US2694228A

US2694228A - Method of making display assemblies

Info

Publication number: US2694228A
Application number: US162309A
Authority: US
Inventors: Clark A Mathis
Original assignee: Individual
Current assignee: Individual
Priority date: 1950-05-16
Filing date: 1950-05-16
Publication date: 1954-11-16
Anticipated expiration: 1971-11-16

Description

Unite 8 Claims. (Cl. 18--59) This invention relates to display assemblies, such as signs, having letters, symbols or like display elements extending through a ably projecting beyond at least one face thereof.

In accordance with the present invention, while the panel material is in liquid state, preformed display elements, usually of glass, or of synthetic resin, such as Lucite, Plexiglas or like material having desired optical properties, are partially immersed in a confined body or layer of the liquid panel material and retained in their resired spatial relation during transition of the panel material from liquid to solid state. Thus regardless of the complexity of the outline or configuration of the display elements, the panel exactly conforms to the elements extending therethrough without laborious slitting and fitting operations. Preferably, the panel material is of character forming a bond directly to the display elements in avoidance of need for cement, adhesive or other bonding medium. Furthermore, the tray or container for holding the panel material during its setting about the preformed display elements is preferably of shape corresponding with the outline of the finished panel in avoidance of the cost and waste of subsequentshaping operations.

Further in accordance with preferred forms of my invention, the panel material, while liquid and during setting thereof about the display elements, is supported in spaced relation from the bottom of the tray or mold by an underlying layer of material which receives the lower ends of the display elements to preclude formation thereon of a coating of the panel material. When the underlying layer is liquid during setting of the panel material, it should be of higher density than, inert with respect to, and non-miscible with the liquid panel material; when the underlying layer is a non-deformable solid during setting of the panel material, it should be of nature permitting its subsequent removal as by application of an agent such as heat or a solvent; as another alternative, the underlying layer may be a deformable solid, as soft rubber or silicone, at all stages of the process.

The invention further resides in methods and products thereof having features of novelty and utility hereinafter more fully described and claimed.

For a more detailed understanding of my invention, reference is made to the accompanying drawings, in which:

Fig. 1 is a perspective view of discrete display sign elements;

Fig. 2 is a perspective view referred to in discussion of several methods of making signs incorporating the elements of Fig. 1;

Figs. 3A, 3B and 3C are sectional views of difierent types of signs embodying and made in accordance with the invention;

Fig. 4 is a cross sectional view of a sign having a display element having its opposite ends projecting beyond opposite faces of the mounting panel;

Fig. 5 is a cross sectional view of a sign having a display element Whose opposite ends are respectively flush with and projecting beyond opposite faces of the mounting panel;

Fig. 6 is a cross sectional view of a sign having a display element Whose opposite ends are flush with opposite faces of the mounting panel;

Fig. 7 is a perspective view of a sign of cross-section such as shown in Fig. 4 or Fig. 5; and

Fig. 8. is a perspective view, in part broken away, of

panel or similar mount and prefer- States Patent 0 gr illuminated sign embodying the display assembly of As explanatory of various specifically diiferent methods of making of glass, Plexiglas, Lucite or like transparent, trans lucent or colored material which transmits light from a light source disposed to the rear of their mounting panel which is opaque or of substantially diflerent optical property to serve as a contrasting background.

Referring to Fig. 2, the tray or container 10 is of size and outline corresponding with that of the mountmg panel of the finished sign; in the simple case illustrated, the tray 10 is rectangular.

The sign elements 11A, 11B and remain separate their density or flows about the thereof, regardless of how complex, between parallel planes intermediate the upper and lower edges of the group of display elements. The level of the lower plane or under face of layer 13L with respect to the sign elements depends upon the selected thickness of the under- 15L should not be less than inch as otherwise the high viscosity prevents free flow. The liquid panel ma terial, specific examples of which are later mentioned, is such nature that it hardens into a solid panel about the sign elements while they are retained in their ultimate position. When the panel material is completely hardened, the assembly comprising the panel 138 and the mounted sign elements may be removed as a unit from the mold and as so removed may be used for display purposes with little or no further processing.

To facllitate removal of the display assembly or sign, the inner side walls of the tray 10 are lightly pre-coated with oil, glycerine or the like to preclude adhesion to the panel material.

The panel material be collodion which hardens by evaporation of its it may be Kelon,

the panel thickness and add to the strength of the resultlng assembly. Also, if desired, the panel material may include filler such as talc, wood the like, or ing b between the sign elements.

The fillers, when used, may also provide the desired opacity or color of the panel: alternatively, or in additron, pigment, or other coloring material may be added for such purpose to the panel material while in liquid form and before pouring into the mold about the preformed sign elements.

The lower layer 12 may be a low melting point material, such as Woods metal or wax, which can be poured into the mold in liquid state and permitted toharden about the lower ends of the display elements. Upon hardening of this material, it forms a layer 12 having a smooth upper face exactly conforming with the outlines of the various display elements and serves rigidly temporarily to hold the display elements in their prearranged grouping. Thereafter, the panel material is poured thereon to form layer 13L and is permitted to harden as panel 138. It is thus insured the panel 138 is of uniform thickness, that both of its faces are smooth and parallel and that the panel has an air-tight or light-tight joint with each display element that extends through it. After hardening of the panel material, the mold may be heated to melt the wax or Woods metal, permitting the sign assembly, consisting of the hardened panel and mounted display elements, to be removed as a unit. Alternatively, the lower layer 12 may be of a material which can be dissolved by application of a solvent for such removal. The melting temperature of Woods metals and Wax is well below the softening temperature of many available panel and display-element materials: for example, the melting points (117 F. and 158 F.) of Belmont fusible alloys 2451 and 2502 are well below 212 F. at which hardened Castolite and Plexiglas will not melt or soften.

Alternatively, the lower layer 12 may be of material, such as glycerine or mercury, which is liquid throughout the making of the sign. If mercury is used, extraordinary precautions should be taken to guard against its toxic fumes when hardening of the liquid panel 13L is accelerated by heating to recommended temperature of the order of 120 F. to 170 F. Again the underlying layer forms a smooth surface supporting the liquid panel material in desired position with respect to the display elements. It is, of course, necessary that the liquid so used as the underlying layer 12 shall be of greater density than, and non-miscible with, the liquid panel material: it should also be chemically inert to the liquid panel material and the chemical hardener therefor, if used.

The underlying layer may less desirably be modeling wax or powdered or granular material such as talc, diatomaceous earth, or other free-flowing solid state material into which the display elements are pressed prior to pouring of the liquid panel material for hardening about the display elements.

In general, the underlying layer 12, in any of its herein described forms, serves as a temporary matrix or shield which prevents the lower edges of the preformed display elements from being coated with panel liquid. It is thus insured there is no impairment of the transmission of light through the display elements. The underlying layer 12 also in each instance acts as a temporary supporting surface of adjustable height for the layer of panel liquid during its setting about the display elements. The underlying layer 12 also in each case serves as a heat-transfer medium, minimizing temperature gradients in the panel during its hardening or transition from liquid to solid state and during melting of layer 12 when of wax, for example. The underlying layer also insures that the under face of the panel 135 will be plane or flat despite any irregularities in the bottom of the mold 10.

As more clearly appears from Fig. 3A, the thickness of the lower layer 12 may be selected so that each sign element, generically represented by element 11, will project substantially above and below the upper and lower faces of the layer 131. of panel material, the extent of projection being easily controlled by the adjustment of the amount of material poured into, or left in, the tray 10 to form the lower layer 12.

When, for example, the lower layer is of Woods metal or mercury, the meniscus 14 which forms immediately adjacent the sign elements is of such curvature as to increase the thickness of the layer 13L of panel material at this point, resulting in an enhanced bonding area between the sign elements and the hardened panel.

When, however, glycerine for example is used as the lower layer, it tends to wet Plexiglas preforms and to form an upwardly curved meniscus. The wetting action tends to interfere with or prevent satisfactory bonding of the panel material to the preformed sign elements. This difficulty may be avoided in various ways: for example, the preforms 11 may be initially immersed to less than their final depth in the layer 12 and are moved to their final position only after the casting liquid has been poured upon the surface of liquid 12 and forms a layer 13L around the preforms. Alternatively, the panel liquid may be first poured upon the liquid 12 after which the display elements 11 are lowered to their final casting position. Both procedures insure that the display elements are wetted at the bonding or welding line by the liquid panel material rather than by the liquid 12 and so insure a good bond between the hardened panel and the display elements.

Though the specific gravity and low cost of sodium silicate (waterglass) suggests its suitability for the lower layer 12, it is at best or limited utility because its water content adversely affects the catalyst or the thermosetting properties of liquid panel materials which form satisfactory bonds to Plexiglas and Lucite. Conversely, those casting plastics whose setting properties are not affected by contact with water, usually do not bond satisfactorily to Plexiglas and Lucite.

When there is used any of the methods above described, the display elements 11 of the finished sign extend, as shown in the cross-sectional view of Fig. 4, through the mounting panel 138 and substantially beyond it on both sides. Preferably, the panel material is of such nature that it forms a direct bond or weld to the sign elements so firmly holding them in position without need for use of any cement which not only presents difficulty in application without impairing the appearance of the sign, but would also affect the light transmission at the joints between the two materials. Such direct bonding occurs when, for example, the display elements are of Plexiglas or Lucite and the panel material is Kelon or Castolite.

When it is desired, as shown in Fig. 5, that the display elements project from one side of the panel and be flush 'ith the opposite side, the same general method may be used except that the underlying layer 12, if liquid, should be suitably thin: however, it should be sufiiciently thick to fill in imperfections in the bottom of the trough 10 and to compensate for lack of absolute flatness of the under face of the sign elements.

Alternatively, the type sign shown in Fig. 5 may be made by coating the bottom edges of the display elements with-a light film of oil or heated parafiin before they are disposed in the mold. This prevents adhesion or welding of the panel material to them and any splinters or fragments formed by flow of the liquid panel material into irregularities of the bottom edges and the pan bot tom are easily broken or trimmed away to expose the clear bottom edges of the sign elements.

However, for the production of this type of sign (Fig. 5), it is more convenient that the underlying layer be a layer 12A, Fig. 3B, of deformable solid, such as soft rubber sheeting. The side walls of the tray 10 and also the upper face of the rubber pad should be lightly coated with oil, glycerine or the like to preclude adhesion of panel material. The sign elements are pressed, as by a weight or clamping jaw 15, so that the lower end of each of them slightly depresses the upper face of the layer 12A. While the sign elements are so held, the panel material, in liquid form, is poured into the mold to flow into intimate engagement with the sign elements; engagement with the under face of their lower ends being precluded by the lower layer 12A which receives them. After the layer 13L of panel material has hardened, the unit assembly of panel 138 and mounted display elements may be removed, the upper surface of the underlying layer 12 resuming its original fiat condition because of the resiliency or plasticity of the rubber. Instead of rubber sheeting, the layer 12A may also be of a known form of silicone which deforms readily under pressure but which slowly resumes its original surface configuration upon release thereof. So far as their action is here concerned, both soft rubber and silicone act like highly viscous liquids, and are substantially equivalent to glycerine and molten Woods metal.

Alternatively, the type of sign shown in Fig. 5 may be made, asshown in Fig. BC, by pouring into the mold 10 a transparent thermosetting panel material to form an underlying liquid layer 1213 of depth at least sufiicient to fill in the irregularities of the bottom face of the preforms. After this underlying layer has sufficiently set, a second layer 13L of thermosetting panel material suitably colored or including opaque filler may be poured on the upper surface of layer 1213 about the display elements 11 for bonding to them and to the lower layer. It is thus assured that the rear or lower faces of the sign elemets are covered with transparent plastic for transmission of light. In this modification,

the upper layer 13L may be replaced by a surface of paint, brushed or sprayed on panel 12B while still in the mold or after its removal therefrom.

As indicated in Fig. 6, the display elements of the sign may extend through the panel 13$ for exposure on both sides thereof but terminating flush with them. In general, this sign is less desirable because less striking optically and also because it is somewhat more difficult to make. It can, however, be made in a manner similar to that shown in Figs. 3B and 30 by careful control of the pouring of the layer of liquid panel material.

As viewed from the left, the sign of either of Figs. 4 and 5 appears as in Fig. 7 with the display elements extending substantially in front of the mounting panel 138. As above stated, the display elements may be of material or may be processed to exhibit a desired property such as color, phospherescence, fluorescence, light piping, or the like, and the mounting panel 13S may be of material or processed to form a contrasting background of optical properties differing in nature or degree and including opacity or color.

As indicated in Fig. 8, a display assembly, such as shown in Fig. 7, may be mounted as the front face of a box or housing 16 having therein a source of visible or invisible light 17, preferably diffused as by ground glass screen 18, to impress radiation upon the exposed inner edges or portions of the display elements held in their prearranged grouping by the panel 138. The light transmitted through the sign elements or exciting the fluorescent or phosphorescent material therein produces striking visibility of the projecting three-dimensional display elements against the contrasting background afforded by the panel. This example is, of course, illustrative of other arrangements for eifective utilization of display assemblies produced by my novel methods.

What is claimed is:

1. A method of making display signs having one or more preformed display elements projecting through and beyond a mounting panel which comprises supporting said elements in a mold corresponding in outline with said panel; pouring into said mold a fluid composition which is non-bonding with respect to said display elements and which is in amount to provide in said mold a lower layer in depth corresponding with the desired extent of projection of said display elements from a face of said mounting panel; pouring into said mold a hardenable liquid plastic which is of composition bonding with respect to said display elements and which is in amount to provide in said mold an upper layer corresponding with the desired thickness of said mounting panel; and after hardening of said upper layer about said display elements, removing from said mold and said lower layer the resultant display sign having said display elements extending therethrough and projecting therefrom.

2. A method as in claim 1 in which the lower layer is of composition which is in liquid state before, during and after hardening of the upper layer about said display elements and which is non-miscible with, inert to and of greater specific gravity than the composition of the upper layer.

3. A method as in claim 1 in which the lower layer is of composition which hardens about the display elements, in which pouring of the upper layer is after hardening of the lower layer, and in which an agent is applied to remove the lower layer after hardening of the upper layer about said display elements.

4. A method as in claim 1 in which the combined depth of the two layers determines the extent of projection of the display elements from the upper side of the upper layer, the depth of the lower layer determining the extent of projection of the display elements from the under side of the upper layer.

5. A method as in claim 1 including the additional step of aerating the hardenable liquid plastic for enhanced thickness of the panel formed thereby upon hardening about the display elements.

6. A method as in claim 1 including the step of adding a foaming agent to said hardenable liquid plastic for enhanced thickness of the panel formed thereby upon hardening about the display elements.

7. A method as in claim 1 in which the hardenable liquid plastic for the upper layer is a polyester liquidcasting resin and in which the fluid composition for the lower layer is glycerine or mercury.

8. A method as in claim 1 in which the hardenable liquid plastic for the upper layer is a polyester liquidcasting resin and in which the lower layer is of material having a melting point lower than the softening point of the hardened upper layer.

References Cited in the file of this patent UNITED STATES PATENTS Fields Jan. 16, 1951