US326453A

US326453A - Sectional chalk-rack

Info

Publication number: US326453A
Authority: US
Publication date: 1885-09-15
Anticipated expiration: 1902-09-15

Description

(No Model.)

J. G. PLOWMAN.

SEOTIONAL CHALK RACK. No. 326,453." Patented Sept; 15, 1885."

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JOSEPH GEE PLOVVMAN, OF WHITE PIGEON, MICHIGAN.

SECTIONAL CHALK=RACl L BFECIFICATZQN forming part of Letters Patent No. 326,453, dated September 15, 1885.

Application filed March 16, 1885. (X0 model.)

T 0 all whom it may concern.-

Be it known that l, JOSEPH GEE PLOWMAN, residing at White Pigeon, in the county of St. Joseph and State of Michigan, have invented certain new and useful Improvements in Chalk-Racks; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to letters or figures of reference marked thereon, which form a part/0f this specification.

Figure 1 of the drawings is a representation of this invention, and is a front view. Fig. 2 is a perspective view of the chalk-rack. Fig. 3 is a longitudinal vertical sectional view taken on the lines 00 m of Fig. 1, and Fig. 4 is a transverse sectional view taken on the lines 3 y of Fig. 1. i

This invention has relation to certain improvements upon my chalk-rack for blackboards, for which Letters Patent of the United States were granted August 26, 188i; and it consists in the construction and novel arrangement of devices, as hereinafter set forth, and pointed out in the appended claims.

In the accompanying drawings, the letter A designates the blackboard, and 13 its lower marginal ledge, having brackets or arms 0, adapted to hold the removable chalk trough E, which is provided with a false bottom, H, of wire-cloth or other material having perforations or interstices, or may be made of transverse slats. Usually I prefer the wire-cloth, which may be conveniently attached to the trough by forming vertical grooves V in the side walls thereof, and

bending the edges of the wire-cloth downward to enter said grooves. Usually, also, I make the trough in sections,as indicated, these sections fitting each other at the ends by an angular joint, the projecting angular end F of one section fitting in the angularly-notched end of the next section, and so on until the proper length for the blackboard is fitted in place. This angular joint forms a close seam, and is designed to strengthen the rack and to guard against particles of chalk falling through. The joints are secured by a clasp, G, on the outer lower portion, said clasp being pivoted to the bottom of one section and secured to the next section by a turn-button, H, passing through a slot, I, of the vertical portion J of the clasp. This clasp may be made in other common modes, and should form a brace to the joint, in order that the sections may be supported in position with as few brackets or arms as possible. The ends of the sections are in some cases provided with transverse guard-partitions or end wall K, to prevent the chalk-dust from getting down between the ends of the sections into the joint.

S represents a guard-strip, of rubber, oilcloth, leather, listing, or other suitable material having some pliability, and yet being sufficiently stiff to project by its inner edge from the upper edge, L, of the wall N of the rack. Usually this edge L,which is next the blackboard,is beveled to form an oblique hearing, to which said strip is attached. The projecting edge of this guard-strip will therefore extend upward obliquely against the surface of the blackboard, hugging the same closely by its free edge when the trough is in proper position. All particles of chalk-dust which may fall from the blackboard will be caught by this guard-strip and guided to the cavity of the trough, and will therefore be prevented from falling between the trough and blackboard.

In making the trough or trough-sections I prefer to use single lengths of wood, grooving them to form the trough-cavity, and making vertical saw-kerfs in the side walls to receive the edges of the false bottom.

Having described this invention, what I claim, and desire to secure by Letters Patent, is-

1. The combination, with the removable chalk-trough for blackboards, of the flexible guard-strip S, attached to the upper edge of the inner wall of the said trough, and projecting from said edge to engage the surface of the blackboard, substantially as specified.

2. The sectional chalk-trough for blackboards having a bracing-clasp adapted to connect the sections, substantially as specified.

3. A chalk-rack for blackboards, consisting of sections having angular joint ends and In testimony whereof I aflix my signature in presence of two witnesses.

JOSEPH GEE PLOVVMA'N.

connected by bracing'clasps, substantially as speoified.

4. A chalk-rack forblackboards, consisting of one or more trough-shaped sections hav- 5 ing vertical grooves in their side walls, and

an interstitial false bottom having its edges Witnesses: bent downwardly into the said grooves, sub- GEO. W. BEISEL, stantially as specified. CHAS. LAVERTY.