US508468A

US508468A - Drawing-slate

Info

Publication number: US508468A
Authority: US
Publication date: 1893-11-14
Anticipated expiration: 1910-11-14

Description

(No Model.)

A. K. CROSS.

DRAWING SLATE.

A TTOHNE Y.

`To. all, t mayconceru:

tion of theV slate.

STATES YPA'TinvT Orricafs.

. y 'f AnsonA Cnossen BojsToN, MASSACHUSETTS;

D RAwl NGSLATE.

' SPECIFICATION forming part of nettersratnt Nofeoees, dated November f Applimipnilammri,1893. serrait. 464,189- ftNomodelJ Be it knownthat I, Anson K. CROSS', a Citizien ofthe United States, residing at Boston, in the county of Suffolk and State of Massa` k chusetts, have invented new and useful Im:

provernents in DraWing-Slates, of which the following, taken in connection with the accompanying drawings, is a specification.

My invention relates to drawing slates, and it has for its object to provide such a slate that when adapted to be drawn upon will present an opaque appearance, but which canV readily be changed in a moment to present a transparent appearance, in order that the object drawn may be viewed through the slate and the lines of the drawing compared with the lines ofthe object to testthe accuracy ot' the drawing.

My invention consists generally of a slate of some transparent substance, such as glass, and provided with a removable screen for covering and uncovering one side of said slate.

My invention further consists ot' certain features and details of construction, all as hereinafter particularly described.

In 4the accompanying drawings, Figure l .1 illustrates a bottom plan ofv my improved Y,drawing slate with the transparent portion of the same covered by thev screen, sothat the slate when reversed is ready to be drawn upon. Fig. 2 is a longitudinal section of the saine. Fig. 3 is an end view looking from the right end of Figs. l and 2. Fig. 4 is a top plan of a modification 0f the construction shown in the preceding figures, and with the screen drawn back from the transparent por- Fig. 5 is anl end view of the construction shown in Fig. 4.

Similar letters represent like parts in all the figures.

A is a plate of some transparent substance preferably glass, which is held in an ordinary frameV B. Extending into said frame from its inner-edges and adjacent to the back of the plate A is a groove a, for a purpose to be hereinafter explained.

Extending .over one end of the frame B on its under side is a roller D, which is journaled in brackets d, the .ends of said roller inside the brackets being provided with reels E E, to each of which reels is attached one end of an elastic cord or strip e, the other ends of said strips being secured in holes ff,

i ,or in any other appropriatemanner to Athe sides of the frame B. i

C is a screen, or curtain of opaque material, which is secured at one end to the roller D, and adapted to be wound upon and -unwound from the same. The curtain C and the elastic strips e e are in such relations to each other that-when said curtain is wound on its `roller D, the strips e e will be unwound from the reels E E, and have the least tension upon them, but when the curtain C is drawn out or unwound from its roller, the revolution ot the latter by said unwinding of the curtain, will cause the reels E E to revolve, and Wind up the elastic strips e e upon them,and cause the tension of said strips. As soon as the curtain is released the tension of the strips e e will revolve the roller D, thus winding up the curtain C.

F is a rigid strip secured to the free end ot' lthe curtain C -to keep the latter even and smooth, and k is a loop or other catch, secured to said strip and adapted for attachment to a hook or pin h on the end of the frame opposite the roller D, when the curtain C is drawn to cover the slate A.

G G are two slides spanning respectively the edges of the tWo ends of the frame B, and engaging with grooves b b in said ends, in which the slides are adapted to move.

H H are two arms which are pivoted respectively near `one end to the slides G G. The opposite ends of said arms are pivoted respectively to one end of other arms K K, said arms being also pivoted at their opposite ends to the outer edges of the ends of the frame B. By moving the slides G intheir guideways, the arms H and K are made to serve as braces to hold the slate at any desired angle with the table that supports it.

In a more simple form of my improved slate the curtain and its accessories may be dispensed with, and in the place thereof a I sheet of paper or card-board may be used to cover the transparent slate, and heldin place by its edges being inserted in the grooves a, or any removable opaque back may be used, as for example an ordinary flap, which may be hinged to one/end or side of the frame B. In Figs. t and 5 the slate is shown without the slides G and supporting arms H and K, but with other features which. are more generally valuable. 'f l In order that the slate may be held at right angles to the direction in which an object is seen, the edges of the slate frame may be beveled at such angles that they may all be seen when the slate is held in the hand. To distinguish said beveled edges from the face of the frame, they may be painted black or any color different from that of the face of the frame. The bevel being the same on all the sides or on opposite sides, when the slate is held at right angles to the line of vision the opposite beveled edges will appear of equal widths, and these edges thus serve as sights to bring the frame into the correct position. In Figs. 4 and 5 S shows such a beveled edge.

A spirit level may be suitably attached to the frame of the slate to show whenit is horizontal. L in Figs. 4 and represents such a level.

P in Figs. 4 and 5 represents a narrow band of metal, which constitutes the frame for the lower edge of the slate, and which extends a short distance upon each side of the glass A to protect the same. The ends P P of the band may be enlarged sufficiently to receive the rivets r r. 'lhe ends P P maybe fastened in the center of the side pieces of the frame B as shown in Figs. 4 and 5, or upon the outer surfaces of said pieces. The narrow band P forming one side of the frame B allows a drawing to extend quite to the edge of the slate, and this form of frame is desirable for young students who may wish to rest the slate upon the desk or table, in which case the wide protecting frame B would hide a considerable portion of the table oranyob- Ject just behind or touching the slate and resting upon the table.

In the practical application of my slate, the opaque curtain or screen is made to cover the back of the slate A as above described (and if the curtain C be used, said curtain is drawn down and held in place as shown in Figs. l and 2) so that said slate A from its uncovered surface will appear opaque. Any object is then drawn upon the slate A, and after the drawing is completed, the curtain or screen is Withdrawn from the back of said slate. When the slate has been placed in position between the object that has been drawn and the students eyes at the proper distance, so that the lines of the drawing conform with or approximate the lines of the object, the accuracy of the drawing can be tested, and any deviations in the drawing from the appearance of the object can be readily detected and corrected. The slate should be held in a position at right angles to the line of vision of the object, in order to compare the drawing correctly.

What I claim as new, and desire to secure by Letters Patent, is-

1. The improved drawing slate made of transparent material combined with a remov-` able screen to give the slate an opaque effect when it is desired to draw upon the opposite side of the saine, and whereby when said screen is removed, the object drawn may be seen through the slate, and the linesof the drawing compared with those of the object, all as set forth.

2. The improved drawing slate of transparent material inclosed in a frame, and a curtain secured to a roller which is attached to one side of said frame, whereby the curtain may be made to cover one side of the slate and be wound upon said roller when the slate is uncovered, all as and for the purposes set forth.

3. The improved drawing slate of transparent material inclosed in a frame, and a curtain secured to a spring roller attachedto one side of said frame, whereby the curtain may be drawn to cover one side of the slate and wind up the spring, and when released to 4be withdrawn from the slate by the unwinding of the spring, all as and for the purposes set forth.

4. The improved drawing slate of transparent material inclosed in aframe,a removable screen attachable to said frame, and` adapted for covering and uncovering one side of said slate, and adjustable braces attached to opposite sides of the frame whereby the slate may be supported at any desired angle, all as and for the purposes set forth.

5. The improved drawing slate of transparent material inclosed in a frame, a removable screen attachable to said frame, and adapted for covering and uncovering one side of said slate, and the arms I-I K, H K, pivoted as described to opposite sides ot' the frame, and two slides pivoted respectively to the arms H II and adapted to move in guideways in the adjacent sides of the frame, all as and for the purposes described.

6. A drawing slate of transparent material, inclosed in a frame provided with beveled surfaces, serving as sights, combined with a removable screen attachable to said frame and adapted for covering and uncovering one side ot said slate substantially as described.

7. A` drawing slate of transparent mate rial inclosed in a frame, having a spirit level thereon in combination with a removable screen attachable to said frame and adapted for covering and uncovering one sid'e of said slate, substantially as described.

S. A drawing slate of transparent material inclosed in a frame, one side of which consists of a narrow metal band, in combination with a removable screen attachable to said frame and adapted for covering and uncovering one side of said slate, substantially as described.

In testimony whereof I have signed my name to this specification, in the presence of .two subscribing witnesses, on this 25th day of Witnesses l CHAs. F. PERKINS, FRED. W. SMALL.

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