Acceleration device to divide one or more continuous rows of products into equidistant groups of one or several products

For each continuous row of products (1), two accelerating belts (3, 4) acting continuously upon both sides of the respective continuous row of products (1). In a non-launching condition, the belts hold the products at a predetermined waiting position and, under launching conditions, launch a group of products (1) at the speed of a support conveyor belt (7) while bringing the following products in the continuous row to the waiting position. Preferably the accelerating belts (3, 4) are powered through DC servomotors with permanent rare-earth magnets.

FIELD OF THE INVENTION 
The invention pertains to an acceleration device to divide one or more 
continuous rows of products into equidistant groups of one or several 
products. 
BACKGROUND OF THE INVENTION 
One of the most important problems to be solved in managing any production 
line is the achievement of the greatest possible result with a given 
operative configuration of the machines forming the line itself. That 
means the possibility of controlling the product flow during the whole 
process and the possibility of supplying the downstream machine with said 
products depending upon the working step and the production capacity of 
the machine itself. 
Such a problem is for example to be solved between the machine or machines 
for the manufacture of any product and the machine or machines designed to 
wrap or pack it. 
On coming out of the manufacturing machines, finished products are usually 
disposed according to one or more continuous rows whereas the wrapping 
machines need to receive the products individually spaced apart or in 
groups and fed at the same speed with which they come out of the 
manufacturing machine or machines. 
For this purpose a device designed to space apart the products and to form 
different groups is usually provided between the manufacturing machines 
and the wrapping machines. 
Most devices of this kind comprise a continuously moved conveyor, a pair of 
members adapted to intercept the first product of the continuous row, and 
gripping elements acting on the first product of the second group. Upon 
request of another group, downstream of this device, the intercepting 
members are deactivated; the group being free to move along the conveyor. 
Then the gripping elements too are deactivated and, after a certain lapse 
of time, necessary for the passage of a group of products, the 
intercepting members stop the first product of the second, now first, 
group. As a result, all of the continuous row is activated. Finally, the 
gripping elements too are activated again and they act now on the first 
product of the third, now second, group of the continuous row. 
Other devices adopt solutions in which at regular intervals they act on the 
moving-forward products and impart a certain acceleration to the same so 
that they are spaced apart from the rest of the row. 
In many cases said acceleration is imparted to the products by powered belt 
conveyors which at regular intervals are pressed against the products as 
they move forward. 
However, as it is not possible to check the acceleration degree, in order 
to be sure that said products may at least receive a sufficient 
acceleration, it is necessary to impart to them the maximum acceleration 
possible, which causes the products to be ill-treated. 
However sometimes a machine located upstream or downstream of this device 
may happen to be temporarily stopped for any reason, for example due to a 
clogging caused by the product or the paperboard or because it is 
necessary to change the wrapping band. 
Should for example a manufacturing machine temporarily stop, the products 
could come to the acceleration device disposed in irregular groups and not 
on a continuous row, which would cause the wrapping machine to stop, that 
is, to wait for the regular feed of the products to be restored and this 
would be unproductive. 
SUMMARY OF THE INVENTION 
The object of the present invention is therefore to eliminate the above 
mentioned drawbacks. The invention, as defined in the claims, solves the 
problem of supplying an acceleration device adapted to divide one or more 
continuous rows of products into equidistant groups of one or several 
products that move forward at the same speed as the continuous rows. 
The advantages achieved by the present invention consist essentially in 
that the continuous rows are uninterruptedly positively held at a 
predetermined waiting position by the launching means itself. This 
launching means, on receiving an appropriate signal from suitably arranged 
detecting means, launches a group of products, imparting to said products 
the necessary acceleration so that they may reach a speed identical with 
that of a conveyor belt supporting them, and brings the next products in 
the row to a waiting position, at which position they will remain waiting 
for another signal enabling a second group of products to be launched. 
A further advantage of the device according to the present invention 
resides in that the products are not submitted to sudden accelerations 
that might damage them, due to the fact that they are submitted to an 
acceleration the speed of which is known and therefore suitably adjustable 
to the necessary value. 
A still further advantage of the present invention, which can be attained 
above all when the launching means consists of two accelerating belts 
acting on two longitudinal facing sides of the continuous row of products, 
resides in that the continuous row is constantly compacted and the 
launching means is constantly in contact with the products holding them, 
so that at the moment they are launched you can be sure that all products 
forming the group are launched, and within the stated time. The certitude 
that the launched groups are always built up of the identical number of 
products also results from the presence of detecting means adapted to 
constantly detect whether the continuous row is provided at least with the 
number of products necessary to form a group. 
Yet another advantage of the present invention is due to the fact that, by 
virtue of the presence of detecting means adapted to continuously check 
the operation of the different members of the device and of the presence 
of programmable means interlocked to the detecting means, it is possible 
to be sure of the perfect operation of the acceleration device even when 
the operation of the machines located upstream or downstream of the same 
is temporarily altered.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to FIGS. 1 to 3 and particularly to FIG. 1, it is possible to see 
that the acceleration device according to the present invention, to divide 
one or more continuous rows of products into groups of one or several 
products, essentially consists, for each continuous row of products fed in 
by one or more machines, of a conveyor belt 7 for supporting the 
respective continuous row of products 1 and of launching means 2. 
A single conveyor belt 7 for a continuous row of products 1 is shown in 
FIG. 1 but it is apparent that any number of rows is possible without 
invalidating the inventive significance of the present acceleration 
device. Furthermore, in the following the terms "front" and "back" will 
always be used with respect to the feed direction of the products 1, which 
feed direction is from left to right looking at FIGS. 1 and 2. 
The transport speed V of the conveyor belt 7 is identical with that 
provided for the continuous row of products 1 arriving at the accelerating 
device in question. 
In the figures the launching means 2 is shown in the form of two 
accelerating endless belts 3 and 4 disposed along the feed direction of 
the respective continous product row 1. 
The accelerating belts 3 and 4 are driven by respective motors (not shown) 
adapted to make the corresponding accelerating belts 3 and 4 move forward 
in a way concordant or discordant with the feed direction of the products 
1. Said motors must also have a very short response time and the 
acceleration and deceleration impressed on the products 1 must always be 
programmable at will, these features being determinable, taking into 
account present techniques involving motors, for example in DC servomotors 
with permanent rare-earth magnets. 
The accelerating belts 3 and 4 are both preferably disposed at right angles 
to the conveyor belt 7 (FIGS. 2 and 3) and slightly converging towards 
their front end. In this way each accelerating belt 3 in combination with 
the respective accelerating belt 4 forms a channel 20 defined at its lower 
part by the respective conveyor belt 7. 
The accelerating belts 3 and 4 are spaced apart from each other by an 
amount substantially equal to the width of the products 1 so that they are 
able to hold the products 1 even in spite of the movement of the 
underlying conveyor belt 7. 
Since the length of the conveyor belt 7 is greater than that of the 
accelerating belts 3 and 4, as shown in FIGS. 1 and 2, provision is made 
for the use of a pair of guide walls 26 and 27 substantially aligned with 
the accelerating belts 3 and 4 respectively. 
As visible in FIG. 4, one of the accelerating belts, 3 or 4 (in the figure 
the accelerating belt 3), could be parallel, instead of at right angles, 
to the conveyor belt 7. In this case, opposition to the accelerating belt 
which has remained perpendicular to the conveyor belt 7, identified at 4 
in FIG. 4, is made by means of a fixed reference plane 8, at right angles 
to the conveyor belt 7 as well. 
The acceleration device according to the present invention also comprises 
detecting means 5, 30, 10 adapted to control the feed of the products 1. 
The above detecting means 5, 30, 10 and other detecting elements not shown 
lead off to programmable control means so that the acceleration device in 
question will be able to operate as hereinafter explained. 
The first detecting means 5 acts within the channel 20, is located in the 
vicinity of the front end of the accelerating belts 3 and 4 and is adapted 
to directly control the motors of the accelerating belts 3 and 4 in order 
to cause the first product 1 in the continuous product row to be disposed 
so that its front edge is in vertical alignment with said accelerating 
belts (see in particular FIG. 7). If the first detecting means 5 detects 
that the first product 1, owing to the thrust produced by the continuous 
product row urging against it, has moved forward a little amount farther 
and has reached the position 1b (dashed line) in FIG. 7, it will actuate 
the motors of the accelerating belts 3 and 4 so that the whole continuous 
row of products 1 will be caused to move back. On the contrary, if the 
continuous row of products 1 has occupied a backward position, such as for 
example the position 1a (dotted line) in FIG. 7, it acts on the motors of 
the accelerating belts 3 and 4 so as to cause the continuous row of 
products 1 to move forward a little. For the above reason and above all in 
order to obtain a perfect launching of the products 1, it is necessary 
that the motors of the accelerating belts 3 and 4 have a very short 
response time so that the greatest effectiveness of the acceleration 
device in reference may be achieved. 
The second detecting means 30 is located downstream of the conveyor belt 7 
and is adapted to detect the front of the group of products 1 launched by 
the accelerating belts 3 and 4 and to interrupt the launching operation of 
the latter. As a matter of fact, it is intended to detect when the 
accelerating belts 3 and 4 have launched a complete group of products 1. 
The position of the second detecting means 30 is adjustable along the 
longitudinal direction of the conveyor belt 7 depending upon the number of 
products 1 forming each product group. Assuming that said product groups 
consist of three products 1 and that the second detecting means 30 is 
disposed at a distance from the first detecting means 5 which is slightly 
greater than three times the length of a product 1, when the second 
detecting means 30 is actuated by the front of the group of products 1 
launched by the accelerating belts 3 and 4 and has stopped the operation 
of said accelerating belts, it has exactly launched a group of products 1 
as requested. 
The third detecting means 10 acts again within the channel 20 and is 
located in such a position that it can detect whether between the 
accelerating belts 3 and 4, or or in any case in the launching area, at 
least a complete group of products 1 ready to be launched is present. 
In FIGS. 1 and 2 is shown a conveyor belt 13 aligned with the conveyor belt 
7 and to which groups of products 1 are fed from the accelerating device 
in reference. 
When the whole line, of which the accelerating device in reference is part, 
is operating, the first detecting means 5 acts on the motors of the 
accelerating belts 3 and 4 in order to maintain the front of the 
continuous row of products 1 vertically aligned with the first detecting 
means 5 itself as explained above. Upon request of a group of products 1 
by the machine located downstream of the device in question, enablement of 
the launching is provided by the third detecting means 10, if it detects 
the presence of at least a group of products 1 between the accelerating 
belts 3 and 4 or in any case in the launching area. At this point the 
motors of the accelerating belts 3 and 4 are actuated until said 
accelerating belts 3 and 4 reach the speed V which is the advance speed of 
the conveyor belt 7. Said speed V can be reached through a single ramp 
waveform for the velocity, above all in the case of groups consisting of a 
single product 1 (see FIG. 5), or through two velocity waveform ramps 
having different inclinations and separated by a short portion having a 
constant speed, when groups of several products 1 are concerned (see FIG. 
6). In the latter case, the first ramp should have a lower inclination 
than the second one in order to allow the launching of the first product 1 
of the first continuous row and a better holding of the following products 
1 by the accelerating belts 3 and 4. Once they have reached the speed V 
the accelerating belts 3 and 4 are maintained at this speed V for a 
certain time depending upon the number of products 1 to be launched, in 
order to bring the products 1 following those launched to the waiting 
position defined by the first detecting means 5. Then they are decelerated 
through a velocity ramp having an inclination different from the velocity 
ramp or ramps for the acceleration (see FIGS. 5 and 6). Afterwards a group 
of products 1 for each continuous product row is launched onto the 
conveyor belt 13, i.e. it is accelerated up to the achievement of the 
speed V of the conveyor belts 7 and 13, and simultaneously the products 1 
of the continuous row following those launched are first accelerated like 
the first ones, then decelerated and stopped at a waiting position by the 
accelerating belts 3 and 4. At this point the acceleration device in 
reference is ready to repeat the above described cycle. 
The invention as envisaged is susceptible of many modifications and 
variations, all falling within the scope of the inventive idea. 
Furthermore, all details can be replaced by technically equivalent 
elements.