US2048346A - Means for securing material to boards and tablets - Google Patents

Description

y 1935 v. c. E. MARTEN-GWILLIAM 2,048,346

MEANS FOR SECURING MATERIAL TO BOARDS AND TABLETS Filed Dec.

FIG. 1. F562 n I'L I N VE N TOR:

Vin: an Charles Eric Marfen-Gwll0nL By, Att s.

Patented July 21, 1936 PATENT OFFICE.

. ami MEANS ,FoR SEGURINGMATERIAL To 3 BOARDS AND TABLETS Vivianbharles am Marten-Gwilliam,

. Aldeburgh England Application December 13, 1934, Serial No. 757,353 'In' Great Britain December 14, 1933 'ioiai is. (01.45421) "This-invention is devised for the object of effectively attaching, holding or retaining in position, any material such as drawing paper, writing material, or tracing cloth or both onto any 3 existing drawing board, deskor tablet which has been prepared in a manner sis-hereinafter described; and means whereby the said drawing paper or the like may be expeditiously released therefrom. 1' i i I0 *In general the invention takes the form of two precisely similar attachments situatedalong the top and bottom edges of the drawing board or thelike each of which consists of:--

I. A thin metal bar extending approximately the entire length of the drawing board or other surface ,(hereinafter called the clamping bar) and having an inturned edge or lip whereby, under the influence of spring pressure the drawing or writing material is secured to said surface.

II. Means whereby the said clamping bar may i be raised by cam action against the said spring pressure for the purpose of releasing the said drawing or writing material.

Since by the invention the use of drawing pins is entirely obviated, the surface on which the material is to be aflixed is prepared as hereinafter explained for the reception and retention of the said material.

A particular arrangement and application of the device is illustrated in and fully described by reference to the accompanying drawing;

Figures 1, 2, and 3 show respectively a side elevation, a plan and an end elevation of a portion of the bottom edge of a drawing board fitted with the attachment which is the subject of this invention.

The clamping bar A may be formed to the sec-' tion shown from steel plate by rolling or draw- 40 ing and may be covered with leather cloth or otherwise as a suitable finish.

symmetrically and perpendicularly to the length of the bar A are attached leaf springs such as B which, in turn, are secured to the underside of the drawing board D by the screws C.

Mounted within the bar A is a bar E (hereinafter called the cam bar) of rectangular section and preferably of brass. This is arranged to slide longitudinally, being provided with two knobs such as F, situated near the ends of bar A, which operate in slots such as G cut therein.

Situated perpendicularly to the edge and symmetrically to the length of the drawing board are mounted three or more pins such as H.

These project into corresponding inclined slots J cut in-the cam bar E so that when the latter is moved downwards (Fig. 1) by the knob F the clamping bar A is raised to the position shown dotted in Fig; 3 thus releasing the drawing or u writing material. The length of E is equal to that of A less the projected length of slots J which thus governs that of slots G.

In order that, when in use, the lip of the clampingbar A may not foul the T square or set-squares, the topand bottom edges of the drawing board may be chamfered-as shown at K Fig. 3;

The top or the bottom of the drawing board is also provided with a longitudinal saw-cut L to accommodate the inturned edge of the drawing pad or packing sheet M which may be plain or may have printed on it any system of graph lines so that when using semi-transparent drawing or writing materials, scales may be dispensed with for certain classes of work.

As shown in Fig. 1 some or all of the inclined 20 slots in the said cam bar may be arranged to depress the said clamping bar as well as raise 5 it, thus providing means of applying a somewhat greater pressure on the material being clamped 25 than the said springs can exert, when so desired. For example, the inclined slot engaging with the central pin or projection on the edge of the board may be arranged to only depress the clamping bar whilst the slots at the extremities may be devised to merely raise it; suitable clearances in the cam bar above or below the slots being provided. Or again the cam bar may be in separate portions; one portion being arranged to raise the clamping bar, whilst others serve to 35 depress it.

For production on a large scale an alternative method of construction, which however in no wise departs from the spirit and principle of the invention described, consists in making the cam 40 bar E from drawn steel or brass and of a shallow channel or similar section; the inclined slots and cam faces for engagement with the said projecting pinsor brackets being punched and pressed out where required. 45

I claim:-

1. A surface board, two opposite edges thereof partially bevelled or chamfered, means for holding or retaining thereon drawing, writing or similar material, comprising clamping bars of suitable section and of a length approximately equal to the aforesaid surface board, means for mounting said clamping bars along the top and bottom vertical edges thereof, said mounting means consisting of a suitable number of like members fixed 55 perpendicularly to said clamping bars and firmly attached to the under side of the aforesaid surface at points remote from the board edges, fixed projections mounted on said edges, horizontally movable cam bars for raising and depressing said clamping bars relative to the board surface, said cam bars associated with and slidably mounted within the section'of the clamping bars, and having inclined slots engaging with said fixedprojections, upper edges on said clamping bars serving to secure the said material with uniformpressure everywhere along the said partiallybev elled or chamfered upper surfaces of the board edges.

2. A surface board, means 'forholdingand stretching thereon drawing or writing material,

the longest opposite vertical edges of the surface board being partially bevelled or chamferedat the uppermost corners thereof, metal clamping bars of channel section and of length'ap'pipxi 3. A surface board, means for stretching and retaining thereon drawing or writing material comprising clamping bars of hollow section and of length approximately equal to said surface board, two opposite partially bevelled edges on 5 board contiguous with the surface thereof and parallel to said clamping bars, horizontally movable cam bars "for raising and depressing said clamping bars relative to said bevelled edges,

means for mounting said clamping bars along said bevelled edges, said mounting means consisting of a suitable number of like members attached to the underside of the board and having their bending or hinging points situated below and remote from the upper edges of said clamp- *ingbar's, upper edges of opposite clamping bars moving in curved paths away from each other when being depressed towards said bevelled edges and thereby clamping material in a taut manner over the board surface.

4, A surface board, meansfor securing drawing orwriting material thereon, comprising camoperated clamping bars and bevelled edges as claimed in claim 1, a detachable packing sheet or pad having one edge inturned or formed approxi- 25 mately to aV-section for use with said material, means for mounting said packing sheet on surface board independentlyof said material consisting of a horizontal slit or sawcut beneath one bevelled; edge of surfaceboard to accommodatesaid 3 0;

inturned edge. Y j, r I VIVIAN CHARLES ERIC MARTEN I

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