US2804194A - Barn cleaning apparatus - Google Patents

Description

Allg 27, 1957 G. CARLSON ErAL y 2,804,194

BARN CLEANING APPARATUS Filed Aug. 31. 1954 4 Sheets-Sheet l Aug. 27, 1957 G. B. CARLSON ETAL 2,804,194

BARN CLEANING APPARATUS Filed Aug. 3l,A 1954 4 Sheets-Sheet 2 l h "hi JZZZ/.EJZZVRJ G50/96E 5. causa/v AAwoLo E. cansa ARM/(M 0. CAM son my M) Aug. 27, 19574 Filed Aug. 51, 1954 G. B. CARLSON EVAL BARN CLEANING APPARATUS 4 Sheets-Sheet 3 Aug. 27, 1957 Filed Aug. 31, 1954 G. B. CARLSON Erm. 2,804,194

BARN CLEANING APPARATUS 4 Sheets-Shea?l 4 United States Patent 2,804,194 Patented Aug. k27, 1957 ice BARN CLEANING APPARATUS' George B. Carlson and Arthur O. Carlson, Minneapolis, and Arnold E. Carlson, Carver, Minn.

Application August 31, 1954, Serial No. 453,280

3 Claims. (Cl. 198-230) This invention relates to barn cleaning apparatus and more speciiically relates to apparatus for cleaning the gutters of a cattle barn.

Although various types of apparatus have been devised for cleaning the gutters of a barn, the operation of most of such apparatus must be supplemented by manual labor. Such manual labor is required for placing of the waste materials into the proper gutter or for manually handling the waste material conveying apparatus. Most of such types of apparatus are cumbersome and inconvenient to use and operate at less than maximum possible cleaning efficiency. Another disadvantage of many of such types of barn cleaning apparatus is that the gutters in the barn are not scraped clean throughout the length thereof. The reason the gutters are not thoroughly cleaned lies in the fact that often times the side walls of the barn gutters are irregular to make some portions of the gutter wider than other portions of the gutter. Because the gutter- Scrapers can be no longer than the width of the narrowest portion of the gutters, such gutter-Scrapers will disengage the gutter walls in the Wider portions of the gutter and of course will therefore not collect all of the waste materials adjacent tosuch gutter walls. In addition, another disadvantage of such known types of barn cleaning apparatus is that most of such apparatus lack eicient mechanism for cleaning the conveying apparatus passing through the barn gutter after emergence therefrom. Cleaning of the apparatus is obviously necessary for sanitary reasons and for eliminating unpleasant odors and the like emanating from waste material retained on the gutter cleaning apparatus.

A further disadvantage of some of the barn cleaning apparatus which discharge the collected waste materials outside of the barn is that a portion of the apparatus will be subjected to freezing during cold weather. As a result of such freezing of portions of the apparatus, the barn cleaning apparatus will become inoperative and may be caused to break down.

Therefore, with the foregoing in mind, we have devised apparatus seeking to overcome these and other disadvantages and in addition to incorporate other novel features into our apparatus.

A general object of our invention is to provide improved apparatus which substantially automatically cleans all of the gutters of a barn.

Another object of our invention is to provide novel apparatus for removing the waste materials from the gutters in a barn, which apparatus is readily and easily used without requiring manual labor supplementing its operation.

Still another object of our invention is the provision of a novel barn cleaning system which cleans each of the gutters adjacent to the stanchions in a barn and which carries the waste material collected out of the barn for deposit into a wagon.

Still another object of our invention is to provide integrally of a barn cleaning system, a novel elevator which may extend out of the barn for depositing the waste material in a wagon and which is shiftable into the barn for storage.

A further object of our invention is to provide in a barn cleaning system novel apparatus for positively cleaning and removing waste materials from all portions of the gutters of a barn even though such gutters may be irregularly shaped.

A still further object of our invention is to provide in a barn cleaning system improved apparatus for cleaning the gutter-scraping portions of the system.

A still further object of our invention is the provision in a barn cleaning system of a new apparatus for positively guiding a chain which is clogged and surrounded by waste materials so as to prevent meshing of the conventional type sprocket wheels therewith.

These and other objects and advantages of our invention will more fully appear from the following description made in connection with the accompanying drawings wherein like reference characters refer to the same parts throughout the several views and in which:

Fig, l is a diagrammatic representation of our barn cleaning system showing the interaction between the apparatus for collecting Lwaste materials in the stanchion gutters of a barn and of the apparatus discharging the collected waste materials out of the barn;

Fig. 2 is an elevation view taken substantially at 2 2 of Fig. 6 with parts of the barn in section showing the waste material discharging apparatus in detail;

Fig. 3 is a detail plan view of a portion of the waste material discharging apparatus taken substantially at 3 3 of Fig. 2;

Fig. 4 is a detail elevation view showing a portion of the waste material discharging apparatus taken substanr tially at 4 4 of Fig. 2;

Fig. 5 is a perspective detail view showing a portion of the waste material conveying apparatus used in the barn cleaning system;

Fig. 6 is a detail view of a portion of the waste material discharging .apparatus taken on an inclined plane substantially at 6 6 of Fig. 2;

Fig. 7 is a sectional elevation view taken substantially at 7 7 of Fig. 6;

Fig. 8 is an elevation view taken substantially at 8 3 of Fig. 2 showing the waste material collecting apparatus operating in the stanchion gutters of a barn in detail;

Fig. 9 is a detail plan view of a portion of the waste material collecting apparatus taken substantially at 9 9 of Fig. 8;

Fig. 10 is a detail view partly in section of a portion of the waste material collecting apparatus and taken on an inclined plane substantially at 10-10 of Fig. 8, and

Fig. l1 is a detail View of one of the laterally oscillating `straw rakes for sweeping material from the chain.

The barn cleaning system including our invention as shown diagrammatically in its entirety in Fig. l includes several waste material receiving or collecting gutters 15 or stanchion gutters formed in a barn floor in the conventional arrangement behind the cattle stanchions. A waste material conveyor designated in general by numeral 16 is provided in each of the stanchion gutters l5 for carrying waste material collected therein to one end thereof. Conveyor 16 may be of any of several known types vand in the form shown is of the type having an endless elongated flexible element traveling in an endless path,

' traveling through the gutter 15 and thence returning in an overhead location.

A waste material discharging gutter 17, which in the form shown is deeper than the waste material receiving gutter 15, is also formed in the barn floor and arranged to intersect the several waste material-receiving gutters 15 and to communicate therewith and receive waste material therefrom.V An inclined elevator chute designated in general by numeral 18 is provided t@ communicate with one end of the waste material discharging gutter 17 and to extend outwardly of .the barn. In the form shown .chute 1.8 Ais .inclined upwardly from the gutter and kvi111 a direction outwardly of the barn to allow wasute rriateriual to be carried over theoutstanding 1andupperend thereof in to` a wagon placed therebelow. NA waste material dischargingconveyor designated in generalby numeral 19 is provided in ,discharging gutter 11,7 and elevator Chut@ 18 for carrying materials deposited therein toward chute 18 and toward the upper end portieri thereof to discharge such wastematerials out of the barn.` Conveyor V19 may be of any of several known types. anclinthe form shown ,includes an elongated endless flexible element traveling in an endless path traveling in a direction outwardly of the barn through the gutter 1 7 and chute 18 and returning tothe gutter 17 in an overhead position. Y

The material clisllx'a'drging apparatus is shown in detail in Figs. 2-7. Conveyor 1 9 includes an endless elongated flexible element such as chain 20 and also includes a -plurality of gutter-scraping members or cleats 21 secured thereto. The gutter-scraping members 21 are constructed timing methane@ includes e Pair f spaced apart @101.1- gated` guide rails 35 which `are mounted in an overhead position relative to discharge gutter` 17 and which extend substantially longitudinally of chain and are lixedly secured to the barn framework F. A pair of shiftable supporting members 36 are pivotally connected by pivots 36a to the opposite nsides of the upper end portion 18b of elevator ychute 18 at one `end thereof. Each of the support rods 36 has `at the inner end thereof a guide collar 37 which is slidably carried on the respective` guide rail 35. Collars 37 are interconnected by a brace 37a. As chute 18 is shifted upwardly in the vertical plane, support members 36 and collars 37 will shift inwardly of the barn wall W on guide rails 35 to support the upper end portion 18b of elevator chute 18.

The chute-positioning mechanism includes elongated ` ilexible members 38 and 39 such as wire cables. A handoperated winch is provided having a rotatable drum 40 Y journalled on the baarn framework F and having xedly of a rigid material and are attached to chain 20, as by bolts 22 and plates 22a to extend laterally in one direction therefrom. Each of the gutter-scraping members extends from chain 20 in a direction opposite to which adjacent gutter-scraping members 21extend and each engages the corresponding side wall of the discharge gutter 17. Chain 20 is guided in its endless path and through the material discharging gutter 17 by a number of guide members 23 which may comprise sprocket wheels meshed with certain of the links thereof. One of the guide members 23 is secured to the upper end portion of elevator chute 18 to guide chain 20 upwardly therethrough. One of the guide members 23 comprises a chain-guiding wheel 24 which is mounted in a vertical plane in the waste material discharging gutter 17 adjacentrto the lower :end portion of elevator chute I18. Wheel 24 is journalled on shiftable axle 25 -which is carried by framework 26 to permit` shifting thereof in a substantially vertical direction and in a direction substantially normal to the direction of shifting of chain 20. Frame 26 extends substantially in a horizontal direction and is swingably ymounted at one end vthereof Yas by pivot shaft 27 yand mounting plates 28 to the side walls of gutter 17. Ver.n tical shifting of axle 2S and wheel 24 is restricted by a resilient guide mechanism which includes rigid tubular members 29 mounted in upstanding relation in gutter 17 and secured therein by a mounting member 30 which is secured to the side walls of gutter 17. .Tubular members 29 are positioned above the opposite ends of axle 25 and each carries compression` spring 31 in the interior thereof and carries a shiftable guide shaft 32 therein which engages spring 31 and is swingably secured to axle 25 of wheel 24.v Wheelj24 is thereby free to shift in a substantially vertical direction about. pivot shaft 27, but is resiliently urged in a downward direction by spring 31 acting through shafts 32 on axle 25.

A plurality of distending elements 33 are secured to Awheel 24 adjacent to the periphery thereof and extend outwardly radially therefrom and engage chain 20 for guiding the same. Distending elements 33 have a portion 33a thereof at the radially outward terminus thereof extending laterally of wheel 24 and chain 20 for engaging chain 20 for guiding the same.

Elevator chute 18 is swingably imounted as by pivot 34 at its lower end portion 18a -in discharge gutter 17 to swing in a vertical plane to permit the upper end portion 18b of chute 18 to swing into and outr of thebarn. The upper end portion 18b `of elevator chute 18 is supported by the chute positioning` mechanism which is anchored in the barn wall Wand supporting frame F thereof.

As best shown in Fig. 2 and in Fig. 4in which some of the chain' carrying mechanism on elevator chute v18 -has Abeen eliminated for sake of clarity, the chute posisecured at one end thereof a bevel gear 41 which `is meshed with a smaller b evel gear 42 which may be turned 'as by crank 43. A number lof sheaves 44 are also carried on the barn framework F as by shaft 45 and are positioned above the winch drum 40. Another pair of sheaves 46 are journalled adjacent to the inner end portion of guide rails 35. Each of the cables 39 are iixedly Vsecured at one end portion thereof to one of the collars 37 and are trained'about the corresponding sheave 46 and `then trained about the `corresponding sheave 44 and are wound on drum 40 in similar directions, being fixedly secured thereto at the other end portion thereof. Cable 38 is secured at one endthereof to the central portion of brace 37a which ,interconnects collars 37 and cable 38 is then trained around the corresponding sheave 44 and is then wound on drum 40 in a direction opposite to which cables 39 are wound thereon. When crank 43 is turned in one direction, drum 40 will turn to unwind cable 38 and wind-up cables 39 to cause support rods 36 and elevator chute 18 to shift inwardly of the barn into Idotted position B.` When crank 43 and drum 40 are turned in the opposite direction, cable 38 will windfup and cables 39 will unwind to shift elevator chute 18 outwardly of the barn into the full line position. i

The chute-positioning mechanism'including 4the chain guiding member 23 carried on the upper end portion of chute 18, and the shiftable guide wheel 24 coact to comprise tension control means for chain 20. As the upper end .portion 18a of chute V18 is shifted outwardly of the barn, tension on chain 20 is increased, and the tension of chain 20 is decreased when chute 18 is shifted inwardly of the barnY As best shownrin Fig. 2 the barn wall W may be constructed toV enclose elevator chute 18 in shifted position VB and may be provided with swingable doors D which may be opened when elevator chute 18 is to be shifted outwardly of the barn. l

Overhead return trough 47 may be provided for carrying conveyor 19 in its return from elevator 18 to discharge gutter 17. i

A cleaning mechanism, as best showntin Figs. 6, 7 and ll, is provided on the upper end portion 18a of elevator chute 18. Because elevator chute 18 comprises an extension of discharge gutter 17', the cleaning mechanism can be considered to be positioned adjacent to the discharge `end of the gutter. The cleaning mechanism is mounted on framework 48 `which extends upwardly and `longitudinally of elevator chute 18 and which includes -me'nt with chain 20 and gutterscraping `cleats 21. The .cleaning members may include `abrush S0 having a lower `,bristlet'portion mountedlto swing about pivot 51 in the direction of movement of chain 20. The cleaning members may also include several straw rakes 52 and 53, each of which has a plurality of elongated teeth or engaging elements 52a and 53a made of somewhat rigid material such as spring steel wire, and in the form shown, rake 52 has four such teeth 52a and rake 53 has two such teeth 53a.

Means are provided for oscillating shaft 49 and cleaning members secured thereto t-o swing said cleaning members laterally across chain 20. Such means may include any suitable mechanism and in the form shown, includes a crank arm 54 ixedly secured to shaft 49 to turn therewith and a connecting link 55 pivotally connected at one end to arm 54 and eccentrically swivelly connected at the other end thereof to spindle shaft 56 which is journalled on frame 48. A bevel gear 57 is also carried on spindle shaft 56 and is meshed with another bevel gear S which is fixedly secured to rotatable shaft 59 which is journalled on frame members 4S.` Power is supplied to rotatable shaft 59 through a sheave 60 xedly secured thereto, belt 61 trained over sheave 60, and sheave 62 which is ixedly secured to shaft 63 and which carries the other end of belt 61. Shaft 63 is journalled in frame members 4S and carries chain guiding sprocket wheel 23 thereon and is turned thereby.

A pair yof cleat Scrapers 64 and 65 are swingably mounted on the cross frame 481) to swing in a substantially horizontal plane. Each of the gutter-scraping members 64 and 65 extend diagonally across chain 2t) and are shiftable at their outer end portions in a direction outwardly from chain 29. Each of the cleat-scraping members 64 and 65 have a tension spring 64a and 65a respectively connected thereto and to the frame members 48 for returning the corresponding cleat-scraping member inwardly toward chain 20 after having been shifted in an outward direction by cleats 21.

Means are provided for supplying power to conveyor 19 and chain 29 for shifting the same through the discharge gutter 17 and around the endless path thereof. Such means may include motor 66 which transmits power through belt 67, and gear train 68 to the sprocket wheel 23 which is turned by one of the gears of gear train 68.

The waste material receiving gutters are each cleaned by a mechanism substantially similar to that which cleans and carries waste material from discharge gutter 17. The stanchion gutter-cleaning apparatus will include a conveyor in gutters 15 which may include an endless elongated iiexible element 69 such as a chain being trained around guide elements 70 which may constitute sprocket wheels for meshing with chain 69. A plurality of gutter-scraping members similar to cleats 21 as shown in Fig. 5 are secured to chain 69 and each of the gutter-scraping members extend laterally from chain 69 in a direction opposite to which adajcent gutter-scraping members extend and into engagement with the side wall of gutter 15. As shown in Figs. 8 and 9 the stanchion gutter-cleaning apparatus may include cleaning mechanism designated in general as numeral 71 having an oscillator mechanism 72 connected to the chain-cleaning members including brush 73 and straw rakes 74 which engage chain 69 and oscillate laterally over chain 69 for removing waste material therefrom; Chaincleaning members 73 and 74 are of substantially similar construction to those shown in Figs. 6 and 7. Cleatscraping members 75, which are of similar construction and operation to those corresponding elements shown in Figs, 6 and 7, are also provided to clean the gutterscraping cleats of the stanchion cleaning apparatus. Oscillating mechanism 72 includes rocker arm 72a which is connected to an eccentric 72b and is powered through belt 72e and pulleys 72d which are driven by motor 82.

One of the chain-guide sprocket members 70 as shown in detail in Fig. l0 is shiftably mounted to provide tension control mechanism for chain 69. Wheel 70 is xedly secured to shaft 76 which is carried at the opposite ends thereof by shiftable support rods 77 which extend into tubular members 73 and engage compression springs 79 therein which resiliently urge shaft 76 and wheel 70 in a direction to provide tension on chain 69. Tubular members '78 are secured as by eye bolts 79 and bolts 80 to the framework F of the barn.

Overhead return through 81 is provided for carrying chain 69 adjacent to the ceiling of the barn.

Means are provided for supplying power for moving chain 69 through its endless path for carrying waste material through the stanchion gutter 15. Such means may include motor 82 supplying power through belt 83 and gear train S4 to one of the sprocket guide wheels 70 for moving the chain thereover.

Operation To clean the gutters of a barn, the doors D of the barn will be opened and the crank 43 will be turned to shift the elevator chute 18 outwardly of the barn to provide tension on conveyor 19 of the waste material discharging apparatus. Motors 66 and 38 are then energized to actuate the conveyors operating in the waste material receiving gutters 15 and the waste material discharging gutter 17 Chain 69 will travel in the direction of arrow A and will carry waste material through gutter 15 toward the intersection thereof with discharge gutter 17. Tension will be maintained on chain 69 by operation of the spring loaded shiftable guide Wheel '76. The gutter-scraping cleats secured to chain 69 will engage the side walls of gutter 15 and will also engage the bottom of gutter 15, each of the gutter-scraping members or cleats engaging only one of the side walls of gutter 15. Because of the tension maintained on chain 69, each of the gutter-scraping cleats secured thereto will constantly be engaged with the respective side wall of the gutter when traveling therethrough, and will thereby thoroughly clean all of the waste material from gutter 15. The waste material will be discharged into gutter 17 at the intersection thereof with gutter 15.

The oscillating mechanism 72 operates to shift the chain-cleaning members back and forth lacross chain 69 and the cleats attached thereto. Straw rakes 74 oscillate to sweep straw from the chain and brush 73 cleans substantially all the remaining solid material from chain 69. As each of the gutter-scraping cleats is shifted toward the cleaning mechanism 71, it Vwill be engaged adjacent to chain 69 by one of the cleat-scraping members 75. As the cleat progresses forwardly in the direction of arrow A, the engaged cleat-scraping member 75 will shift laterally of chain 69 `along the cleat, scraping waste material therefrom. The engaged cleat-scraping member will 'subsequently shift around the laterally extending outward end portion of the cleat `and will be returned to chain 69 by the spring 75a associated therewith. Chain 69 and the gutter-scraping cleats secured thereto will thereupon pass out of the stanchion gutter 15 and travel upwardly and through return trough 81 and back into stanchion gutter 15.

The waste material discharging gutters receive such waste material from the stanchion gutters 1S and the conveyor 19 carries such waste material therethrough and toward the upper end portion 1S!) of elevator chute 18. Because tension is maintained on chain 2t), each of the gutter-scraping cleats 21 will be maintained in contact with the side walls of gutter 17 to thoroughly 'scrape and clean the gutter. The laterally extending distending members 33 of guide wheel 24 guide the chain 26 through gutter 17 and chute 1S and when waste material becomes piled on or under chain 20, wheel 24 may shift upwardly without becoming disengaged therewith.

As the gutter-scraping cleats pass over the upper end portion 18h of elevator chute 18 the waste material carried thereby will be discharged onto a wagon which may be placed therebelow. The laterally shiftable cleaning members Iare oscillated back and forth across chain 20 to clean the waste material therefrom, straw fakes 52 and 53 cleaning a major portion of the solids and straw ,from chain 20 and brush SDcleaning substantially all of the remainder of lsolids from chain 20. lif `a large chunk of solid material is carried on chain 20 in such 'a manner to preclude removal thereof by brush 50, the brush 50 may swing about pivot 51 to `allow thegchunk of solid material to pass thereby. yBrush t) will thereupon swing back into operating position. When a cleat 21 engages one of the cleat-scraping members 64 Vor 65, the cleat-scraper will shift laterally outwardly from chain 20 `along cleat 21 to remove waste material therefrom and then swing around the outer end portion of clea-t 21 and be returned to chain 20 by action of the tension spring secured thereto. The chain Aand cleats will then return in `an overhead position through trough 47 to the gutter 17 again.

When the gutters have been cleaned, chute 18 may then again be shifted upwardly and inwardly of the barn by turning crank 43 to prevent freezing of the chain guiding and cleaning mechanism carried on the upper end portion 18b thereof.

It will be seen that our barn cleaning apparatus provides the advantages of substantially automatically cleaning all of the gutters of a barn without requiring manual labor to supplement its operation land of carrying the waste material outof 'the barn to be deposi-ted into a wagon or similar container.

It should also be noted that we have provided in our barn cleaning apparatus for the cleaning and removal of substantially `all of the waste material from the gutters of the barn, even though the side walls of the gutter may be irregularly spaced apart.

It will also be quite obvious that we have provided in our new yand novel barn cleaning system lfor the positive guiding of the waste material conveying apparatus when such apparatus is clogged and substantially surrounded by such waste material, and provided for the efficient cleaning of such apparatus when the bulk of the waste material has been discharged therefrom. Y

It will, of course, be understood that various changes maybe made in the form, detail, arrangement and proportion of the parts without departing from the scope of our invention which consists of -t-he matter described herein and set forth in the appended claims.

What we claim is: A

1. In apparatus for removing waste material-s from a barn gutter through the discharge end thereof, the combination of ka single elongated flexible element having a sec-tion thereof guided f for movement longitudinally through such a barn gutter to the discharge endithrereof, a number of guide elements carrying said flexible element, a plurality of gutter-scraping members secured to said flexible element and traveling therewith, a `broom-type brush positioned at the discharge end of the gutterand depending into engagement with said flexible element, said brush being mounted for oscillatory shifting transversely of said flexible element for removing waste material therefrom, and said brush being swingable in the direction of movement of said flexible element to permi-t clods and chunks lof waste material lodged on the flexible element to pass thereby, means for moving said flexible element toward the discharge end of the gutter 'and drivably connected to said brush for oscillating the same .transversely across said flexible element, whereby said brush will sweep said flexible element clean of debris and waste material and will swing in the direction of movement of the flexible element and away therefrom when engaged by chunks vand clods of material which cannot be removed from i the ilexibleelement by the brush.

2. In apparatus for removing waste materials from the gutters of a barn, the combination of an upwardly nclined chute having a lower end communicating with the discharge end of such a gutter and having an upper outer end portion extending outwardly of the barn, an elongated flexible element having a portion thereof guided forY movement `through such a barn gutter and through said chute, anumber of guide elements carrying said flexible element, a plurality of gutter-scraping `members secured to saidwflexible element and traveling therewith for carrying s oscillate transversely of said flexible elementlfor sweeping waste] material therefrom, means supplying power to said flexible element and moving the same through the barn gutter andtoward the upper discharge end of said chute and power means drivably connected to said cleaning `member for oscillating the same transversely of said flexible element, whereby the waste material is discharged out of the, barn from theupper end of said chute and the flexible element is cleaned as it passes beyond the `upper discharge end ofsaid chute to be readied for subsequent storage in the barn.

3. I n apparatus for removing waste materials such as manure andy straw from a barn gutter through the discharge end thereof,` the combination of an elongated flexible element having a section thereof guided for movement through such a barn gutter and toward the discharge end thereof, a number of gu-ide elements carrying said flexible element, a plurality of gutter-scraping members secured to said ilexibleelement and traveling therewith, a

number of cleaning `members mounted at the discharge t end of the gutter and being spaced longitudinally of said flexible elementvfrom each other, at least one of said cleaning members having a plurality of depending and elongated engaging elements spaced from each other in a direction transversely of saidflexible element and extending into engagement with said flexible element, said last mentioned cleaning member being shiftable transversely of said flexible element for moving said engaging elements transversely thereacross and sweeping straw and other material therefrom, means drivably connected with said last Ymentioned cleaning member for oscillating the ysame transversely of said flexible element, and means suppling power` to said flexible element for moving the same through the barn gutter and toward the discharge end thereof, whereby said spaced engaging elements will sweep said flexible element `clear of straw and other large chunks of waste material.

References Cited in the le of this patent 'y UNITED STATES PATENTS 888,765 Stevens May 26, 1908 1,077,339 Farrell Nov, 4, 1913 1,159,129 Tellefson Nov. 2, 1915 1,182,458 Coleman :May 9, 19,16 1,197,060 Petersen et al. Sept. 5, 1916 1,274,219 Ulbrecht July 30, 1918 1,600,357 Peil Sept. 21, 1926 1,640,825 Flintrop Aug. 30, 1927 1,728,664 Comstock Sept. 17, 1929 2,512,073 Sandberg June 20, 1950 2,558,424 Dretzke Iune26, 1951 2,621,773 Coggins et al Dec. 16, 1952 2,635,771 Black Apr. 21, 1953 2,636,593 Baehr Apr, 28, 1953 V FOREIGN PATENTS 30,080 Denmark Aug.,5, 1922

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