US1958579A - Blackboard - Google Patents

Description

May 15, 1934. J. F. JOHNSON El AL BLACKBOAFD Filed Feb. 27, 1933 2 Sheets-Sheet l y 1934- J. F. JOHNSON El AL 1,958,579

BLACKBOARD Filed Feb. 27, 1933 2 Sheets-Sheet 2 Patented May 15, 1934 UNITED STATES PATENT OFFICE BLACKBOARD John F. Johnson and Robert B. Lawton,

Chicago Application February 27, 1933, Serial No. 658,799

7 Claims.

This invention relates in general to blackboards, and is more particularly concerned with improvements in a portable blackboard construction such as described in our patent No. 1,881,636, issued October 11th, 1932.

In the aforementioned patent, a portable blackboard is described, which comprises a plurality of blackboard panels that are swingably mounted on a common pivot, this pivot being removably sup ported in spaced wall brackets. Locking means are provided by which the several panels may be locked in parallel juxtaposed relation so that the students are unable to ascertain the content of the matter on the panels until such time as the instructor desires to unlock and open the blackboard panels, whereupon the matter thereon is at once visible.

Further, the arrangement disclosed in the aforementioned patent enables the device to be readily moved from one room to another as the occasion demands, it being only necessary to have a pair of permanently installed supporting brackets in each room, where it is desired to use the device.

In addition to the advantages and features embraced by our patented structure, briefly described above, the present invention seeks to provide an improved structure, wherein the individual panels are so mounted as to be readily detachable, thus enabling the removal of any desired panel for mounting in another location, as, for example, when it is desired to support one of the panels on an easel or the like, for individual display of the matter thereon.

A further object of the invention is to provide means whereby the several panels may be automatically interlocked, when the panels are moved into parallel juxtaposed relation, thereby preventing the removal of any panel so long as the panels are locked or otherwise retained in parallel juxtaposed relation.

It is also an object of the present invention to provide a blackboard of the character described, wherein the panels may be removed as a unit assembly from their supporting structure, or may be individually removed, as desired.

Other objects andfeatures of the present invention will more fully appear from the following detail description taken in connection with the accompanying drawings which illustrate a single embodiment thereof and in which Figure 1 is a front elevation showing a blackboard embracing the features of the present invention applied to a vertical wall structure;

Figure 2 is an enlarged fragmentary plan view showing the individual blackboard panels of the same in angularly disposed relation, taken substantially on line II-II of Figure 1;

Figure 3 is a similar view showing the individ ual panels in parallel juxtaposed relation;

Figure 4 is an enlarged fragmentary side elevational view, the panels being in parallel superposed relation and removed as a unit from the wall supporting structure;

Figure 5 is an enlarged fragmentary view partially in cross-section to show the constructional details of means for detachably mounting one of the blackboard panels;

Figure 6 is an enlarged fragmentary sectional view taken through one of the hinge supports for one of the blackboard panels, taken substantially on line VI-VI of Figure 1.

As shown on the drawings:

As illustrative of the present invention, there is shown in Figure 1 a conventional wall structure 10 having a pair of vertically aligned angle brackets 11 and 12 secured thereto in spaced relationship in any suitable manner, as for example, by means of screws 13 which extend through each bracket into the wall.

The horizontally disposed legs of these angle brackets are provided with aligned apertures for receiving therethrough a pivot member 14, this pivot member having its lower end threaded for receiving a wing nut 15 which coacts with a collar 16 spaced from the lower end of the pivot member, the Wing nut and collar engaging the opposed sides of the horizontal leg of the lower angle bracket, whereby the pivot member is retained against longitudinal movement through the bracket.

It will be observed that the'blackboard embraces a plurality of individual blackboard panels 17, each panel being composed of a substantially rectangular frame 18 which is preferably of channel-shaped cross-section and constructed of suitable metallic material such as aluminum, steel and the like. Supported within each frame 18 is a panel 19 of blackboard material having its opposed surfaces finished in a manner well known in the art so as to provide suitable writing surfaces.

The frames containing the blackboard panels are respectively connected to the pivot member 14 in such a manner as to enable the blackboard panels to be swung in a plane at right angles to the plane of the wall structure 10, either to a position where in the panels are in parallel juxtaposed relation as shown in Figure 1, or in angularly disposed relation as shown in Figure 2.

GOT

Moreover, the connection between each panel and the pivot member is so arranged that the panels may be individually removed from the pivot when desired.

This connection is accomplished by means of a plurality of pairs of clips 20 and 21 which are secured to the opposed surfaces of one side of the frame 18 as by screws 22. The inner edges of the clips are deflected as shown at 23 so as to extend around the inner edge of the frame 18, and the outer ends of each pair of clips are deflected towards each other as shown at 24. It will be observed that the deflected ends 24 are outwardly spaced from the outer edge of the frame 18 to provide a T-shaped groove: 25 which is adapted to receive a T-shaped end 26 formed at the free end of a hinge member 27 which is pivoted at its other end on the pivot member 14. At the upper end of the T-shaped groove 25, the clipmembers 20 and 21 are inwardly deflected as shown at 28 to form'an abutment against which the T-shaped end of the hinge member will strike, the lower end of the groove being left open so that the T- shaped end of the hinge member may be inserted from below.

With the arrangement just described, it will be apparent that a blackboard panel may be quickly and easily secured to: a hinge member simply. by lowering a panel and letting the T-shaped end of the hinge member pass into the lower end of the T-shaped groove formed by the clips 20 and 21 and move therein until the T-shaped end strikes or abuts the inwardly turnedends 28 oi the clips, the blackboard panel. being retained in this position by its inherent weight. To remove a panel it is simply raised until the clips are disengaged.

Although in practice it may be suiflcient inthe smaller devices to support each blackboard'panel upon a single hinge member, in the larger devices, it will be desirable to provide a pair of hinges, these hinges being vertically spaced sufiiciently to properly support the larger size panel. Irre spective of whether the panels are each mounted on a single hinge or a pair of spaced. hinges, the hinge members of the outermost panels, when disposed in. parallel juxtaposed relation, are provided with angularly disposed portions as illustrated at 29 in order to compensate for the fact that the panels are in different planes. Except for this offset portion, the hinge members of the outermost panels are of the same construction as those for the innermost panels.

Where each panel is to'be supported on a pair of spaced hinges a pair of clips as previously described are provided for cooperating with each of the hinges. Referring to Figure 5', when the construction is such as to necessitate the use of two hinges, these hinges are interconnected by meansof a rod member 30 which serves to maintain at all times the hinges in alignment so as to facilitate the attachment of a panel thereto. The lowermost hinge member is cons ructed in substantially the same manner as the uppermost hinge member, that is the free end of the hinge member is provided with a T-shaped end for insertion into the groove defined by the lower pair of clips. It will be observed, however, that the T-shaped end of the lowermost hinge member is terminated substantially at the mid-point between the upper and lower edges of the hinge member, as shown at 31. This construction facilitates the attachment of a panel in cases where two hinges are utilized, since the T-shaped end of the upper hinge may be started into the opening between the upper clips and the straight sided portion of the lower hinge member inserted between the ends 24-24 of the lower clips, thereby making it unnecessary to start both hinges into the clips at the same time.

The upper hinge members of the panels are grouped together on the pivot 14, and the lower hinge members likewise are grouped together. The hinge members of each group are separated by spacing collars as shown at 32 in Figure l, and the. entire group is held against axial movement on the pivot member by means of collars 33 and 34.

Due to this grouping of the hinges and the fact that the hinges are connected to the respective panels at different levels, the clips of the panels will successively overlap as shown in Figure 4. It will therefore be apparent that since a panel must be raised in order to remove it from its associated hinge members, the panels may all be interlocked against removal by the provision of means which will effectively retain the panel having the uppermost clips secured against removal when the panels are in parallel juxtaposed relation. For this purpose, a projection or extension 35' is provided on one of the hinge members of the panel adjacent the outermost panel having the uppermost clips thereon, this projection being formed with a hook end 36 which will extend over one of the clip members and retain the associated panel against removal. Since the clips of the respective panels successively overlie each other, all the panels will be interlocked against removal from their hinge members, when the panels are in parallel juxtaposed position. As soon as the panels are angularly disposed, the hook end of the extension 35 will not overlie the clip as previously described, and it will therefore be possible to remove any panel desired from its hinge members.

In order to enable the panels to be secured in juxtaposed parallel relation and thereby conceal the matter thereon and also prevent the removal of any of the panels, a hasp as shown at 3'7 and adapted to receive a suitable lock, is connected between the outermost panels.

With the panels locked in juxtaposed parallel relation, as shown in Figure 1, the device forms a unit assembly which may be easily moved from one location to another. In order to remove the device from the wall brackets, it is only necessary to loosen the wing nut 15, whereupon the pivot member together with the panels may be raised sufficiently to permit the lower end of the pivot member to be swung out sufficiently to clear the lower wall bracket. The downward movement will then release the upper end of the pivot member from the upper bracket, whereupon the en tire unit may be transported to another location and supported in a similar set of wall brackets.

From the foregoing, it will be apparent that our invention provides an improved portable blackboard which may be folded so as to be easily transported from one location to another; and which is so constructed that the individual panels thereof may be individually removed for separate display of the matter thereon; and in which interlocking and locking means are provided for locking the panels in parallel superposed relation, at which time the interlocking means is effective to prevent individual removal of the panels, the interlocking means being ineifective when the panels are swung so as to be in angularly disposed relation.

Now, it is of course to be understood that although we have described in detail the preferred embodiment of our invention, the invention is not to be thus limited but only insofar as defined by the scope and spirit of the appended claims.

We claim as our invention:

1. In combination, a support, a plurality of individually detachable panels swingably mounted on said support for movement to parallel juxtaposed relation and angularly disposed relation, and interlocking means operative to secure said panels against detachment when in parallel juxtaposed relation, and release the panels for detachment when in angularly disposed relation.

2. In combination, a support, a plurality of individually detachable panels swingably mounted on said support for movement to parallel juxtaposed relation and angularly disposed relation, interlocking means operative to secure said panels against detachment when in parallel juxtaposed relation, said means being ineffective when the panels are in angularly disposed relation, and means to lock said panels in parallel juxtaposed relation.

3, In combination, a supporting structure, a blackboard panel, a pair of vertically spaced hinges connecting said panel to said support for swinging movement, a slip-joint connection between said panel and hinges to enable the panels to be attached and detached, and means to maintain the movable parts of said hinges against relative swinging movement, when the panel is detached.

4. The combination comprising a supporting structure, a pair of vertically spaced hinge members pivoted on said support, a blackboard panel removably connected to the free ends of said members, and a rod spanning said members to retain them against relative pivotal movement, when the panel is removed.

5. A blackboard structure comprising a support, brackets pivoted on said support for swinging movement, a plurality of panels, members removably connecting said panels to said brackets, whereby the panels may be moved into angularly disposed relation and parallel juxtaposed relation, said members being positioned at different levels so as to successively overlap, when the panels are in parallel juxtaposed relation, and means carried by one of said brackets having parts arranged for cooperation with said members so as to retain the panels against removal from the brackets when the panels are in the last mentioned position.

6. A blackboard structure comprising a support, brackets pivoted on said support for swinging movement, a plurality of panels, members removably connecting said panels to said brackets whereby the panels may be moved into angularly disposed relation and parallel juxtaposed relation, said members being positioned at different levels so as to successively overlap, when the panels are in parallel juxtaposed relation, and a projecting member on one of said brackets having a deflected end positioned to overlie the uppermost of said members, when the panels are in the latter position, whereby the panels are retained against removal from the brackets.

7. A blackboard structure comprising a support, brackets pivoted on said support for swinging movement, a plurality of panels, said panels including parts removably connecting the panels to said brackets for swinging movement therewith and for interlocking the panels when in parallel juxtaposed relation, and means cooperative with said parts when the panels are so disposed to retain the panels against removal from the brackets.

JOHN F. JOHNSON. ROBERT B. LAWTON.

Images