oftanks containing Water at Vtemperatures in stepped relationship, said tanks `'being concurrently `usejdboth for. increasing pand reducing the Vtemp'eral-,ure of" said "containers, thereby` ensuring substantial :compensation *,fbetween lthe heat calories used for-"heating 'and "cooling said Acontainers.

Furth'er objects 'and advantages of "the invention will bei pointed fout las ithe 'description proceeds in reference' to/'the Vacccmip'a'-nying drawings given'by Way of'example only, of severaloperative .embodiments jof the-invention.

Fig. 5'1 is a diagrammatical'sketch of .an example of an"endless"cir'cuit Ifor* the circulation of baskets .through :varioustreating tanks.

, vdia'grammatically illustrates in elevation aV treatingapparatusenabling through theuse of `feed selecting fdevi'ce'sfa 'rapid Yspeed'of rotation oi the baskets. y

Fig. 4 'is t'a diagrammatic section-on line `I-V---iI'V 'of Figf2. Y Figsfgandi"fillustratejat'enlargedscaleone basket associated "with 'the conveyor chains 'providedwith pushingiing'ers andfwithrunways.

ig..l 8..sh`ows, 'atgenlargedscala the .filling A'and ejecting stations.

.Figi 91is adia'gramr'riatic illustration 1in y.crosss'e'ction of .an apparatus specially 'designedffor .treatment `in 'stje'anir yunderpressure.

VlFig, l0 diagrammati'c'ally 'illustrates 'in section an .apparatus .designed for treatment lirfh'ot Water under.pressureenabling.operation under anoverpressure.

' Fig. 11 diagramrr'atcallyj illustrates Ain 'section an apparatus designed Tor. the treatment ofecentainersmade ofy 'glassjor `other brittle..material 'ne v'for example'for 'the ipaSteur'ning hof. bottled eer.

Figsf 12 toflfi. respectively illustrate in.. elevational, p'la'njand' sidefiiewjlan. automatic 'chaincontrolledplun'ger, "for extractionLprovidingli 4required' for thefup'setting of the 'ramming arm Vat the end o`f its stroke.

Fig. 15. .shows .in .elevational-.section .a ,plunger acting for thefiilling] of .thelbasket ligsjlil yandi'l' showfa plunger.fprovided with sa scoopor trough.

J Jin Fig 1lan :endless-g cireulati,ngA circuit forti-1e baskets 23 is constituted by a pair of parallel runways 3 the spacing of which corresponds to the length of the baskets, and which successively pass through

various tanks

28, 2i and 22 containing the heat treating iluids. Along each path 3, an endless chain 2 provided with driving lingers i ensures the travelling of baskets 23 on runways 3. At some point in the circuit, such as A, the containers to be treated are introduced into the baskets 23 at B, the treated containers are extracted therefrom, the direction of travelling of the baskets 23 'being indicated by the arrow f.

Said baskets 23 are, for example, constituted by a perforated metal sheet 80 and are preferably mounted on two annular end members 8l so as to be able to roll on the guideor runways 3 (Figs. 5 to '7) in cross-section, but the latter is preferably selected according to the containers to be treated.

The machine illustrated in Figs. 2, 3 and e is specially designed for products wherein intense agitation is preferable during treatment. It comprises two

tanks

24 and 25, one for cold and the other for hot water. In said tanks there are respectively arranged endless circulating

runways

26 and 26a along which the baskets 23 are made to circulate in self-rotation by being pushed along by the fingers l and la of endless chains 2 and 2a driven by wheels l and 4a mounted on shafts 5 and 5a. The total number of fingers in each chain is suitably determined according to requirements.

Pairs ofV star-shaped wheels 3 1 and 6ft-1a, synchronously rotated with the displacement of the endless chains 2, 2a, respectively provide for introducing baskets V23 into, and removing same from, the endless circuits 26 and 28a guiding said baskets in the tanks. The wheels of each pair mounted on parallel axes and rotated in the same direction, are disposed opposite one another` and are separated by a partition 21 or 21a having a suitable section and shape for laterally maintaining baskets 23 within the corresponding notches of the star-shaped wheels. The number of notches in said star-shaped wheels, and the the number of fingers in the endless chains, are chosen in any suitable way in relation with the operation of extracting arms 8 and 3d, actuated for instance by cams not shown but familiar in the art, operated synchronously with the displacement of the endless Vchains 2 and 2a and the 4star-shaped wheels, in such a way that the baskets will be extracted from the

runways

23 and 26a after having sojourned for a suitable period of time in the tanks. Thus,for example, there will be iingers on each of the endless chains 2,

each'wheels

6, 6a, 1 and 1a comprising 8 notches.

A conveyor arranged at the upper part of the tanks and constituted by two'lateral runways 28 each having an endless chainZii` provided with iingers 30 similar to fingers l ensures the transfer of the baskets from one tank to another in cooperation with the star-,shaped wheels placed in said tanks. Moreover, and according to an irnportant feature vof the present invention, a

shelved, or downwardlyoifset, portion 3l is pro-V vided in the runway 2B for allowing the baskets to remain stationary for a certain Vtime so as to enable them to be filled and drawn off with greater ease.

V,Operation of the device is yas follows: y

At X and Y, two baskets at least are in stationary condition, at X the treated containers are extracted from the basket 23a, and at Y the containers to be treated are inserted in-to the Said baskets may have Aany desired shape Y basket 23b. An arm 3, actuated by any suitable means synchronously with the displacement of the endless chains 29 introduces the basket 23e into the conveyor formed by said chains 29 and the guideways 28 at regularly spaced intervals so as to introduce one basket after the passingiof each group of. eight fingers 3G. This basket 23 is introduced, by the star-shaped wheel 6, into the hot water -tank 25, and travels several times around its circuit until it is again introduced into the upper conveyor, by the arm 8 and the starshaped wheel 1. According to the adjustment of the arm 3, the basket 23 may travel as many as eight times around the circuit provided in the tank 25. The basket then passes into the circuit of tank 24, according to the same principles of operation, and emerges by means of the star-shaped wheel 1a by which it is conveyed into extracting position las shown at X (see also Fig 8).

It is obvious that the tank circuits which have been shown in the drawing as comprising two stages may include three or four stages or more.

The number of fingers and chains 2 and the number of notches in wheels 6 and i will be selected according to requirements. Similarly, instead of the pair of tanks illustrated there could be a plurality of tanks, at stepped temperatures, as described hereinafter with reference to Fig. 1l.

rlhe machine which -is diagrammatically shown in section in Fig. 9 is more particularly designed for the treatment of containers by means of steam under pressure. For this purpose, the actual treatment is carried out in a sealed enclosure 33 illed with steam. Said enclosure 33 comprises at Iits lower portion a iiuid tight partition 3@ deiining a space 35 connecting through a tunnel 36 with a chamber 31 divided in two columns at the upper portion thereof by a partition 38. Said chamber 31 is lled with' water up to a level which is adjusted as a function of the steam pressure which it is desired to maintain in the treating enclosure 33. The guideways 39 for baskets 23 which form the continuous circulating circuit for said baskets 23 pass into enclosure 33 and chamber 31, and the chains 40 provided with driving iingers 3i pass around counter-motion pulleys s2 suitably arranged so that said chains l? will extend along the path of the guideways 39 substantially throughout the whole length of said guideways. Baskets 23 lled with containers to be treated enter at P the waterlled chamber 31, then arrive in the treating enclosure 33, pass out of the latter to again enter chamber 31, whence they again emerge at Q. Cold water is admitted at 43, is heated by contact with the baskets 23 fed through the enclosure 33, and is evacuated at lill, a constant level being maintained in chamber 31 at the desired height depending on the steam pressure within enclosure 33. Said steam is admitted through a suitable valve (not shown) controlled by a float [i5 in such a way as to maintain a constant pressure of steam within enclosure 33.

Cutside enclosure 33 and chamber 31, there is provided at 65a a displacement of the guideway with respect to the drive chains 4U in order to obtain a stationary condition of baskets 23 during a certain period of time enabling such baskets to be filled and drawn off respectively in position X and Y thereof. An arm 66, controlled by a cam 41 or an equivalent device driven syn- Vchronously ywith the driving chains d0, provides for extracting the baskets from said drive chains and transfers them to the offset ,portion 45 of the guideways whereas they are emptied and then filled before again being engaged at 48 by the driving fingers 4l of said chains.

More particularly in the event where the bottoms of metallic cans are liable to be puied, or expand, during treatment and in order to avoid damage to such cans and to the baskets in which they are contained by reason of such increase in volume, a device may be provided adapted to reserve within the basket a certain space remaining empty of cans. In one form of embodiment which appears advantageous at present, such device consists of a linger 49 which, as the basket is filled, is caused to extend into the end of said basket opposite to that at which said basket is filled to the desired extent. Said finger 9 is actuated by any suitable means and for example by levers (not shown) driven from the cam M actuating the arm 45.

The machine diagrammatically illustrated in Fig. l is more particularly designed for treating containers in hot water, which may be subject to an excess pressure. For that purpose,'the treating chamber 50 filled with hot water opens at its upper portion in an enclosure comprising a pair of columns l and 52 forming a U. Column 5l is lled with a mixture of air and vapour, while column 52, open at its upper end, contains water, the upper level of which with respect to the level of water in the branch 5l determines ythe degree of excess pressure which it is desired to apply to the hot water contained in the treating chamber 5t. Circulating runways 53 with their chains and fingers for driving baskets 2S similar to those described in the preceding devices are provided for within chamber 5B and columns 5l and 52, and said runways 53 also comprise an offset portion and an extractor arm for the baskets as in the example or" Fig. 5, so as to ensure a stationary condition of the baskets for a certain length of time for loading and unloading purposes.

In the machine diagrammatically shown in Fig. 11, baskets 23 are circulated by means of guiding and driving devices similar to those decribed in the other embodiments, within tanks or

chambers

60, 6l and 62 filled with a heated fluid, the temperatures of which are so adjusted that the containers to be treated will progressively pass from the temperature at which they have been filled to the maximum temperature of the fluid contained in the tank 60, and viceversa, the displacement of the endless chains driving the baskets being in the direction of arrows fi. This type of installation is particularly suitable for the treating of brittle containers such as glass containers, for instance for the pasteurizing of beer, fruit juice and the like.

In 6| and 62, the water transfers the heat calories from the treated containers to those to be treated, thus providing in the simplest possible manner for the gradual progression of the temperatures and a saving in the heating steam and cooling water.

The tanks may, of course, be provided in any desired number.

In all the devices described hereinb'efo're, adjusting means for regulating the rate of displacement of the endless drive chains are provided for so as to carry out the desired appropriate treatment in optimum conditions.

Figs. 13 to 16 show diagrammatically and by way of example, one form of embodiment oi a mechanical device which may be used for lilling containers to be treated into the baskets, and

6 also for ejecting said containers at the end of the treatment, during'the stationary period of the baskets.

This device essentially consists of a plunger 10, the shape and dimensions of whichV correspond to the interior of the baskets. Said plunger 10 is slidably mounted in a guide-member 1I, the open end of which is positioned in register with a basket 23- which is in stationary position at x or y (Fig. 8). The plunger 10 is reciprocally driven by an arm 'I5 pivotally mounted on a pin 15a carried by the plunger 10, said arm being connected by a nger 82 toa chain l2 the path of which is contained in a` plane perpendicular to the vertical planes containing the chains 29 and which is trained over a pair of spaced sprockets 'I3 and lll, at least one of which is power driven by any appropriate means in such a way that plunger 'I0 is reciprocated-'in guide 'Il and engages the insideof the basket 23 which is in register therewith.l Owing to such an engagement, the plunger 10 which' is in register relationship with basket 23a, stationary at X (Figs. 2 and 8) discharges the containers fill--v ing said basket 23a by forcing them out said basket, while the plunger 'l0 which-is inregister relationship with basket 23h (Figs. 2 and 8) may charge said basket .23h with containers to be treated. In the latter case, the guide *71 (Fig. 15) is formed with an aperture 80` at itsvtopl through which pass the containers which are to be introduced into said basket 23h whilethe orresponding plungerll) is at its rearmost posiion.

In the event the containers to be extracted from the baskets are brittle, as for instance made of glass, plunger 10 is provided with a trough or scoop 3 (Figs. 16 and 17) of appropriate shape which is introduced into the basket at the bottom thereof under said containers, to thereafter carry said containers out of said basket. The containers may be cleared, or disengaged, from said trough or channel arm by any suitable means and for example by a partial upsetting of said trough at the end of its stroke. Such upsetting could be produced by a lug integral with the trough and movable within an aperture of suitable contour formed in the guide of said trough. A similar device may be provided for loading the containers into the baskets.

What I claim as my invention and desire to secure by Letters Patent is:

1. The combination with an apparatus for thermal treatment of stuffs in containers and of the type comprising an enclosure containing a thermal treating fluid, at least a pair of two continuously driven chains respectively arranged inr parallel closed circuits positioned in vertical planes within the enclosure and pushing members distributed upon said chains, of tubular baskets open at each end, adapted to receive containers and having a length slightly less than the distance existing between the parallel chains vand a diameter less than the distance existing between two successive pushing members of the chains, a pair of guiding tracks respectively coextensive with each pair of parallel chains and positioned with respect to said chains at .a distance slightly larger than the outer radius of said tubular baskets, said baskets being rrespec tively guided by the two tracks of each pair of chains between two successive pairs of pushing members and being unattached to said chains,

said guiding tracks being further formed with respect to one of the closed circuits 'with a pair of facing offset portions departing from said chains and forming an offset place, means for successively and periodically extracting at least one of Said baskets from said last closed circuit and for conveying the same to said offset place, each extracted basket remaining motionless in said place between two successive extractions, whereby each extracted basket may be discharged and charged at said offset place during predetermined stopping periods without being taken out of the treating apparatus, and means for reintroducing said extracted baskets when charged into said last closed circuit.

2. An apparatus for the thermal treatment of stuffs in containers, according to claim 1, wherein the means for extracting the basket from the closed circuit comprises a rotary member formed with at least a radial projection adapted to extract one basket from the closed circuit corresponding to the offset place and means for rotatably driving said member in synchronized relationship with the motion of the parallel chains.

3. An apparatus for the thermal treatment of stuis in containers, according to claim 1, further comprising means for removing the containers from each basket in predetermined stationary position in the oiset place and for charging the same with containers, said means respectively having a plunger reciprocably movable along the axis of the stationary basket for penetrating within said basket, an auxiliary endless chain arranged inrclosed circuit positioned in a vertical plane perpendicular to the vertical plane containing the parallel chains, and a nger xedly mounted on said auxiliary chain and connected with said plunger.

4. An apparatus for the thermal treatment of stuis in containers, according to claim 1, further comprising, ,in the case where the containers are glass containers, means for removing said containers from each basket in predetermined stationary position in the oset place and for charging the same with containers, said means respectively having a plunger reciprocably movable along the axis of the stationary basket for penetrating within said basket, and auxiliary endless chain arranged in closed circuit positioned in a plane perpendicular to the vertical planes containing the parallel chains, and a iinger iixedly mounted on said auxiliary chain and connected lwith said plunger, said plunger being provided with a scoop directed toward said basket and of appropriate shape for passing first below the containers all along the basket and then conveying them out of the basket with a view to avoid any risk of jamming in the case any container is broken.

5. In an apparatus for the thermal treatment of stuffs in containers, at least two enclosures containing the thermal treating iiuids, within each of said enclosures two treating endless conveyor chains arranged in two closed circuits positioned in vertical planes on each side of the corresponding enclosure, series of regularly spaced opposite fingers xedly mounted on said chains and projecting between said vertical planes and two runways substantially co-extensive with said conveyor chains, tubularbaskets unattached to the chains, filled with containers, provided with outwardly cylindrical end members lying upon said runways and located between two successive fingers of each of said chains for being propelled along said runways by the pushing action of said 'fingers against said cylindrical end members, and

an interconnecting assembly for connecting to gether said various closed circuits located within said enclosures and comprising two common endless conveyor chains similar to said treating conveyor chains and provided with ngers similar to those of said treating conveyor chains, said common conveyor chains being arranged in vertical common closed circuits located above said various treating conveyor chains, two runways substantially co-extensive with said common conveyor chains throughout a major portion thereof and provided with respect to the lower flights thereof with an offset portion, star-shaped rotary members for transferring the baskets from said common conveyor chains to each of said treating conveyor chains and reciprocally, means for successively periodically extracting said baskets one by one from said common closed circuits and for conveying the same on said oiset portion, each extracted basket remaining motionless on said offset portion between two successive extractions and being displaced when an extraction occurs by contact with the following extracted basket, whereby each extracted basket may be discharged and charged at said offset pl-ace during predetermined stopping periods without being taken out of the treating apparatus, and means for reintroducing one by one said extracted baskets when charged into said corn-mon closed circuits.

6. An apparatus for the thermal treatment of stuffs in containers, according to claim 5, comprising means for causing several travels of the basket around each treating closed circuit before being transferred by the corresponding starshaped rotary member to the common conveyor chain.

'7. An apparatus for the thermal treatment of stuffs in containers, according to claim 6, wherein the number of notches in the star-shaped rotary members is a prime number with respect to the number of fingers in the treating endless conveyor chains.

8. In an apparatus for the thermal treatment of stuis in containers by means of steam under pressure, an enclosure containing vsteam under pressure and sealed at its upper part, two successive pressure columns containing a liquid and connected with the lower part of said enclosure, two endless conveyor chains arranged in two closed circuits travelling successively within the first pressure column, said enclosure and the second pressure column, Vsaid closed circuits being positioned in spaced parallel vertical planes, series of regularly spaced opposite ngers xedly mounted on said chains and projecting between said vertical planes, two runways substantially co-extensive with said conveyor chains throughout a major portion thereof and provided with respect to a portion of said chains with an offset portion, tubular baskets unattached to said chains, lled with containers, provided with outwardly cylindrical end members guided by said runways and located between two successive lingers of each of said chains for being propelled along said runways by the pushing action of said nngers against said cylindrical end members, means for successively periodically extracting at least one of said baskets from said closed circuits and for conveying the same on said offset portion, each extracted basket remaining motionless on said offset portion between two successive extractions, whereby each extracted basket may be discharged and charged at-said offset place during predetermined stopping periods without being taken out of the treating apparatus, and means for reintroducing said extracted baskets when charged into said closed circuits.

9. An apparatus for the thermal treatment of stuffs in containers by means of steam under pressure, according to claim 8, comprising means for continuously and adjustably introducing the liquid in the upper part of the second pressure column and means for discharging said liquid from the upper part of the rst pressure column.

10. In an apparatus for the thermal treatment of stuls in containers by means of a hot liquid subjected to an excess pressure, an enclosure containing hot liquid and sealed at its lower part, an intermediate chamber containing inactive gas and connected at its upper part with the upper part of said enclosure, two successive water pressure columns, two endless conveyor chains arranged in two closed circuits travelling successively within the first pressure column, said intermediate chamber, said enclosure, said intermediate chamber anew and the second pressure column, said closed circuits being positioned in spaced parallel vertical planes, series of regularly spaced opposite fingers xedly mounted on said chains and projecting between said vertical planes, two runways substantially rio-extensive with said conveyor chains throughout a major portion thereof and provided with respect to a portion of said chains with an oiset portion, tubular baskets unattached to said chains, lled with containers, provided with outwardly cylindrical end members guided by said runways and located between two successive fingers of each of said chains for being'propelled along said runways by the pushing action of said fingers against said cylindrical end members, means for successively periodically extracting at least one of said baskets from said closed circuits and for conveying the same on said offset portion, each extracted basket remaining motionless on said offset portion between two successive extractions, whereby each extracted basket may be discharged and charged at said oiset place during predetermined stopping periods without being taken out of the treating apparatus, and means for reintroducing said extracted baskets when charged into said closed circuits.

11. In an apparatus for the thermal treatment 10 of stuffs in containers, more particularly in glass containers, a plurality of successive enclosures containing thermal treating iiuid the tempera- Iture of which increases gradually from one enclosure to the adjacent one, two endless conveyor chains arranged in .two closed lcircuits travelling successively within said successive enclosures, said closed circuits being positioned in spaced parallel vertical planes, series of regularly spaced opposite fingers iixedly mounted on said chains and projecting between said vertical planes, .two runways substantially co-ex-tensive with said conveyor chains throughout a major portion thereof, and provided with respect to a portion of said vchains with :an oiset portion, Itubular baskets unattached to said chains, lled with containers, provided with outwardly cylindrical end m-embers guided by said runways and located between two successive ngers of each of said chains for being :propelled along said runways by the pushing action of sai-d ngers against said cylindrical end members, means for successively and periodically extracting at least one of said baskets from said closed circuits and for conveying the same on said offset portion, each extracted basket remaining motionless lon said oiset portion between two successive extractions, whereby each extracted basket may be ldischarged and charged at said offset place during predetermined stopping periods wi-thout being .taken out of the -treating apparatus, and means for reintroducing said extracted baskets when charged into said closed circuits.

PIERRE CARVALLO.

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

UNITED STATES PATENTS Number Name Date 674,685 Payson May 21, 1901 782,878 Ruff Feb. 21, 1905 `1,307,689 Murray June 24, 1919 1,418,572 Hoyt et al June 6, 1922 1,467,960 Thompson Sept. 11, 1923 1,835,799 Meyer Dec. 8, 1931 1,987,414 Omsted Jfan. 8, 1935 2,124,010 smith et al July 19, 1938 2,154,987 Galvin Apr. 18, 1939 2,262,921 Carvallo Nov. 18, 1941