US1592645A - Illuminated sign - Google Patents

Description

July 13 1926.

A. B. RAMSDELL ILLUMINATED S IGN Filed Oct. 18, 1922 Patented July 13, 1926.

UNrrED STATES PA'riszN'rh oFFlcE.

LB'LHUB B. BAMSDELL, 0l' CICAGO, ILLINOIS; ADA. VIOLA RAMSDELL EXECUTRIX Ol' SAID ABTHUBVB. RAISDELL, DECEASED.

ILLUMINATED SIGN.

Application led October 18, 1928. Serial No. 585,943.

on the face thereof, even where no legiblel character appears on the face of the sign. These rays will enter the sign through the face and be reflected by any interior reflecting surface so that`the sign will be legible, although not illuminated from within by the means provided for such a pur- .ose.

P Such legible Showing of the sign as the result of primary exterior illumination I refer to as a phantom.

In brief, my invention comprises a closed compartment with a suitably located and focused source of illuminationY on the interior thereof and with the side to be illuminated formed of an opaque background surrounding a translucent or transparent character, which translucent or transparent character is so constituted that suflicient light to illuminate the same cannot pass therethrough from the exterior and be reflected back from the interior.

Preferably also this illuminated face of the compartment comprises a sand-blasted, etched or similarv surface, preferably on the exterior thereof.

The many other objects and advantages of the present invention will be better understood by reference to the following speciication when considered in connection with the accompanying drawing illustrating selected embodiments thereof, in which Fig. 1 is a perspective view of the sign or signal comp ete.

Fi 2 is a vertical section of the line 2 2 of Fig. 1.

Fig. 3 is a fragmentary top view.

display an emblem, letter,

Fig. 4 is an enlarged transverse sectional view of a portion of the front plate or panel of the sign or signal.

Fig. 5 is a rear elevation of the front panel, and

Fig. 6 is a fragmentary side elevation of the sign or signal provided with a visor.

Referring tov the drawings, the signal is shown as provided with a box or casing 10 which in the present embodiment is divided into compartments by a series of parallel `partitions 11 extending from front to rear thereof. The front face of each compartment is closed by a front plate or panel 12 forming a portion of the sign. These panels 12 are mounted in suitable frames 13 on the casing 10 and are insertable therein at the top thereof. One letter is formed on each of the panels. A lamp 14 is pro- `vided in each compartment and a reflector 15 is preferably mounted in rear of the lamp and focused on the character at the front of the compartment.

The panel 12 is preferably made of heavy glass such as pressed or plate-glass having a raised letter 16 cast upon the inner face thereof with the rear face 17 of this letter preferably provided with a prismatic surface. The entire front face 18 of the panel -12 is ground, sand-blasted or otherwise treated so that the letter thereon is absolutely invisible except when the lamp behind the same is burning. The portion of the back-face or background 19 of the panel not included in the letter is rendered impervious to light by the use of black paint or any other suitable means. When the sign is intended to indicate danger, it is customary to use a panel of ruby glass.

It is believed that this raised letter by offering a sufficient depth of glass operates materially in obstructing and diiusing the entry of exterior light and the free return passage of such exterior light when reflected back by the reflector. Also by providing a `raised letter, the opaque background is more readily applied when 'for example the surface of the glass surrounding the raised letter is enameled or otherwise rendered opaque. p Q

The sign or signal may be either automatically or manually controlled. In the case of a warning signal at a railway crossing, an approaching train will automatically cause current to e supplied to the lamps within the compartments and the signal will be illuminated and will continue to show4 until the crossing is again safe for highway traiic. This signal may be used to replace the familiar warning bell or may be used inr conjunction therewith.

The inding, sand-blasting or like treatment orthe entire front face of the panel and particularly that portion directly in front of the letter forms a screen which con` ceals the letter and prevents the assage through the panel of sufficient light rom an 'external source to produce phantom signals due to the reflection of such light from within. The raised letter on the rear face of the panel facilitates the application of the paint forming the opaque background, obstructs and diffuses any light entering from without and materially strengthens the illumination of the sign. The prismatic rear lface of the letters brightens the letters when viewed from the front and the illumination of the sign is from within and also co-operates with the ground face of the panel to prevent phantom signals.

While it is advantageous to use a divided casing with a separate lamp and reflector in each compartment thereof, my improved panel or front plate construction is also applicable to any type of illuminated sign and particularly to traiiic signals or indicators for automobiles. More than one character may obviously be placed upon a panel.

For best results, however, the raised letter should afford such obstruction to the passage of light from the exterior that each letter will require a separately focused light in a compartment excludin all other interior light, to properly illuminate it. This arrangement so locates the reflector that it will not reflect external light in such manner as to provide a phantom.

While I have shown and described a prismatic back, the claims contemplate any corrugation or other treatment or formation of the back whereby a similar light effect is attained.

Frosting may be considered generic for any suitable treatment of front surface to render it relatively non-transparent while remaining translucent. In the resent application the term colored is intended to indicate a color other than white.

With reference to the foregoing specification and the following claims which are not to be limited to the specific structure shown exce t where such limitation is necessitated by t e prior art, it is to be noted:

Lussac-is For convenience the term translucent has been used in its secondary meaning as applying to a substance having the quality o passin light which substance may or may not e4 transparent, except where the term is used with an indicated more limited meaning or such more limited meaning is necessitated by the prior art. v

While I have found the simplest and most convenient way of treating the exteriorx face of the sign is to sand-blast that face, it will be understood that the purpose of suoli treatment is supposed to provide a surface which will not to any considerable degree reflect a light directed thereon as such reection tends to confuse the clarity of the danger signal, and also to provide for a diffusion of light entering the signal chamber from the exterior, while not affording an objectionable barrier for the assage of the concentrated and focused ight from the interior.

For the second purpose above specified, it is immaterial whether the sand-blasted surface is on the exterior or is interposed at any effective point between the exterior and the interior of the sign.

Also so far as the broad idea of the invention is concerned, it is immaterial whether the sand-blasted or similar surface is integral with the translucent or transparent letters or characters of the sign, or is on a separate element. I note also that while in its broader aspects I contemplate the use of any suitable reiector, I have obtained the best results by means of a so-called X-ray reflector now on the market.

While I have shown and described the back of the letter or character as formed with prismatic surfaces, and in practice have found such structure most ei'ective for the purposes intended, the term prismatic may be considered as suiciently generic for the purposes of this application to indicate any formation of the rear surface of the characters or letters which will effectively interrupt and diffuse light rays entering from the exterior while either affording no material obstruction to light rays reflected from the source of illumination in the interior, or serving to increase the effective 'illumination fromthe interior.

While I have attained the results described by means of a device comprising raised letters formed integral with a relatively thin front sheet or pane of glass, it is obvious that to some extent at least the saine results and advantages will be attained by making the entire sheet of glass of such thickness that the light rays have to traverse the same depth of glass as when such raised lettersare used. Y

It' is believed that if desired the effect of diffusion of entering light without mate- 'rially interfering with intentional illuminallt) tion may be substantially assisted by the character of the glass of which the legible characters are made, such as Alba glass now in commercial use.

l am aware that the sign construction herein vshown and described is capable of material modification Without departing from the spirit of my invention, and I reserve the rlght to make such a's fairly falls within the scope ot' the following claims.

1 claim 1. In a sign, a panel of transparent material having a raised character on the back thereof and integra] therewith, and au opaque background having an opening therein through which said character projects, the front face of said panel being frosted opposite said character.

2. In a sign, a panel of transparent material having a raised character formed on the back thereof With the rear face of said character prismatic, and a layer of opaque material on said back except in the portions occupied by said character, the front facel of said plate being frosted.

3. An illuminated sign comprising a casing divided by partitions into a plurality of separate compartments open at the front, a lamp in each compartment, and a closure for each of said compartments including a plate of translucent material having a raised character on the back thereof and integral therewith, and a layer of opaque material on said back except in the portion occupied by said character, the front face of said plate being frosted opposite said character.

4, The combination with a closed housing, of a panel closing one side thereof and comprising a translucent element having an opaque background surrounding a character opening, means for obstructing and diffusing the passage of light when entering said element from the front, to such extent that such light will not be reflected back through said opening to show a legible character when viewed from the exterior of said housing, and means arranged within said housing to so illuminate said panel that the charaeter will be visible from the exterior of said housing when so illuminated, portions of the inner face of said translucent element being formed with a prismatic surface.

5. A sign for the purpose described comprising a closed housing having one panel thereof provided with a letter 0r character formed of translucent material, an opaque background surrounding said letter or character, a frosted surface in front of said letter or character, the back of said letter or character being provided with a prismatic surface all in combination With a source of illumination on the interior of said housing for lighting and setting off said source of illumination, a reflector arranged to effectively focus the light from said source of illumination upon the back of said letter or character, said frostedrface being of such density as .to obstruct. and diffuse light rays entering said panel from the exterior thereof so as to prevent any phantom showing of said letter or character.

(i. In a sign, a plate of substantiall y transparent material having a raised character on the back thereof and integral therewith, a translucent screen in front of said character and opposite thereto, and an opaque background having an opening therein through which said character projects.

T. l, glass panel for an illuminated sign having a frosted front face and provided on its back with a translucent outlined character, the back of the panel around the character being opaque, and the back of the character having a. 'prismatic surface.

8. A. panel for an illuminated sign comprising an opaque portion and a translucent portion, means for diffusing light-rays passing through the translucent portion comprising prismatic portions on the back of the translucent portion, and means for rendering the front of the translucent portion non- .distinguishable from the surrounding panel portion when viewed from the front and in the absence of illumination from the rear.

9. A panel for an illuminated sign comprising an opaque portion and a translucent Jortion said translucent ortion bein rovided at its rear with prismatic means for diffusing light rays passing therethrough, and means for rendering the front of the translucent portion non-distinguishable from the surrounding panel portion When viewed from the front and in the absence of illumination from the rear.

10. A sign panel for an illuminated sign comprising a translucent member, an opaque member having a character opening therein disposed at the back of the translucent member, and means including a prismatic surface for accentuating the character opening when the panel is viewed from the front and illuminated from the rear, said translucent member concealing the character When viewed from the front and not illuminated from the rear.

11. In an illuminated sign, an opaque panel having a character opening therein, a

translucent member for said character opening and provided at its rear with prismatic means for accentuating the character when viewed from the front and the panel is illuminated from the rear, the character member and the panel being treated so that the character is not distinguishable from the surrounding panel when the sign is viewed from the front and not illuminated from the rear.

12. A sign panel, for an internally illumi- 'nated sign, having a character on the back of the panel, thepanel portions around the character bein opaque, the character and the panel portion aligned therewith -permitting the passage of ight therethrough, the front of the panel inL alignment with the character having the propertyof concealin the character when the panel is illuminate from the front thereof, and the back of the i0 character having a prismatic face for difpassing' therethrough from the fusing li ht ghe panel.

front of 13. A panel for an illuminated sign'hav ing an opaque portion and a translucent portion the front faces of the opaque and translucent portions being mutually nondistin- ARTHUR B. RAMS'DELL.

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