US2842865A

US2842865A - Impingement dry box assembly

Info

Publication number: US2842865A
Application number: US617076A
Authority: US
Inventors: Enkelmann Walter
Original assignee: UNICORN ENGINEERING CORP
Current assignee: UNICORN ENGINEERING Corp
Priority date: 1956-10-19
Filing date: 1956-10-19
Publication date: 1958-07-15
Anticipated expiration: 1975-07-15

Description

July 15, 1958 w. ENKELMANN IMPINGEMENT DRY BOX ASSEMBLY 3 Sheets-Sheet 1 Filed Oct. 19, 1956 INVENTOR.

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July 15, 19 58 IMPINGEMENT DRY BbX ASSEMBLY Filed Oct. 19. 1956 INVENTOR. #5 4251 fA AELMAMV .ll( 1 1 A1: liiillllll Arm/ems) United States IMPINGEMENT DRY BOX ASSEMBLY Application October 19, 1956, Serial No. 617,076

16 Claims. (Cl. 34-=159) This invention relates to apparatus for processing motion picture film and particularly to a so-called impingement dry box for drying the film after it emerges from the final wash solution of a film developing machine.

In developing motion picture film, the latter is generally run, in continuous fashion, through a series of tanks containing developing solutions, rinse solutions, fixing solutions, and finally wash solutions. After its emergence from the final wash solution, the film is run through one or more drying cabinets, or so-called dry boxes, for drying of the film. Various forms of dry boxes are in existence, this invention being concerned with a so-called impingement dry box. In dry boxes of this type, the film is moved between a series of plenum chambers. Air is supplied to the interior of these chambers and is exhausted through perforations in the walls thereof toward the film so as to impinge the latter.

In drying cabinets of this character, the film is generally supported on sets of upper and lower film rollers around which the'film is wound in a series of loops. The plenum chambers comprise hollow, narrow, generally rectangular casings some of which are arranged between the runs of film in these loops. Other plenum chambers are arranged in slightly spaced, parallel relationship to these intermediate plenum chambers and located outwardly of the runs of film in the loops. The arrangement is such that the film moves between the chambers, the air exhausted from the intermediate plenum chambers impinging the inner surfaces of the film and the air exhausted from the outer plenum chambers impinging the outer surfaces of the film.

The spacing between the opposing walls of the intermediate plenum chambers and the outer plenum chambers, through which spacing the film moves, is made sufiicient to clear the film so as to prevent contact of the latter with the walls. This spacing is, however, relatively narrow as compared to the width of a hand, for example, and the chambers are relatively Wide in a horizontal direction so that insertion of an operators hand between the chambers to accomplish threading of the film through the cabinets is prevented. Accordingly, dry boxes of this character must be arranged to permit retraction of certain of the plenum chambers so that threading of the film-through the cabinets may be accomplished.

A general object of this invention is the provision of a new and improved impingement dry box for drying motion picture film.

A more specific object of the invention is the provision of an impingement dry box which is uniquely constructed and arranged to facilitate and vastly simplify threading of film through the box.

Another object of the invention is the provision of an impingement dry box of the character described wherein the film supporting rollers and the intermediate plenum chambers are mounted on common supporting atent "ice . remainder of the dry box so as to permit ready access structure which is capable of being elevated above the to the film supporting means for threading of film through the dry box and to the loops of film supported on the rollers for inspection purposes.

Yet another object of the invention is the provision of an impingement dry box of the character described wherein the film supporting rollers and intermediate plenum chambers are capable of being elevated vertical- 1y above the dry box housing and wherein air inlet openings in the intermediate plenum chambers are automatically registered with air exhaust openings in the housing upon subsequent lowering of the intermediate chambers and film supporting rollers into the housing so as to provide for air flow from conduits in the dry box into the intermediate plenum chambers.

Further objects of the invention reside in the provision of an impingement dry box of the character described which is relatively inexpensive to manufacture, simple in construction, and otherwise uniquely adapted and well suited to its intended function.

Briefly, these and other objects of the invention are achieved in the illustrative embodiment thereof by the provision of a hollow, rectangular housing open at its top and having vertical end and side walls and a horizontal bottom wall. The side walls of the housing comprise spaced panels which define therebetween flow spaces communicating with an inlet to which air is delivered by a blower or other suitable means. Bridging these side walls of the housing within the latter are a series of horizontally spaced, relatively fixed plenum chambers having opposing vertical walls which are perforated. The interiors of these fixed plenum chambers communicate with the flow spaces between the panels of the housing side walls so that air flowing through these flow spaces enters the interiors of the fixed plenum chambers and is then exhausted through the perforations in the opposing side walls of the latter.

A top panel or cover assembly of the dry box is mounted on a hoist mechanism and supports depending hanger rods mounting film supporting and driving rollers around which film to be dried is passed in a seris of loops. Also supported on these depending hanger rods are intermediate removable plenum chambers having perforated side walls and inclined end walls formed with relatively large air inlet openings. When the cover assembly is lowered to engage sealing strips about its periphery with the upper edge of the housing side and end walls, these openings in the ends of the removable plenum chambers register with openings in the inner panels of the housing side walls. Communication is thereby established between the interiors of the removable plenum chambers and the aforementioned flow spaces in the housing side walls. Air may thus fiow into the intermediate plenum chambers and be exhausted through the perforations in the side walls of the latter.

These intermediate plenum chambers are mounted in the vertical planes of the upper lower film supporting rollers and have a width which is somewhat less than the spacing between the runs of film in the film loops about the rollers. The arrangement is such that air is exhausted through the perforations in the side walls of the intermediate plenum chambers onto the inner surfaces of the film in these loops. Also, the spacings between the stationary outer plenum chambers is somewhat greater than the spacings between the runs of film in the loops and are vertically aligned with the film supporting rollers so that the film supporting rollers, film loops passing therearound, and the intermediate plenum chambers are adapted to move vertically between the stationary outer plenum chambers. In the lowered operative position of the cover assembly and parts carried thereon, the intermediate and outer plenum chambers are correspondingly downwardly convergent. When the cover assembly is lowered, the intermediate plenum chambers are wedged between the inner panels of the housing side walls. An efiicient seal is thereby formed between the end walls of the intermediate plenum chambers and the inner panels of the housing side walls.

The invention may be best understood by referring to the following detailed description taken in connectio with the annexed drawings wherein:

Fig. l is a vertical section through the present impingement dry box showing the cover assembly, film supporting and driving means, and intermediate plenum chambers in lowered operative position within the dry box housing;

Fig. 2 is a section taken along line 22 of Fig. 1;

Fig. 3 is a top plan view, partially broken away, of the present dry box;

Figs. 4 and 5 are views on reduced scale, showing the hoist means cover assembly, film supporting and driving means, and intermediate plenum chambers in elevated position.

In Fig. 1 there is illustrated a portion of a film developing machine embodying the present impingement dry box 11. Developing machine 10 comprises, generally, a series of tanks containing the various film processing solutions employed in the developing of motion picture film and including a final tank 12 containing a wash solution. Only the final wash tank 12 has been illustrated for the sake of simplicity. Associated with each of these tanks is a film supporting and driving means identical to that indicated at 14 in the final wash tank 12. These film supporting and driving means may be of the type shown in my copending application Serial No. 560,413, filed January 20, 1956, or Patent No. 2,146,170, issued February 7, 1939.

In use of the developing machine 10, film 16 leading from a supply reel, not shown, is passed around the several film rollers comprising each of a film supporting and driving means 14 so as to pass through the solution tanks of the machine in successive fashion. After emerging from the final wash solution contained in tank 12, the film is fed to the present impingement dry box 11.

As discussed in my aforementioned copending application, the film supporting and driving means 14 are supported on a hoist mechanism including a hydraulic hoist assembly 18 and horizontal frame 29 at the upper end of the hoist assembly 18. This frame 20 includes parallel, longitudinally extending drive frames 24 one of which encloses a chain drive 26 which is trained around a series of sprockets associated with each of the film driving and supporting means 14 for driving the same. This chain is driven from a drive motor and reduction gear assembly 28 mounted at the right hand end of the frame 20, as viewed in the drawings.

The arrangement is such that the frame 20 may be elevated by operation of hoist 18 to elevate the film supporting and driving means 14, and film loops passing therearound, out of the solution tanks for initial threading of the film about the rollers of the film supporting and driving means. As will be presently described, such elevation of the frame 20 also accomplishes elevating of the film supporting and driving means and removable plenum chambers, associated with the present impingement dry box 11, above the stationary housing 30 of the dry box.

The housing 30 of the present impingement dry box, comprises a bottom panel 32 which is supported on channels 34 so as to be spaced a distance above a supporting platform 36. Rising from opposite side edges of the bottom panel 32 are side walls 38 of the housing which are joined at their opposite ends by end walls 40 so that the housing 39 is of generally hollow, rectangular construction, the top of the housing being open, as shown.

Generally indicated at 42 is a cover assembly which is carried on the hoist frame 29 so as to be elevated and lowered with the latter. Cover assembly 42 includes a hollow, generally rectangular cover frame 44 having upper, inwardly extending flanges 46 defining an upper rectangular opening 43. Opening 48 is closed by a sheet 50 of transparent material, such as glass, to permit viewing of the interior of the housing 30 from above.

The cover frame 44 includes a vertical rectangular web 52 extending downwardly from the outer edges of the flanges 4-6. The lower edges of web 52 which parallel the end Walls 40 of dry box housing 30 are inwardly flanged at 54 (Fig. l) and secured to supporting frames 56 extending the width of walls 40. These supporting frames 56 mount sealing strips 58 adapted to rest on the upper edges of the walls 40.

The lower longitudinally extending edges of cover frame web 52 which parallel housing side walls 38 are outwardly flanged (Fig. 2) and secured to supporting frames 60, mounting sealing strips 62 adapted to rest on the upper edges of walls 38. The supporting frames 56 and 60 and the sealing strips 58 and 62 are joined at their ends so as to be coextensive with the upper edges of the

housing walls

38 and 40. There is thereby formed a substantially air tight seal between the cover assembly 42 and the dry box housing 30.

As shown most clearly in Fig. 2, the supporting frames 60 are secured to the outwardly extending flanges of cover frame web 52 by means of reinforcing plates 64 welded or otherwise fixed to the supporting frames and flanges. These plates are, in turn, Welded or otherwise secured to the undersides of the drive frames 24 of the hoist frame 26 so that the cover assembly 42 is supported on the hoist frame. Also, as shown in Fig. 3, these outwardly extending flanges on the cover frame web 52 have reinforcing bars 66 welded to their upper surfaces and supported from the drive frames 24 by means of stififeners 68.

As shown in Fig. l, the film 16 leads from the film supporting and driving means 14 in the final wash tank 12 to an idler roller 70 supported on and above the hoist frame 20 from whence it passes over a second idler roller 72 overlying the dry box 11. From the idler roller 72, the film passes through a film inlet 74, mounted on one of the upper flanges 46 of the cover assembly frame 44, to the interior of the dry box housing 36.

Within the dry box housing 3% are a pair of identical film supporting and driving means 76 including hanger rods 78 at opposite sides of the dry box and upper and lower film supporting rollers 81) and 82, respectively, supported on the hanger rods. The hanger rods 78 are suspended from the outwardly directed flanges on the cover frame web 52, as shown.

These film supporting and driving means 76 are substantially identical to the film supporting and driving means 14, more fully described as previously mentioned, in my copending application and the above mentioned patent so that no detailed description thereof will be given at this time. Suffice it to say, that the lower film rollers 82 are journaled on shafts 84 which are fixed at opposite ends to the hanger rods 78 against axial movement along the latter. The upper film rollers are journaled on shafts 86 opposite ends of which are supported in bearing blocks 88 slidably supported on the hanger rods 78. Bearing blocks 88 are resiliently suspended in position by means of compression springs 90 the lower ends of which seat on collars 92 which may be vertically adjusted by manipulation of adjusting sleeves 94 on the upper ends of the hanger rods exterior of the cover assembly 42. I

Certain of the upper film rollers 80 are periphery engaged with friction drive rollers 94 fixed on drive shafts 96. Shafts 96 are journaled in the drive frames 24 and driven through the aforementioned chain drive 26 within one of the drive frames. Film 16 passes in a series of loops ass-ages around the first set of upper and lower film rollers in the dry box and then leads to and passes in a series of loops around the second set of upper and lower film rollers in the dry box. From the last roller of this latter set, the film passes upwardly through a film exit 98, around an idler roller 100, to a take-up reel, not shown. A pair of wiping rollers 102 are supported at opposite ends on the hanger rods 78 intermediate the upper and

lower film rollers

80 and 82 and have their surfaces in wiping engagement with the inner surfaces of the runs of film in the several film loops around the upper and lower film rollers.

Indicated at 104 are pairs of fixed upper and lower plenum chambers having opposing, perforated side walls 106 spaced to receive therebetween the loops of film supported on the

film rollers

80 and 82. These fixed plenum chambers 104 are supported at opposite ends on inner panels 110 of the housing side walls 38 and have their interiors communicating with the spaces 112 between the inner panels 110 and outer panels 114 of the housing side walls 38 through enlarged openings 116 (Fig. 3) formed in the inner panels.

The spaces 112 between the

panels

110 and 114 form flow spaces communicating at one end with a manifold 118 fixed to one of the end walls 40 of the dry box housing 30. Air is delivered into manifold 118 through an inlet opening 120 from a blower 122 or the like. Air thus flows from the blower 122, through the inlet opening 120 into the manifold 118 and thence into each of the flow spaces 112 between the housing side wall panels to the openings 116 in the inner panels 110.

Air entering the stationary outer plenum chambers 104 through openings 116 is exhausted through the perforations in the inner walls 106 of these chambers and impinges the outer surfaces of the film 116 in the several film loops. Air is exhausted from the interior of the housing 30 through anop'enin'g 124 in the bottom panel 32 of the housing communicating with an exhaust manifold 126. Manifold 126 may lead to a cooling unit (not shown) wherein the air is cooled and subsequently recirculated to the plenum chambers.

To provide for impingement of air on the inner surfaces of the film in the film loops between the fixed plenum chambers 104, removable plenum chambers 128 are located in the loops. Both side walls 130 of these removable plenum chambers are formed with perforations 132 and the width of the latter plenum chambers is somewhat less than the spacing between the runs of film in the film loops so that their side walls 130 are spaced from the inner surfaces of the film.

As shown most clearly in Fig. 2, the upper and lower walls 134 of the removable plenum chambers 128 have openings receiving the hanger rods 78 therethrough. Fixed at opposite ends to these top and bottom walls 134 of the removable plenum chambers and registered with the openings in such walls are sleeves 136 through which the hanger rods '78 slidably extend and which seal off the interiors of the chambers.

As described more fully below, the removable plenum chambers 128 are adapted to be elevated out of the dry box housing 30 with the cover assembly 42. In the lowered operative position of these parts shown in Fig. 2, air fiow from the spaces 112 to the interior of the removable plenum chambers 128 takes place through openings 138 in the inner housing panels 110 which register with openings in the end walls 140 of the removable plenum chambers. To assure proper positioning of the removable plenum chambers and efficient seals between the latter and the inner panels 110 of the dry box side walls 38, the inner panels 110 and the ends of the removable plenum chambers are downwardly convergent, as shown. The arrangement is such that when the removable plenum chambers are lowered in the housing, they become wedged between the inner panels 110 to provide substantially air tight seals'between the chambers and panels 110. Tracks 142 maybe provided on the panels to guide the plenum chambers in this vertical movement.

To accommodate raising of the plenum chambers 128 out of the dry box by upward movement of the hanger rods 78, the latter mount fixed collars 144. When the cover assembly and hanger rods are in lowered position, collars 144 are spaced somewhat below the bottom walls 134 of the removable plenum chambers so that the latter can firmly seat against the inclined side panels 110. Accordingly, when the dry box is in use, air flows from the flow spaces 112 through the openings 138 in the housing side panels 110 and open ends of the plenum chambers 128 into the interiors of the latter from whence it is exhausted through the perforations 132 against the inner surfaces of the film in the several film loops.

Operation of the present impingement dry box is believed to be obvious from the foregoing description. Thus, in use of the dry box, the cover assembly and the film supporting and driving means 76 and removable plenum chambers 123 occupy the lower positions shown in Figs. 1 and 2 wherein the sealing strips 58 and 62 on the cover assembly seal the latter to the dry box housing 30. Air entering the stationary plenum chambers 104 and the removable plenum chambers 128 from the flow spaces 112 between the side panels 110 and 114' of the dry box housing 30 is exhausted through the perforations in the side Walls of the plenum chambers onto the inner and outer surfaces of the film in the several film loops. The wiping rollers 102 aid in drying of the film and also serve to guide the film. During this drying operation, the interior. of the dry box may be viewed through the transparent window 50 for inspection purposes.

To accomplish initial threading of the film through the several film solution tanks as well as the dry box 11, the hoist frame 20 may be elevated to lift the several film supporting and driving means 14' out of the solution tanks and the film supporting and driving means 76 and removable plenum chambers 128 out of the dry box housing 30 as shown in Figs. 4 and 5.

There has thus been described an impingement dry box which is fully capable of attaining the numerous objects and advantages preliminarily set forth. While a present preferred embodiment of the dry box has been described and illustrated, it will be evident that numerous modifications in design and arrangement of parts thereof are possible within the scope of the following claims.

I claim:

1. In an impingement dry box, a hollow housing having an open side, at least one fixed plenum chamber stationarily mounted within the housing and including a side wall having air discharge openings, means on the housing defining a flow passage for air communicating to the interior of said plenum chamber, at least one removable plenum chamber movable into and out of said housing through said open side and including at least one side wall having air discharge openings, said removable plenum chamber being adapted to occupy an operative position within the housing wherein said side wall of the removable plenum chamber is slightly spaced from said side wall. of the fixed plenum chamber, said housing and removable plenum chamber having openings which register in said operative position of the removable plenum chamber, said latter opening in the housing communicating to said flow passage, means for moving said removable plenum chamber into and out of the housing, and strip supporting means on said second-mentioned means for supporting strip material for movement along a path passing between said plenum chambers.

2. The subject matter of claim 1, including a closure for said open side of the housing, said closure being carried on said second-mentioned means and closing said open side of the housing when said removable plenum chamber is in operative position.

3. The subject matter of claim 1 wherein said strip supporting means comprise parallel sets of coaxial rollers r 7 adapted to have a strip of material passed therearound in a series of loops, said removable plenum chamber being located between and in a plane missing through the axes of said sets of rollers so as to be positioned within loops of a strip passing about the rollers.

4. The subject matter of claim 1 wherein said housing includes a pair of spaced walls extending to said open side, at least one of said latter walls having spaced panels defining said fiow passage.

5. An impingement dry box comprising a hollow housing having an open side and a pair of spaced walls extending to said open side, at least one fixed plenum chamber stationarily mounted between said walls within the housing and having a side wall formed with air discharge openings, said housing having a flow passage for air, said passage having an inlet and communicating to the interior of said chamber, at least one removable plenum chamber movable into and out of the housing through said open side and including at least one wall having air discharge openings and which is slightly spaced from said wall of the fixed plenum chamber when said removable plenum chamber is in operative position in the housing, said removable plenum chamber bridging said spaced walls of the housing in operative position, an end of said removable plenum chamber and at least one of said spaced walls of the housing having openings which register in the operative position of the removable plenum chamber, said opening in the housing wall communicating with said flow passage, means for moving said removable plenum chamber into and out of the housing, and strip supporting means on said first-mentioned means for supporting strip material for movement along a path passing between said plenum chambers.

6. The subject matter of claim 5 wherein at least said one wall of the housing includes spaced inner and outer panels defining said flow passage therebetween, said inner panel being formed with said opening in the housing wall.

7. The subject matter of claim 5 wherein said spaced walls of said housing and the ends of said removable plenum chamber diverge toward said open side whereby said removable plenum chamber is wedged between said spaced housing walls in operative position to form a substantially air tight seal about said registering openings in the removable plenum chamber and one wall of the housing.

8. An impingement dry box comprising a hollow housing having an open top and spaced vertical side walls extending to said open top, hoist means, film supporting means on said hoist means including vertically alined and spaced upper and lower film supporting rollers vertically movable into and out of said housing through said open top by operation of said hoist means, said film rollers being adapted to have motion picture film passed therearound in a series of loops, a removable plenum chamber supported on said film supporting means between and in a plane passing through the axes of said upper and lower film rollers whereby to be positioned within said loops of film, said chamber having opposite, vertical, perforated side walls spaced inwardly of planes tangent to said upper and lower film rollers, said removable plenum chamber being raised and lowered with the film supporting means and being adapted to occupy a lowered position in the housing, said removable plenum chamber extending between said housing side walls in lowered position, said housing having an air passage with an inlet, at least one side wall of the housing having an opening communicating with said passage and registering with an opening in an end of the removable plenum chamber when the latter is in lowered position, and at least one fixed plenum chamber stationarily mounted between said housing side walls Within the housing, said fixed plenum chamber having its interior communicating to said passage and having a vertical perforated wall horizontally spaced from the perforated wall of the removable plenum chamber when the latter is in lowered position.

9. The subject matter of claim 8 wherein said housing side walls and the ends of said removable plenum chamber are downwardly convergent and said removable plenum chamber is wedged between said housing side walls in lowered position to provide a substantially air tight seal between said one housing side wall and removable plenum chamber about said registering openings.

10. The subject matter of claim 9 wherein said removable plenum chamber is mounted for limited vertical movement on said film supporting means to accommodate Wedging of the chamber between said housing side walls.

11. The subject matter of claim 8 including a cover on the hoist means closing said open top of the housing in the lowered position of the removable plenum chamber.

12. An impingement dry box comprising a hollow housing having an open top and spaced vertical side walls extending to said open top, the inner surfaces of said side walls being downwardly convergent, at least one of the side walls including spaced inner and outer panels defining an air passage therebetween having an inlet, at least two fixed, horizontally spaced plenum chambers stationarily mounted between said side walls within the housing, said chambers including opposing vertical, perforated side walls and having their interiors communicating to said passage, hoist means over the housing, film supporting means on the hoist means including upper and lower film rollers vertically movable into and out of the housing between said plenum chambers by operation of the hoist means, said film supporting means including spaced depending hanger rods supporting said film rollers and said film rollers being adapted to have film passed therearound in a series of loops, a removable plenum chamber supported for limited vertical movement on said rods for raising and lowering of the removable plenum chamber with the film supporting means into and out of said housing between said stationary plenum chambers, said removable plenum chamber being positioned to be located within said film loops and having vertical perforated side walls spaced inwardly of planes tangent to said upper and lower film rollers whereby to be spaced from the film in said loops, the ends of said removable plenum chamber being downwardly convergent and parallel to said inner surfaces of the housing side walls for wedging between the latter walls in lowered position, said inner panel of the housing side wall and the adjacent end of said removable plenum chamber'having openings which register in the lowered position of the removable plenum chamber whereby to place the interior of the latter in communication with said air passage, and a cover on said hoist means closing said open top of the housing in the lowered position of the hoist means and removable plenum chamber.

13. In an impingement dry box, a hollow housing having an open side, a removable plenum chamber movable to an operative position within said housing, and removable from the latter through said open side, said plenum chamber having an air inlet opening and at least one side wall formed with air discharge openings, said housing having an air supply system including an exhaust opening which registers with said inlet opening when said plenum chamber is in said operative position, means for moving said plenum chamber into and out of said housing, and strip supporting means on said first-mentioned means for supporting a strip of material for movement along a path passing close to said wall of the plenum chamber.

14. The subject matter of claim 13 wherein said housing has spaced walls which extend to and diverge toward said open side, said plenum chamber extending between said spaced walls and having tapered ends for wedging of the plenum chamber between said spaced walls when in said operative position, said inlet opening being in one tapered end of said plenum chamber and said exhaust opening being in one of said spaced walls, said wedging of the plenum chamber forming a seal about said inlet and exhaust openings.

15. The subject matter of claim 14 wherein said firstmentioned means comprise support members extending substantially normal to said open side and movable into and out of said housing through said open side, said plenum chamber being mounted for limited movement on said members.

16. In a film processing machine, a plurality of tanks having open tops, hoist means extending over said tanks, a plurality of support means each asociated with one of said tanks depending from said hoist means and movable into and out of said tanks by operation of said hoist means, said support means including strip supporting means adapted to have a length of strip material looped therearound for feeding of said material through said tanks successively, at least one of said tanks being adapted to contain a solution, a plenum chamber carried on the first-mentioned support means associated with another one of said tanks, said plenum chamber having an air inlet opening and a Wall formed with air discharge openings past which said strip material moves, said chamber being movable into and out of said latter tank with said latter support means, and an air supply system having an exhaust opening which registers with said inlet opening in the plenum chamber when the latter is lowered in its tank.

References Cited in the file of this patent UNITED STATES PATENTS 1,996,020 Hurxthal Mar. 26, 1935 2,456,301 Miller et al. Dec. 14, 1948 FOREIGN PATENTS 18,852 Great Britain Aug. 13, 1914