INTERLOCKING PLASTIC DISPLAY

Abstract: A display device (10) has two interlocked contrasting elements. A first, display, element (12) includes indicia and a first locking member (18). The second, background, element (14) includes a second locking member (26) complementarily shaped to conform to the shape of the first locking member. The first locking member has two portions (20, 24). The first portion (20) is a waffle plate which tapers from top to bottom. The second portion (24) includes a plurality of frusto-conical pads (30) disposed beneath nodes of the waffle plate of the second portion (24).

Description: INTERLOCKING PLASTIC DISPLAY BACKGROUND OF THE INVENTION The present invention relates to interlocking plastic displays and, more particularly, interlocking plastic displays having improved stability. In our earlier patent, U. S. Patent No. 4,835,890, the disclosure of which is here incorporated by reference, we disclosed an interlocking plastic display having t interlocking members. A first, display, member includes indicia formed therein, and a fi locking element formed beneath the indicia. The second, background, member, includ a second locking element configured to interlock with the first locking element. The fi locking element includes a portion of reduced depth, so that the first and second locki elements may interlock, with portions of each locking element underlying portions of t other locking element. The two members are made of different colored materials, so th they offer good contrast and ease of readability. The patented device has proven to work quite well for its intended purpose, but so problems have arisen in the field. When working with larger signs, we have noticed th some warping in the device may develop over time, and that the manufacture of su larger devices may result in some production difficulties, such as uneven flow of materi in the two-shot injection molding process. We have discovered that these larger display devices benefit from increased streng and resistance to warping provided by an additional layer of locking and supporti elements. OBJECTS AND SUMMARY OF THE INVENTION Accordingly, it is an object of the invention to provide an interlocking plastic displ which overcomes the drawbacks of the prior art. It is a further object of the invention to provide an interlocking plastic display havi improved structural rigidity. It is a still further object of the invention to provide an interlocking plastic displ having additional layers of locking and supporting elements. Briefly stated, there is provided a display device which has two interlocked contrasti elements. A first, display, element includes indicia and a first locking member. T second, background, element includes a second locking member complementarily shap to conform to the shape of the first locking member. The first locking member has t portions. The first portion is a waffle plate which tapers from top to bottom. The seco portion includes a plurality of frusto-conical pads disposed beneath nodes of the waf plate of the second portion. In accordance with these and other objects of the invention, there is provided a disp device comprising: a display member having a top surface and a bottom surface, s display member including indicia disposed on said top surface, and further including fi locking means disposed beneath said top surface; and a background member also havi a top surface and a bottom surface, said background member including second locki means configured to interlock with said first locking means; said first locking means havi first and second portions, each with top and bottom surfaces and a horizontal cross-secti said bottom surface of said first portion overlying at least part of said top surface of s second portion; said cross-section of said second portion being smaller than said cro section of said first portion; said second locking means substantially underlying at least of said first and second portions of said first locking means; whereby said display mem and said background member are locked together by the interlocking of said first second locking means. According to a feature of the invention, there is further provided a display dev comprising a display member having a top surface and a bottom surface, said disp member including indicia disposed on said top surface, and further including first lock means disposed beneath said top surface; and a background member also having a surface and a bottom surface, said background member including second locking me configured to interlock with said first locking means; said first locking means havin waffle plate with a top surface, a bottom surface and a horizontal cross-section; said locking means further having a plurality of pads, each having a top surface and an ove horizontal cross-section; said bottom surface of said waffle plate overlying at least par said top surface of said plurality of pads; said cross-section of said plurality of pads be smaller than said cross-section of said waffle plate; said second locking means substanti underlying a portion of said first locking means; whereby said display member and s background member are locked together by the interlocking of said first and sec locking means. The above, and other objects, features and advantages of the present invention w become apparent from the following description read in conjunction with the accompanyi drawings, in which like reference numerals designate the same elements. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a vertical cross-section of a display device according to the invention. Fig. 2 is a bottom plan of the display member of the device of Fig. 1. Fig. 3 is bottom perspective of a portion of the display member of Fig. 2, shown part in cross-section. Fig. 4 is a bottom plan of a portion of a secondary embodiment of the displ member of the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to Fig. 1, there is shown, generally at 10, a display device in accordanc witlTthe invention. Display device 10 includes a display member 12 and a background member 14. Th composition and possible methods of manufacture of inventive display device 10 ar essentially the same as described in our earlier referenced patent, and so are not furthe described in detail here. As shown in Fig. 1, display member 12 includes three distinct layers, or portions. Th uppermost portion of display member 12 comprises indicia 16. The lower portion together comprise a first locking element 18. First locking element 18 includes an upper portion 20, having a tapered side wall 2 and a lower portion 24. In the preferred embodiment, depicted in Fig. 1, background member 14 is configure to complement the structure of display member 12, so that display device 10 has generally rectangular overall vertical cross-section. This is not the only possibl embodiment, however. In other embodiments, not separately shown, background member 14 may n completely encapsulate the sides of display member 12, but rather may be co-termino therewith. Furthermore, the top of display member 12 and background member 14 ne not be co-planar. The possible alternative embodiments are also discussed in our earli patent, and so are not discussed further here. The primary difference between the device disclosed in our earlier patent and t instant device relates to the configuration of first locking element 18 hereof, and so t following discussion will be directed to that element. While background member includes a second locking element 26 which differs form the analogous member of o patented device, the shape thereof is determined by the shape of first locking element 1 so no separate discussion thereof is believed necessary. Turning now to Fig. 2, first locking element 18 is shown in further detail. Figure is a bottom plan view of display member 12, with indicia 16 omitted, for clarity. Whi indicia 16 and the remainder of display member 12 are described as though they a discrete components, it will be appreciated that, in fact, they together comprise a sing unitary element, in the preferred embodiment. Upper portion 20 is preferably formed as a waffle plate, having generally squa passages 28 therein. The overall appearance of first locking element 18, when viewed fro the top, resembles that of a waffle iron. Upper portion 20 is generally similar to the first locking means described in our earli patent. The difference is the addition of lower portion 24. Lower portion 24 has a total cross-section substantially smaller than that of upp portion 20. As illustrated, in the most preferred embodiment, lower portion 24 compris a plurality of pads. It is further preferred that the pads of lower portion 24 be form as frusto-conical pads (see Fig. 3). In the preferred embodiment, passages 28 a approximately .090" on each side, with an eighteen degree (18°) taper per side, with t distance between adjacent passages set at .1875". Pads 30 are preferably .062" high, w a ten degree (10°) taper. The widest diameter of pads 30 is approximately .125", and t the smallest diameter would be approximately .103". Display device 10 is preferably manufactured in a molding operation in which disp member 12 is formed, and then placed in a mold where the material comprisi background member 14 is injected. That material flows about display member substantially encapsulating it. However, the bottom of lower portion 24 and the top indicia 16 contact the opposing sides of the mold, so that indicia 16 are not covered by t flowing material, and remain visible. Since lower portion 24 has such a relatively sm cross-section, more of background member 14 flows under display member 12; there importing greater structural resistance to warping. It will be appreciated that the illustrated design is not the only possible configuratio of the invention. For example, it is possible that the presence of the regular rectiline structure of first portion 20 may lead to the creation of a weakness in the structure of large sign. It could cause a "bend line", facilitating deformation of the display memb along a single line. Alternative constructions, not illustrated, could overcome this. For example, instead of forming upper portion 20 as a rectangular waffle plate, could be formed hexagonally, resembling a honeycomb, or with circular apertures therei As another alternative, alternate rows of a rectilinear structure may be offset. Thi embodiment is shown in Fig. 4, where elements similar to those of the preferre embodiment are denominated by primes. Such a construction would be more difficult an expensive to realize, but would probably be best performed in known fashion by electri discharge machining. Many other, different, configurations may be best for different applications, and som minor experimentation may be useful to determine the best arrangement for any specifi application. Similarly, the number and positioning of pads 30 may vary depending on th application. The addition of pads 30 to the display device of our prior patent provides th superior strength which may be found in the instant device. The illustrated embodimen shows pads 30 positioned at alternating nodes 31 of upper portion 20. This positionin maximizes the surface area of pads 30 which contact upper portion 20, while minimizin the amount of volume to be removed from the mold which is used to form displa member 12. In placing pads 30 in the desired structure, it is important to exceed minimum diameter on the surface of pad 30 which contacts upper portion 20 to facilitat the molding process, while also maintaining a degree of integrity of the shape of pads 3 during the remainder of the molding process during which background member 14 i fabricated. If too many pads 30 are used, the cost of the mold will be increased, and th flow of the molded background material could be impeded. All of the application- specifi parameters would be easily understood and implemented by the ordinary artisan skille in the practice of injection molding, and so no further specific teachings thereon ar believed necessary. It is believed that the number and shape of pads 30 should be calculated so that t total volume of pads 30 is approximately equal to the total volume of the material whi forms indicia 16. This will tend to equalize the flow of background material about displ member 12, thereby minimizing warpage. Having described preferred embodiments of the invention with reference to t accompanying drawings, it is to be understood that the invention is not limited to tho precise embodiments, and that various changes and modifications may be affected ther by one skilled in the art without departing from the scope or spirit of the invention defined in the appended claims. T

Claims: What is claimed is: 1. A display device comprising: a display member having a top surface and a bottom surface, said display memb including indicia disposed on said top surface, and further including first locking mea 5 disposed beneath said top surface; and a background member also having a top surface and a bottom surface, sa background member including second locking means configured to interlock with said fir locking means; said first locking means having first and second portions, each with top and botto 10 surfaces and a horizontal cross-section; said bottom surface of said first portion overlying at least part of said top surface said second portion; said cross-section of said second portion being smaller than said cross-section of sai first portion; 15 said second locking means substantially underlying at least one of said first and secon portions of said first locking means; whereby said display member and said background member are locked together by th interlocking of said first and second locking means. 2. The display device of Claim 1, wherein said second portion comprises 20 plurality of pads, each having a top surface in contact with said bottom surface of said fir portion. 3. The display device of Claim 2, wherein said pads are frusto-conically shape J 4. The display device of Claim 2, wherein the total volume of said indicia i approximately equal to the total volume of said plurality of pads. 25 5. The display device of Qaim 1, wherein said first portion includes a waffle plat 6. The display device of Claim 5, wherein said waffle plate is substantially rectilinea 7. The display device of Claim 5, wherein said second portion comprises plurality of pads, each underlying nodes of said waffle plate. 8. The display device of Qaim 7, wherein said pads are frusto-conically shap 9. The display device of Qaim 5, wherein the total volume of said indicia approximately equal to the total volume of said second portion. 10. The display device of Claim 1, wherein the total volume of said indicia approximately equal to the total volume of said second portion. 11. A display device comprising: a display member having a top surface and a bottom surface, said display mem including indicia disposed on said top surface, and further including first locking me disposed beneath said top surface; and a background member also having a top surface and a bottom surface, s background member including second locking means configured to interlock with said fi locking means; said first locking means having a waffle plate with a top surface, a bottom surface a a horizontal cross-section; said first locking means further having a plurality of pads, each having a top surf and an overall horizontal cross-section; said bottom surface of said waffle plate overlying at least part of said top surface said plurality of pads; said cross-section of said plurality of pads being smaller than said cross-section of s waffle plate; said second locking means substantially underlying a portion of said first lock means; whereby said display member and said background member are locked together by interlocking of said first and second locking means. 12. The display device of Claim 11, wherein said pads are frusto-conically shap 13. The display device of Claim 11, wherein the total volume of said indicia approximately equal to the total volume of said plurality of pads. 14. The display device of Qaim 11, wherein said waffle plate is substantiall rectilinear. 15. The display device of Qaim 11, wherein at least some of said plurality of pad each underlie nodes of said waffle plate.

Inventors: NELSON KENNETH W, ROGGENBURG STANLEY L, NELSON, KENNETH, W., ROGGENBURG, STANLEY, L.
Applicants: NELSON KENNETH W, NELSON, KENNETH, W.
Application year: 1991
Main classification: G09F19
IPC codes: G09F7