US212945A

US212945A - Improvement in blackboards

Info

Publication number: US212945A
Authority: US
Publication date: 1879-03-04
Anticipated expiration: 1896-03-04

Description

11G. JOHNSON. Blackboard.

WITNESSES: INVENTOR: 6%

NFEIERIS. PHDTO-LITHbGRAFHER, mspgnrom o c.

Fig. 2 illustrates the device as folded up or UNITED STATES PATENT OFFICE.-

FRANK G. JOHNSON, OF BROOKLYN, NEW YORK.

IMPROVEMENT IN BLACKBOARD'S.

Specification forming part of Letters Patent No. 212,945, dated March 4, 1879; application filed April 30, 1878.

To all whom it may concern:

Be it known that I, FRANK G. JOHNSON, of the city of Brooklyn, county of Kings, and State of New York, have invented new and useful Improvements in Portable Blackboards and 1 do hereby declare that the following is a full, clear, and exact description of the construction and operation of the same, reference being had to the accompanying drawings, making a part of this specification, in which- Figure 1 represents the blackboard as spread out and hanging on the wall ready for use, and

partially folded.

The nature and object of my invention consist in providing a blackboard for public lecturers, and music, Sunday-school, and other teachers, which can be folded up and carried in the hand, in a trunk, or in a box, and when unfolded can be stretched and suspended for use by simply hanging it on the wall of the room without the use of nails.

Slated cloth has been employed; but heretofore it has been stretched and nailed fast to the wall in order to smooth it out and keep it in place.

The object of my invention is to facilitate the use of this slated cloth by obviating the necessity of nailing it to the wall or a rigid frame. To accomplish this Ifasten the slated cloth D upon a suitable piece of molding, A, at the top, and a suitable-sized roller, B, at the bottom. On the ends of the molding A, with l a flgxible joint, 0 c, are attached distention-rods O The lower ends of these rods are provided with a tongue, 12 which slide into a groove, b, in the roller B in such a manner that as they enter the groove they stand obliquely to a per pendicular line; but when they reach the outer end of the groove they will stand in a perpen dicular position, by means of which the slated cloth D is distended and stretched.

To provide for the elongation of the cloth by use, the connection between the molding A and distention-rods G O is such that the distention-rods can be slightlyincreased in length.

In the upper side of the roller B there is pro vided a large deep groove, part of which is shown at b, Fig. 1, for holding the chalk or crayon.

Fig. 2 represents the apparatus with the distention-rods O 0 turned up in a line with the molding A, to show the relative position of the roller, molding, and rods when the device is to be packed for transportation.

I claim- The flexible blackboard secured to the molding a'and roller B, in combination with the distention side pieces, 0 G, substantially as and for the purpose set forth.

FRANK Gr. JOHNSON.

Witnesses:

E. G. LUNn, ERNEST E. MALMAR.