US2472423A - Scaffolding - Google Patents

Description

June 7, 1949. A, H, HAWES 2,472,423

SGAFFOLDING Filed sept. 11, 194e 3 sheets-sheet 1 v l g3 I 2A 4 F'\G\. 4e `l I\ Linn-'- INVENTOR.

June 7, 1949.

lA. H. HAwEs SCAFFOLDING 3 Sheets-Sheet 2 Filed Sept. 1l, 1946 INVENTOR M ATT'RNEY.

June 7, 1949. A. HQ HAwEs 2,472,423,

SCAFFOLDING Filed sept. 11, 194s sf`sheets-sheet s v "i" "vl" t zggigm INVENTOR ii n ATTORNEY Patented June 7, 1949 SCAFFOLDING Albert Henry Hawes, Erdington, Birmingham, England, assignor, by mesne assignments, to Kwikiorm Limited, Small Heath, Birmingham, England, a British company Application September 11, 1946, Serial No. 696,081 In Great Britain October 2, 1945 7 Claims.

This invention relates to scaffolding of the kind which incorporates metal tubular elements and which is used in the assembly of a scaffolding structure for supporting a substantially horizontal platform or staging for workmen.

In assembling such a structure from scaffolding of the above kind it is at present usual to erect at suitable intervals two rows of vertical columns, adjacent columns in the two rows being connected together by transverse putlogs secured to the columns by separate clamps, each pair of columns so formed being also connected to the next pair or pairs by horizontal ledgers which again are held in place by separate clamping devices. A staging or working platform consisting of a plurality of parallel wooden 'battens is then laid upon the putlogs to form the platform or staging. 1

The connected pairs of columns require to be placed at a prescribed distance apart, depending on the thickness of the battens, and the consequent relatively close spacing of the pairs of columns results in a structure incorporating a very large number of separate elements, whose strength is out of all proportion to the load to be carried.

. Furthermore, unless the transverse putlogs are very carefully located during assembly of the scaiolding, the battens laid thereon will not provide a level platform and it may be necessary to overlap the ends of adjacent battens, or adjacent sections of the staging with the result that dangerous steps liable to trip a workman are produced. y

The present invention has for its object the provision of an improved construction of scaiolding of the above kind for supporting a substantiallyhorizontal platform or staging, which construction whilst being fully as strong as those hitherto employed nevertheless comprises a very much smaller num-ber of elements and can be erected much more rapidly and cheaply, thus facilitating the provision of a substantially horizontal platform or staging as is required, which platform or staging is level so that dangerous steps liable to trip a workman are avoided.

The invention is illustrated in the accompanying drawings, wherein:

Figure 1 is a perspective View of one form of scaffolding structure in accordance with this invention and incorporating scaffold frame units as aforesaid, which structure is intended for use in the construction of walls.

Figure 2 is a detailed perspective View of part of a scaffold frame unit of this construction.

Figure 3 is a cross sectional view of part of the construction shown in Figure 1.

Figure 4 is a View similar to Figure 3 showing a slightly modified construction.

Figures 5 and 6 are perspective views showing two further modified constructions.

Figure 7 is a cross sectional view showing th application of the invention to the supporting of shuttering for use in the construction of walls or the like from concrete or similar material.

Figure 8 is an enlarged cross sectional view of the upper part of the structure shown in Figure 1.

Figure 9 is a detailed perspective view illustrating a further modification of the invention.

Figure l0 is an enlarged side elevation of part of the construction shown in Figure 9.

Referring firstly to the construction shown in Figures 1 to 3 and 8 of the drawings, each of the scaiold frame units there depicted and which are indicated generally at 20 comprises two vertical tubular members 2|, 22 rigidly and permanently connected together by a horizontal member 23, which in the construction illustrated is also formed as a tube, which horizontal member is adapted to engage and support a substantially horizontal staging or platform which extends transversely of the frame unit, which platform or staging in the arrangement illustrated is constituted by a plurality of wooden battens 24.

Each frame unit further comprises a pair of clamping devices 25 disposed adjacent to the junction of the horizontal member 23 with each of the two vertical members 2l, 22 .the clamping devices in the arrangement illustrated being provided on the inner side of each of the vertical members and below the adjacent horizontal member and each clamping device comprises a bracket 26 in the form of a gusset piece shown most clearly in Figures 2 and 3 and disposed in the angle between the horizontal and vertical members, the bracket extending between the two members and having its ends 21 secured permanently to both of these members so that it provides a reinforcement to the junction between the horizontal member 23 and each vertical member 2|, 22. f

Intermediate its ends the bracket is formed with a transverse opening 28 adapted to receive a transversely extending tubular ledger element 29 which is inserted in position by sliding it endclamping screw 3 i and the inner end of the clamping screw is rotatably connected to a pressure plate 32 curved to engage with the tubular ledger element 29, the pressure plate being provided along opposite edges with spaced ears 33 which engage oneoneach sidefof the'bracketso as to prevent the plate from rotating-when the screw is turned, turning being effected by means of a tommy bar which is inserted within the eye 24: of the screw so as to clamp the ledger element..

tightly to the frame unit.

The bracket 25 by its connection; t0 both.th e horizontal and vertical memberszof` the't frame unit serves to retain the ledger' element in position on the frame unit while the clamping screw' 3| is being tightened.

Each frame unit is further providediwi-thafllair,

the clamping screwsaof the. built in clamping -Y device; 2,5.

Thehorizontalzlplatform or staging formed of the battens 24 would then be laid upon horisV zontal membersls." of: the lowerf units shown in Figure,y ll with -thegbattensi extending transversely ofithe said horizontalmembersf.

In order toenabletheheight" of the staging tobeincreased-as the height of the-wallincreases, each frameunit. is provided.- with an adjustable support comprisingapairofvertical metal bars 3B1ofpolygonalsection twisvted'fabout` its axis to formv in effect 4a multiple stariixscrew thread having'A avery large pitch; inirelation vto its diameter, the lowerv end. ofreachbarl being connected to a horizontal plateA 3;'1; which plates form feet for engaging; with.y the groundf andthe upper part of F each bar; extends: withinv one oi thevertical' tubular. members` of, each-:frame.

Each bar is.; furtheri provided with a pair of socketmembers .Stir-having an external formation ofishape corresponding: to .thatlofthe twisted bar and; provided-each with ailockingscrew` 39', the inner.` end-of whichis-adaptedto act upon one face ofthe bar.

The upper of: each-.oithese two sockets 38v is provided on each side witha' pairofupstand-ing parti-circular flanges; d'llito locate it in relation to; the lowerendpf the adjacent tubular member andfeach of the; upper sockets 38is adaptedto.

engage-with theqlower end ofsaid member so that by; loosening thescrewsr a-nd raising-both sockets along their: respective bars the structure formed by the soassembled frame units can be secured; at. varying: heightsx in relation to the groundand-d raised as the@ height; ofv the wall increases;

In order to enable the height of the stagingA orfplatform formed burma-battens Mito be increasedstill further,` for-example, as the height of the wallincreases a11piovisionsisi-made to enable fui-ther sets of framesunits; tube: mounted in vertical superposed reiationshipiulorrthe; lower set of units indicated'in Figure-411; and iorgthis purpose the. upper end; of each ofi; the vertical, tubular members 2 I; ,2 2fis made; offrexucedsection to .proa

vide at this end a spigot 4l adapted to engage within the socket 42 provided by the lower end of the vertical members of the unit immediately thereabove as will be apparent from Figures 1 and 3 of the drawings so that the unit frames can be assembled detachably oneeabcive, the ,other in the manner illustra-ted.

In the modified construction shown in Figure 4 ofthe bracket 25 forming part of the clamping y devices 25 is secured permanently to the vertical member only of the frame unit adjacent to its junction withthe horizontal Imember 23, the free end 4310i; thev bracket carrying the clamping screw 31 anditsassociated pressure plate 32 with the end-43 spacedsuiciently from the horizontal member 23; to. enablewthe ledger element 29 to be inserted therebetween by a horizontal movement transverse to its length instead of only by an axial .movement as in the preceding construction. In this arrangement the ears 33 are provided on oneside only;A offthefpressure;plate;32:.

In each of the above; described. constructions;

thediameter'orthe horizontal member 23: is made somewhat lesstthantthe.:diameter'of the vertical; members 2|, 2,2;ofithe framefurut; which latter; diameter is thesame,aszthefdiameterfoithe other scaiolding elements used in' building; up.I the; structure andin theparrangementshown in Figa ures 1 to 3` theconigurationaoithe openingk 28i1in.. relationto theadiacent; vertical member, of the.

frame unit, is suchzthat;withthegledger element,

29 tightly clamped: the distance ,betweenzthe uppersurface ofthelatterzandthefupper surface yof theV horizontal memberl 23,; corresponds to the diam eter of suchscaioldingz'element; there being au, small clearanceindicated 2.1;.;44V betweenfthe upper"A surface of the f elementv 2R95 andathe lower surface of the member 23.

In, the Y modiedarrangement; shown in Figure 4 it is consequentlynecessaryfto; provide, on the;-

underV surface of thee-,member Z3. adistance piece 45 of a thickness*corresponding; to such clearance, which distance piece.; may be welded in position.

With; .either form: thearraneement: is suclithata.

the ledger elements 29 are supported byv theclamping: devicesA 2.5'; in; such:H a position that when anotherv scaffolding element known as; a; putlog.` element'. iszilai, transverselyy across they ledger elemer1t$12 9,--andjof1az diameterv correspondiinggto thel diameterA of: theledgerelements, its upper surface will be:le.ve1;-with the uppersuriacex ofthe members 23 to1providealevel:supportffor` the battens 24.

This will bezunderstoomfrom. a consideration of Figuresvl and18,`oi1 the `drawings .in which the putlog ,elementsinz the eform of shortmetal tub ea. of the same;diameter'as;theledger elements arel indicatedl at 4.6;. extending parallel to .and interI4 mediate the; horizontal., members 2'3' with their; upper fsurfaceslevel, with the upper f surfacesy of; the members-'23 as fvshow-nrin Figure 8. The put'- logY elements are, secured z to the ledgerl elements by putlog clamps-A1.; theconstruction of' which clampsv forms'ztheasubject Vof patent application' This.. construction. is4 particularlyi suitable for' supporting substantially horizontal a trestle platform for use, for example, in the plastering, distempering or painting of walls or ceilings of buildings wherein considerable variation in the height of the platform is frequently required, although the arrangement may be used for supporting any other platform or staging wherein vertical adjustment is necessary.

In this construction vertical adjustment is obtained by the use of helically twisted bars 36 as in the preceding arrangement but the bars are supported on a more robust base than in the construction shown in Figure 1, the base comprising a pair of vertical tubular members 49 within which the lower ends of the bars are secured or alternatively placed so that they extend for the full length of the said members, the latter being provided with feet 31 and connected by a pair of horizontal bracing members 50.

In this arrangement the upper end of each of the vertical members, 2|, 22 of the frame unit are spigoted as in the previous construction and the internal diameter of the spigot 4I is less than the diameter of the twisted bar 36 so that the maximum vertical adjustment cannot be greater than the length of the vertical member of the frame unit.

A much greater vertical adjustment is obtained with the alternative construction shown in Figure 6 in which the spigots are omitted and twisted bars 36 of a considerably greater length than in the preceding constructions are used, the bar projecting through and beyond the upper end of each of the vertical tubular members 2 I, 22 along the length of which bars the frame unit can be adjusted in the manner already described.

In this construction the frame unit is provided with a second horizontal member 23 which joins the two vertical members near their lower ends, a second pair of clamping devices 25 being provided adjacent the junction of the two members so as to provide for a second set of ledger elements 29 for connecting a number of these frame units together in horizontally spaced transverse relationship. The twisted bars are again provided with feet 3l for engaging with the ground.

The construction shown in Figure 6 is particularly suitable for supporting shuttering for use in the construction of walls or the like from concrete or similar material which is confined during setting by removable shuttering plates,-

the concrete or similar material being poured in stages and the shuttering plates being raised bodily periodically so that their upper edge maintains a substantially constant relationship to the upper surface of the cast material, the shuttering used being of such a height that the cast material progressively uncovered by the lower edge of the shuttering plates has had time to solidify, this progressive elevation of the shuttering plates permitting the use of a shuttering assembly whose height is only a fraction of that of the wall or the like to be built.

, The application of the construction shown in Figure 6 to the construction of such walls is depicted, in Figure '7 wherein the wall in process of construction is shown at 5I and the twisted bars 36 are arranged in two rows namely, an inner row close to the wall and an outer row spaced therefrom with the vertical members 2|, 22 of each frame unit mounted on the inner and outer rows respectively.

To the inner tubular members 2l are attached.

specification No. 2,396,174 and these shuttering being provided between the outer face of ther plates and the adjacent vertical member.

The upper horizontal member, or if desired,`

the lower horizontal member 23 of the frame unit carries transverse battens 2li which extend for the full length of the wall to provide a platform for the Workmen during the operation of pouring the concrete or the like and the frame units disposed at spaced intervals along the length of the wall are raised progressively carrying the shuttering plates with them as the casting operation proceeds, raising being effected by adjusting the socket members 38 along the length of the bars 3E, only one set of socket members being provided in the arrangement shown.

In Figure 9 there is shown a more rigid form of scaffolding structure embodying the frame units 29 than is the case with any of the constructions so far described, which structure is used for the purpose of supporting a verticallyy adjustable platform or staging and in this arrangement the spaced frame units 2li in addition to being joined by transverse ledger elements 29 are joined also by transversely disposed connecting frames 55 of a form similar to the frame units 26, with the exception that the clamping devices 25 are omitted, although in place of the connecting frames 55 frame units 20 including clamping devices can be utilised if so desired.

These connecting units include vertical tubular members 56 connected rigidly by horizontal tubular members 5l and provided also with diagonal bracing members 58 as in the construction shown in Figure 1 and the vertical members 55 are secured to the vertical members 2|, 22 of the frame units by means of a special form of scaiolding clamp indicated generally at 59 in the drawings, which clamp serves to secure the members and 2l or 22 in abutting parallel relationship. The clamp 59 forms the subject of patent application Ser. No. 691,932 filed August 21, 1946.

This abutment between the members 25 and 2l or 22 is lpermitted by reason of the fact that the overall width of both forms of the clamping devices 25 in adirection along the length of the ledger elements 29 is less than the diameter of the vertical members 2|, 22 so that the clamping devices do not project 'transversely of the units beyond said vertical members as will be apparent from Figure 8.

rIhe upper ends of the members 55 of the connecting units are spigoted in a manner similar to the upper ends of the members 2|, 22 and are made of the same length as these members and the clamps 59 further serve to secure the spigots l' di of the members 2i, 22 and 56 to the tubular lower ends 92 of the corresponding members immediately thereabove as shown more particularly in 'Figure 10.

What I claim then is:

1. A scaffold frame unit comprising two vertifcal tubular members, a horizontal member connecting said vertical members rigidly and permanently together, said horizontal member being adapted to engage and support a substantially and horizontally of the frame unit to secure the' latten-to. .ai-.second similar'unit. or, othenstructure: saidx. clampingy devicess. being: disposed-.z one! adiazf. cent toeach junction betweentthersaid horizon.i taLand vertical` membersfofztheframeunit, eachi clampingg.- device comprising: a f bracketz disposedi in, the.v angle; betweenz the: said; horizontalY and verticali members anda extending; between; said; members. `to .each of; whichzit'- is :permanently-sea cured to'. proyidesa reinforcement?, for saidfjunc-rtion', the bracket, having; a: t-ransverse-.` opening, to: receive the .transverse scaioldingrv element by..i as movementY along; itss length; said bracket' having; also adjacent. tosaid opening a; threadedsccken. as. clampingv screw` working. inv said threaded; socket; a. pressure plate onsaid..clampingscrem the; latten being: rotatable; relative, to said, plate; saidplate being adapted. for `clam-ping;` engage ment with. said; transverse scaioldingelement, andi said: plate having' a pair.: of spaced: ears adapted to engage: one onA each side.- ofY said'.- bracket.

2. A scaioldframeunit; comprising twogverftical tubular membersg. a horizontalmember con necting: said vertical: membersl` rigidly andl per manently together, said horizontal member.V being.- adapted to engagepand: support a substantially:- horzontal platform-.or staging extending; transf versely of; saidiframe;` unit. a-.nair--ot clamping; devicesV secured permanently i to the; frame unit( and adaptedior clamping engagementwitn tubua lar. scaffolding elements@ extending transversely. andi horizontally off theefrarneIV unit: to. secure: thel latter toga'` secondsimilan unitor, other structure, said clamping;- devices, being, disposed one` adjacent to. each junctionbetween the-.said,hori. 35;'

zontal andvertical;members-.ofy the frame,- un.t, eachv clamping device Ycomprisingjj a ,Y bracket diseposed.y in. the anglebetween thesaid horizontal.; andvertical memberst said bracket being see-- cured permanently atoneend toone of the said. two. members. and having-Sits.. other end spacedfsufeciently from .the other.: member to...p,ermit. of.4 the.- tubular scaffoldingt element being .disposed in said;- clamping device bya.I movement transverse of.. the length of said member, said' bracket having.J atits said .other end a threaded so.cket, a.clamp ing. screw Working. in.said.threaded socket, a.; pressureplate on said clamping screw, l,thelatten beingprotatable relative to. said. plate, said. plate` being adapted. for.. clamping engagement' with;- said. transverse. scaffolding element,- and. said, plate. having a pairof spacediearsA adapted to engage oneon eachside. of said bracket..

31 A scaffold frame unit comprising,twotvertie cal tubular members,l a. horizontalmember connetting saidlvertical members rigidly andjper.- manently together, said'horizontaLmember lie-.- ingvadapted' to engage andsuppprt a substantially horizontalv platform or staging extending.; transversely of.. said.' frame unitma, pair. of .clamp-` ing devices secured permanently to the. frame; unit.. and. adapted. .f or. clampingengaement with, tubular scaioldi'ng elements ext'endi'ng Y transe. versely and horizontally of the. frame.V unitto secure the. latter to` a.- second. similar. unit or other structure, said'clamping devicesbeing. dise posed one adjacent to eachjunction betweentthel, said' horizontal and' vertical members` off thev frame unit, each. clamping device comprising.- a-` bracket disposed, in the. angle., betweenV the. said'; horizontal and vertical;V members andi' extending,r between said. members` toea'ch of. whichl itis. permanently securedjto provide. a reinforcement?. for, said junction, tiieib'racket having a transverse;

clampingf engagement: with'.v the' said. transverse.

scaiiolding:y element; a; support upon which the' trarne-f is mounted; for adjustable' vertical move-- ment, said supporttcomprising apair off verti cal metall bars; extending into. eachverticaii tubux lai` memberi of.. the' frameunia. meansnfor'supe porting'saidibars inraivertical position on' the` grounclzor.A other external? support, each; of said: barsrbzeing: of polygonal sectionA and'.` being: twisteedll aboutits'. axisr tof. form in effect a; multi-startr screw.l thread havingrfa. very'I large pitchin'y rela-i tion to its-diameter, azsocketmember on each-of: said bars:1 of' corresponding; shape". engaging; the: lower. end: oteachzvertical tubular member,` andK each socket member carrying a: clamping,.fscrew\. adapted` tofactson: oneface of: the; twisted'bar so a'srto securethefframe unit. in'. its adjustedfposi-v tiem 4 Ai scaffold f-rameunitrcomprising. two verti-kY cal.. tubularl members, a` horizontal member. con-- nesting. said?- verticalrmernbersy rigidly. andl perma nently.I together, said. horizontal member being adapted to engage and support a substantially: horizontal;` platform ory staging' extending transverselyv ofqsaid 'frame unit,V apair of clamping `devices;securedfpermanentlyf to vthe frame unit and azdaptecl for clamping engagement' with tubular scaffolding: elements' extending4 transversely andiv liorizontallynf the'frame unit;to securextheflatter to; ar second; similar unit. or other structure, said'` clamping-devices: bei-ng disposed one: adjacent tof eachjunction between thersaidhorizontal andi vertica-imembers, of the; frame. unit, each ciamping; device; comprising-fa biaclteti disposed in the-x ang-ie;` betweenA the: said: horizontal and.- vertical-v members; saidi brackets; being secured permafr nently-ationer enditofoneof the said;two members;A andhaving its. other -endzfspaced suiiiciently from:` the other'memberfto: peimiti ot the tubular scaffolding: element: being disposed in saidv clamping deviceby'- amovement transverse'of the length of:

saidzimembelgsaid bracket-.havingtatits said other; endfa threat/ledsocket,l a ,clamping-screw-Working in-saidthreaded socketisaid clamping screw beingt adaptedf for clamping,-` engagement; with .the said transversescafoldingelementi wherein said plu-.-v rality; of..V horizontallyand.4 transversely spaced. scaiold frame units. are-.connected together by`l horizontal tubular ledger elementszextending `be-r tween theframe unitsand secui'ed.thereto byy thei said clampirlge devices,. and'. the said: horizontal;y members ofthe spacediframe. unitsbeingadapted to...supp,ort.a substantially. horizontal 'platform or: staging extending. transversely of the spaced.. frameiunits` 5..,A scaffold. frame. unit comprisingtwo ver-N tical tubular members, a .horizontal member con-4 necth'ig. said.. vertical members rigidly and. permanently together, said` horizontal member. be im adapted toengage and, support a substantial- 1y, horizontal. platform.. or. staging. extending. transversely of. said. frame unit, a pairv of. U shaped bracketsldisposedteach. in` the angle. between the., said horizontal and vertical mem- A bers, theli'mbs of eachbracket having their free, ends.securedjpermanently and .rigidly oneto the..

horizontal member..and the; other tothe adjacent.4 vertical member, the limbs of each bracket beingspaced apart relatively to receive therebetween aY tubularscaiiol'ding element extending.,

openingtoreceive the,transverse.scaiiiidinglef-4 75; transversely, andhorizontally ofthe. frame unit;

said bracket member being joined by a connecting part, a nut associated with said connecting part, a clamping screw working in said nut and adapted to apply clamping pressure to the transverse tubular scaffolding element and secure the same in the said angle between the horizontal and adjacent vertical members oi' the frame unit.

6. A scaioid frame unit comprising two Vertical tubular members, a horizontal member connecting said vertical members rigidly and permanently together, said horizontal member being adapted to engage and support a substantially horizontal platform or staging extending transversely of said frame unit, a pair of clamping devices secured permanently to the frame unit and adapted for clamping engagement with tubular scaffolding elements extending transversely and horizontally of the frame unit to secure the latter to a second similar unit, said ,Y

clamping devices being disposed one adjacent to each junction between the said horizontal and vertical members of the frame unit, each clamping device comprising a bracket disposed in the angle between the said horizontal and vertical members, each bracket being secured permanent- 1y and rigidly to one of said frame unit members, each of said brackets co-operating with the respective vertical and horizontal member adjacent said angle in providing an opening to b receive one of said transverse scaffolding elements, a nut rigid with each -of said brackets, a clamping screw working in said nut, a pressure plate on said clamping screw, the latter being rotatable relative to said plate, said plate being adapted for clamping engagement with said transverse scalolding element, and means on said plate adapted to engage with said bracket to prevent rotation of said plate.

7. A scaffold frame unit comprising two vertical tubular members, a horizontal member connecting said vertical members rigidly and permanently together, said horizontal member being adapted to engage and support a substantially horizontal platform or staging extending transversely of said frame unit, a pair of clamping devices secured permanently to the frame unit and adapted for clamping engagement with 10 tubular scaffolding elements extending transversely and horizontally of the frame unit t0 secure the latter to a second similar unit, said clamping devices being disposed one adjacent to each junction between the said horizontal and vertical members of the frame unit, each clamping device comprising a bracket disposed in the angle between the said horizontal and vertical members, each of said brackets co-operating with the respective vertical and horizontal member adjacent said angle in providing an opening to receive one of said transverse scaffolding elements, each of said brackets comprising a substantially flat plate disposed with its plane vertical and parallel to the axes of each of said frame unit members, a nut rigid with each of said bracket plates, a clamping screw Working in said nut, a pressure plate on said clamping screw, the latter being rotatable relative to said plate, said plate being adapted for clamping engagement with said transverse scaffolding element, means on said plate adapted to engage with said bracket to prevent rotation of said plate, and said clamping devices having an overall width such that they do not project transversely beyond the vertical members of the frame unit, for the purpose specied.

ALBERT HENRY HAWES.

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

UNITED STATES PATENTS Number Name Date 1,880,767 Burt Oct. 4, 1932 1,920,130 Pease et a1 July 25, 1933 2,057,329 Dui Oct. 13, 1936 2,089,871 Adams Aug. 10, 1937 2,195,906 Uecker et al Apr. 2, 1940 2,294,240 Pollman Aug. 25, 1942 2,379,446 Krueger July 3, 1945 2,389,899 Deddo Nov. 27, 1945 2,399,681 Kemner Majf 7, 1946 FOREIGN PATENTS Number Country Date 96,611 Sweden Aug. 22, 1939

Images