US2761573A - Vehicle dumping apparatus - Google Patents

Description

Sept. 4, 1956 J. H. FULPER VEHICLE DUMPING APPARATUS 4 Sheets-Sheet 1 Filed Dec. '14, 1950 INVENTOR. 0/02 ff. f2067 fla Sept. 4, 1956 J. H. FULPER VEHICLE DUMPING APPARATUS 4 Sheets-Sheet 2 Filed D60. 14. 1950 INVENTOR 4 Sheets-Sheet 3 Filed Dec. 14, 1950 fie/mam Sept. 4, 1956 J. H. FULPER VEHICLE DUMPING APPARATUS 4 Sheet-Sheet 4 Filed Dec. 14, 1950 INVENTOR. f7. 24 726/ United States PatentO VEHICLE DUMPING APPARATUS John H. 'Fulper, Kewanee, 11]., assignor, by mesne assignments, to Screw Conveyor Corporation, Hammond, Ind., a corporation of Illinois Application December 14, 1950, Serial No. 200,759

4 Claims. (Cl. 214-49) This invention relates to improvements in a vehicle dumping apparatus adapted for elevating a vehicle to an inclined position to discharge the contents of the vehicle through the end gate thereof and into an elevating or conveying mechanism.

In vehicle dumpers of the past, a great deal of expense was involved in providing extensive below ground excavations lined with concrete structures generally comprising walled pits which were used to house the operating mechanisms of the dumper. .Such below ground concrete structures and excavations have been employed in the past as housings to contain the relatively large operating mechanisms used to elevate the vehicle carrying platforms to a given inclination to dump a loaded vehicle.

With the present day use of highway transportation in hauling grain or cotton seed, as the case may be, larger trucks have been employed which bring such materials longer distances to central points having mills or facilities for processing the transported materials. For this reason, dumpers have been designed with extremely long platforms to accommodate vehicles of this larger type so that the operating mechanisms used to raise such large platforms must necessarily be further increased in capacity and size.

In other words, with the elevating equipment used which includes hydraulic cylinders, such cylinders must have a greater extensibility to raise the forward swingable end of such a large platform into the required inclined position so that the contents of trucks or semitrailers can be emptied into receiving pits. Pneumatic or hydraulic cylinders employed in raising such dumper platforms were formerly mounted in deep below ground pits which required considerable depth even for smaller platforms, since the reactionary foundation point of such cylinders was located a considerable distance below the ground.

It is one of the main objects of the present invention to construct a dumper operating mechanism in a location at or above the ground level with the reactionary cylinder supporting point of said mechanism located substantially at the normal ground line. In this same category, the entire dumper platform supporting structure has been arranged to comprise a plurality of piers on footings which are all relatively near to the surface of the ground and which no longer require the large excavations above referred to. The hydraulically operated actuators for swinging the platforms upwardly to dischargethe contents of a vehicle are thus firmly mounted upon piers supported on footings, and the entire supporting foundation design of the dumper includes relatively small. concrete requirements in contrast to the concrete structures formerly used for dumpers in carrying out this same mode of operation.

The entire dumper and its associated operating mechanisms are adapted for location adjacent a delivery pit which houses elevating or conveying mechanism to carry away the unloaded materials into a mill or processing plant. These pits for the elevating and conveying mechanism are covered, requiring an access door in line with the dumper, which door can be readily opened during the unloading of the vehicles. The operation of this door may be synchronized with the operation of the platform through the same hydraulic system in order to open the door while the vehicle is being raised into its inclined position to discharge the vehicle load through the door opening into the material conveying pit. Prior door structures have been inefficient in operation as well as expensive in construction by reason of complicated door opening mechanism. Furthermore, a door of this type must at all times be operably removable from underneath the tail end of an elevated vehicle and this requirement cannot be satisfied with an ordinary swinging door since that would interfere with the normal unloading of a vehicle into the conveying mechanism of the delivery pit.

It is another object, therefore, of the present invention to provide a quickly opening door that will in no way interfere with the balance of the structure of the dumper or with the vehicle supported in dumping relation upon the platform of the dumper.

A further object of this invention is to provide a door of this character which, when in open position, forms a backdrop which will guide all materials being unloaded into the delivery pit, thus preventing loss of misdirected material which might overshoot the width of the pit receiving the same.

Further objects and advantages relating to the vehicle dumping apparatus of the present invention shall hereinafter appear in the following detail description having reference to the accompanying drawings forming a part of the specification.

In the drawings:

Fig. 1 is a side elevational view of the vehicle dumping apparatus of the present invention including a changed position in broken lines of the vehicle platform support ing a vehicle thereon in raised dumping position.

Fig. 2 is a plan view of the dumper of this invention diagrammatically illustrating the hydraulic power means and hydraulic connections for operating the entire dumping apparatus;

Fig. 3 is a fragmentary side elevational view of the vehicle receiving end of the platform and the hydraulic lifting mechanism illustrated on a larger scale to show certain details of construction thereof;

Fig. 4 is a fragmentary cross sectional view taken substantially along the line 44 in Fig. 3 to illustrate one of the hydraulic lifting units and a portion of the dumper platform and their foundations;

Fig. 5 is a plan sectional view taken substantially along the line 5-5 in Fig. 4 to show further details of construction;

Fig. 6 is a longitudinal cross sectional view on an enlarged scale of the pit door and its operating mechanism taken substantially along the line 66 in Fig. 2;

Fig. 7 is a transverse cross sectional view of the pit door arrangement illustrated in Fig. 6 and as viewed substantially along the line 7-7 in Fig. 6;

Fig. 8 is a fragmentary detail view of a portion of the pit door guiding mechanism;

Fig. 9 is a modified arrangement of the hydraulic dumper mechanism as applied to a swingable platform that is mounted upon scales to normally weigh the platform and a supported vehicle and its load;

Fig. 10 is an enlarged fragmentary view of a portion of the hydraulic lift means employed in the arrangement using scales illustrated in Fig. 9; and

. Fig. 11 is a detail view of the upper free end of the cylinder positioning means embodied in the modified dumper construction illustrated in Fig. 9.

As best illustrated in Figs. 1 and 2, the present invention incorporates a swingableplatform 1 located adjacent a material receiving pit 2 which houses delivery means such as elevating or conveying mechanism 3, the platform 1 providing a runway for the reception of vehicles such as the truck 4 to tilt the latter into an elevated or inclined position as shown in Fig. 1 thereby discharging the contents of the truck through the end gate thereof and into the pit 2 upon the conveyor 3.

The foundation of the present dumper construction comprises a plurality of individual piers as a skeleton foundation in contrast to the continuous deep pit walls formerly employed for the same purpose. Furthermore, the present foundation might be termed a ground level arrangement, Whereas the former walled foundation required considerable below ground pouring of concrete, particularly at the dump cylinder locations where such foundations were of considerable depth underground. All the piers of the present dumping apparatus are supported upon suitable footings designed to carry a predetermined load and according to the requirements of the ground conditions.

As shown in Figs. 1 and 3, piers 5 and 6 are arranged to support the front end of the platform 1 and are situated adjacent an earth ramp retaining wall 7. Intermediate pairs of piers 8-9 and 1tl-11 provide bearing means to support the intermediate portions of the platform 1. Piers 12 and 13 are located adjacent one wall of the pit 2, and the latter two piers provide the means for supporting the pivoted end of the platform 1. In addition to the piers described, the foundation also includes a pair of larger intermediate piers 14 and 15 which are arranged to support hydraulic lift mechanisms for the vehicle dumping apparatus.

All of the piers described terminate in coplanar rela tionship above the ground with each of the piers carrying bearing plates 16 as illustrated in Fig. 3, to provide a plurality of solid metallic surfaces to support the entire load carrying platform 1 while in its inoperative position. Referring now more particularly to Figs. 1 to 4 inclusive, the platform 1 is a rigid structure composed generally of longitudinal side girders 17 and 18 that extend the full length of the platform with cross beams 19 secured to the inner portion of the bottom flange and adjacent side of each of the girders to support intermediate longitudinal I-beams 20 capped by wooden stringers 21. To prevent lateral deflection of this assembled rectilinear structure comprising the girders 17 and 18, and the several cross beams 19, at least one pair of diagonal beams 22 and 23 are connected between the girders 17 and 18 as best illustrated in Fig. 2.

The platform 1 is completed by suitable planking 24 that rests upon the girders 17 and 18 and upon the stringers 21, the planking 24 having guide rails 25 and 26 secured to the longitudinal marginal edges thereof and running the length of the platform. The platform 1 terminates adjacent the conveying pit and each girder has a bearing 27 secured to a portion of the girder to be pivotally connected upon one of the aligned cross shafts 28 carried in bearings 29 supported upon piers 12 and 13, respectively. Thus, the forward truck receiving end of the platform 1 becomes the freely swingable end with the entire platform hinging about the shafts 28 as a single body.

The operating mechanism comprises a like pair of telescoping cylinders 30 and 31 located forwardly of the center of the platform 1 and each cylinder carries supporting cars 32 pivotally mounted upon stub shafts 33 that are mounted in bearings 34 supported upon piers 14 and 15, respectively. Each of the cylinders 30 and 31 are hydraulically operated and include the plurality of nested extensible cylinders 35 as best illustrated in Fig. 3, with the smallest inner cylinder thereof having a clevis 36 pivotally connected with a cross pin 37 that is supported in a suitable overhead bearing 38. Bearings 38 are each connected with fore and aft beams 39 and 40, respectively, comprising integral parts of A-frames 41 and 42 mounted at the opposite sides of the platform 1.

Each of the A-frames comprises an I-beam 43 vertical to the surface of platform 1 and an I-beam 44 inclined as shown, and these beams are rigidly secured to the adjacent girder by bolting or welding. Obviously, the I- beams 43 and 44 as connected by their respective fore and aft beams 39 and each comprise A-frames that constitute spaced rigid lifting structures that are engaged by the extensible ends of each of the hydraulic cylinders 3-) and 31 for the purpose of swinging the entire platform 1 about its pivotal end to accomplish the dumping operation.

These A-frames 41 and 42 are preferably secured to the girders 17 and 18 in the manner best illustrated in Figs. 4 and 5, which illustrate the A-frame 41 in detail. The particular attachment used consists of structural Ts 45 and 47 welded to the upper and lower flanges at the outside of girder 17 and also connected with the girder web by stems 46 and 48 of the T each welded to the girder web. T's 45 and 47, therefore, present relatively fiat surfaces to which the I-beams 43 and 44 of the A- frame 41 may be bolted as best illustrated in Fig. 5. This structure provides a removable A-frame arrangement which is advantageous in shipping and in making repairs or replacements.

The angling of the rearward leg or I-beam 44 of each A-frame has been done for purposes of clearance as may be best understood by referring to Fig. l in the raised platform position. This spread of the legs of the A-frame distributes the stresses at spaced points along the length of the girder. The deep beams 19a as in Fig. 2 will counteract lateral tilting of the A-frame by stabilizing girders 17 and 18 under load conditions.

In mounting the A-frames described in Figs. 4 and 5, standard materials can be employed without the use of special parts, and the overhang of the frames laterally of the platform is reduced to a minimum. At the same time minimum roadway clearance is maintained.

With the A-frames 41 and 42 providing overhead platform actuating means, they also provide protective structures for the operating cylinders 30 and 31, respectively. Protection fore and aft of the platform is provided by the beams 43 and 44, respectively, while the beam depths are such as to shield the cylinder from the truck bodies or chassis laterally of the platform. This is an important consideration and advantage since the cylinders and their associated parts depend upon true alignment to function in their designed capacities.

Attention is also directed to the cylinder bearings 34 which are supported immediately adjacent the platform sides and at ground level, or as shown in Fig. 3, slightly above ground level. Prior practice supported the cylinder ends in deep pits with the top or extensible operating end of each cylinder secured to the underside of the platform. It should be noted that this above ground level apparatus is ideally situated for servicing or repairing if necessary over long periods of use.

In furthering this over ground concept in the construction of the vehicle dumping apparatus, the hydraulic power equipment 49 has been taken out of the ground pit that was formerly located under the platform, and is now placed in some above ground location as illustrated in Fig. 2. Then by placing a control board 50 at the conveyor pit end of the dumper to operate the hydraulic equipment 49, the entire dumping operation can be quickly carried out by one operator. Suitable pipe lines 51 lead to the hydraulic wheel stop cylinders and the door operating cylinder hereinafter to be described. A further divided pipe line 52 leads to the telescoping power cylinders 30 and 31 to lift the platform 1. These various operations can be synchronized by proper valve control means to obtain the best mode of operation for various specified load dumping conditions.

As seen in Fig. 2, a pair'of wheel stops 53 and 54 are operatively mounted in the platform 1 to be rotated by suitable hydraulic cylinders into the path of the wheels of avtruck which is being backed along the platform 1. Another pair of wheel stops 55 and 56 are located adjacent the forward wall 57 of the pit 2 asbest shown in Fig. 6 to be actuated into the broken line positionthere illustrated to engage the rear. wheels of a truck 4. By further referring to Fig. 6 the wheel stop 55 briefly includes a power actuated hydraulic cylinder 58 that is connected with thehydraulic equipment 49 to actuate the wheel stop 55 into its upper position as shown in broken lines in Fig. 6. A hydraulic cylinder such as 58 is provided for each of the wheel stops 53, 54 and 56 and the function of the wheel stops is to prevent movement of the truck during the elevation of the platform. The locations of the two sets of wheel stops provides a flexible arrangement whereby trucks which have a greater body length extending beyond the rear wheels can be positioned and retained in the forward location while the trucks with the shorter distance to the tail gates can be positioned as shown in Fig. 6.

Referring now more particularly to Figs. 6, 7 and 8, pit 2 is provided with the movable door 59 arranged for actuation from the closed full line position shown in Fig. 6 into the broken line position 60 during the dumping operation. The door 59 is shown as a plank covered door providing a complete cover or closure for the opening in the pit 2, but it should also be understood that a door may be provided comprising large grating which could be used in its closed position to receive grain since that is a flowable material. A door made of grating will have to be opened to receive such materials as cotton seed, etc., inasmuch as cotton seeds mat together to form a rather large mass which is incapable of finding its Way through a grating. However, the door 59 shown in Fig. 6 comprises a steel framework 61 supporting the planking 62 thereon. The framework 61 comprises the fore and aft I-bearns 63, 64, 65, 66, 67, 68 and 69, which are secured to terminal channels 70 and 71. A pair of rollers 72 and 73 are mounted at the forward edge of the door as best illustrated in Figs. 6 and 7.

' The entire door rests within an opening formed by a fixed pit framework 74 that is carried in the concrete pit walls, this framework including fixed side channels 75 and 76 that bridge the pit 2 and extend in a longitudinal direction of the dumper. The rollers 72 and 73 on the front end of the door 59 are positioned to operate within the confines of the channels 75 and 76, respectively.

The operating mechanism for the door comprises a pair of swinging arms 77 and 78 having their outer ends pivotally connected at.79 and 80 to adjacently disposed I- beams 63.64 and 6869 of thedoor. The other ends of the arms 77 and 78 are secured to an operating tube 81 pivotally carried by suitable brackets such as 82 disposed in alignment and carried by a member of the pit frame 74. The operating tube 81 also carries a pair of intermediate arms 83 and 84 that are rigidly secured to the tube 81 and which are pivotally connected at 85 to the ram or plunger 86 of a hydraulic cylinder 87. The latter is pivotally carried at 88 on a bracket 89 that is fastened to the rear wall'90 of the pit 2.

*By actuating the plunger 86 with the hydraulic cylinder 87, the ".arms 83 and 84 rotate the operating tube 81, thusbodilyswinging both arms 77 and 78 to bodily raise the door upwardly and rearwardly through the connections of the arms 7778 at 80 and into the position shown by the broken. linesat 60in Fig. 6. During the operation of the mechanism described as accomplished by swinging of the arms 77 and 78, the forward end of the door is guided by fneans of the rollers 72 and 73 through their cooperative engagement within the trackway forming flanges of the- channels 75 and 76. This produces a predetermined endwise but bodily rotating motion of the door as simulated by the arrow 91 in Fig. 6, since the roller end of the door 59 follows the general straight line path determined by the fixed channels 75 and 76. And when the door 59 is in its raised position as shown in the brokenlines in Fig. 6, this door functions as a back stop or raised baffle to prevent any grain or other material beingdumped from overshooting the pit, the door guiding such grain and material directly into the pit 2.

When the door operating mechanism is actuated to close the door by the retraction of the plunger 86, the door will approach the I-beam 92 of the pit door frame at a considerable angle before the door closes entirely as is illus-.

' trated in Fig. 8 showing the door 59 in broken lines as it approaches the I-beam 92. When the door 59 is com-. pletely closed it rests upon the I-beam 92 and upon the corresponding I-beam 93 at the other side of the pit which carries the bearing brackets 82. Referring to Figs. 6, 7 and 8, it should be noted that the rollers 72 and 73 are smaller in diameter than the distance between the top and bottom flanges 94 and 95 of the channels 75 and 76. By providing double ended ramps 96 on the bottom legs 95 at the front end of the channels 75 and 76, the forward end of the door when approaching closed position will be raised by the rollers to elevate the lower forward corner 97 of the door frame structure as indicated in Fig. 8. As the door approaches its fully closed position, the roller 73 will ride downwardly along the surface 98 of the ramp 96, bringing the corner 97 of the door to rest upon the upper surface 99 of the I-beam 92. By proper arrangement of the roller location and ramp height, this corner 97 of the door 59 strikes the top surface 99 of the I-beam 92 substantially at the pit side thereof so that the door will thereafter ride across the top of the surface 99 of the I-beam 92. In this respect the door will have a scraping action to clean dumped materials off of the L beam 92 so that such materials will not have a tendency to pile up and pack upon such I-beam, thereby eventually interferring with the closing operation of the door 59. In the full closed position the door rests upon the I-beam 92 with the roller 73 out of engagement with either the ramp 96 or the bottom flange 95 of the channel 76 substantially as illustrated in Fig. 6.

It should also be noted that a suitable wide mesh net 100 is strung across the door opening of the pit and beneath the door frame to safeguard the conveying system from oversized objects which might get into the pit through the unloading materials. It should also be noted that the entire door operating mechanism and the door itself are located across the top of the pit 2 and that the cylinder 87 and its mounting 89 are at the top of the pit and immediately adjacent the framework 74 supporting the :door operating mechanism. By confining these associated mechanisms substantially to the upper portion of .the pit, with only the cylinder 87 extending partially into the pit but diagonally away from the opening thereof, the pit 2 is free to receive any elevating and conveying mechanism such as 3 that a user may prefer. The

entire door operating mechanism offers no interferences by reason of its location high up and adjacent the top of the pit.

Referring now to Figs. 9, l0 and 11, the platform 1 in this arrangement is provided with a number of supporting pads 101, 102 and 103 which rest upon a sub-frame 104 in the Fig. 1 construction. However, the hydraulic operating cylinder in this case is not pivotally connected directly to any portion of the A-fralmes 109 since the entire platform 1 and its integral parts must in this case be free from any support that would interfere with the weighing of the supported truck and its load while the later is resting upon the platform 1.

To accommodate this particular situation, this modified arrangement uses a pair of telescoping cylinders 110 that are pivotallly carried at 111 upon a bracket 112 mounted upon foundation piers 104a much the same as piers 14 and 15 in Fig. 2. The cylinders 110 are arranged to incline forwardly from the vertical when in inoperative position, and a suitable bracket 113 is mounted upon the piers 104a to 'dispose an arcuate abutment strip 114 in a predetermined position above the piers to normally support the cylinders 110 as illustrated in Fig. 9. This bracket 113 and cylinder support 114 are further illustrated in Fig. 11.

The innermost extensible cylinder 115 of each of the main power cylinders 110 is provided with a stub end 116 having a hardened rounded cap 117 as an abutment member. In direct cooperation with this stub end abutment 117, the A-frames 109 each carry a socket 118 having hemispherical recesses 119 for the reception of the cap 117 of the stub end 116 of the hydraulic cylinder 110. This socket unit includes a forwardly positioned apron which counteracts displacement of the free abutment end of the hydraulic cylinder as the cap 117 seats in the recess 119 of the socket 118. When the platform 1 has been raised to its maximum inclination as shown in broken lines in Fig. 9, the change in angularity between the head beam member of the A-frame and the socket 118 with respect to the centerline of the cylinder 110 illustrates the function of the socket apron 120.

As an added means to make the cylinders 110 assume their slightly forwardly inclined positions when at rest as shown in Fig. 9, each of the A-frames includes a loop spring 121 mounted on a web 122 of one of the frame members in a predetermined position to engage the side walls of one or more of the retracting telescoping cylinders to urge the same forwardly as such cylinders become nested in the retracted position after lowering the platform. In other words, the spring 121 will give the loosely mounted cylinders the necessary forward urge with respect to the platform 1 as the stub end 116 leaves the confines of the recess 119 of socket 118. This will always dispose the cylinders in positions for efiicient operation to raise the entire platform when dumping but without interference with the weighing operation of the scale 105 as the latter is used for first determining the total weight of a truck and its contents prior to the dumping thereof.

This arrangement, therefore, includes the same type of hydraulic equipment and above ground A-frame supports for raising the platform as in the dumper described in connection with Fig. l. The latter modification contemplates the use of the same type of above ground structure as applied to a weighing arrangement that is desirable in certain installations of the vehicle dumping apparatus of the present invention.

The foregoing description has been directed to the embodiments disclosed in the drawings which illustrate preferred arrangements incorporating the principles of the present invention. Certain changes may be evolved without departure from the fundamental concept of the invention, but the latitude of such changes and modifications shall, however, be governed by the breadth and scope of the language of the appended claims defining the invention.

What I claim is:

1. In a vehicle dumping apparatus, a foundation having load bearing areas disposed substantially at ground level, a vehicle platform supported upon certain said foundation areas and arranged for swinging upwardly therefrom, a pair of A-frames secured to the platform sides and extending upwardly from the latter, and extensible hydraulic cylinders each bodily mounted upon certain of said foundation areas adjacent opposite sides of said platform, said cylinders being positioned within said A-frame parts, pivotal means maintaining said cyl- 8 inders in permanent operative connection with the upper ends of said frames respectively to operatively and guidedly actuate said A-frames and said platform upon its supporting foundation areas and to swing said platform away from such foundation areas.

2. In a vehicle dumping apparatus, a foundation having load bearing areas disposed substantially at ground level, a vehicle platform supported upon said foundation areas and arranged for swinging upwardly therefrom, a pair of A-frames secured to the platform sides and extending upwardly from the latter, and extensible hydraulic cylinders each bodily mounted upon certain of said foundation areas adjacent opposite sides of said platform and extending upwardly into said A-frarne parts for connection with the upper ends thereof and adapted to operatively swing said platform away from said foundation areas, said A-frames each comprising fore and aft beams secured to said platform and connected with a cross beam at their terminal ends above said platform, and said cylinders each being connected with an A-frame cross beam and normally confined within the A-frame beams while said cylinders are disposed in inoperative retracted positions with the platform lowered into vehicle receiving or discharging position.

3. In a vehicle dumping apparatus, a foundation having supports disposed adjacent the ground level, a vehicle dumping platform mounted upon said supports for movement relative thereto, A-frames secured to said platform in laterally overhanging relation at the opposite sides thereof, each A-frame comprising upright beams each secured to a platform side at spaced points thereon and extending upwardly away from said platform and including a rigid terminal member to rigidly connect the upper ends of said beams, said beams and member providing a protective skeleton framework open at the bottom end, and extensible hydraulic cylinders each housed within one of said open ended skeleton frames and having operative connection with one of the frame parts, said cylinders each being bodily mounted upon a foundation support adjacent the platform to establish a reactionary point at ground level to move said platform relatively to said supports.

4. A vehicle dumping apparatus comprising ground level support units, a vehicle runway carried at ground level upon said support units comprising a flat bed pivoted at one end upon certain of said support units, and cradle structures for said flat bed comprising A-frames secured in outboard relation to the opposite sides of said bed and bodily movable therewith, and said A-frames having closed tops and being open downwardly, and extensible actuating mechanisms interposed between the closed tops and certain of said support units whereby said mechanisms are entirely positioned above the ground level and in offside relation out of the path of vehicles moving over said flat bed, said frames comprising protective enclosures to prevent accidental contact with said mechanism by a vehicle part or by means carried thereby, and said mechanisms providing means to swing said fiat bed about its pivotal support upon said units and comprising cooperative means to raise said bed in guided vertical relation with respect to the bed pivot through the instrumentality of said spaced cradle structures whereby to counteract lateral shifting of the vehicle and its load relatively to said bed.

References Cited in the file of this patent UNITED STATES PATENTS 519,257 Hageney May 1, 1894 936,294 Boggess Oct. 12, 1909 1,250,974 Cooley Dec. 25, 1917 1,338,798 Swanson May 4, 1920' 1,341,499 De Vol May 25, 1920 (Other references on following page) 10 UNITED STATES PATENTS 1,596,905 Uklenkott Aug. 24, 1926 1,382 933 Rush June 28, 921 2,275,945 Castilla y RuiZ M31. 10, 1942 1,387,036 Benson et a1. Aug. 9, 1921 2501231 Mefierd 1950 1,453,331 Anfindsen May 1, 1923 2,603,366 Adams July 151 1952 1,494,273 Moran May 13, 1924 5 FOREIGN PATENTS 1,507,008 Stone P 2, 1924 2 270 Germany M Feb. 22, 193

1,555,499 K635 P 29, 1925 77 252 Germany June 22, 1939

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