US368976A - Blackboard - Google Patents

Description

' .(No Model.)

S G. SESSIONS.

BLAGKBOARD.

Patented Aug. 30, 1887.

dec f SW N. PETERS. Phnlo-hmognphar. wumn mhuc UNITED STATES PATENT OFFICE.

STEPHEN CARR SESSIONS, OF LOUISVILLE, KENTUCKY.

BLACKBOIARD.

SPECIFICATION forming part of Letters Patent No. 368,976, dated August 30, 1887.

Application filed May Q3, 1887.

To all whom it mag concern:

Be it known that I, STEPHEN CARR Snsmom, a citizen of the United States, residing at Louisville, in the county of Jefferson and State of Kentucky, have invented a new and useful Improvement in Blackboards, of which the following is a specification.

My invention consists in providing a blackboard with counterbalancing-weights, whereby it may be raised out of the way when not in use and lowered when needed, and also in providing means to preventablackboard from splitting or warping.

In the drawings, Figure l is a perspective view of a blackboard set in a casement and provided with counterbalancing weights. Fig. 2 is a vertical longitudinal section of the same. Fig. 8 is a detail perspective view of the board, showing one of the end cleats detached. Fig. 4 isa detail section of the same.

Referring to the drawings, the arrangement shown in the drawings is one that may be used with advantage in schools, the slate or blackboard taking the place of the stained or ground glass in the interior partition-walls. The object is to enable all the rooms on the same door to be thrown into one by raising the sashes in the said partititions during general or chapel exercises, and to separate the said rooms during class exercises.

I have shown in the drawings a casement suitable for use in a situation of this kind, it being evident that the blackboards may be raised during general and lowered during class exercises, thus enabling the classes to same when they are lowered.

A designates the easement, having the stiles B B, provided with the pulleys b b at the upper ends.

0 O are beads secured in the opening in the easement on each side of the blackboard to form the grooves for the board to operate in. The said board D is provided with the cleats E on the ends, the said cleats having an L- shaped groove therein.

The ends of the board Dare provided at the extreme edges with the small blocks d d, two, three, or more in number, and when the end cleats are placed on the boards the said blocks use the pass into the offset in the L-shaped groove.

Serial No. 239,148. (N 0 model.)

It will be seen that the blocks d will prevent the cleats from being removed by accident or otherwise, except by slipping them off lengthwise, thus allowing the said blocks to move longitudinally in the grooves. To prevent this longitudinal movement a pin, 6, is passed through the cleat at the center and inserted in the edge of the board. Near the upper ends of the said cleats are formed grooves f, and in the said grooves are secured the lower ends of the cords G,which pass over the pulleys b b at the upper ends of thestiles and are provided on the ends with the weights H. The weights are designed to exactly counterbalance the blackboard, and therefore it may be raised or lowered, and it will remain where placed.

The joint herein described between the board and the cleats may with advantage be used in connection with tailors boards, and in many other connections where it is desired to prevent a thin board from warping. This joint is especially of advantage where the board is composed of a number of narrow pieces placed edge to edge.

Having described my invention, I claim- 1. The combination, with the casement and the pulleys b nearthe upper end thereof, of the blackboard having the blocksor offsets d on the ends, the cleats E, to fit over the ends of the board and the blocks and secured thereon, and the cords attached to the said cleats passing over the pulleys b, and having counterbalancing-weights on the ends, substantially as specified.

2. The blackboard having the small blocks d d on the ends, the cleats E, having the L- shaped longitudinal grooves therein to be placed on the said ends, and the pins e to engage said cleats and board, to prevent the cleats from being displaced longitudinally, substantially as and for the purpose set forth.

In testimony thatlclaim the foregoing as my own I have hereto aifixcd my signature in presence of two witnesses.

STEPHEN CARR SESSIONS.

Witnesses:

WM. J. DAVIS, GEo. H. TINGLEY, J r,

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