Modular mounting assembly comprising variable channel volume system

A modular mounting assembly for compressibly mounting on a corner of a structure comprising:

• a first subassembly comprising a first mounting plate, a first pair of fixed, non-pivotable and non-rotatable inwardly depending and opposing angled standoff elements and a pair of inwardly depending and opposing first bracket arms;
• the angled standoff elements comprising respective angled standoff surfaces;
• a second subassembly comprising a second mounting plate, a second pair of fixed, non-pivotable and non-rotatable inwardly depending and opposing second bracket arms and a pair of opposing interior corner attachments;
• the interior corner attachments each comprising a respective interior corner attachment face and an adjustable compression means;
• the first bracket arms configured to be adjustably telescopically received by the respective second bracket arms whereby a distance between the first mounting plate and second mounting plate may be varied solely by linear translation along the longitudinal axis of the modular mounting assembly;
• locking means to selectively urge or compress the first bracket arms against the respective second bracket arms to define a substantially rigid connection between the first subassembly and the second subassembly;
• the angled standoff elements and compression means configured to define a channel volume;
• the first mounting plate and the second mounting plate configured to adjustably receive and compressively capture two angularly disposed and adjacent corner portions of a wall or structure comprising a pair of opposed lateral wall surfaces therebetween and within the channel volume.