US3484956A

US3484956A - Apparatus for use in the manner of using a blackboard

Info

Publication number: US3484956A
Application number: US579286A
Authority: US
Inventors: Jack Warwick Nightingale
Original assignee: Pilkington Brothers Ltd
Current assignee: Pilkington Group Ltd
Priority date: 1965-09-21
Filing date: 1966-09-14
Publication date: 1969-12-23
Anticipated expiration: 1986-12-23
Also published as: GB1123603A

Description

Dec. 23, 1969 .J. w. NIGHTINGALE APPARATUS FOR USE IN THE MANNER OF USING A BLACKBOARD Filed Sept. 14, 1966 Inventor United States Patent O 3,484,956 APPARATUS FOR USE IN THE MANNER OF USING A BLACKBOARD Jack Warwick Nightingale, Liverpool, England, assignor to Pilkington Brothers Limited, Liverpool, England, a corporation of Great Britain Filed Sept. 14, 1966, Ser. No. 579,286 Claims priority, application Great Britain, Sept. 21, 1965, 40,214/ 65 Int. Cl. B43] 1/12 US. C]. 35-66 1 Claim ABSTRACT OF THE DISCLOSURE Apparatus having a repeatedly usable writing surface in the manner of a blackboard is constructed with a panel of normally transparent material with parallel obverse and reverse faces, and with a panel of opaque material arranged in contiguity with said reverse face and presenting a design bearing surface showing through the panel of transparent material when viewed through the obverse face of said panel, said faces being roughened, the obverse face to render it receptive to writing and the reverse face to prevent a secondary image of the writing on the obverse face, and a mounting frame for the panel of normally transparent material and for the opaque panel which delimits a writing area of the obverse face of the panel of normally transparent material.

This invention relates to apparatus for use in the manner of using a blackboard, and has for its main object to provide a better surface for receiving inscriptions and information, as well as a background which contrasts more clearly with the inscriptions or information, and a fur her object is to devise apparatus of the kind referred to which can be used as a screen for a projector.

Apparatus for use in the manner of using a blackboard constructed according to the present invention comprises a panel of transparent material, having parallel faces of which the obverse face is rendered diffuse reflecting and the reverse face is sandblasted to prevent formation of a secondary image when information appears on the obverse face, e.g. whenusing a crayon,-and an operatively associated backing of an opaque material.

The backing preferably consists of a separate backing element and may carry graph paper markings or other design, but alternatively the backing may be a suitable opaque coating, (eg. emulsion paint), applied to the reverse face of the panel of transparent material.

Apparatus according to the invention may be used on easels, in the usual way of supporting blackboards, or may be mounted on a wall support. In the latter case the apparatus may include a frame for the panel, and the backing element may be slidably mounted in the frame behind the panel to facilitate changing the backing element when required. If the backing element is the same size as the panel of transparent material, the latter may have a cut out portion at one edge to allow the thumb to be used in changing the backing element. Alternatively, the backing element may be of greater length than the frame, and may have sections of different surface appearance so that movement thereof in either direction can effect a change of the background. To facilitate this change of the background the backing element may be wound on rollers on either side of the panel.

3,484,956 Patented Dec. 23, 1969 Preferably apparatus constructed according to the invention comprises a panel of toughened glass, although in some circumstances a panel formed from a transparent industrial plastic with a sufficiently hard surface can be employed.

When the apparatus is intended to be used as a screen for a projector, the backing associated with the reverse face of the panel may comprise a white pigment.

In order that the invention may be more clearly understood, a simple form of construction will now be described, with reference to the accompanying diagrammatic drawing:

In the drawing a glass panel 1 is shown inset in a frame 2, the front 3 of the frame being delineated from the rest of the frame to give easy access to the panel, and between the frame part 3 and the obverse face of the panel is a marginal strip 4 of shock absorbing material, for example sponge rubber packing material. At the back of the panel 1 and in contiguity therewih is a backing element 5, the face of which is ruled horizontally and vertically to simulate the ruling on graph paper.

The obverse face 6 of the panel may be covered with stippling or otherwise sufficiently roughened to render it diffuse reflecting, and the rear face 7 is roughened, for example by heavily sand-blasting the face, sufliciently to prevent the formation of a secondary image on the reverse face when information is written on the obverse face.

The diffuse reflecting face 6 of the panel may be of sufliciently fine texture so that the inscription may be delineated by using a pen and water soluble ink.

In the construction described it is possible to remove the front part 3 of the frame and then change the opaque backing element, either to show different rulings from those already described, or to substitute a surface suitable for use with a projector.

From the foregoing it will be observed that the diffuse reflecting surface of the glass panel is facing outwards, or in other words the panel of non-reflecting glass has the non-reflecting surface facing outwards, whilst the nature of the rear face of the panel is such as to prevent the formation of a secondary image.

Apparatus according to the invention can constitute notice boards and it has the advantage that any notice written on the obverse face can easily be removed by a. damp cloth, thereby providing an eflicient and continuously serviceable apparatus of the kind referred to.

Iclaim:

1. Apparatus having a repeatedly usable writing surface in the manner of a blackboard comprising a panel of normally transparent material with parallel obverse and reverse faces, and a panel of opaque material arranged in contiguity of said reverse face and representing a design bearing surface showing through the panel of transparent material when viewed through the obverse face of said panel of normally transparent material, said obverse face being roughened to provide a fine textured diffusely reflecting surface sufficient to render it receptive to writing as in the normal use of a blackboard, and said reverse face being sandblasted to a roughness suffi cient to prevent a secondary image of such writing on the obverse face when viewed from the front thereof but without preventing observation of said surface of the panel of opaque material, a mounting frame for the panel of normally transparent material and for the opaque panel 5 6 which delimits a writing area of the obverse face of said 1,381,022 6/1921 Schulze 161-35 panel of normally transparent material. 1,559,665 11/1925 Beery et a1. 35-26 R f Ct d FOREIGN PATENTS e e 500,443 2/1939 Great Britain. UNITED STATES PATENTS 823,795 1/1938 France.

7/1896 Mishler 35 66 20,668 1907 Great Britain. 8/1926 35-43 EUGENE R. CAPOZIO, Primary Examiner. 1/1931 Masters 35-63 7/1959 Rohrman 35 65 10 HARLAND S. SKOGQUIST, Assrstant Examlner 8/1960 Masters 35-65 US. Cl. X.R. 12/1885 Stewart 35-66 161-35 (5/69) UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. '3, ,8 +,956 Dated December 23, 1969 Inventor(s) Jack Warwick Nightingale It is certified that error appears in the above-identified patent and that said Letters Patent: are hereby corrected as shown below:

Column 2, line 53 "of should read --with-- line 53 "represent" should read --present-- EEIGNED AND SEM. El?

@EAL} Attest:

WILLIAM SGHUYLER, m Edward M. Fhtcher, Ir.

Comism e atantfl Attestiug Officer