Insertion station for envelope-stuffing apparatus or for a section thereof of mail handling apparatus

An insertion station for a mail-handling machine includes a driving lever 25 and a means for swivelling the driving lever 25 back-and-forth according to an operating cycle. Axle members 18, 19 have a cam 20 mounted therebetween and a spring 26 extends between the driving lever 25 and the cam. A base plate 1 includes grooves 2, 3, 4 and finger-roller guides 28 have front and rear ends mounted above the base plate. Insertion ramps 35, 36, 37 are located below the rear ends of the finger-roller guides; and, inserting arm means 8, 9, 10 and 14, 15, 16 have fingers 5, 6, 7 and finger rollers 27, 38, 39 attached thereto. The inserting arm means 8, 9, 10 and 14, 15, 16 are connected to the axles 18, 19; the fingers 5, 6 and 7 are mounted on the insertion arms which are adapted to slide the fingers 5, 6, and 7 forwardly in an input direction in the grooves 2, 3, 4 of the base plate 1; and, the finger rollers 27, 38, 39 are in engagement with the finger-roller guides 28 for movement backwardly and upwardly above the base plate under control of the finger-roller guides, wherein, upon reaching the rear end of the finger-roller guides, the finger rollers 27, 38, 39 fall onto the insertion ramps 35, 36, 37 for the gradual insertion of the input fingers into the corresponding grooves 2, 3, 4 of the base plate 1. Rotary tension-adjustment means are connected between the axles 18, 19 and the inserting arm means for reducing bounce of the inserting-arm means.

BACKGROUND 
This invention relates to an insertion station for envelope-stuffing 
apparatus or for envelop-stuffing apparatus sections of mail handling 
apparatus. Frequently- used insertion stations of the prior art comprise a 
driving lever which swivels back and forth, in accordance with an 
operating cycle, and vertically to the feeding direction of the material 
to be inserted into envelopes. An axle arrangement is mounted thereto and 
is spring-loaded, perpendicularly to a base plate and parallel to the 
driving lever--the axles having insertion arms with an adjustment block 
mounted to each of them. Fingers of the insertion arms slide forwardly in 
an input direction in grooves of the base plate and are cyclically moved 
backwardly and upwardly above the base plate in a movement controlled by a 
finger roller guide. After the fingers reach the rear end of the finger 
roller guide, they transition from the backward location to forward input 
movement while at least one of the input finger rollers falls onto a 
substantially wedge-shaped insertion ramp for a gradual insertion of the 
input finger into the corresponding groove of the base plate. 
The insertion stations of the prior art are generally time-tested, but one 
particular problem arises due to continuous increases in the operational 
speeds of mail handling apparatus. That is, the finger roller mounted onto 
an insertion arm abruptly leaves a finger roller guide at the end of a 
return movement in a cycle during which the finger roller guide is lowered 
onto and raised above the base plate upon the return movement. Tension of 
spring devices between the axle arrangement and the driving lever then 
causes the entire insertion-arm group to snap downwardly in the direction 
of the base plate. This movement causes the fingers of the insertion arms 
to noisily hit the grooves of the base plate and possibly bounce back such 
that the ends of the fingers reach above the material to be enveloped, and 
thus cause malfunctions. 
It is a further disadvantage of apparatus of the prior art that the slack 
or play between the axle arrangement and the axle-ends of the insertion 
arms becomes uncontrollably larger after a comparatively short operation 
period such that irregular operation of individual insertion arms must be 
expected. Attempts have been made in apparatus of the prior art to correct 
this by adjusting the spring tension between the axle arrangement and the 
back-and-forth swivelling driving lever. These attempts, however, have not 
been satisfactory because of increases in the above-mentioned problems of 
noisy snapping movements of the insertion arms at the end of a return 
movement before the insertion movement. 
It is an object of this invention to provide an insertion station of the 
type described above wherein increases in operational speed nevertheless 
allow reliable functioning, a longer operation span between required 
adjustments of assemblies, lower noise levels and lower maintenance. 
SUMMARY 
The foregoing and other objectives of this invention are achieved by 
including a tension-adjustment mechanism between an above-described axle 
arrangement and the insertion arms so that the objectional insertion-arm 
bounce is substantially reduced.

The insertion station as depicted in FIG. 1 is part of an envelope-stuffing 
apparatus section which, for example, may be the last station in a 
mail-handling conveyor chain schematically indicated by a dot-dash arrow 
P. The mail-handling station of FIG. 1 may have handling stations arranged 
ahead, or in front, for collecting form-sheet stacks and/or for conveying 
form sheets or form sheet stacks. Thus, in accordance with an operation 
cycle, sheet stacks introduced by the conveyor chain from previous 
stations, may be inserted into the insertion station of FIG. 1 as material 
to be enveloped by the structure according to FIG. 1. 
The insertion station has a base plate 1 with grooves 2, 3, 4 arranged 
laterally to the feeding path of the conveyor chain P. These grooves 
interact with insertion fingers 5, 6, 7, made from flexible, hardplastic 
material, in a manner described in the following. 
As depicted in FIG. 1, block-shaped portions of insertion fingers 5, 6, 7 
have slots, or notches, parallel to the grooves 2, 3, 4 into which the 
front ends of insertion arms 8, 9, 10 are fitted for fastening to the 
insertion fingers 5, 6, 7 by means of shaped plates 11, 12, 13. The rear 
portions of the insertion arms 8, 9, 10 have bearing blocks 14, 15, 16 
holding the rear portions of the insertion arms in rear slots as shown. 
The rear ends of the insertion arms 8, 9, 10 are fastened to the rear 
slots by any suitable means such as the screws shown in FIG. 2. 
The bearing blocks 14, 15, 16 have bearing bore holes 17 (FIG. 2). An axle 
18 extends through the bearing bore hole 17 of the bearing block 14; and, 
an axle 19 extends through the bearing bore hole 17 of the bearing blocks 
15 and 16. The axles 18 and 19 are arranged parallel to the direction of 
the conveyor chain P, laterally to the direction of the grooves 2, 3, 4 
and parallel to one another. 
A cam or link 20 is fixedly coupled to and positioned between the axles 18 
and 19. In working embodiments of the insertion station of this invention, 
the cam 20 has certain adjustment features and a certain shape, but those 
matters are not significant here and will not be further discussed. The 
axles 18 and 19 and the fixedly-coupled cam 20 make up an axle arrangement 
onto which the insertion arms 8, 9, 10 are mounted with limited adjustment 
for rotational slack. 
This rotational slack adjustment is, for example, as known from prior art 
arranged such that the axles 18 and 19 respectively have a bore hole 21 in 
the area inside the bearing blocks 14, 15, 16. A screw 23 is screwed into 
a partially-threaded hole through the respective insertion arm 9 and 
bearing block 15 and a tapered or stepped pin-shaped end 22 extends into 
the bore hole 21. In this respect, as shown in FIG. 2, the end 22 has a 
smaller diameter than the bore hole 21. 
The thusly arranged rotational tensioning or slack adjustment between the 
axle 19 and the insertion arm is for ensuring even, smooth engagement, or 
contact, of the insertion fingers 5, 6, 7, with the matching grooves 2, 3, 
4 of the base plate , notwithstanding small adjustment errors, or 
misalignments, between the direction of the base plate 1 and the axle 
arrangements. 
The end portions of the axle 18 extending from both sides of the cam 20 
extend into legs 24 of the fork-shaped driving lever 25, which is cyclicly 
swivelled back and forth in the direction of an arrow A laterally to the 
direction (P) of the conveyor chain as determined by the machine cycle of 
the insertion machine. In this manner, the insertion arms 8, 9, 10 are 
moved along, in the direction corresponding to the grooves 2, 3, 4 of the 
base plate 1. 
During the above-described swivel movement of the driving lever 25, the 
insertion arms 8, 9, 10 are also continuously biased, or spring-loaded, 
with regard to the corresponding grooves 2, 3, 4 by a spring 26 arranged 
between the driving lever 25 and the cam 20 and, thereby, also between the 
driving lever 2 and the axle arrangement 18, 19. 
For moving the material to be enveloped onto the base plate 1 and 
underneath the insertion arms during their return movement, a roll-shaped 
finger roller 27 is mounted to a side of the insertion finger 5. The 
finger roller 27 cooperates with a strip-shaped finger-roller guide 28 
such that the finger-roller guide 28 is moved upwardly and downwardly by 
conventional means about an axis 29 which is parallel to the feeding path 
(P) in the direction of the arrow K in accordance with the operating cycle 
of the insertion machine. When the insertion arms 8, 9, 10 have executed 
an insertion movement, the finger roller 27, during the return movement, 
rolls onto a front portion of the finger-roller guide 28 which is 
substantially touching the base plate 1. The finger-roller guide 28 is 
then swivelled, or moved, upwardly about its axis 29, thereby lifting up 
all of the insertion arms 8, 9, 10 linked, or coupled, by means of the 
axle arrangement above the base plate 1. 
According to an important feature of the insertion station of this 
invention, the individual torsional or rotational slack-adjustment 
assemblies between (1) the axles 18 and 19 and (2) the bearing blocks 14, 
15, 16 are individually spring-loaded, or biased, by 
schematically-illustrated spring devices 30 (FIG. 2) such that the 
pin-shaped ends 22 of the screws 23 fasten off-center to the associated 
hole 21. In this manner, as shown in FIG. 2, the ends 22 abut the side of 
the hole 21 that is closest to the insertion fingers 5, 6, 7. 
The spring devices 30 can be comprised of a helical spring 31 (FIG. 1) 
extending between spring bearings on the bearing block 14 and a forked leg 
24 of the driving lever 25 or by helical springs 32 and 33 arranged about 
the axle 19 and extending between (1) the bearing blocks 15 and 16 and (2) 
an adjustment ring 34 which is fastened such as by a radial bore and screw 
arrangement to the axle 19 between the bearing blocks 15 and 16. The 
biasing means, or springs, 30 effect automatic activation of the 
rotation-slack-adjustment assemblies between the axle arrangement and the 
insertion arms 8, 9, 10 such that the insertion arms 8, 9, 10 do not snap, 
or bounce, even at maximum rotary slack along the axes of the axle 
arrangement. 
Wedge-shaped insertion ramps, or finger-roller guide ramps 35, 36, 37 are 
arranged adjacent the rear portion of the grooves 2, 3, 4, wherein the 
wedge-shaped insertion ramp 35 interacts with the finger roller 27 of the 
insertion arm 8, while the further wedge-shaped insertion ramps 36 and 37 
interact with roll-shaped finger rollers 38 and 39, which are located 
adjacent the block-shaped insertion fingers 6 and 7. At the end of a 
return movement of the driving lever 25 the finger roller 27 leaves the 
finger roller guide 28 and the spring 26 allows the insertion arms 8, 9, 
10 to swivel downwardly while the cam 20 is pivoted. The insertion fingers 
5, 6, 7, however, do not fall immediately into the corresponding grooves 
2, 3, 4 of the base plate 1. Instead their finger rollers 27, 38, 39 first 
reach the wedge-shaped insertion ramps 35, 36, 37 so that, during the 
following insertion movement, the insertion fingers 5, 6, 7 enter the 
grooves 2, 3, 4 gradually and gently, thus avoiding loud noise and the 
development of bouncing that may lead to malfunctions. 
FIG. 3 shows a swivelling strip-shaped brush 41 which may be a metal strip 
with a bevelled edge facing downwardly, for holding down the material to 
be stuffed into envelopes. The brush or strip 41 hangs from a rod mounted 
at one end to a block 40, while the other end is suspended in a cantilever 
manner and arranged at the rear end of the base plate 1 between the 
grooves 2, 3, 4. In this manner, material that is to be inserted by the 
insertion fingers 5, 6, 7 passes underneath the swivelling brush 41 before 
being inserted into an envelope 42 shown in FIG. 1 by dot-dash lines. 
Prior art devices for holding down the material to be stuffed into 
envelopes have been plate-shaped and spring-loaded. In contrast, the 
swivelling brush or strip 41 of the instant invention has the shape of a 
metal strip with a bevelled edge facing downwardly; and, this improves 
accessibility of the insertion station in a relatively uncomplicated, or 
simplified arrangement. 
While the invention has been specifically shown and described with 
reference to preferred embodiments, it will be understood by those skilled 
in the art that various changes in form and detail may be made therein 
without departing from the spirit and scope of the invention.