Stubless multi-part assembly
RELATED APPLICATIONS 
     This application relates to U.S. application Ser. No. 708,176, filed July 23, 1976, and to U.S. application Ser. No. 623,393, filed Oct. 17, 1975, both commonly owned herewith. 
     BACKGROUND OF THE INVENTION 
     Assemblies of several superimposed parts are generally detachably secured together by means of a common stub which, as pointed out in the above-mentioned related applications, obviously represents a completely unusable portion of the assembly since it cannot accept writing or printing and must be ultimately discarded. This wasteful use of the multi-part assembly applies equally as well to mailer constructions wherein one or more parts may be detachably connected to a stub. 
     SUMMARY OF THE INVENTION 
     It is therefore an object of the present invention to provide a multi-part assembly constructed for use as a mailer having a top removable cover ply or first part and which completely avoids provision of a stub thereby rendering the unit more economical and more usable from the standpoint of the writing material which may be carried by the several parts. 
     The stubless multi-part construction of the invention has detachable glue flaps along opposite edges of the first and second plies, respectively, from the top, the flaps being folded to underlie the bottom ply and being adhesively secured thereto. The intermediate ply is anchored in place as the glue on the top cover or first ply extends through marginal openings provided in the intermediate ply so as to thereby function as a rivet between the interconnected top and bottom plies. Holes may also be provided in the bottom part in axial alignment with the intermediate ply holes, except that the bottom ply holes are of a smaller size so as to partially mask the glue extending through the intermediate ply holes whereby the intermediate ply is released by simply separating the top and bottom plies so as to break the adhesive. 
     A three-part assembly is likewise contemplated by the invention wherein holes provided in the bottom ply permit the glue on the cover ply flap to extend therethrough so as to secure the intermediate ply in place. 
     Other objects, advantages and novel features of the invention will become more apparent from the detailed description thereof. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a top plan view of a multi-part mailer assembly constructed in accordance with the invention, several plies thereof being broken away for clarity; 
     FIG. 2 is a cross-sectional view of the assembly taken substantially along line 2--2 of FIG. 1; 
     FIG. 3 is an expanded perspective view of the FIG. 1 assembly, slightly enlarged, showing the details of the invention; 
     FIG. 4 is a view similar to FIG. 3 of another embodiment according to the invention; and 
     FIG. 5 is a sectional view similar to FIG. 2 of the FIG. 4 assembly. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Turning now to the drawings wherein like reference characters refer to like and corresponding parts throughout the several views, the assembly according to the invention is generally designated 10 in FIG. 1 and comprises several superimposed parts or plies as, for example, a cover ply 11 (first part), a top ply 12 (second part), an intermediate ply 13 (third part) and a bottom ply 14 (fourth part). It will become apparent that the assembly of FIG. 1 is a minimum four-part assembly and that additional like parts may be similarly superimposed without departing from the invention. 
     Holes 15, of some desired number and spacing, are provided along the marginal edge of part 13, holes 16 being provided in part 14 in axial alignment with holes 15, respectively. As shown, both sets of holes are circular with the diameter of holes 16 being smaller than that of holes 15. Nevertheless, both sets of holes may be of a different configuration so long as the relative size differential between them is maintained so as to define a mask portion 17 surrounding each hole 16 by virtue of this hole size differtial. The purpose and operation of the mask portions will be more clearly described hereinafter. 
     Part 11, the cover ply, has a flap 18 detachably connected along a marginal edge thereof by means of line 21 of weakening. And, a flap 19 is detachably secured along a marginal edge of part 12, such edge being opposite the edge along which flap 18 is secured. Flap 19 is made detachable as by line 22 of weakening, and both flaps have strips 23 and 24 of adhesive thereon for respectively securing the flaps to the underside of part 14. 
     Portions 23a of the adhesive on flap 18 extend through aligned holes 15 and 16 whereupon parts 12 and 14 are adhesively secured together and, because of the different relative sizes of the aligned holes which define mask portions 17, portions 23a of adhesive are confined to the smaller sizes of holes 16 (see FIG. 2). These portions 23a therefore lie slightly inwardly of the margins of larger holes 15. Part 13 is therefore immobilized or anchored in place by glue portions 23a which act in the manner of rivets extending between parts 12 and 14. 
     With such a construction as aforedescribed, it can be seen that assembly 10 comprises a mailer unit of interconnected parts 12, 13 and 14 open along its opposite sides perpendicular to line 22. Part 11 which serves as a cover or record ply may be removed from the assembly by tearing along line 21 of weakening whereupon the remaining interconnected parts 12, 13 and 14 remain intact. As typically provided for business forms on this type, sheets of carbon coated material may be interleaved between the four parts of the assembly, or carbonless transfer material may be coated on the mating surfaces of the four parts in whole or in part for the transfer of images from part 11 onto parts 12, 13 and 14. Cover ply 11 would normally be removed before the assembly is mailed so that, upon receipt by the addressee, part 12 may be completely separated from the assembly by tearing along line 22 and by pulling it away from the underlying parts so as to thereby break glue portions 23a for freeing each of the parts 12, 13 and 14 from one another. Or, it may be desirable to utilize the assembly other than as a mailer unit whereupon part 11 remains connected to part 14 and part 13 is pulled outwardly of one of the open sides whereupon parts 12 and 14 remain interconnected. 
     In accordance with another embodiment of the invention, an assembly 10&#39; is shown in FIGS. 4 and 5 as being similar to assembly 10 except that a three-part construction is formed of parts 11, 12 and 13 which are identical to like parts forming the assembly 10 construction. Glue flaps 18 and 19, respectively on opposite side edges of parts 11 and 12, underlie part 13 and are adhesively secured thereto as shown in FIG. 5. Portion 23a of adhesive 23 extends through each opening 15 of part 13 so as to secure parts 12 and 13 together. Assembly 10&#39; may therefore be used similarly as assembly 10 by first removing part 11 as a record ply before the remaining parts forming a mailing unit are mailed out. Parts 12 and 13 thereupon remain intact and may be separated by tearing along line 22 of weakening and pulling part 12 away from part 13 so as to break adhesive portions 23a. Otherwise, assembly 10&#39; may be utilized as a three-part business form whereupon removal of part 11 by tearing along line 21 and the separation of parts 12 and 13 as aforedescribed releases all the parts from one another. 
     It can be seen by those having ordinary skill in the art that a stubless business form unit has been devised whereupon paper waste has been eliminated since no stub need be discarded and each of the parts forming the assembly may receive a larger amount of writing as compared to a similarly sized stub assembly. The assemblies may be used as mailers or other types of business forms as desired. 
     Obviously, many modifications and variations of the invention are made possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.