Power stacking apparatus

A power stacker for collecting delivered articles such as envelopes from a mailing machine is comprised of a support housing having a deck fixably mounted along the housing. A registration wall is fixably mounted to the housing and extending generally perpendicular relative to the deck. A stack wall is slidably mounted to the housing at one end of the deck and has a reclined surface extended generally upwardly from the deck, the stack wall being slidably mounted to the housing such that the stack wall can be horizontally displaced relative to the deck. Support rods are provided for providing article support between the deck and displaced stack wall as well as between the registration and displaced stack wall. Threaded hubs are provided for causing the delivered articles to be collected against the stack wall and assume a generally parallel stacked orientation generally parallel to the reclined surface.

BACKGROUND OF THE INVENTION 
This invention relates to stacking apparatus for singularly receiving a 
stream of articles and causing the articles to be placed in a stack. 
It is known, for example, in mail processing systems to use a drop power 
stacker for receiving envelopes ejected from a mailing machine. A 
conventional drop power stacker is generally a fixed length apparatus and 
includes a receiving deck mounted throughout to a base. Conventionally the 
power stacker is supportably placed on a table abutting at one end to a 
mailing machine. 
In one such conventional power stacker, envelopes ejected from the mailing 
machine are drop fed onto the deck of the power stacker. The power stacker 
includes one or more endless belts for advancing the envelopes along the 
stacker deck. The endless belts are driven at a rate of speed chosen to 
cause the received envelopes to assume a shingled alignment along the 
stacker deck. A rotatively driven wheel is mounted to the power stacker to 
engage a portion of the upper envelopes' surface to assist in providing 
the proper shingling drive force to the envelopes. As the envelopes 
encounter the power stacker end wall, shingle space compression accrues 
causing the envelopes to assume a fan orientation characterized by fan or 
shingle angle. As a result the capacity of the power stacker in addition 
to its length its maximum shingle angle. 
SUMMARY OF THE PRESENT INVENTION 
It is an object of the present invention to present a power stacker which 
has a substantially reduced foot print and is characterized by increased 
capacity. 
It is a further objective of the present invention to present a power 
stacker not subject to shingle angle limitations. 
A power stacker in accordance with the present invention is comprised of a 
base section having transversely spaced apart rear and forward walls and 
enclosing end walls. A plurality of vertically extending support posts are 
fixably mounted at one end to the base of the power stacker and support, 
in conjunction with the forward, rear and end walls, a deck such that the 
deck is placed at a rearwardly reclining angle of approximately 15.degree. 
(fifteen degrees). A registration wall is fixably mounted generally 
vertical along the rear wall of the power stacker such that the 
registration wall assumes a generally perpendicular orientation with 
respect to the deck. 
The deck includes a plurality of parallel aligned slots extending 
longitudinally. A first and second shaft is rotatively mounted to the 
underside of the deck in longitudinal spaced apart relationship. Each 
shaft includes a plurality of friction rollers fixably mounted around the 
shaft vertically aligned to a respective slot in the deck. An endless belt 
is placed around a respective pair of friction rollers. 
One of the end walls includes a plurality of threaded hubs (augers) 
rotatively mounted thereto. Each hub extends partially through a recess 
formed in the deck. A bevel gear is fixably mounted to one end of each of 
the hub in mesh with a respective bevel gear fixably mounted to the first 
shaft. The first shaft is driven by a motor fixably mounted to the 
underside of the housing. 
An additional threaded hub is rotatively mounted to the registration wall 
such that a portion extends through a slot formed in the registration 
wall. A end portion of the first shaft extends through an aperture in the 
rear wall of the stacker base. An endless belt communication threaded hub 
is mounted to the registration wall with the first shaft. 
A stack wall is slidably mounted to forward and rear walls abutting the 
other end wall. The stack wall includes a forward facing surface aligned 
opposite to the end wall and a reclined surface extending generally 
vertically from the facing surface. A plurality of rods are fixably 
mounted at one to the stack wall and extends through end wall apertures. 
Each rod is slidably mounted longitudinally to the underside of the deck. 
The power stacker further includes a yoke pivotally mounted to the 
registration wall having a rotatably mounted wheel in bearing contact with 
the belts. 
Envelopes are received by the power stacker and transported by the belts to 
the stack wall whereupon the threaded hubs engage the envelopes. The hub 
engagement of the envelopes forcibly causes the envelope to assume a 
generally vertical biased position against the stack wall causing the 
stack wall to journey outward in response to forced engagement of the 
envelopes. 
Other benefits and advantages of the present invention will be noted or be 
apparent to one reasonable skilled in the art upon a reading of the 
following detailed description of the preferred embodiment of the 
invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to FIGS. 1 through 4, the power stacker, generally indicated at 
11, is comprised of a base housing 12 having a base 13. A plurality of 
vertically extending support posts 15 and 17 (support post 17 shown in 
FIG. 3) are fixably mounted to base 13 at one end. The base 13 also has 
fixably mounted thereto in vertical alignment, a forward wall 21 and rear 
wall 23 in transversely spaced apart parallel alignment. End walls 25 and 
27 are fixably mounted to the base 13 in spaced apart relationship and at 
there ends to respective walls 21 and 23. 
A deck is fixably mounted to walls 21, 23, 25 and 27 and along its 
underside to the support posts 15 and 17, such that the deck assumes a 
reclined position, front to rear, of approximately 15.degree. (fifteen 
degrees) from the horizontal. A deck 31 contains a plurality of slots 33, 
35, and 37. Fixably mounted to the underside of the deck 31 at the 
receiving or forward end is a first and second adjustable tension brace 
assemblies 41 and 43. Also fixably mounted to the underside of the deck 31 
are braces 45. The braces 45 are longitudinally aligned to a respective 
brace assembly 41 and 43. 
Fixably mounted to the underside of deck 31 is a motor mount 48 having a 
motor 49 mounted thereto. The motor 49 includes an output shaft 51 having 
a pulley gear 52 fixably mounted around the output shaft 51. A shaft 53 
carrying a plurality of fixably mounted friction wheels 55, 57, and 59 
therearound is rotatively mounted in the braces 45. The friction wheels 
are radially aligned to respective first slots 33, 35 and 37. A second 
shaft 63 is rotatively mounted in brace assemblies 41 and 42. The shaft 63 
carries a plurality of friction wheels 65, 67 and 69 radially aligned to 
the respective second slots 33, 35 and 37. A plurality of endless belts 
71, 73, and 74 extend around the respective friction wheel pairs 55-67, 
59-65 and 57-69. 
The shaft 53 further includes a pulley gear 81 which is in endless belt 83 
communication with the motor 49 for providing driving force to shaft 53. 
The shaft 53 further includes bevel gears 85 and 87 fixably mounted 
therearound in axially spaced apart relationship. The rear wall 23 
includes an aperture 89 through which an end portion of the shaft 53 
extends and has fixably mounted therealong a pulley 91. 
End wall 25 has formed thereon a plurality of studs 91 and 93 through which 
extends a respective shaft 95 and 97 seated at one end in the end wall 25. 
Rotatively mounted around the other end of shafts 95 and 97 is a 
respective threaded hub 101 and 103. The threaded hubs 101 and 103 are 
mounted such that the threaded hubs 101 and 103 partially extend into 
respective recesses 104 and 106 formed into the deck 31. A bevel gear 92 
and 93 is rotatively mounted around the respective shafts 95 and 97 in 
driving communication with the respective threaded hubs 101 and 103. The 
bevel gears 92 and 93 are in constant mesh with respective bevel gears 85 
and 87. 
A stack wall 111 has a formed facing surface 113 abutting to the outer face 
of end wall 25 vertically leading to a vertically reclined surface 115. A 
plurality of guide rods 117, 119, and 121 are fixably mounted at one end 
to the facing surface of the stack wall 111. The guide rods 117, 119, and 
121 extend slidably through respective apertures in the end wall and are 
slidably received by respective guide tabs 123, 125, and 127. The guide 
tabs 123, 125, and 127 are fixably mounted to the underside of the deck. 
Referring particularly to FIGS. 2 and 4, slide rail assemblies 141 and 143 
having a rail portion is fixably mounted to the respective side walls 21 
and 23. Another rail portion of rail assemblies 141 and 143 are fixably 
mounted at one end to the facing surface 113 of the stack wall 111 such 
that the stack wall 111 can be longitudinally displaced relative to end 
wall 27. 
Referring more particularly to FIGS. 2 and 4, a registration wall 145 is 
fixably mounted longitudinally along the rear wall 23 and orientated 
generally perpendicular to the deck. The registration wall 145 includes a 
recess 147 angled generally perpendicular to the reclined surface 115 of 
stack wall 111. A brace 149 is fixably mounted to the back surface of the 
registration wall 145. The brace 149 includes a shaft 151 rotatively 
mounted therein such that the shaft 151 extends generally perpendicular to 
the recline surface 115 of the stack wall 111. A pulley 153 is fixably 
mounted to the of shaft 151. The pulley 153 is an endless belt 155 in 
driven communication with the pulley 91 mounted shaft 63. A threaded hub 
157 is fixably mounted around the shaft 151. 
The registration wall 145 further includes a slot 160. A yoke 165 is 
pivotally mounted in slot 160 to the registration wall 145. The yoke 165 
carries a yoke wheel 167 rotatively mounted between the forks of the yoke 
165. The yoke 165 is adjustably mounted in slot 160 such that the yoke 
wheel rests on the deck 31. Also fixably mounted to the back face of the 
registration wall 145 is a guide rod 168 which extends slidably through a 
slide member 166 fixably mounted to the registration wall 145 and 
pivotally mounted at one end to the stack wall 111. A return spring 
assembly 170 is fixably mounted to base 13 having one end of its flex 
strip 172 fixably mounted to the stack wall 111. 
Referring to FIGS. 1, 2, and 5, in operation, a suitable motor controller 
171 is in electrical communication through line 173 with a envelope feed 
device 175, for example, a mailing machine, and through line 177 with the 
motor 49 of the power stacker 12. The motor 171 controller synchronously 
controls the operating speed of the power stacker 11 and the feed device 
175 such that envelopes, for example, 5 inch envelopes delivered by the 
feed device are received by the power stacker in a shingled fashion with 
approximately a 0.75 inch spacing between the leading edges of successive 
envelopes. The envelopes are transported by the belts 55, 57 and 59, which 
are under the drive influence of motor 49 through belt 83 and shaft 53, 
under the yoke roller 167 such that the leading edge of the lead envelopes 
engages the stack wall facing 115 and is caused assume a generally 
vertical position against the stack wall. The subsequent envelopes are 
caused to assume a generally parallel orientation relative to the lead 
envelope. The positioning of envelopes is assisted by the the edge 
engagement of the envelopes with the threaded hubs 101, 103 and 157. 
As the envelopes are caused to vertically stack, edge engagement of the 
envelopes with the threaded hubs 101, 103 and 157 cause the stack wall 111 
to displace outwardly. The rods 117, 119, 121, and 168 support the stacked 
envelopes as the stack wall is displaced. 
The afore description is of the preferred embodiment of the present 
invention and should not be view as limiting to the invention. The scope 
of the invention is defined by the appendix claims.