US 2586009 A
Description (OCR text may contain errors)
Feb. 19, 1952 c. N. DICKEY INTERCHANGEABLE LETTER DISPLAY DEVICE Filed Sept. 20, 1947 v swam: TAV mm: STEAK $2.569
INVENTOR. CHARLES N. DICKEY.
Patented Feb. 19, 1952 STATES INTERCHANGEABLE LETTEREDISPLAY DEVICE Charles N.'Dickey, Northville, Mich., assignor, by "1 mesne; assignments, to James'S. Cushman, New .:York, N. Y., and Harold F. Moonert, "Wil- .ApplicationSeptember 20, 1947,Serial No." 775,229
. 1 'Ihisinvention relates to a display device for interchangeable letters and "decorative material and for "design-element's for assembly upon the 'surface 'or'suitable background without special preparation of the surface orseparate fastening :device for the display elements.
There havel'beenmany attempts to provide .zinterchangingdevices of this charaoter'because -oftheir iinherent usefulness to businessestztb- :Jlishments such :asrestaurants, retail stores, de-
wherein the objects aremaintainedion the panel byrstaticrelectrical energy. This. arrangement is -notdependable and. the letters are of exceedingly thin flexible material because of thesmallmagnitude. :of' the" retaining force.
It: .is an object .of this invention to produce L IBttEI'ST of such a nature that they-iwill be; retained 'xon alsmoothhardsurface without the. use' ofad- -hesive 'crude'rubber facings, adhesives, felt..pads, water :films, slotted, grooved or specially constructed supporting surfaces, or vacuum cups, and
which will remain. in;:place indefinitely. This I "accomplish-byforming;the letters ofisheetri'flex- 1 :ible, rubber-like r'plastic material which 1 may :be formedasirather thin sheetsbut which mayaalso comprise arlaminated articlehaving a :facingsof --the1 rubberelikermaterial described :backed up by clothpmetal, plywood-orthejike. Theiundersides :of the.letters'zoridisplay elements; in e.,* the sides serving to mount them, are formed witha smooth "polished: surface. iLetters ofithis; type whenrap- "plied to a support .panel haveaa asmooth polished surface will remain firmlyx adherent to the support-until the user desires toremovethem. The letters are readily removed .by merely peeling them off therpanel, but the force:of:gravity and the 1 action :of. air-currents and normally encoun- -tered vibration have no effect .upon theiadhesion of the-letters.tothe support. I
Fig. 1 shows a sign embodying the invention; Fig. 2 shows a letter embodyingithe invention; imd
Fig. 3 shows'a'laminated letter 'embodying'the invention.
As seen in the: drawings,Fig. l represents a sign made up of the letters and other decorative elements-according to the principlesof my invention. In the' preferred form,the support panel I0 is made of glass. Ordinary window glass has a surface which is smooth enough to produce highly satisfactory results when employed in conjunction with my novel letters, and enameled 'metal plates are also satisfactory. .The..letters or design elements L, seen in Fig. .2,l.have an undersurface ll which-is smooth..,and .polished. The-outer surface 12 maybe of any texture suitable to display. I
,I have found that letters madeof flexible elastomeric vinyl plastic sheet material having a press-polished undersurface adhere toapaneof :glass or polished metalwith a great degree of tenacity.
'It is probable that the adhesionresults from :several factors. .For example, when the smooth surface H is pressed against the smooth panel I0, alarge art of the .air is excluded from between the surfaces, whereupon atmospheric pressure exertslan unbalanced force on theouter surface of-the letters. .Withthis pressure, the coefficient of friction between. the letters and the panel issufiicient to. retain the letters in .mounted position against the force of gravity.
Itis also probable that due to the polished nature of the letter surface and of. thepanel, a certain degree of .molecularvadhesion is obtained .in-accordance .with the well-known principles of the Johannsen gauge blocks and the like. Ihave experimented with mountingletters on a panel in .a bell. jar. and exhausting the air from the jar. I Even though they surface of the letters wassmooth .to the touch without a semblance of tackiness and even. though the glass was perfectly clean and 5 dry, the letters remained mounted on the panel in v the vacuum.
' smooth molded or polished surface, it .will tend. to
adhere. in .the same manner. I-IoweverNI have found that the tenacity .of vthe. mounting when rubb eriarticlesmanufactured in accordance with -:.normalacommercialrpractice areemployedds not equal to that when the aforesaid synthetic plastic i letters are used; I 3 1:; assume:-Lthatv-theaadditional adhesion of the plastic material is due to one or both of two differences between letters formed of such material and those formed of rubber. In the first place, the inyl plastic materials respond readily to the production of a very smooth or press-polished finish, and according to the principles of my invention, the smoother the finish of the letters the greater will be the air pressure effects and the molecular adhesion referred to.
Secondly, it is probable that some of the plasticizer in the synthetic letters assists to increase the tenacity of the union. Although letters formed according to my invention appear perfectly smooth to the touch and show no tendency to adhere to the fingers or clothes of the user, it may be that upon pressing the smooth surface of the letters on the smooth surface of the panel, a minute amount of plasticizer exudes and assists in augmenting the intimate engagement of the parts.
An example of one composition that I have found produces good results in as follows:
Composition by weight 100 parts of polyvinyl chloride (powdered resin) 50 parts of dioctyl phthalate (plasticizer) 1 part of color pigment; for example, Channel Black 0.5 part lead stearate 2 parts of a resin stabilizer blended together and the resulting mixture is then placed on a hot plastic or rubber mill and milled approximately ten minutes at 275 F. This milling knits the mass into a homogeneous sheet of plastic. The milled stock is then transferred to the cavity of a hot mold in a hydraulic press for press polishing. The interior of the mold has a highly polished mirror-like surface, such as is produced by chrome plating and polishing. The press is closed and the plastic molded at 320 F. for two minutes at approximately 100 p. s. i. pressure. Before reducing the pressure the mold is cooled to room temperature. The pressure is then released and the sheet removed from the mold. I mold the sheet approximately .025" thick although thickner or thinner sections may be used. From this sheet the letters and designs may then be die cut.
Press-polished vinyl sheet or film might also conceivably be made by molding or casting the vinyl resins in molds having a smooth surface from solutions or dispersions of the plastic. The material might also be applied as a thin coating on other materials such as wood, paper or metal providing the mounting surface of the plastic material has a smooth, polished appearance or a smooth highly glossed surface. For example, a laminated letter L appears in Fig. 3 wherein a coating 20 of the plastic material is applied to a wood backing member 2|. The underside 22 of the composite letter is smooth and polished to effeet the mode of operation described. If the backing member is flexible the letter is readily applied and removed, but if the backing member is rigid the letter should not be excessively large or the unit pressure of application will be too low.
Other elastomeric viny1 polymers nad copolymers would prove suitable for my purpose. For example, a plasticized vinyl chloride-vinyl acetate copolymer would work equally well. Certain rubber compounds will work to a lesser degree. The main disadvantage to the rubber compounds is that they lack a free plasticizer and it is diflicult to obtain the highly polished surface required for best results. Consequently, greater effort is required to squeeze the rubber sheet against the smooth supporting surface and obtain a good vacuum seal.
Although glass is considered to be an ideal background for the letters and lends itself to illumination, I have found that any polished material or polished pane object will support the letters satisfactorily. This includes objects with a smooth polished surface coat of vitreous or baked enamel or certain paints not subject to softening by migration of the plastlcizer. If compounded with a non-migrating plasticizer the letters could be used on any type of painted surface without any softening or damage to paint or to the letter. I find that display elements made as described may be pressed together with which a good union is effected. Thus, the panel could comprise an outer sheet of polished vinyl plastic or the like which sheet may be applied to cloth, wood, paper, etc., having a smooth outer surface. The plastic material, like the letters themselves, may be applied as a sheet of material fastened to the backing, or may be in the form of a coating for the backing.
Also, although I have explained at some length how to form a preferred kind of material, it will be understood that the claimsare not necessarily limited to such material. The essence'of the invention is in the provision of a design element having a surface formed of rubber-like or elastomeric material having a smooth or polished surface, or a lamination of such material with another material, which may be applied to panes of glass or other panels having a similar smooth surface. The term polished surface as employed in the claims refers to a smooth or glossy surface whether producedby an actual polishing application, cast, molded, or the like.
Throughout the specification the display has been referred to usually as letters but it will be understood that the invention is not limited to letters of the alphabet because the purpose of the invention may be employed regardless of the configuration of the applied object. For example, educational kits of letters, animals, objects, etc.. may be made under the invention.
The terms elastomeric as used in this specification and the claims are terms generic to a class of synthetic substances having the properties of natural rubber, namely a very high deree of flexibility coupled with the ability to return to its original dimension after a certain degree of stretching. However, it is understood that the elasticity or percent elongation which produces no permanent set need not be anywhere near as high as that of natural rubber to carry out the present invention. The term includes synthetic plastic material including a 'plastloizer or its equivalent and having the properties described necessary to effect the invention.
Having thus described the present invention so that others skilled in the art may understand and practice the same, I state that what I desire to secure by Letters Patent is defined in what is claimed. u
What is claimed is:
1. A character for use as a display element,
formed as a homogeneous element adapted to be attached to a glossy support merely by application of slight pressure, said character being formed of a synthetic resinous elastomeric material and including a plasticizer therefor substantially in the proportion of two parts of elastomeric material and onepart of plasticizer, said character comprising a piece of flat, flexible, airimpervious plastic material having at least one glossy, press polished, non-tacky surface by which said character may be firmly attached to said support, the amount of plasticizer in said material being sufficient to make the material flexible for attachment as defined, but insufiicient to make the material flabby so as to be nonselfsupporting. i
2. A display comprising a support having a smooth, glossy, air-impervious surface, and a character formed as a homogeneous element adapted to be attached to said support surface merely by the application of slight pressure, said character being formed of a synthetic resinous elastomeric material and including a plasticizer therefor substantially in the proportion of two parts of elastomeric material and one part of 1.5
plasticizer, said character comprising a piece of fiat, flexible, air-impervious plastic material having at least one glossy, press polished, non-tacky surface by which said character may be firmly attached to said support, the amount of plasticizer in said material being suflicient to make the material flexible for attachment as defined, but insumcient to make the material flabby so as to be nonself-supporting.
CHARLES N. DICKEY.
REFERENCES CITED The following references are of record in the file of this patent:
UNITED STATES PATENTS Number Name Date 1,530,997 Gjorup Mar. 24, 1925 2,046,924 Pendergast July 7, 1936 2,095,879 Kittredge et a1. Oct. 12, 1937 2,200,203 Heintz May 7, 1940 2,293,887 Chamberlain Aug. 25, 1942 2,303,828 Derby Dec. 1, 1942 2,331,776 Heggedal Oct. 12, 1943 2,383,598 Glidden Aug. 28, 1945 2,435,464 Radcliffe Feb. 3, 1948 FOREIGN PATENTS Number Country Date 475,555 Great Britain Nov. 19, 1937 427,737 Great Britain Apr. 23, 1935