Inserting apparatus

An inserting apparatus comprises an envelope holder for holding an envelope in a filling position, a document feed path and a flap holder for holding a flap of an envelope in an open position. On the side of the document supply path where the flap holder is also located, the most downstream roller is formed by a return pulley of a conveyor belt. Owing to a conveyor belt being trained over the most downstream roller on that side of the document feed path where the flap holder is also located, a small roller can be used without this leading to run-in problems. The documents are moreover forcefully advanced at the end of the document feed path into a nip between two rollers.

FIELD AND BACKGROUND OF THE INVENTION 
This invention relates to an inserting apparatus with an envelope holder 
for holding an envelope in or against a particular surface, a flap holder 
for holding in an open position a flap of an envelope being held in the 
envelope holder, and a document feed path, of which most downstream 
operative transport elements are formed by an extreme downstream conveyor 
roller on a first side of the document feed path proximal to the flap 
holder, which also constitutes the extreme downstream guide on the first 
side of the document feed path proximal to the flap holder, and an 
opposite, circulating conveying element, defining a nip together with the 
aforementioned downstream conveyor roller, which constitutes the extreme 
downstream conveying element on a second side of the document feed path. 
Such an inserting apparatus is known from U.S. Pat. No. 4,852,334. U.S. 
Pat. No. 4,888,938 also discloses such an apparatus. 
Such inserting apparatuses are intended for the insertion into an envelope 
of documents to be mailed in that envelope and are generally further 
equipped with facilities for closing the flap of the envelope. 
In the mechanical insertion of documents into an envelope, it is important 
that all documents are moved beyond the fold line which separates the flap 
from the rest of the envelope. If this is not the case, documents will be 
folded or damaged during closure of the flap and the closure of the flap 
will be impeded or prevented. 
In order that the documents to be inserted into an envelope be moved as 
reliably as possible beyond the fold edge bounding the flap in spite of 
the frictional resistance between the envelope and those documents, in the 
known apparatuses the document feed path includes guide and transport 
means very close to the envelope holder, so that the documents can be 
driven to a point very far into the envelope. 
On the side of the flap holder there is little space available for these 
guide and transport means, because the angle between the document feed 
path and the envelope, on account of the limited flexibility of the 
envelope supplied via the flap holder, has to be fairly acute. In order to 
yet enable the most downstream nip of the document feed path to be 
provided at a point far downstream, in the known apparatuses the most 
downstream roller of the document feed path on the side of the flap 
holder, which at the same time constitutes the most downstream guide on 
that side of the document feed path, is therefore designed as a 
free-running press-on roller with, relatively, a very small diameter. 
However, a drawback of this construction is that the press-on roller does 
not drive any documents on the side of a stack to be inserted remote from 
the flap holder but only presses on them. In order to generate such 
friction that the friction between the stacked documents reliably 
overcomes the friction between the documents and the envelope, the 
press-on force with which this free-running roller is pressed against the 
passing documents must therefore be fairly large. 
The large press-on force and the small diameter of the free-running roller, 
however, render more difficult the run-in of documents gathered into a 
stack. This applies the more so according as the stack of documents is 
thicker. The press-on force to be chosen will therefore have to be a 
compromise between, on the one hand, the desire to increase the press-on 
force so as to generate sufficient friction within the stacks and, on the 
other, the desire to lower the press-on force so as to prevent problems 
during the infeed of the documents. 
U.S. Pat. No. 5,388,388 discloses an inserting apparatus where the 
downstream end of the document feed path on the side of the flap holder is 
constituted by a stationary document guide over which the documents are 
guided. To this document guide, on the upstream side thereof, connects a 
circulating conveyor belt. The downstream end of this conveyor belt is 
located further from the envelope holder than the downstream end of an 
opposite conveyor belt located on the side of the document feed path 
remote from the flap holder. In order to be able to effect displacement of 
documents to be inserted into an envelope over the guide until the 
documents are disposed for the greater part in the envelope, the apparatus 
is provided with most downstream operative transport elements in the form 
of a separate drive with circulating fingers on the side of the document 
feed path remote from the flap holder. This construction is complicated 
and requires a fast, accurate control and drive. 
British patent application 2,283,479 and German patent application 29 13 
428 also disclose inserting apparatuses which are equipped with separate 
transport elements operative downstream of opposite conveyor belts, in the 
form of circulating transport fingers. In operation, these most downstream 
operative transport elements of the document feed path press documents to 
be inserted further into an envelope, after they have come clear of the 
more upstream opposite conveyor belts of the document feed path. 
SUMMARY OF THE INVENTION 
The object of the invention is to provide an inserting apparatus by which 
stacks of documents--without additional provisions for the further drive, 
downstream of the document feed path, of displacements of the documents to 
be inserted into envelopes--can be reliably inserted into envelopes, 
without this leading to problems during the lead-in of thicker stacks of 
documents. 
This object is realized according to the invention in that in an inserting 
apparatus of the type initially described the extreme downstream roller on 
the first side of the document feed path is designed as a downstream 
return pulley of a circulating conveyor belt. 
Owing to the feature that in the apparatus according to the invention the 
most downstream guide of the document feed path on the side of the flap 
holder is constituted by a conveyor belt trained over a roller, a 
relatively small roller can be used, without this leading to run-in 
problems, so that in a simple manner a reliable drive of the documents on 
the side of the flap holder to a point very close to an envelope held in 
the envelope holder can be obtained. Moreover, the press-on force can be 
chosen to be relatively high without this leading to run-in problems. 
Preferably, the most downstream roller on the side of the document feed 
path proximal to the flap holder and the opposite roller form a nip, 
between which the documents are forcefully clamped, so that even on the 
last, trailing part of the documents to be inserted into an envelope a 
large frictional force can be exerted and the exerted press-on force does 
not result in a dip in the document feed path. 
Further aspects, embodiments and advantages of the invention are further 
illustrated and explained on the basis of an exemplary embodiment, with 
reference to the drawings.

DETAILED DESCRIPTION 
The inserting apparatus shown in the drawing comprises an envelope holder 
in the form of a supporting table 1. The surface of the supporting table 1 
constitutes the reference surface against which each envelope 2 is held 
prior to and during filling. To save space in the drawing, only a proximal 
portion of the envelope 2 and of the supporting table 1 is represented. 
In the apparatus shown, a document feed path 3 connects to the envelope 
holder 1. This document feed path is defined by a section 4 of a conveyor 
belt 6 extending along the path 3 on a first, lower side of the document 
feed path 3, and an opposite portion of a circulating conveying surface. 
In the example shown, this portion of the circulating conveying surface is 
formed by section 5 of a second conveyor belt 7, extending along the 
document feed path 3, which second conveyor belt section 5 is located 
opposite the first-mentioned conveyor belt section 4, on a second, upper 
side of the document feed path 3. 
Upstream of the conveyor belt sections 4, 5, the document feed path is 
defined by a pair of conveyor rollers 8, 9 which are suspended in rockers 
12, 13 for rotation about rotation axes 10, 11. These rockers 12, 13 in 
turn are pivotable about pivots 14, 15 relative to a fixed portion of the 
apparatus shown. The rockers are provided with meshing teeth 16, 17 which 
ensure that the rockers are always in approximately mirror-symmetrical 
positions with respect to the document feed path 3. For a further 
description of this transport assembly, reference is made to applicant's 
Dutch patent application 1001828, the content of which is incorporated 
herein by reference. 
In order for the supplied documents to be guided in a substantially planar 
position, a guide table 30 extends just below the document feed path 3, 
the width thereof being adapted to the width of the documents to be 
transported. 
The conveyor belt sections 4, 5 are directed towards the envelope holder 1 
for conveying to the envelope holder individual or stacked documents to be 
inserted into an envelope. On the side of the conveyor belt sections 4, 5 
proximal to the envelope holder 1, the sections 4, 5 merge into conveyor 
belt sections 20, 21 which pass over opposite downstream return rollers or 
pulleys 18, 19. The end of the document feed path 3 on the side of the 
envelope holder 1 is formed by these transitional portions where the 
mutually parallel conveyor belt sections 4, 5 merge into the diverging 
conveyor belt sections 20, 21 which pass over the opposite return pulleys 
18, 19. 
Further arranged on the lower side of the document feed path 3 is a flap 
holder 22 for holding in an open position a flap 23 of an envelope 2 
waiting in the envelope holder 1. In the apparatus according to the 
embodiment shown, the flap holder 22 is formed by downstream guides 25, 
26, 27 and conveyor rollers 28, 29 which define an envelope feed path 24. 
Owing to the feature that the guide located on the lower side of the 
document feed path 3 closest to the envelope holder 1 is formed by a 
conveyor belt section which is trained over the most downstream return 
roller 18 on the lower side of the document feed path 3 (on which side the 
flap holder 22 is also located), a relatively small, most downstream 
roller 18 can be used, without this leading to infeed problems. Moreover, 
the press-on force at the location of the downstream end area of the 
document feed path 3 can be chosen to be rather high without this causing 
run-in problems. 
The opposite rollers 18, 19 form a nip on the downstream end of the 
document feed path, which is located very close to the envelope holder, in 
which nip, in operation, very close to the opening of the envelope large 
frictional forces can be exerted on the last trailing part of the 
documents to be inserted, so that these documents are reliably inserted 
into the envelope. 
In principle, the circulating conveying surfaces extending on opposite 
sides along the document feed path can end on the downstream side of the 
document feed path at different distances from the envelope holder 1. In 
the apparatus according to the example shown, however, the roller 19 
located opposite the downstream return pulley 18 on the lower side of the 
document feed path 3 is also an end pulley. Over this end pulley the 
second conveyor belt 7 is trained. 
In order to obtain an optimum advancement of the documents on both sides of 
the stacks to be inserted, the apparatus according to the example shown is 
provided with a drive 31 for driving the section 4 of the conveyor belt 6 
on the lower side of the document feed path 3 and a drive 32 for driving 
the opposite portion 5 of the circulating conveying surface which is 
formed by the circulating conveyor belt 7. 
The drive 31 of the conveyor belt 6 on the lower side of the document feed 
path 3 comprises a transmission gear 33, a toothed belt 34 and a toothed 
pulley 36 bearing-mounted coaxially with an upstream return pulley 35 over 
which the conveyor belt 6 is trained. The drive 32 of the conveyor belt 7 
on the upper side of the document feed path 3 comprises a transmission 
gear 37 bearing-mounted coaxially with the conveyor roller 9 on the upper 
side of the document feed path 3, a toothed belt 38 and a toothed pulley 
40 bearing-mounted coaxially with an upstream return pulley 30 over which 
the conveyor belt 7 is trained. 
The drive 31 for driving the conveyor belt 6 on the lower side of the 
document feed path 3 is adapted for generating a higher peripheral 
velocity than the other drive 32, which other drive is provided with a 
freewheel clutch 41. This design of the drives 31, 32 provides the 
advantage that on the one hand tensional differences between the drives 
31, 32, which lead to accelerated wear and moreover can lead to derailing 
of the conveyor belts 6, 7 are avoided and on the other a lagging document 
on the upper side of a stack is forced to move at least as fast as the 
peripheral velocity of the conveyor belt 7 on the upper side of the 
document feed path 3. It is noted that the above-mentioned effects can 
also be achieved by designing the drives 31, 32 in such a manner that the 
circulating conveying surface on the upper side of the document feed path 
3 travels faster than the peripheral velocity of the conveyor belt 6 on 
the lower side of the document feed path 3 and equipping the drive on the 
lower side of the document feed path 3 with a freewheel clutch. 
In order to limit the extent to which a lagging document can lag relative 
to the other documents in the stack, the drives 31, 32 are so designed 
that in operation the difference between driven peripheral velocities is 
less than 10% and preferably 0.5 to 1.0%. 
If the drives on both sides of the document feed path are each equipped 
with a freewheel clutch, it is also possible to drive the conveying 
surfaces on opposite sides of the document feed path with the same nominal 
peripheral velocity. This provides the advantage that documents on 
opposite sides of each stack of supplied documents, apart from the 
differences in speed between the circulating surfaces on opposite sides of 
the document feed path 3 caused by tolerances, are advanced at the same 
speed. 
The circulating conveying belt 7 on the upper side of the document feed 
path 3 forms part of a belt conveyor which further consists inter alia of 
a support 42 and the return pulleys 19, 39 mentioned earlier, which are 
bearing-mounted relative to the support 42. The support 42 is suspended 
from a rocker 44 for pivoting motion about a first pivot 42, the rocker 44 
being adapted to pivot about a second pivot 11 (this is also the rotation 
axis of the conveyor rollers 9 on the upper side of the document feed 
path) spaced from the first pivot. As a result, the section 5 of the 
conveyor belt 7 passing along the document feed path 3 can easily adjust 
to passing sets of documents of different thicknesses. The movability of 
the support 42 of the belt conveyor obtained by virtue of the suspension 
with the intermediate rocker 44 further provides the advantage that this 
belt conveyor can easily be displaced for the purpose of rendering the 
document feed path 3 accessible for cleaning, maintenance, repairs, or 
removing any jammed documents. 
Owing to one of the rollers 19, 39 being arranged coaxially with the first 
pivot 43 and being coupled with a transmission gear 37 which is arranged 
coaxially with the second pivot 11, in spite of the movability of the belt 
conveyor, yet a drive of this belt conveyor has been effected in a simple 
manner. 
The conveyor belt 6 on the lower side of the document feed path 3 has a 
return conveyor belt section 45, projecting from the return pulley 18, on 
the side of the conveyor belt 6 remote from the document feed path 3. Some 
of the guides 27 of the flap holder 22 are located adjacent to and, at 
least partly, on the side of the return conveyor belt section 45 remote 
from the document feed path 3. These guides prevent the possibility that a 
supplied envelope or the flap 23 of an envelope 2 disposed in the envelope 
holder 1 comes into contact with this return conveyor belt section 45 
which in operation moves counter to the feeding direction of the 
envelopes. 
These guides 27 are designed as flanges projecting with respect to the 
return conveyor belt section 45 towards the envelope feed path 24. As a 
result, it is not necessary to arrange between the envelope feed path 24 
and the return conveyor belt section 45 a guide with a wall thickness and 
the required amounts of play. This saves space between the envelope feed 
path 24 and the return conveyor belt section 45. As a consequence, the end 
pulley 18 can be placed very close to the envelope feed path 24 and hence 
in a position which in operation is very close to the envelope 2 to be 
filled. Instead of several guides, optionally a single guide can be used 
in view of the stiffness of the envelopes supplied in curved position. 
Owing to the flange 27 also forming part of a supporting structure 46 in 
which the return pulley 18 is bearing-mounted, positioning problems 
through tolerances at the position of the conveyor belt 6 relative to the 
other guides and rollers of the envelope feed path 24 are prevented. 
Engaging the external surface of the return conveyor belt section 45 is a 
tensioning roller 47 for tensioning the conveyor belt 6. This tensioning 
roller 47 is bearing-mounted in a rocker 49 adapted to pivot about a pivot 
48. This position of the tensioning roller provides the advantage that the 
return conveyor belt section 45 is urged away from the envelope feed path 
24, thereby providing space for having the envelope feed path 24 connect 
to the envelope holder 1 via a gentle curve. 
For tensioning the conveyor belt 7 on the upper side of the document feed 
path 3, the apparatus comprises a tensioning roller 50 which is 
bearing-mounted in a rocker 52 suspended for pivoting movement about a 
pivot 51. 
For opening the envelope 2 and for holding open the envelope 2 during the 
insertion of documents, the apparatus comprises an opener assembly 53 
reciprocally movable approximately parallel to the conveying path, which 
assembly 53 is reciprocally movable between the position depicted and a 
second position. The position in the second condition of the end 53' of 
the opener assembly 53 on the side of the envelope holder is indicated by 
chain-dotted lines. 
Wetting and closing and discharging filled envelopes can be carried out in 
a conventional manner, known per se, and with conventional means, known 
per se. These operations and the provisions for carrying out those 
operations are therefore not described in this application. For a further 
description of the supply, the filling, the closure and the discharge of 
envelopes, reference is made to a Dutch patent application in applicant's 
name, filed simultaneously with the present application, entitled 
"Apparatus and method for inserting documents into an envelope", the 
content of which is incorporated herein by reference. It is noted that on 
the basis of the insights set out hereinabove, many possibilities within 
the scope of the present invention other than the examples described 
hereinabove have been brought within reach of those skilled in the art. 
For instance, the first side of the document feed path, on which side the 
flap holder is located, can constitute, rather than the lower side, the 
upper side of the document feed path, as is typically the case with 
inserting apparatuses in which envelopes are supplied from above and 
documents are inserted in a face-up position into the envelope held in 
readiness. The circulating conveying surface on the second side of the 
document feed path, rather than being designed as the outer circumference 
of a conveyor belt, can also be designed as the circumferential surface of 
a conveyor roller. Preferably, several conveyor belts and conveying 
rollers side by side should be used in order to distribute the frictional 
forces in the width direction across the supplied documents. It is also 
possible, however, to use single conveyor belts and rollers. It is then 
preferred, however, to make them of broad design.