Roller chain guide arrangement

In an arrangement in which a group of roller chains packed closely together, side by side, in a manner in which they can advance independently of each other, with the chains advancing parallel to each other in common plane in one area and the chains leaving the common plane at one point and thereafter following separate paths and then coming together again at an entry point for the common plane, guides are provided to prevent adjacent roller chains from running up on to each other as they return to the common plane.

BACKGROUND OF THE INVENTION 
This invention relates to apparatus utilizing a plurality of packed endless 
roller chains capable of moving independently with respect to each other, 
which chains over a portion of their travel are separated and in another 
portion come together into a common plane in general, and more 
particularly to apparatus for preventing the chains from running up upon 
one another as they enter into the common plane. 
A particularly important application for a plurality of packed endless 
roller chains arranged side by side is in the type of continuous press 
apparatus described in U.S. Pat. No. 3,851,685 issued to K. Ahrweiler et 
al on Dec. 3, 1974. In the apparatus disclosed therein, an advancing web 
which starts out as a plurality of wood chips or the like is conducted 
through the press and formed into wood chip board or a similar product. In 
the apparatus the web is conducted between endless conveyor belts which 
both revolve moving along with the web which is conducted therebetween. 
Pressure is applied to the conveyor belts by means of support structures, 
one being disposed above and one below the web of material. The conveyor 
belts have a width equal to that of the web and there are disposed between 
the support structures above and below and the two conveyor belts, two 
sets of closely packed roller chains with the individual chains in each 
group capable of moving independently with respect to other chains in the 
group. 
The chains are used to transmit pressure from the support structure to the 
conveyor belts. In the apparatus disclosed the chains, after leaving the 
pressing area of the press, return through the support structure in 
channels arranged in two different planes parallel to the plane of the 
web. 
The roller chains each contain a plurality of adjacent rollers per link 
with the links connected by plates disposed only on the inside between 
adjacent rollers. In other words, the outer rollers of each link are 
cantilevered on the roller pin. This permits adjoining roller chains to be 
directly adjacent to each other to obtain a uniform rolling action over 
the entire pressure area of the press. Such uniform rolling is further 
assured by the chain construction shown in FIGS. 9-11 of that patent in 
which the individual rollers of a link are offset with respect to adjacent 
rollers to avoid the formation of elongated gaps between rollers. 
In the apparatus described in the aforementioned patent, the roller chains 
are returned from the end of the pressure section to its beginning through 
a return plate which is disposed within the support structure for the 
conveyor belt. The chains return through slots extending in the travel 
direction within the support structure. Because the roller chains are 
immediately adjacent, the slots cannot be arranged in a single plane, 
[otherwise the pressure could not properly be transmitted]. Instead, they 
are disposed in two planes parallel to the plane of the web. When the 
roller chains arrive back at the beginning of the pressure section, they 
must be returned from the two planes into a single plane before entering 
the pressure section. Because the roller chains have a certain amount of 
mobility and are immediately adjacent, it is possible for rollers of 
adjacent chains to run with their edges up on to the edges of the rollers 
of an adjacent roller chain as they re-enter the common plane. Although in 
the further course of movement they may slide off, the proper running of 
the roller chains is adversely effected to a considerable degree by such 
interference of one chain with the other. 
The same problems can occur in other apparatus than the type of press 
disclosed in the aforementioned patent. Essentially, this can be a problem 
in any type of device using a plurality of closely spaced chains. For 
example, there are types of apparatus where over a certain area chains are 
caused to leave a common plane because of the individual action of 
separate chain tighteners on each of the individual chains. In this case 
also, the chains must again at some point enter a common plane and the 
same problems can occur. 
In view of these difficulties, the need for an improved apparatus for 
preventing the edges of adjacent chains from rolling up onto one another 
as the chains re-enter a common plane becomes evident. 
SUMMARY OF THE INVENTION 
The present invention provides a solution to this problem. In accordance 
with the present invention, guide members are provided for spacing the 
roller chains apart from each other transversely to the travel direction 
of the group of chains before the roller chains re-enter the common plane 
after once having left that plane. Thus, while the roller chains run 
immediately adjacent to each other in the working strand, i.e. during the 
transmission of pressure and in some cases heat, they are spread apart 
laterally in the return strand, at least in the area immediately before 
re-entry into the common plane. As a result sufficient spacing exists 
during the re-entry preventing the edges from running up onto each other 
due to the play which results from the mobility of the roller chains. The 
spacing need only correspond to the expected range of lateral displacement 
of the lateral boundaries of the roller chains. In a typical embodiment, 
in which roller chains have three rollers per link and are about 55 mm 
wide and in which the rollers have a diameter of 12.5 mm, spacing on the 
order of 0.8 mm is sufficient to insure trouble free re-entry of the 
roller chains. 
In one embodiment illustrated herein the guide members are stationary guide 
bodies with lateral guide surfaces. The guide bodies spread the roller 
chains apart laterally by the required amount prior to their re-entry. In 
a press such as that described in the aforementioned patent, the guide 
members are designed as shaped pieces which are bolted onto the exit of 
the return plate located at the beginning of the pressure section. In 
accordance with a further feature of the disclosed invention, convergence 
members which are arranged to bring the chains together in the area of 
these members gradually until the roller chains are close together for 
re-entry into the pressure section are also provided. This arrangement 
acts to counter-act the tendency of the roller chains to retain the 
spacing imparted to them by the guide members and to urge them back into a 
closely packed condition. As illustrated, the convergence members will 
preferably by guide pieces arranged on both sides of a group of roller 
chains which engage the outermost chains of the group. Also illustrated is 
the use of guide rollers which revolve about an axis perpendicular to the 
plane of the group of chains, the guide rollers rolling on the outermost 
chains of the group. 
As illustrated, the convergence members are designed and placed such that 
they urge the group of chains together i.e., they funnel them into the 
desired packing. To accomplish this, the guide pieces have an extended, 
obliquely arranged sliding surface or the guide rollers have a 
sufficiently large diameter so that convergence does not occur too 
abrutly. Alternatively, a plurality of guide rollers are arranged in a 
staggered fashion one behind the other.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
FIG. 1 is a schematic plan view helpful in illustrating the principle of 
the present invention. Shown as dash-dot lines are a plurality of five 
roller chains 60 running side by side. In the roller chains, each link has 
a plurality of rollers running side by side with the outer rollers 
cantilevered. Thus, the outer rollers of adjoining roller chains 60 are 
immediately adjacent to each other. The roller chains 60 can advance 
freely and independently of each other. Together they form an area 61 
which is a common plane in the illustrated example of FIG. 1. 
As illustrated by FIG. 2, at the point 62 some of the roller chains 60, 
e.g. the first, third and fifth roller chain from the bottom as shown on 
FIG. 1, rise from the plane 61 and run a certain distance above the plane 
61. At a point 63, the roller chains return to the plane 61. In this 
process, they merge between the roller chains which remain in the plane 
61. 
In order that the edges of the roller chains 60 cannot run up onto each 
other in this process, guide members 64 are provided which spread the 
roller chains 60 apart to a larger spacing so that they cannot touch each 
other when they return. The increase in spacing is exaggerated as shown in 
FIG. 1. In actuality, it need be made only large enough so that the 
possible lateral displacements of the freely running roller chains are 
taken into account. As noted above, these roller chains are themselves 
movable and not strictly guided. The guide members 64 are in the form of 
stationary guide bodies having lateral guide surfaces 69. 
After passing the point 63, the roller chains 60 are once again in the 
plane 61. However, there are still spaced transversely to the travel 
direction 65 because of the spacing which was imparted to them by the 
guide members 64. In order to cause the roller chains 60 to converge again 
into a tightly packed group which is closed in the transverse direction, 
convergence members are provided. Shown is a convergence member 66 which 
is a guide piece having an obliquely arranged sliding surface 67 on one 
side and guide rollers 68 revolving about axis perpendicular to the plane 
61 on the other side. The guide pieces 66 and the guide rollers 68 engage 
the outermost roller chains 60 of the group urging them inward and acting 
to funnel them into a closely packed group. As illustrated on FIG. 1, 
funneling takes place in the travel direction 65. After passing the 
convergence members 66 and 68 the roller chains 60 again are immediately 
adjacent to each other. 
FIG. 3 illustrates a continuous press in which the present invention is 
utilized. As illustrated, and as more fully described in the 
aforementioned U.S. patent, this press includes an upper conveyor belt 1 
of sheet steel which runs in an endless path over rollers or drums 5 and 6 
disposed transverse to the web. Also shown is a lower conveyor belt 2 also 
made of sheet steel which runs over the drums 11 and 12. The conveyor 
belts 1 and 2 are driven by means of the drums. 
The conveyor belts 1 and 2 run through the machine in the direction 
indicated by the arrows 16 with the material 4' which is to be pressed, 
and which is applied by means not shown, to the righthand side of FIG. 3. 
This material 4' is drawn into the pressure section designated generally 
as 3. After compression therein, the compressed web 4 is removed from the 
lefthand side of the press by apparatus also not shown. Within the 
pressure section 3 an upper support structure 17 is disposed inside the 
conveyor belt 1. It cooperates with a support structure 18 disposed inside 
the lower conveyor belt 2 to apply pressure to the areas of the conveyor 
belts 1 and 2 facing the web thereby pressing it against the web 4 and 
applying this pressure with a great degree of force over the area 3. 
The support structures 17 and 18 each comprise a plurality of individual 
beams 19 or 20 which are arranged opposite each other above and below the 
conveyor belts 1 and 2 and the web 4. Each pair of beams 19 and 20 is 
clamped together laterally outside the web to form individual pressure 
members closed on themselves. Disposed between the beams 19 and 20 and the 
conveyor belts 1 and 2 are, respectively, heavy plates 26 which transmit 
the force exerted by the individual pressure members 19 and 20 evenly over 
the area of the conveyor belts 1 and 2. Also within these heavy plates are 
channels in which heater elements are arranged or through which a heating 
medium is conducted. 
Between the sides of the plates 26 and 27 facing each other and the 
conveyor belts 1 and 2, roller chains 60 are disposed. The conveyor belts 
1 and 2 opposite the plates 26 and 27 roll on these roller chains. The 
roller chains revolve endlessly about the plates 26 and 27 in a vertical 
longitudinal plane. The rollers of the roller chain 60 transmit both the 
pressure and the heat of the plates 26 and 27 to the conveyor belts 1 and 
2 and thus to the web 4. 
When the roller chains have arrived at the end of the pressure section 3 
they are returned to the beginning of the pressure section within the area 
of the support structure. This is shown in a schematic fashion on FIG. 3 
and is shown in more detail in FIGS. 4-6. In these latter figures, only 
one of the plates 26 or 27 is shown in each case. It will be recognized 
that the arrangement associated with one plate will also be present on the 
other side of the web. 
As illustrated, the plates 26 and 27 include a heating and support plate 43 
and a separate return plate 44. The plate 43 contains heating canals 40 
which have their ends connected by means of pipe elbows 45 to form a 
closed conduction path through which the heating medium is pumped. An 
intermediate heat insulating plate 42 is disposed between the return plate 
44 and the beams 19 or 20 so as to inhibit the flow of heat into the 
support structures 17 and 18. The plate 43 is flat on its underside. 
Between this underside and the conveyor belt 1, the roller chains 60 run. 
In this region they are immediately adjacent to each other. This area is 
the pressure section or working section. Each of the roller chains 60 
consists of three rollers per link with the outer rollers cantilevered. 
Connecting straps are arranged between the links of each chain. At the 
lateral boundaries of the plate 43, the guide pieces 66 described in 
connection with FIGS. 1 and 2 are attached to urge the roller chains 60 in 
the lower working section to form a closely packed lateral group. (See 
particularly FIG. 4). Because FIG. 4 is a cross-sectional view, only a 
small part of the guide piece 66 is visible thereon. A view of that piece 
looking upward in the direction of the arrow, IVa is shown on FIG. 4a. As 
is evident, therefrom, the shape of this guide structure essentially 
corresponds to the guide structure 66 of FIG. 1. 
Since the roller chains 60 are immediately adjacent to each other, they 
cannot be returned in a single plane within the return plate 44. 
Otherwise, there would be no structure remaining to transmit the force 
from the beams 19 to the heating and support plate 43. Because of this, 
the return plate 44 is more than twice as thick as the diameter of the 
rollers of the roller chains 60 and return slots 47 are provided on the 
side facing the beam 19 and additional return slots 48 on the side facing 
the upper side of the plate 43. The slots 47 and 48 are staggered with 
respect to each other in a transverse direction. The force is transmitted 
by the area 51 in between which occurs because of the thickness of the 
plate 44 exceeding twice the roller diameter. While the roller chains 60 
are immediately adjacent each other in the working region, they are caused 
to have a certain lateral spacing in the region of the return plate 44. 
This is brought about in the return plate 44 by means of the lands 64 
between the individual slots 47 and 48, respectively. It will be noted, 
that since these lands 64 perform the function shown by the guide members 
64 of FIGS. 1 and 2 they have been given the same designation. Thus, the 
lateral boundary surfaces 49 and 50 of the roller chains 60 no longer lie 
exactly on top of each other but have the spacing mentioned above which 
need be only relatively small. On FIGS. 4 and 6 this small spacing is 
designated as 70. 
At the ends of the plates 26 and 27, shaped pieces 52 are provided to 
deflect the roller chains 60 from the undersides of the plates to the 
upper side and vice versa. For adjacent roller chains 60, the shaped 
pieces 52 have different deflection radii so that the roller chains 60 are 
guided into the respective slots 47 and 48 which are at different heights 
in the plate 44. The point 63 at which the roller chains which have been 
in two different planes in the region of the return plate 44 again merge 
into a common plane is indicated on FIG. 5 at the outside of the shaped 
piece 52. Because the roller chains 60 have been spaced apart in the 
forming plate 44, the lateral edges of the roller chain 60 can not run up 
onto each other. Such is evident particularly from the view of FIG. 6. 
FIGS. 7 to 10 illustrate in more detail the design of the exit side of the 
return plate 44. FIG. 7 is a front view of the re-entry end, i.e. the end 
shown on FIG. 5, without the chains. FIG. 8 is a plan view of the same 
area showing in more detail the construction of the guide members 64. As 
is more clearly illustrated on FIG. 9, which is an enlarged cross 
sectional view of the area encircled on FIG. 7, the slots 47 and 48 are 
formed by shaped pieces which are bolted together. As shown, a plurality 
of guide members 64 are bolted to a base to obtain the spacing 70 shown on 
FIG. 9. Further details of the construction are illustrated by the cross 
sectional view of FIG. 10 which is taken along the line X--X of FIG. 7. 
This shows how the chains are guided from the plate 44 onto the shaped 
pieces 52. As illustrated, an oblique shaped piece 71 is bolted to the end 
of the plate 44 and conducts the roller chains 60 from the upper slots 47 
onto the shaped piece 52. In between the roller chains 60, which come out 
of the slots 48, the shaped pieces 71 are connected to each other and 
covered by a bar 72 which extends transversely across the exit of the 
return plate 44.