US 2135982 A
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Description (OCR text may contain errors)
NOV. 8, 1938. A M MASTERS 2,135,982
BLACKBOARD FRAME ('JONSTRUCTION Filed May 27, 1936 I l au, ATTORNEYS.
Patented Nov. 8, 1938` BLACKBOARD IFRAME --C'ONSTRUCTION Albert Masters, philadelphia. Pa.
Application May 27, 1936, Serial No. 82,063
This :inventionwrelates vto an improved/iframe construction for permanently mounting blackboard slate-orsimilar -fleldnrateri-al onthe Wall a class room; conferencerroomf, or the like, but more aparticularly-to anall-'metal frame construction of 'this character.
`It is Lthe-usual practice to mount these frames vonlthe walls-of 'the 'building in which-they 'are beinglused -when the building is/being erected.
` "ib For this V'reason it lis -especially desirable lthey'be so designed that Athey may be assembled Vin sections and lto employ ga base section or v"ground which" can be attached `to the wall before `the vlatter isplasteredfif plaster is used.v It is also W desirable thattheybe susceptibleof being readily disassembled at any timeto permit the replace- -ment of the`-'blackboard "slate infcase such* renplacementis necessary. Also,thexu'rlust loe-sturdy ofconstructioneand'pleasing ini apparance as f90 well as f not tao expensive to maii'ufacture and assemble. l
`Ordinarily the slatesfin `these-boards `as .furnis-hed varyin-thicknessboth-With'respect to each other and overtheir individual lengthand height, 135 'and "several pieces dare 'employed in each-board. `Because of this' lvariation in vthickness somewhat `ci av problem islv presented inethe Amounting of fthe jslats as Ait is necessaryffthat their outer or writing surface -be perfectly smoothf whenj installed. With r`the, Iforegoing*inmind itfis 'an `object of this iriventionto` providers. blackboard `frame construction of rthe character referred to which will satisfy Yall' ofjthe requirements.. mentioned. Another `Objectis to provide a clamping arrangein; ment for-engaging the blackboard Islate in-'frames foff-this type whichl automatically, aligns the 'exsurfaces #oft the slate vwh'eng-tl'ie slates are drawn in placeby clamps, thereby eliminating the necessity of any special adjustment Kor-b1ocking `around the edges. f
These and various-other'objects' as well as fthe various' :other novel jfeatures and v`advantages of theinvention'will'be apparentwh'en-th'e following ldetaileddescriptionf is' read in* conjunctionwith 45 .the .accompanying :drawing :fof-whchiigal is "a `front `-e1evationa11- 1v.view f: of a typical vrblackboard assembly constructed' in `accordance withthe invention; fFig. 2 2a sectional lview .takeni on the line II---IIFiofFig.v l; IF1'ga'3 akfviewusimilarfto 450 Figil of-ia modiiiedform'ofithe invention; Figal an. :elevatonal view.: of onefof lthe l`slate-engaging `and molds-'Supporting clipstattachedf to :the louter surface of the frame-supporting ground; and-Fig.
5 .a sectional: ViewV oma-modiedormfof fground.
55 A* tRaeferringein f detail.y to .otite.sdra'viringax and more 'particularly to Figs. 1 land 2, the numeral I designates thefield'of the blackboard'on which the chalk marks are received andwhich is made ofslateorother equivalent material. The Anumeral 2 likewise designates a field of cork` or sim- 5 ilar composition provided for the mounting of maps or other papersV by means 4oi thumb tacks, stickers or the like, being shown merely as an adjunct to the board proper. It `will be readily appreciated, of course, by those skilledr in the 10 art, that this combined assembly mayV take various other shapes. f
As la main support for vthe assembly a continuous frame `or ground@ is employed. 'This consists preferably of a rolled `or extruded anl5 gular metal sectionhaving a flat side which is Vsecuredito the Vsupporting-wall!! either before or after'the plaster -is placed on'the wall and' a side rparallel therewith but spaced therefrom to which the slate'is anchored'bly'clipsfand clamps. As l20 `shown nin Fig.' 2 fa `.ground 13 is 'illustrated which comprises a hollow :rectangularly shaped section Shav'inga protruding fiangea on the'sidelthere- Voi which isdi'sposed against thezwall. 'Through this flange-"3a whichas will'be appreciated'may `25 be projected from eitherfside of the rsectionthe nails-afer fother means such'asscrewsor toggle bolts employedto 'fasten Athe ground'to `the wall are passed.` `When the ange 3a is yprojected in theopposite direction it is, of course,` covered 30 ov'eby ntheplaster :which has `strengthening advantages. While' 'inrthe form shown'it is qafforded `the support of the plaster ononeside-only; it is radapted tobefsecured'to `the vWall neither before orxafter'fthe plaster -fis-1r1ut-onf` y Y .l 35
When inyrposition the 4outer surface 3U of the groundframe '3 is 'disposed in a--plane parallel Ato the-wall -4 and preferably flush with theiplaster infcase plaster isused. To this outer portion` 3b there. is ,secured in spaced .relation by means of '40 screw sbolts or. sheet .metal screws-6 a'plurality of..oute r clampinembers,` ore-.clips J for engaging theoutersurface 4of ,the slatel or cork surface y2. vTo hold thesescrews ,in place either nuts mayy be used or theopenings 3c threadedas indicated .or 45 punched for sheet metal screws.
Cooperating with. theclips 'l is a plurality of complementary clamps 8 which engagev the linner surface of the slate at its edges. These clampsl as shown-arel heldin-place and tightened I against the slate by means of screws V9 which are passed through the openings.l 1c and'threadably engaged in `threaded'openings28d.iin the clamps 8;?r While individuali holes may be provided in.v .the clips -IJ to accommodate. iboth the -screws 6 and 9, a single slot as shown in Fig. 4 is preferably provided and made slightly longer than the normal spacing between the two screws. The p-urpose of this is to permit the clamps 8 Vto be mounted as close as possible to the edge flanges 8b which may be rested against the side 3d of the ground.
By reaso-n of the fact that the clipsl are rigidly secured to the outer portion 3b of the frame 3 and that the clamps 8'are adjusted with respect to the clips l', the louter surface of the slate l is always maintained in an even and xed plane irrespective of any variation in thickness o f Vthe slate. Hence, by simply tighten-ing the clamps 8 against the slate, the slate is rigidly drawn to place and its outer surface brought into perfect alignment without any special adjustment, notwithstanding any variations in the thickness of the slate.
In additionV to functioning as a means for engaging the slate, the clips 1 areV also adapted Yto function as a means for mounting ,a molding I2 over the edges of the assembly to enclose the opening therein and also to provide the assembly with a pleasing appearance. A To so function the lclips are provided with a curled bead 'la at one end and an outwardly flared edge 1b at the other. `The molding l2 is in turn made in the formvof a channel section and provided at the ends of its flanges with inwardly turned shoulders I2a. The upper of these shoulders 12a when assembling the molding is engaged behind the outwardly ared edges Thof the clips, and the other then snapped over the curled bead 1a; VIn this way the molding'is firmly and rigidly .held in place Vbut in such away that it-can be readilyremoved if suchfis desired'to permit access to the'clamps so that the, slate can be replaced if desired.
,To provide a support for chalk and erasers at Vthe base of theframe, a shelf-like'moldingg is substituted along the bottom of the blackboard for the molding I2. This shelf comprisesa somewhat triangular-shaped hollow section, .which is'adapted to Vbesecur'ed by lthe-clips l1 in thek same fashion as the molding !2.= The lower side of it,"as shown, is inclined downwardly to functio-n as a strut, and because of the greater distance between the upper and lower edges; there-Y of adjacent the'wall, longer clips 1 than are used about the rest ofthe frame are attached along the bottom of: the frame 3. Preferably the top of such shelf l3'is dished out to provide a retaining cavity ISb forthe chalkjand erasers, and in the particular embodiment shown this dishedoutA portion is divi-ded into parallel grooves with ridges Abetween for supporting the erasers out of contact with the bottoms of the recesses. The purpose of this is to prevent the erasers from coming in contact with'thedust, etc., which co1- lects on Vthe s-helfQ-this being desirable. especially if they have been cleaned before they are placed on the shelf.
As will be, noted, the cork or matting 2 may be laid directly against a thin section of plaster and held in place solely by theclips l, although if desired the clamps 8 may be used for this purpose thesame as they are for the slates, as will be appreciated.
In the embodiment of the invention shown in Fig. 3, wherein the parts thereof are designated by the same reference characters applied to the structures shown in Figs. l, 2 and 4, except that they are distinguished Aby the use of a prime character, a ground frame sectionv 3, is employed which is a simple U-shaped section rather than the hollow rectangular section shown in Fig. 2. This ground, as shown, is mounted with its web Yportion carrying the clips 'l' and its leg ends disposed against the wall 4. When used it is prefarably attached to the Wall by independent screws, although the screws B that are used for attaching the clips 'l' to the frame 3 may be used for this purpose. Wherethe latter is done the screws 6'- are, Vof course, projected through both the clips and frame into the Wall. Instead of a simple U-shaped section, however, the ground-in this embodiment may takey the shape shown in-Fig. 5 `and in which case the flanged edges may be adapted to receive the retaining screws.` ,'I'headvantage of this shape of ground is that while it may be used with plaster as indicated it also lforms a very desirable type 0f frame for use in connection with a glazed orlike wall -whereuno plaster isremployed, as itv presente a finished molded effect around the outside edges ofY theframe whichuordinarily can not be accomplished without the use o-f a separate molding.Y In this connection, as will be appreciated, the Width of the channel `3' maybe varied at thevtop and bottom of the assembly as indicated to Vform a completely closed and Ysmooth-edged,frame. Y Y
VIn assembling a :blackboard Yembodying this invention,vthe frame v3 is of course .first vattached tothe wall. The .clips and clamps Land 8, re-
spectively, at the bottom of the frame are next Vsecured to the ground with the clamp loose. Z'I'he kother clips and clamps are then secured sufficiently tightly to hold them in place around the-sides and upper edges of the slateand the slate -set between the ,clamping elements lprevi- L, .ously attached to thek base of the frame. It is Vthen tilted into theplaneofV the frame where vitisV stopped kby the clips l disposedabout its edges YWhen in this position the sections of slateareadjusted to bring their edges tightly f togethenand the clips 1 moved into Vregistra- .tion with the'h'oles 3c. Wheninsuch position 'thefscrews Gare lengaged in the frame 3 and progressively drawn up until the'clipsV are tightly .securedin place. The clamps 8 bymeans of screws 9 are then drawn tight against the slate and the molding l2 and shelf I3 snapped into position over the clips 1.
Obviously, as will be appreciated, due to clamps 8 being secured to the clips 1 byY screws separately from those used `to attach the clips to Y the ground frame 3, the mounting of the clips and the' erection of the slate are greatly facilitated.` Furthermore, since they screws employed to hold the clips in engagement withthe ground do nothaveitobe adjusted to secure .the slate 'in' position,l the structure provides a more rigid and foolproof arrangement than where only one v utesV-I `have.explainedthe principle Vand conaframssa struction,` of; my invention. -,and-.; have .illustrated pended rclaimsa the yinvention may .be practiced otherwise than as "specifically `,illustrated and described. 1 1 z -I-claimrf "1. In i al blackboardv`4 frame construction, a
ground frame .-of. angular cross-section, anouter clamp. member .detachablysecured to the :outer surface `of `said ground `frame for engaging the `outer surface of the blackboard field-at the `edge `thereof fand kfor :determining the position of the blackboard field; and'V an inner clamp member secured to Ysaid outer clamp member lsowas .to permit movement thereofafter :said
outer .clamp-'member is fixedly positioned` A "2. `In a blackboard frameconstruction, a continuous ground fra-me of 'angular cross-section,
bers whereby the inner clamp member is movable relative to the positively positioned outer clamp member.
3. In a blackboard frame construction, a ground frame of angular cross-section, an outer `clamp member for engaging the outer face of the blackboard field, screw means for attaching said clamp to the outer face of said ground frame, an inner clamp member for engaging the inner face of the field, and independent screw means for adjustably securing the inner clamp member to the outer clamp member to permit movement of the inner clamp member after the outer clamp member is fixedly positioned, said latter member having a slot therein for receiving both said screw means and of a length adapted to permit the spacing of the screws to vary.
4. In a blackboard frame construction, a ground frame having an inner flat surface for attaching it to a supporting wall and an outer spaced parallel fiat surface, an o uter clamp member secured to the latter surface for engaging the outer face of the blackboard field at the edge thereof and determining the position of the `clamp member after said outer clamp member `is positively positioned.
5. In a blackboard frame construction,'a metallic ground frame of angular cross-section having one side provided with a flange disposed to be attached to a supporting wall and a spaced parallel surface for aligning the outer face of the blackboard field, a clamp'member secured to said ground frame for engaging the outer face of the eld, an inner clamp member for engaging the inner face of the eld and clamping it against said first-mentioned clamp, and an independent screw for adjustably securing said clamp members together and for permitting movement of said inner clamp member after said outer clamp member is positively positioned.
6. In a blackboard frame construction, a ground frame having a side wall which is dis- `posed at right Aangles `to its :outer `will; `'a .clamp member for engaging the ,outer face of theiblackboard field at fthe edge ,thereof detachably .secured ,to the outer wall' of -said yframe,f.an.iinner Vclampmember for engaging the `inner facenof said field whichv clampmemberwis lLshaped- :in cross-sectionand arranged .with its :long Yside parallel to said outer clamp and itsgshorteside parallel toithe side of said 'ground frame and directed towards said outer clamp member, and independent means .for adjustably Vsecuring said inner to said outer clamp memberand for permitting movement ,of-said inner clamp member after said outer l.clamp member Ais `positively .po-
sitioned.` i y 7. InA a i blackboard-,1 frame f construction, va ground frame member of angular..cross-section, an outer ,ciampi-ng, member :detachably secured to the outer surface of isaidgroundfframe Afor engaging the outer surface of the blackboard-field and for,` determining :the position of :theblackboard field, securing ,means detachably .securing the outer clamping member to the frame member, an inner clamp member adapted to engage the back of the blackboard, and independent securing means for said inner clamp member carried by one of the aforesaid members and controlling the position of said inner clamp member so as to permit movement thereof after said outer clamp member is xedly positioned.
8. In a blackboard frame construction, a ground frame member having a back surface adapted to rest against a wall, an angular portion extending from the back surface, an outer surface parallel to the back surface and forming a generally U-shaped structure, an outer member detachably secured to the outer surface of said ground frame member for engaging the outer surface of the blackboard field adjacent the edge thereof and for determining the position of the blackboard field, an inner clamping means adapted to engage the back of a blackboard, and operating means carried by one of the aforesaid members and engaging the inner clamping means so as to move the latter forwardly to engage the back of a blackboard after said blackboard is in position and the outer member is in fixed position.
9. In a blackboard frame construction, a ground frame member having a back surface adapted to rest against a wall, an angular portion extending from the back surface, an outer surface parallel to the back surface and forming a generally U-shaped structure, and an inwardly directed surface extending towards the back surface; an outer member for engaging the outer surface of the blackboard eld adjacent the edge thereof and for determining the position of the blackboard field, securing means for detachably securing the outer member to the outer surface of said ground frame member, an inner clamping means adapted to engage the back of a blackboard, and operating means independent of said securing means carried by one of the aforesaid members and engaging the inner clamping means so as to move the latter forwardly to engage the back of a blackboard after said blackboard is in position and the outer member is in fixed position. l
10. In a blackboard frame construction, a ground frame member of angular cross-section, an outer clamping member detachably secured to the outer surface of said ground frame for engaging the outer surface of the blackboard eld and for determining the position of the blackboard field, Asecuring means detachably securing the outer clamping member to the frame mem-V ber, an inner clamp member adapted to engage the back of the blackboard, and independent means for securing said inner clamp memberV and controlling its position so as to permit movement thereof after said outer clamp member is xedly positioned.
' 11. In a blackboard frame construction, a ground frame member having a back surface adapted to rest against a wall, an angular portion extending from the back surface, an outer surface parallel to the back surface and forming a generally U-shaped structure, an outer member detachably secured to the outer surface of said ground frame member for engaging the outer surface of the blackboard field adjacent the edge thereof and for determining the position of the blackboard field; an inner clamping means adapted to engage the back of a blackboard, and operating means engaging with said inner clamping means and adapted to move the latter forwardly to engage the back of a blackboard vafter said blackboard is `in position and the outer member is in xed position..
12. In a Vblackboard frame construction, a ground frame member having a back surface adapted to rest against awall, an angular portion extending from the'back surface, an outer surface parallel to the back surface and forming a generally U-shaped structure, and an inwardly directed surface extending towardsY the back surface; an outer member for engaging the outer surface of the blackboard field adjacentl the edge thereof and for determining the position of the blackboard field, securing means for detachably securing the outer member to the outer surface of said ground frame member, an inner clamping means adapted to engage Vthe back of a blackboard, and operating means independent of said securing means engaging with said inner clamping means'for moving the latter forwardly to engage the back of a blackboard after said blackboard is in position and the outer member is in xed position.
Y ALBERT M. MASTERS.