US 2635276 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
April 21, 1953 E. o. NORRIS 2,635,276
FLOOR SCRUBBING AND DRYING MACHINE Filed Feb. 15, 1946 3 Sheets-Sheet l INVENTOR E DWARD O. NORR/J BY I I ATTORNEY April 21, 1953 E. o. NORRIS 2,635,276
FLOOR SCRUBBING AND DRYING MACHINE Filed Feb. 15, 1946 3 Sheets-Sheet 2 LOOR LINE Tic; 4.
INVENTOR EDWARD O. NORRJ5 COP/ 5? WOOL April 1953 E. o. NORRIS 2,635,276
FLOOR SCRUBBING AND DRYING MACHINE EDWARD O. NORRIS A ORNEY Patented Apr. 21, 1953 UNITED STATES PATENT OFF I CE.
ELOQRSQRUBBING AND DRYING MACHINE Edward Norris, Westport, Conn. Application February. '15, 1946, Serial No. 1647,5120
41 Claims. 1
This invention relates to machines for scrubbing floors, walls and the like; and has for its object. to. provide; a. novel. and. improved machine for; supplyginga.cleaningliquid= to the.- surface torbe: scrubbed. and. ior. drying such. surface by the application. of. suction. after the scrubbin operation.
Anotherobject or thelnvention. is to provide. a. portable scrubbing machine. of theabovetype which. may beconnected to any available. source ofloleaning, liquid. and. to any available. waste re.- ceptacle or drain, andinwhichall of. the mecha nlsms. necessaryto.- the. scrubbing and1 drying operations. are containedwithin thev machine itself"...
Another object of theinventiorn is to provide an; improved hand-controlled valve. mechanism for a scrubbing machine; ofthe. above type. whereby a simple, unidirectional. pump. contained within the. machine may be. utilized for. both the. cleaning, and drying. operation.
Another object. is. to provide a simple and efli. cient. scrubbing. machine. which, is. adapted to. re.- move substantially all. of. the liquid froma. surface.
Still another. object is to provide. a. scrubbing machine of the above. type having novel. and improved detailsof construction, and features. of. operation, 7
Various other objects and. advantages will be. apparent as thenature ottheinvention is more fully disclosed The. scrubbing machine-of. the present. inventioncomprises. a suction. nozzle containing a. blade. or other scrubbing. appliance, a suction device... including, a suction-pressure. pump and, a valve. controlling. the flow of. liquid to andfrom the nozzle, and a support or handle containing a. flexible.- conduitwhichmay be. connected to a. source of. cleaning liquid. such as soapy water: andla similar conduit which maybe connected: to.a..waste. receptacle or drain. In the embodiment. disclosed. herein. for. the purpose of illus.- trating, the invention. the machine is. mounted on wheels and is.adapted to be:- moved. over the floor in the manner. of. a vacuum cleaner, but it. may also, be. made in other. forms and sizes for cleaning floors, windows and. the like.
i 'Ehe." machine is: controlled. by a hand. lever which controls the suction pump and also actuatesz the valve:- which, selectively connects the supply and drain-conduits to-the; nozzle. through. thevalveiandpump mechanisms. Inyoneoperative. nositionot the-hand. lever. and valve, cleareing: liquid. from :the. supply conduit: is: drawn through one valve passage into the pump which discharges the liquid through. another valve pase sage into the nozzle, thus wettingthe floor or other surface which. is thenscrubbed by moving the machine back and forth like a vacuum cleaner: In. another operative position of the hand lever and valve, the liquid on thej 'fioor is drawn up by suction through. the nozzle and one valve passage: into the pump which: dis;- charges: it under pressure-through another valve passage. and the; outgoing flexible: conduit: to. the drain- Although the novel features which are char acteristic of: this invention are setforth: moreiin detail in the. claims-appended-hereto, thenature and. scope of the invention maybe better understood by. referring to the following description, taken, inconnection; with. the; accompanying drawings forming: a. partthereto, in which; a. specificembodiment; has been: set forth: for purposes of illustration.
In the drawingszr Fig. l is a side elevation of a portable: floor. scrubbing,- machineembodying the present invention;
Fig.- 2 isan enlarged: view of the: upper handle, partly" broken awayto. show the control mecha-.-: nism.
Fig: 3 is-a broken front elevation of the nozzle. and. suction device;
Fig; 4is. a transverse sectional view of'the. nozzle, showing the position. of the floating? blade whenthe; nozzle is lifted off the floor;
Fig. 5- is a; longitudinal; sectional view through the machine, showing the :motor, pump: and valve" mechanisms; and.
Figs. 6;. and 8-. are enlarged vertical sectional; viewsof the valve mechanism. of Fig. 5,.showing same; in difierent operative positions.
In the following description certain specific terms are used for. convenience in referring: to thevariousdetails of the invention; These terms, however; areto be interpreted: as broadly: as the; state-of the art will. permit.
Inthe drawin s... Fire. 1 shows: a: portablefloor scrubbing; machinecomprisinga suction: nozzlehaving a flaredlbody portion, 2,, a: suction-.-de.- vice- 3; and a: handle 8 containing aflexible conduit-5 which may be connected to a. sourcemf: cleaning-liquid such as soapywateriandia'simiqlar: conduit; 6 1 which. may be connectedato a waste receptacle-ordrain.
The; handle It of. the machine; carriesrapivoted control. lever; 1 actuating a .micro.-.-switch;. a. anda Bowden wire; 9 which; control the operation of.
aesaave the suction device 3, as hereinafter more fully described. For the present it is sufflcient to say that whenever lever I is moved upwardly from the normal inoperative position shown in Fig. 2, it actuates the micro-switch 8 and thereby energizes the suction device 3. Furthermore, when lever is depressed part way cleaning fluid from conduit 5 is pumped to the flared body portion 2 of the nozzle, whereas when lever I is fully depressed the suction device 3 draws liquid upwardly through the nozzle for drying the surface and discharges the liquid through conduit 6 to a drain.
Suction nozzle The suction nozzle I illustrated herein is of the type disclosed in my application Serial No. 635,049 filed December 14, 1945, now Patent No. 2,516,246 dated July 25, 1950, and comprises a rear wall In (Fig. 4) integral with the flared body portion 2, a front plate I 2 secured to the wall l by screws l3, and suitable end plates supporting wheels |4 (Figs. 1, 3, and 5) by means of which the device may be wheeled across the floor or other surface to be cleaned and maintained in proper spaced relation therewith.
The nozzle contains a chamber I! having an elongated opening |8 at the bottom for the passage of fluid between the chamber l1 and the surface to be cleaned. A passage 9 is formed in the rear wall H) for conveying fluid to and from said chamber H. The edges defining the opening l8 are thin and sharp to prevent'the accumulation of dust and dirt thereon and are shaped to form seats for the floating rectangular blade 20. This floating blade 20, of resilient material such as rubber, extends centrally through the chamber I! and has a longitudinally spaced series of circular transverse holes 2| and is provided with transverse slits 22 extending from said holes to the top of the blade to increase its longitudinal resiliency. The resilient blade 28 is formed with longitudinal shoulders 23 on both sides thereof, which are shaped to engage the edges defining the opening N3 of the nozzle to seal said opening and also to limit the outward movement of the floating blade. Coil springs 24 are mounted in the chamber l1 between the top of said chamber and the top of the blade 20, contacting the portions of the top surface of the blade between the transverse slits 22. These springs 24 are positioned in holes 25 in the front plate |2 of the nozzle. The blade 28 projects outwardly through the opening l8 and has a lower resilient scraping surface 26 which is adapted to engage the surface to be cleaned. The blade is slightly narrower than the openin l8 and thus provides a space for the passage of fluid on one side or the other of the blade as the blade slides back and forth over the surface which is being cleaned. In the embodiment illustrated in Fig. 4, an insert 21 of abrasive material such as pressed copper wool or the like, which has desirable cleaning properties, extends along the entire length of the bottom scraping surface 26 of the blade.
In operating the floor scrubbing machine shown in Figs. 1 to 4, the blade 20 is retracted by contact with the floor to provide a fluid passage to the chamber IT. The hand lever I may be first actuated tosupply liquid such as soapy water from the conduit 5 to the nozzle and thence through the chamber l1 and around the blade 20 to the floor. The machine is then pushed 4 back and forth over the floor to scrub the same, the copper wool 21 assisting in this scrubbin operation. At the end of the scrubbing operation, the hand lever I is actuated to apply suction to the nozzle. The blade 20 scraping along the surface causes the water to pile up at its leading side around the opening I8 and the suction draws this water into the chamber l1 and through the passage 9 into the flared, body 2 for discharge through the conduit 6. I shall now describe the construction and operation of the suction device 3 for accomplishing the foregoing operations.
The suction device 3 shown in Fig. 5 comprises an electric motor 30, a combination suction and pressure pump 3|, and a valve mechanism 32. The motor 38 comprises the field pieces 33, armature 34, shaft 35, and stationary cone or hood 36 through which air is discharged for the purpose of cooling the motor as hereinafter described.
Suction-pressure pump The suction-pressure pump 3| is of the type disclosed in my application Serial No. 64 ,254 filed January 15, 1946, now Patent No. 2,470,319 dated May 17, 1949, and includes a rotary casting or plate 38 secured to motor shaft 35, and a multiple stage rotary suction fan 39 comprising two series of fan blades 48 and 4| which are secured to the shaft 35 on opposite sides of a stationary bafile 42. A rotary cylindrical casing 43 having a lower flared wall 44 is secured to the plate 38, as shown in Fig. 5, and will therefore rotate with said plate when the motor is running. A dished circular suction cut-off plate 46 is secured to the lower end of motor shaft 35 by a retaining nut 41, the outer periphery of this plate being spaced slightly from the cylindrical wall of rotary casin 43 to provide an annular opening 48 therebetween. In the operation of the device the fan 39 sucks air through the opening 48 and through a circular series of openings 49 in rotary plate 38, and this air, after passing over the stationary hood 36 of motor 30 and cooling the latter, is discharged through louvers 50 in the upper end of the suction casing 3.
A pair of stationary annular dished plates or cones 52 and 53 are mounted in the rotary casing 43, these cones being spaced apart slightly so as to form between them a restricted space or annulus 54 for the discharge of liquid which enters the rotary casing 43 in a manner hereinafter described. The cone 52 has its inner peripheral edge integral with a stationary cylinder 56 which extends through the housing 51 of valve mechanism 32. The cone 53 has its inner peripheral edge integral with a short cylindrical collar 58 secured to the inner wall of valve housing 51, and the upper portion of said inner wall of valve housing 51 is spaced from the stationary cylinder 56 to provide an annular valve passage 60 which communicates with the annulus 54 betweenfthe cones 52 and 53, as best shown in Figs. 6 to 8. Vanes 5| are secured between cones 52 and 53 to reduce the rotation of the liquid in annulus 54' due to rotation of the rotary casing 43. A felt ring 62 and rubber ring 63 in the upper end of valve housing 51 surround the collar 58 of cone 53 and seal the lower end of the flared wall 44 of rotary casing 43.
Before describing the construction of the valve mechanism 32 and the operation of the scrubbing machine as a whole, I shall briefly describe the operation of the suction-pressure pump 3|, and for this purpose it is sufiicient to assume that llquid such as: soapy water is sucked: into the rotaryeasing 43 which; is: rotating. along: with motor shaft 3 5;. carriage.- 3B;.suction; fan; 32h and suctiom cut off pl'atea The liquid: rotating. in the rotary casing 431' lines: the cylindrical;v wall. of said. casing; and. fiowsroutwardlythmughithe; annulus; 5&5 into the annular valve passage tin; while theeairin'casing: 43.1.is drawnzby fan. 3.9 through the. annular. opening 481 between cut-cit plate 4.6 and; easing: 4'3; throughriopening; 4-9; in. carriage'; 385 andis; expelled;byy-the;v tan 3.9. through th louvers 5! in the upperrenct. on the suction casing .32.
Thea layer or; liquid...lining theazcylindrical. wall casing 43 may continue to v riseiteward.
theacenter the: casing until; it; closes theannuallaropeningr 48; between. cut-off plate as and. the
oi; the. casing, at; which .time. the: suction of famfifilw-illano longerractwuponthe casing 43 and nor more liquid. will be drawn. into-said. casing until; sufiicient; liquid: has: been expelled through annulus 54' and valve passage 60 to clear. the opening .43 between cut-off. plate 45, and. casing .431. The centriiugalfforce. prevents.- the suction from causing the; liquidate Iiseappreciably toward the center in back of the plate-45. Thesize of the annular opening. 48,. which may be. varied as described in. my. above-mentioned. application Serial No.. 641254;. thus determines the. maxi.- mumdepthand consequent pressure of the liquid inzcasingfl... The. rotatingmass. of liquid in the casing. develops a high centrifugal force. The friction. of. the liquid entering the: restricted. an.- nulusv 54' retards the. rotation oi. the liquid in the. annulus, as" do also. the vanes. 61, which: reduces the. centrifugal force; acting, on the. liquid im the annulus. and develops. a. pressure diiieren-= tie-1; between. the. liquid in. thecasing. (which is under high; centrifugal iorce.) andthe'liquid in the annulus. (which isv under low centriiugal three)... pressure. differential equivalent to a static head and develops. the pressure necessary. to drive. the liquid outthrough, the annulanvalvepassagefill.
Valve mechanism- The lower'end of" valve housing 5'! is secured to the: body" portion 2" of" suction nozzle 1 by a coupiing; 65 and set screwed, as shown" in Fig; 5;
The stationarycylinder' 56' depending ironrcone 52 is" fixed to the inner cylindrical wall of valve housing 51 except for theupper-portion-thereof which is spaced from said wall to'f'orm the-annular valvepassage 60; as described above.
A spiderfi l is secured tothe lower inner wall of cylinder 5.5" and has; anelongated integral tube 68- extending' axially in said cylinder. One armof the spider; 61 contains an inlet port 59 communicating with the valve tube 53 and connected to the flexible conduit 5 which, aspreviouslystated, may be connected to a source of cleaning liquid such as soapy water;
The valve tube 68 containsa hollow slid'abl'e valvep'lunger it, the cylindrical wall of which contains a central valve port Tl which is adapted to" register with the inlet port 69 in spider 6"! whemplunger H? is in the mid-position shown; in Fig; '7; at which time; liquid from conduit 5 will pass through 10113569 and 1-!" into: the hollow in.- terior of plunger Ill.
The valve plunger: is actuated by an elongated valve stem: 13 which is threaded to a plug 'M secured in the lowerend of saidplungerr The lower. end of valvestem T3 is pivoted to a lever which is hinged at 1.6 to.-the.inner wall of valve housing 51; asshowrrin Fig; 5;. I-he Bowdemwire .member. 8.1. having the. following. parts:
9;. actuated by thecontrol'lever'l on. the handle-.4 of the machine}- has-1 its-:lowenend; secured? to the hinged. level: 152. Accordingly; by" manipulating thecontrnilevet 1,, the; lever: 15.- actuating-valve stem: l3..amay be moved: upomits hinge lfi andlthe valve: stem; 1.3: and plunger: 1.0 may. be raiscdigor lowered in the valve tube 68. Whemtheetension on; Bowden; wire 9. released1 the; hinged .lever I5;v stem. i3? and plunger-.10: arefreturnedt'toitheir normal positions: by a. coil; spring. 751 which is compressed: between: the: lever: 15- and a spider 18. in valve. housing; 57.: to which. the; lower" end of tube 68 is secured, as shown in Fig.
The. flexible discharge conduit; 61 which; previouslystated be connected; to; a drain. is connected; directly to; the. annular. valve; passage 59 inthevalvehnusing The? stationary cyliinder 56, which-- constitutes, the inner. wall of. the annular. valve passage: 58;. contains an; arcuate port 89 which is opposite the; terminus of. the conduitfi, as bestshow-n in Figs. 6 to it V Slidably mounted within-the.= upper portion; of the stationary clyinder. 5.615; aunitary valve An outer cylindrical sleeve; 82 which. is: in close: slidiing, engagement with the cylinder 56. and con:- .tains an arcuateport ld,adaptedlto register with the arcuate port in cylinder 56, and aicircumferential series of. arcuate slots-v83- adjacentthe top of said sleeve 82. for. a purpose hereinafter described; a top plate 84 which is adapted: to seat upon and sealthea top edge? of stationary cylinder 56 within the. cone. 52-:when: valve: membet 8! descends to its lower limiting: position within said cylinder 55; asshown in Figs; Sand '7; and a hollow axial. tube or. core 8.5 which. is carried by the top-plate; 84 amt is-slidably=mounted in; the upper portion. of. valve: tube" 68. abovevithe slidable valve plunger. 10; The elongated: valve stem 13 actuating plunger 10.: extends upwardly through a spider 85' securedi in the tube 8.5, and a light coil. spring 81, compressed between the spider 8:6 and; the;- upper end-of: stem! 13;. tends to. hold thetop plate. 8.4 seated duringthe upward movement of the: sleeve. it: A. check valve 6a prevents return flow of. liquidfrom the-conduit 6.
Operation Fig. 6 shows the valve mechanism in its normal. idle state, that. is, when. the floorscrubbing machine. is not.- operating: At:v such time the pivoted control lever l on the handle t of the machine is retractedjas. shownlinFig: 2,. the micro-switch 8 is open. and? the motor Misdeenergized.
When the valyezmechanismis.inltheidle state shownv in Fig. 6, it will. belnoted that. the: valve stem. 13 and its valve; plunger H3 are in. their lowermost position.- with plunger id closing. :the inlet port 59-, hence liquid couldnot enter the machine from: the inlet conduit. 5 even. if: said conduit: were connected to. a source: of. liquid under pressure-.. InFigg. 6,.iurthermore; thesliclable valve. member. dliis in, its down position with its top; plate 84- seated' upon and: sealing the top edge of stationary cylinder: 5.61within' the cone; 52;. and in this position thetcircumfer ential series-of slots-83 in. sleeve-81 of? valvermems be]: 8.1; are completely closed bythe surrounding stationaryacylinder. 5%.. At. the same.- timeuthe arcuatei port it in the; sleeve 32 of. the.- valve member 3'] isjim registrywith thewarcuate-port 8E in-stationary: cylinder. 5.6, whichport 8.1} isopen to. the. annular valvepassage; 60. and hence; toqthe" draim conduit. 6.. In. addition; attentionlis par of suction' device 3. -the Bowden wire 9, thereby raising the hinged "ticularly called to the fact that in Fig. 6 the top of the slidable valve plunger 10 in tube 68 is spaced from the bottom of the axial tube 85 of slidable valve member 8|, hence it is possible for the plunger 70 to ascend an appreciable distance in tube 68 before striking the bottom of the axial tube 85.
In operating the scrubbing machine, the operator grasps the hand lever I (Fig. 2) and raises in handle 4 and thereby energizes the motor 30 It also exerts tension on lever 15 in valve housing 51 and consequently raising the valve stem 13 and valve plunger 10 in the valve tube 68. The valve plunger 70 is raised until it strikes the bottom of the axial tube 85 of slidable valve member 8|, at which time the hand of the operator encounters definite resistance to further movement of the hand lever "1. The operator therefore maintains the hand lever in this partly raised position as long as it is desired to wet the surface which is to be scrubbed.
' Fig. '7 shows the valve mechanism in this position, with the top of valve plunger H3 engaging the bottom of the axial tube 85 of valve member 5|, and with the central valve port 1| of plunger registering with the inlet port 69 in spider Bl connected to the flexible conduit 5. This change in the position of valve plunger is and its stem 13 is the only difierence between Fig. 7 and the "idle position shown in Fig. 6.
The flexible conduit 5, as previously stated, may be connected to a source of cleaning liquid such as soapy water. Accordingly, since the motor 30 and suction fan 39 are now running, liquid is sucked from conduit through ports 69 and 'l I, and the interior of valve plunger 15 and axial tube 85, into the rotary casing 43 of the suctionpressure pump 3|. This liquid is carried around the cylindrical wall of casing 43 and is discharged through the annulus 55 between stationary cones 52 and 53, into the annular valve passage 60.
From valve passage 60 the liquid flows through arcuate port 89 in stationary cylinder 58 and arcuate port 19 in sleeve 82 of valve member 8|, into the' interior of said sleeve 82, and thence into the flared body portion 2 of the suction nozzle I, as indicated by the arrows in Fig. 7. The liquid in valve passage 60 will fail to open the check valve 6a, but instead will drain through ports 80 and 19 to the nozzle I. The liquid entering the nozzle flows through the chamber 17 thereof, and around the blade 25 to the floor, as previously described. The operator pushes the machine back and forth over the floor to scrub the same, and, of course, he may release the hand lever "i and discontinue the feed of liquid during a portion of the scrubbing operation after sufiicient liquid has been deposited on the floor.
At the end of the scrubbing operation the hand lever is raised all the Way to apply suction to the nozzle I, as will now be described. The actuation of hand lever to the limit of its movement exerts a tension on Bowden w 9 which raises the hinged lever 15, valve stem 13 and valve plunger 75 to the upward limit o their travel, The valve plunger 15, in thus ascending-through valve tube 68, strikes against the bottom of the axial tube 85 of slidable valve member 8| and then raises the entire valve member 8| to the position shown in Fig. 8.
In the position of the parts shown in Fig; 8 the valve plunger 10 is raised to a Point where its central valve port 1| no longer registers with the inlet port 69 connected to the flexible inlet conduit 5, and therefore, since let port 69 is now closed by plunger 10, liquid can no longer enter the valve mechanism from conduit 5 even though said conduit is still connected to the source of cleaning liquid.
In Fig. 8, furthermore, the cylindrical sleeve 82 of slidable valve member 8| is elevated to a point where the arcuate port 19 in said sleeve no longer registers with the arcuate port 80 in stationary cylinder 56, the said port 80 now'bein closed by the sleeve 82, as illustrated. In addition, the top plate 8 2 of slidable valve member BI is now raised above the top edge of stationary cylinder 56 and the circumferential series of slots 83 in sleeve 82 (which were closed by the surroundin stationary cylinder 56 in Figs. 6 and 7) are now raised above the top of cylinder 56 and are open to the stationary cone 52, as illustrated in Fig. 8.
With the parts in the position shown in Fi 8, the motor 30 and suction fan 39 are run? 'ning, and, as previously described, the movement of the scrubbing machine over the floor causes liquid on the floor to pile up at the leading side of the scraping blade 20 and around the opening |8 in the nozzle The suction of fan 39 draws this liquid into the body portion g of the nozzle and thence upwardly through stationary cylinder 56 of valve mechanism 32, and through sleeve 82 of valve member 8| and the circumferential slots 83 thereof, into the rotary casing 43. This liquid is carried around the cylindrical wall of casing 43 and is discharged through the annulus 54 between stationary cones 52 and 53, into the annular valve passage 60. From valve passage 60, the liquid, which is under considerable pressure, is pumped through flexible conduit 6 to the drain.
Although a specific embodiment has been shown and described herein for purposes of iilustration, it will be evident to those skilled in the art that the invention is capable of various modifications and adaptations within the scope of the appended claims.
What is claimed is:
1. A scrubber comprising a nozzle to be pushed over a surface, a suction-pressure pum having an intake side and a discharge side, a liquid supply duct and a liquid dis-charge duct, and valve means having means in one position to connect the intake side of said pump to said liquid supply duct and the discharge side of said pump to said nozzle for scrubbing and in another position to connect the intake side of said pump to said nozzle and the discharge side of said pump to said liquid discharge duct for drying said surface, said pump having a suction device and a centrifugal liquid separator to separate the liquid, said discharge side being connected to discharge the separated liquid directly from said separator without passing through said suction liquid supply duct and the discharge side of said pump to said nozzle for scrubbing and in another position to connect the intake side of said pump to said nozzle and the discharge side of said pump to said liquid discharge duct for drying said surface, said valve means comprising a housing having a cylindrical wall and a concentric tube spaced to form concentric inner and outer passages, said outer passage communicating at one end with said nozzle and at its other end with the intake side of said pump, said inner passage communicating at one end with the intake side of said pump, a, valve plunger closing the other end of said inner passage and slidable in said tube, a port in said tube connected to said liquid supply duct and closable by said plunger, a closure for said other end of said outer passage, a port in said cylindrical wall, asleeve closing said last port, a Passage connecting the discharge side of said pump with said liquid discharg duct and with said last port, and interconnected actuating means for said sleeve and plunger connected in one position to open both of said ports for supplyin liquid from said liquid supply duct through said pump to said nozzle, in a second position to close both of Said ports, and in a third position to close said first port and open said second port and said closure for applying suction to said nozzle and discharging liquid therefrom through said discharge duct.
3. A scrubber, as set forth in claim 2, in which said closure comprises an annular plate seating on said cylindrical wall and said tube and carrying said sleeve.
4. A scrubber, as set forth in claim 3, in which said annular plate carries a core slidable in said tube and positioned to be engaged by said plunger for lifting said closure plate.
EDWARD O. NORRIS.
References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 930,623 Squier Aug. 10, 1909 1,034,040 Spencer July 30, 1912 1,303,207 Kelly May 6, 1919 1,498,255 Winchester June 1'7, 1924 1,809,432 Webb June 9, 1931 1,982,345 Kirby Nov 27, 1934 2,011,234 Thompson Aug. 13, 1935 2,198,322 Von Schrader Apr. 23, 1940 2,200,026 Juelson May 7, 1940 2,292,435 Crites Aug. 11, 1942 2,531,370 Thompson Nov. 21, 1950 FOREIGN PATENTS Number Country Date 381,256 France Nov. 4, 1907 763,304 France Feb. 12 1934