Apparatus for manufacturing sealed postal envelope assemblies using a discrete envelope unit split from an envelope-forming continuous sheet and an intermediate element having sizes adapted to be enclosed within said envelope unit, said apparatus comprising:
- (a) a main envelope processing unit for producing envelopes from said envelope-forming continuous sheet, each of said envelopes having a front layer and a rear layer, said envelope-forming continuous sheet having transverse weakening lines at regular intervals to define an envelope unit section between each adjoining pair of said weakening lines,
- said envelope unit section having
- (i) first and second transverse folding lines defining a first area there between for forming said front layer of said envelope,
- (ii) a second area for forming one portion of said rear layer of said envelope, said second area being connected to said first area at said first transverse folding line,
- (iii) a third area for forming the other portion of said rear layer of said envelope, said third area being connected to said first area at said second transverse folding line,
- (iv) longitudinal adhesive layers formed on one surface of said envelope unit section along each of the opposite side edges of said envelope unit section, and
- (v) a transverse adhesive layer formed on the same surface of said envelope unit section as said longitudinal adhesive layers, said transverse adhesive layer being disposed along the transverse edge of said third area distal to said second transverse folding line,
- said main envelope processing unit including,
- (I) a stock of said envelope-forming continuous sheet,
- (II) means for continuously supplying said envelope-forming continuous sheet from said stock,
- (III) means located downstream of said continuous supplying means for successively separating said envelope-forming continuous sheet along said transverse weakening lines into discrete envelope unit sections,
- (IV) first feeder means located downstream of said successively separating means for feeding each of said discrete envelope units to an envelope folding and intermediate element inserting station,
- (V) a folding operation unit in said envelope folding and intermediate element inserting station, said folding operation unit having first folding means for folding said discrete envelope unit along said first transverse folding line and second folding means for folding said discrete envelope unit along said second transverse folding line,
- (VI) second feeder means for feeding said intermediate element to said envelope folding and intermediate element inserting station,
- (VII) first sensor means for detecting the delivery timing of said discrete envelope unit delivered by said first feeder means,
- (VIII) second sensor means for detecting the delivery timing of said intermediate element delivered by said second feeder means,
- (IX) means for controlling the delivery of said discrete envelope unit to said envelope folding and intermediate element inserting station based on output signals from said first and second sensor means to that said intermediate element can be inserted into said discrete envelope unit section, and
- (X) means for sealing said folded discrete envelope unit along said longitudinal and transverse adhesive layers of said discrete envelope unit to form a completed envelope assembly;
- and
- (b) an intermediate element supply unit connected to said main envelope procesing unit for supplying said intermediate element to said second feeder means of said main envelope processing unit, said intermediate element supply unit including, (i) a first unit having a stock of first intermediate element-forming continuous sheet having transverse weakening lines at regular intervals, means for continuously supplying said first intermediate element-forming continuous sheet from said stock, means for folding said first intermediate element-forming continuous sheet in at least one longitudinal direction during the continuous supply of said first intermediate element-forming continuous sheet, means for bursting said first intermediate element-forming continuous sheet folded along said weakening wherein said intermediate supply unit exchangeably and selectively supplies said intermediate element to said second feeder means of said main envelope processing unit.