US1790549A - A cory - Google Patents

Description

Jam-27, 1931. A. M. MASTERS BLACKBOARD FRAME MOUN'HNG,

Filed April 23. 1928 2 Sheets-Sheet l Azerzlzzmszem 44 43 wxmx 3 7 Jan. 27, 1931. A. M. MASTERS 1,790,549 7 BLACKBOARD FRAME MOUNTING Filed April 23,1928 2 Sheets-Sheet 2 Patented Jan. 27, 1931 UNITED STATES PATENT OFFICE ALBERT M. MASTERS, OF FRANKFORD, PHILADELPHIA, PENNSYLVANIA, ASSIGNO R TO MASTERS STEEL FRAME COMPANY, OF PHILADELPHIA, PENNSYLVANIA, A 00R:

PORATION OF DELAWARE BLACKBOARD-FRAME MOUNTING Application filed April 23, 1928. Serial No. 222,230.

I The present invention relates to an improved blackboard frame mounting, the purpose of which is to provide a device of this kind, constructed to removably clamp and support the blackboard in position.

In order to accomplish this, it is the purpose to provide upper and lower sheet metal channel members for the reception of the board, clamps fulcrumed on adjusting screws to force the board toward the outer flanges of the channels and clamp the same in position, therebeing suitable felt pads on opposite sides of the board where it is clamped, to prevent breaking of the board.

Another feature of the invention consists of longitudinal depressions in the back walls of the channels to steady and insure positioning the adjusting screws, in combination with aflange or other support forming a part ofthe lower channel, to support the board.

A further feature of the invention consists in forming the lower channel with a chalk and eraser trough, said trough forming a part of the lower channel.

It is to be understood that the particulars herein given are in no way limitative, and that while still keeping within the scope of the invention, any desired modification of details and proportions may be made in the construction of the appliance according to circumstances.

The invention comprises further features and combination of parts to be hereinafter set forth, shown in the drawings and claimed.

In the drawings:

Figure 1is a view in front elevation of a blackboard frame mounting constructed in accordance of the invention.

Figure 2is a sectional view on line 2-2 of Figure 1, showing the blackboard in position, and the clamping means tightened.

Figure 3is a detailed view in perspective of one of the upper clamps in the upper channel.

Figure 4is a sectional view similar to Figure 2, but showing the clamps loosened. Figure 5is a detailed perspective View of the upper channel.

Figure 6is a detailed perspective View of the lower channel.

Referring to the drawings, 1 identifies parts of the wall construction of a room and 2 and 3 are upper and lower channels for the support of a blackboard 4:.

The upper channel is constructed of sheet metal and has a fibre filler 5, suitable screws 6 passing through the channel and through the filler to hold the channel in place, the screw entering the upper part of the wall 1.

The outer thickness of the channel has a longitudinal shoulder 7 The shoulder 7, though it may not support the part 18 of the jaw member 10 of the upper clamp, it does act asan abutment for the part 18 during its sliding action on the outer wall or thickness of the channel, provided the clamp member is tightened sufficiently to draw the clamp member toward the outer wall of the channel.

Furthermore the shoulder or bend 7 of the" outer wall of the channel permits the outer wall to yield more readily than it would if the shoulder or bend 7 did not exist. The reason for providing yieldability, is to permit the, blackboard to give uniformly throughout its area. For example if the blackboard 4 should be held rigid at its marginal edges with nothing behind the center of the board, the board would tend to yield in the center and if the pressure should be sufficient the board would crack, hence by yield' ably supporting the marginal edges of the board, the board may yield substantially and with uniformity throughout its entire area, and such yieldability is considerably assisted by the paddings 11 and 12.

The inner thickness of the channel 2 has ing in contact with the board which ispreferably made of slate or any other sultable material, hence preventing the blackboard from cracking and to insure holdlng the black board firm, it being obvious that the outer wall of the channel at a point below the filler more or less gives as pressure is applied to the blackboard when writing and especially when erasing or otherwise cleanlng the blackboard. The outer thickness of the channel has an internal flange 13 so as to more or less space the blackboard inwardly.

The lower channel 3 is somewhat similar to the upper channel, but with variations such as forming the outer thickness of the channel with a chalk or eraser receiving trough 14. The outer thickness of the channel 3 also has a longitudinal shoulder 15, as well as the inner thickness of the channel 3 having a longitudinal groove 16 which and the shoulder 15 perform the same function as the corresponding parts on the channel 2. Furthermore the outer thickness of the channel 3 has its inturned flange 13a provided with a laterally inward turned flange 17 on which the lower edge of the blackboard 4 rests.

With these exceptions, as previously stated the lower channel 3 and its attendant parts as well as the clamps substantially correspond with similar features of the channel 2, therefore the same reference characters p y- The clamps 10 in each instance are substantially angular, and their shorter ends 18 have a moving fulcrum or hearing on the outer thickness of the channels, enabling the screws 9 when tightened to cause the clamps to rock ner as to prevent the nuts and thereby draw the clamps tight against the blackboard.

The screws 9 above and below carry nuts 9a, and theedges of these nuts cooperate with shoulders 10a on the clamfs 10 in such manrom turning, when the screws 9 are tightened or loosened, so as 'to draw the clamps and their felt pieces 11 toward the black card. The felt pieces 11 are adhesively fastened to the clamps, while the felt strips ,12 are adhesively fastened to the flanges 13 and 13a and extend longitudinally thereof. The flanges 13;and 13a have reasonable resiliency, so as to provide for a yieldable 7 joint between the flanges andthe blackboard and the blackboard and the clamps. It is a well established fact, and has been for years, that slate blackboard sections or slabs when split from the large blocks mined at thequarry are of varying thickness;.that is, thicker at one end or one side than at th other end or other side, or possibly thicker in the middle; It hasalso'been customary in constructing slate blackboard slabs to surface only one face, in which case the slate blackboard slabs still remain thicker at one end or one side than at an opposite end or opposite side. In view of this, there has been difficulty in mounting the slate blackboard slabs,

so as to arrange the slabs in order that their surfaced faces are all flush, particularly at the joints between the slabs, necessltatmg wedges and the like to force the slabs 1nto position so that their finished faces are all flush.

In view of these facts, one of the essential purposes of the present invention is to proadjustment from the front of the blackboard,

whereas in the mounting oflother slabs, such as glass slabs in store show windows and thelike, the clamps can be adjusted and applied in position from the interior, as well as from the exterior, preferably from the interior. The record of this application will show that it has been a customary practice to use slate blackboard slabs of varying thicknesses, evidence of this fact having been made of record in the application.

The invention having been set forth, what a is claimed is:

1. In a blackboard frame mounting, the combination with upper and lower channels provided with means for fastening the channels to a stationary support, said channels having inner and outer yieldable walls, the" outer wall constituting a jaw member of a clamp, of an element'constituting a second jaw member of said clamp and having a sliding fulcrum on the first jaw member, said clamp adapted to support a blackboard inter-' lnosed between the two 'jaw members, said rst jaw member engaging the blackboard immediately just past the edge of the blackboardto hold the latter,

' and means passing throughthe first jaw member and operatively connecting with the'interme'diate jaw member for tightening the intermediate member against-the blackboard, said intermediate jaw member reaching materially farther toward I the center of the blackboard than the outer jaw member, themarginal edges .of the outer ,walls merely ektending pa's'tithe v edge of the blackboard-far enough toiheldithe board but -not far enough to limit'the amount of writ- 2; In a blackboard frame mounting, the

ing surface 0 the board.

combination with ,upper and lower channels Y provided with means for fastening the chain nels to a statlonary support, said channels; H

having inner and outer walls, each outer wall constituting a jaw member of a clamp, of an element constituting a second jaw member of said clamp and being operatively mounted intermediate the inner and outer walls, said clamp adapted to support a blackboard inter.-

posed and clamped between the outer wall and said element, the outer walls engaging the blackboard immediately just past the edges of the blackboard to hold the latter, means passing through the outer Walls and operatively connected with the intermediate elements for tightening said jaw members against the blackboard, the outer wall of the lower channel terminating in a lateral flange acting asa support with which the blackboard engages to support the board and prevent downward .movement.

3. In a blackboard frame mounting, the combination with upper and lower channels provided with means for fastening the channels to a stationary support, said channels having inner and outer walls, each outer wall constituting a jaw member of a clamp, of an element constituting a second aw member of said clamp and being operatively mounted intermediate the inner and outer walls, said clamp adapted to support a blackboard interposed and clamped between the outer wall and said element, the outer walls engaging the blackboard immediately just past the edges of the blackboard to hold the latter, means passing through the outer walls and operatively connected with the intermediateelements for tightening said jaw members against the blackboard, said second intermediate jaw members engaging with the blackboard and reaching materially farther 'toward the center of the blackboard than the outer walls, the marginal edges of the outer walls merely extending past the marginal edge of the blackboard far enough to hold the board but not far enough to limit the amount of writing surface of the board.

"4. In a blackboard frame'mounting, the combination with upper and lower channels provided with means for fastening the channels to a stationary support, said channels having inner and outer walls, each outer wall constituting a jaw member of a clamp, of an element constituting a second jaw member of said clamp and being operatively mounted intermediate the inner and outer walls, said clamp adapted to support a blackboard interposed and clamped between the outer wall and said element, the outer walls engaging the blackboard immediately ust past the edges of the blackboard to hold the latter,

means passing through the outer walls and 'operatively connected with the intermediate elements for tightening said aw members against the blackboard, the outer wall of the lower channel terminating in a lateral flange acting as a support with'which the blackboard engages to support the board and prevent downward movement, said second intermediate jaw members engaging with the blackboard and reaching materially'farther toward the center of the blackboard than the outer walls, the marginal edges of the outer walls merely extending past the marginal edge of the blackboard far enough toliold the board but not far enough to limit the amount of writing surface of the board.

5. In a blackboard frame mounting, the combination with upper and lower channels .provided with means for fastening the same to a stationary support, said channels having inner and outer walls, each outer wall constituting a jaw member of a clamp, of an element constituting a second jaw member of said clamp and being located intermediate the inner and outer walls, both of said elements having sliding fulcrums on the outer walls,'s-aid clamp adapted to support a blackboard interposed and clamped between both sets of jaw members, screws passing through the outer walls and operatively connecting with the second jaw members for tightening them against the blackboard, and abutment means carried by the outer walls and cooperating with the intermediate-elements for limiting the sliding fulcrums of said second jaw members.

6. In a blackboard frame mounting, the combination with upper and lower channels provided with means for fastening the same to a stationary support, said channels having inner and outer walls, each outer wall constituting a jaw member of aclamp, of an element constituting a second jaw member of said clamp and being located intermediate the inner and outer walls, both of said elements having sliding fulcrums on the outer walls, said clamp adapted to support a blackboard interposed and clamped between both sets of jaw members, screws passing through the outer walls and operatively connecting with the second jaw members for tightening them against the blackboard, and abutment means carried by the outer walls and cooperating with the intermediate elements for limiting the sliding fulcrums of said second jaw members, the outer wall of the lower channel terminating in a lateral flange acting as a support with which the blackboard engages, to support the board and prevent downward movement thereof.

7. In a blackboard frame mounting, the combination with upper and lower channels provided with means for fastening the same sets of jaw members, screws passing through ,the outer walls and operatively connecting with the second jaw members for tightening them against the blackboard, and abutment means carried by the outer walls and-'cooperating with the intermediate elements for l imiting the sliding fulcrums of said second jjaw members, both intermediate jaw memers engaging with the blackboard and reaching materially farther toward the center of the blackboard than the outer walls, the marginal edges of the outer walls merely extend ing past the marginal edges of the board far enough to hold the board but not far enough to limit the amount of writing surface of the board. I

8. In a blackboard frame mounting, the combination with upper and lower channels provided with means for fastening the same to a stationary support, said channels having inner and outer walls, each outer wall constituting a jaw member of a clamp, of an element constituting a second jaw member of said clamp and being located intermediate the inner'and outer walls, both of said elements having sliding fulcrums on the outer walls, said clamp adapted to support a blackboard interposed and clamped between both sets of jaw members, screws assing through the outer walls and operatively connecting with the second jaw members for tightening them against the blackboard, and abutment means carried by the outer wallsand cooperating with the intermediate elements for limiting the sliding fulcrums of said second aw members, both intermediate jaw memers engaging with the blackboard and reachmg materially farther toward the center of the blackboard than the outer walls, the marginal edges of the outer walls merely extending past the marginal edges of the board far enough to hold the board but not far enough to limit the amount of writing surface of the board, the outer wall of the lower channel being outwardly bent on itself, thereby causing a chalk and eraser trough to be formed thereon.

9. In a blackboard frame mounting, upper and lower channels having fillers and provided with means for securing the channels to a stationary support, said channels having inner and, outer yieldable walls extending beyond the fillers, eachof the outer walls constituting ajaw member of a clamp, an element operatively supported intermediate the inner and outer walis of both channels and associated with an outer wall and thereby constituting a second'jaw member of said clamp, both of said second jaw members operatively. connecting with the inner and outer walls, thereby permitting the inner and outer walls of both channels to yield,

said clamp adapted to support a blackboard interposed betweenthe outer walls and the second jaw members, and devices passing through the outer walls and through the second jaw members, with means on said devices and cooperating with the second jaw members to tighten'them into position.

10. In a blackboard frame mounting, upper and, lower channels having fillers and pro- Vided with means for securing the channels to a stationary support, said channels having inner and outer yieldable walls extending beyond the fillers, each of the outer walls constituting a jaw member of a clamp, an element operatively supported intermediate the inner and outer Walls of both channels and associated with an outer wall and thereby constituting a second jaw member of said clamp, both of said second jaw members operatively connecting with the inner and outer walls, thereby permitting the inner and outer nels to a stationary support, said channels having inner and outer yieldable walls extending beyond the fillers, each of the outer walls constituting a jaw member of a clamp, an element operatively supported intermediate the inner and outer walls of both channels and associated with an outer wall and thereby constituting a second jaw member of said clamp, both of said second aw members operatively connecting with the inner and outer walls, thereby permitting the 1nner and outer walls of both channels to yield, said clamp adapted to support a blackboard interposed between the outer walls and the second jaw members, and screws passing through the outer walls and through the second jaw members, nuts on said screws and cooperating with the second jaw members to tighten them in position, said second aw members having means cooperating with the nuts to preventv movement, thereof.-

12. In a blackboard frame mounting, upper and lower channels having fillers and provided with means for securing the channels to a stationary support, said channels having inner and outer yieldable walls extending beyond the fillers, each of the outer walls constituting a jaw member of a clamp, an element operatively supported intermedlate the inner and outer walls of both channels and associated with an outer wall and thereby constituting a second jaw member I of said clamp, both of said second jaw members operatively connecting with the inner and outer walls, thereby permitting the inner and outer walls of both channels to yield,

cooperating with the second jaw members to tighten them in position, said second jaw members having means cooperating with the nuts to prevent movement thereof, the inner walls of both channels having means with which the screws engage to hold the screws straight when adjusted.

13. In a blackboard frame mounting, the combination with upper and lower channels provided with means for fastening the channels to a stationary support, said channels having inner and outer walls, each outer wall constituting a jaw member of a clamp, of an element constituting a second jaw member of said clamp and being operatively mounted intermediate the inner and outer walls, said clamp adapted to support a blackboard interposed and clamped between the outer wall and said element, the outer walls engaging the blackboard immediatelyjust past the edges of the blackboard to hold the latter, means passing through the outer walls and operatively connected with the intermediate elements for tightening. said aw members against the blackboard, the outer wall of the lower channel terminating in a lateral flange acting as a support with which the blackboard engages to support the board and prevent downward movement, the outer walls of both channels and the second jaw members having their adjacent faces padded for engagement with said blackboard.

14;. In a blackboard frame mounting, upper and lower-channels provided with means for securing the channels to a stationary support, said channels having inner and outer yieldable walls, each of said outer wallsconstituting a jaw member of a clamp, an element located intermediate the inner and outer walls and operatively associated with each of the outer walls, and constituting a second jaw member of said clamp, said clamp adapted to support a blackboard interposed between the outer walls and the second jaw members, the outer walls and said second jaw members having their adj acent'faces provided with cushions for engagement with the blackboard, means operatively connecting the outer walls and said second jaw members to clamp the board in position, said' connecting means operatively engaging with the 1nner walls for yieldably supporting the blackboard.

15. In a blackboard frame mounting, upper and lower channels provided with means for securing the channels to a stationary support, saidchannelshaving inner, and outer yieldable walls, each of said outer walls con stituting a jaw member of a clamp, an element located intermediate the inner and outer walls and operatively associated with each of the outer walls, and constituting a second jaw member of said clamp, said clamp adapted to support a blackboard interposed between the outer walls and the second jaw members, the outer Walls and said second jaw members having their adjacent faces provided with cushions for engagement with the blackboard, means operatively connecting the outer walls and said second jaw members to clamp the board in position, said connecting means operatively engaging with the inner Walls for yieldably supporting the blackboard, both of said second jaw members reaching materially farther toward the center of the blackboard than the outer walls, the marginal edges ofthe outer walls merely extending past the marginal edge of the blackboard far enough to hold the board but not far enough to limit'the amount of writ ing surface of the board.

16. In a blackboard frame mounting, upper and lower channels provided with means for securing the channels to a stationary support, said channels having inner and outer yieldable walls, each ofsaid outer walls constituting a jaw member of a clamp, an element located intermediate the inner and outer walls and operatively associated with each of the outer walls, and constituting a second jaw member of said clamp, said clamp adapted to support a blackboard interposed between the outer walls and the second jaw members, the outer walls and said second jaw members having their adjacent faces provided with cushions for engagement with the blackboard, means operatively connecting the outer walls and said second jaw members to clamp the board in position, said connecting means operatively engaging with the inner walls for yieldably supporting the black board, the outer wall of the lower channel having a lateral flange with which the blackboard engages to support and prevent downward movement of same.

17. In a blackboard frame mounting, upper and lower channels provided with means for securing the channels to a stationary sup port, said channels havin inner and outer yieldable walls, each of sa d outer walls constituting a jaw member of a clamp, an element located intermediate the inner and outer walls and operatively associated with each of the outer walls, and constituting a second jaw member of said clamp, said clamp adapted to support a blackboard inter osed between the outer walls and the secon jaw members, the outer walls and said second jaw members havin their adjacent -faces'pro-' vided with cushionsfor engagement with'the blackboard, means operatively connecting the outer 'walls and said second jaw members to alamp the board in position, said connecting means operatively engaging with the inner walls for yieldably supporting the blackboard, the outer wall of the lower channel having a lateral flange with which the blackboard engages to support and prevent downward movement of same, both of said second jaw members reaching materially farhold the board but not far enough to limit the amount of writing surface of the board.

Ext

'18. In a blackboard frame mounting, an outer continuous marginal clamping element, a plurality of slate blackboard sections to be arranged adjacent to and back of said elerality of individual clamping elements arranged at infrequent intervals and adapted to engage with the inner rear uneven faces of the slate blackboard sections, thereby keeping the outer faces of the sections Hush and even throughout their entire area and at the joints, and means operable from the front of the blackboard for connecting the individual clamping elements to the continuous marginal clamping element.

I 19. A blackboard frame mounting, comprising an outer continuous marginal frame constituting one element of a clamp, said clamp adapted toisupport a plurality of slate blackboard sections adjacent and to the rear and engaged with said element, a plurality of individual clamping jaw elements adjacent to and cooperative with the rear' tions flush against the first element, and

use

means connecting the individual clampingjaw elements with the first element, said connecting means being operable from the front of the blackboard to tighten the individual clamping jaw elements against the inner uneven faces of the blackboard sections.

20. A blackboard frame mounting, comprising an outercontinuous ma rginal frame constituting one element of a clamp, said clam adapted to support a plurality of slate black board sections adjacent and to the rear and engaged with said element, a plurality of individual clamping jaw elements adjacent to and cooperative with the rear uneven faces of the blackboard sections, said individual clamping jaw elements having sliding fulcrums-on and cooperative with the first I element and engaging the rear uneven faces of the blackboard sections to retain'the sections with their outer finished surfaces flush,

21. A blackboard frame mountin compris-' ing an outer continuous marginal rame constituting one element of a clamp, said clamp adapted to support a plurality of slate blackboard sections adjacent and to the rear and engaged with said element, a plurality of individual clamping jaw elements adjacent to and cooperative with the rear uneven faces of the blackboard 7 sections, said individual clamping jaw elements having sliding fulcrums on and cooperative with the first element and engaging the rear uneven faces of the blackboard sections to retain the sections with their outer finished surfaces flush, and means connecting the individual jaw elements to the first element, said means being adjustable to increase and decrease the pressure of the individual jaw elements against the blackboard sections, and abutment means carried by the first clamping element and cooperating with the individual jaw elements for limiting the sliding fulcrums of the individual jaw elements.

22. A blackboard frame mounting, comprising a frame of channel construction, having inner and outer walls, said outer wall constituting a jaw member of a clamp, a plurality of individual elements constituting opposing jaw members of said clamp and being located between the walls of the channel, said first jaw elements being marginally continuprising a frame of channel construction hav-- ing inner and outer walls, said outer wall constituting a jaw member of a clamp, a plurality of individual elements constituting opposing jaw members of said clamp and being located between the walls ofthe channel, said first jaw element being marginally continuous, whereby the outer surfaced faces of slate blackboard sections, which are adapted to be supported by said clamp, may assume even and flush positions adjacent the joints between the sections, and means passing through the outer walls of the frame and cooperative vwith the inner walls and connected operatively with the individual clamping elements for adjusting them in position according to the varying thicknesses of the blackboard sections,said individual clamping jaw elements having sliding fulcrums, and means cooperating with the individual clamping jaw elements for limiting the sliding fulcrums.

-24. A blackboard frame mounting, comprising an outer continuous marginal frame constituting a continuous marginal jaw element of a clamp, the lower rail of said frame having means-to support a plurality of slate blackboard sections adapted to be supported by said clamp and having their outer faces surfaced and their inner faces rough and uneven, a plurality of individual elements constituting Opposing jaw elements of said clamp and located in the rear of and engaging with the unfinished faces of said sections, and means for each individual second jaw member for clamping the same against the unfinished surfaces of said sections according to the varying thicknesses of the slate blackboard sections, whereby the finished surfaces of the sections may be held flush at their joints, and against the continuous marginal clamping jaw element. l

25. A blackboard frame mounting, comprising an outer continuous marginal frame -const1tutmg a continuous marginal jaw element ofa clamp, the lower rail of said frame having means to support a lurality of slate blackboard sections adapted to be supported by said clamp and having their outer faces,

surfaced and their inner faces rough and uneven, a plurality of individual elements constituting opposing jaw elements of said clamp and located in the rear of and engaging with the unfinished faces of said sectlons, and

means for each individual second jaw member for clamping the same against the unfinished surfaces of said sections according to the varying thicknesses of the slate blackboard sections, whereby the finished surfaces of the sections may be held fl ush at their joints, and against the continuous marginal clamping jaw element, said means being carried by the continuous marginal jaw member, the upper rail of said frame extending far enough down below said means of the upper rail, wherebythe blackboard sections may be inserted upwardly into said clamp, so that their lower ends may subsequently engage with said supporting means.v

ture. 1

ALBERT M. MASTERS.

In testimony whereof he aflixes his signa-

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