U.S. patent number 3,899,865 [Application Number 05/403,336] was granted by the patent office on 1975-08-19 for wrapping apparatus.
This patent grant is currently assigned to Otto Hansel GmbH. Invention is credited to Leon Revaz.
United States Patent |
3,899,865 |
Revaz |
August 19, 1975 |
Wrapping apparatus
Abstract
A feed conveyor carries a plurality of transport devices for
transporting sweets from a sweet receiving station to a
continuously revolving wrapping head, which in turn carries a
plurality of peripheral gripping and folding devices for wrapping
the sweets transported to the wrapping head. This feed conveyor is
guided around part of the periphery of the wrapping head and
travels in synchronism with the wrapping head so that each sweet
transported on one of the transport devices may be transferred to a
corresponding one of the gripping and folding devices. Another feed
conveyor and a deflector are positioned to feed a wrapper between
each sweet transported on one of the transport devices and the
corresponding one of the gripping and folding devices.
Inventors: |
Revaz; Leon (Bienne,
CH) |
Assignee: |
Otto Hansel GmbH (Hannover,
DT)
|
Family
ID: |
23595412 |
Appl.
No.: |
05/403,336 |
Filed: |
October 3, 1973 |
Current U.S.
Class: |
53/234; 53/227;
53/370; 53/225; 53/233 |
Current CPC
Class: |
B65B
35/24 (20130101); B65B 25/005 (20130101); B65B
11/34 (20130101) |
Current International
Class: |
B65B
11/34 (20060101); B65B 11/06 (20060101); B65B
35/00 (20060101); B65B 35/24 (20060101); B65B
011/34 () |
Field of
Search: |
;53/225,227,230,232,233,234,236,370 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: McGehee; Travis S.
Assistant Examiner: Sipos; John
Attorney, Agent or Firm: Griffin; Roland I.
Claims
I claim:
1. Apparatus for continuously wrapping sweets or like small
objects, said apparatus comprising a continuously revolving
wrapping head carrying a plurality of gripping and folding devices
positioned about its circumference, a feed conveyor carrying a
plurality of sweet carrying devices for feeding sweets
consecutively to the wrapping head, feed means for feeding wrappers
to the wrapping head, means for guiding the feed conveyor from a
sweet receiving station towards the wrapping head and then around
part of the circumference of the wrapping head where the feed
conveyor travels in synchronism with the wrapping head and where
each sweet carried by a sweet carrying device is transferred
therefrom to a corresponding gripping and folding device for
holding and partially wrapping each sweet transferred thereto in a
wrapper from the feed means, and closure means positioned adjacent
to the wrapping head for closing each partially wrapped sweet held
by the gripping and folding devices on the wrapping head within its
wrapper.
2. Apparatus according to claim 1 including deflection means
positioned adjacent to the feed conveyor and said part of the
circumference of the wrapping head for successively deflecting each
sweet carrying device on the feed conveyor towards the
corresponding gripping and folding device on the wrapping head, the
feed means for feeding wrappers to the wrapping head being
positioned adjacent to the circumference of the wrapping head
before the deflection means so that each wrapper enters a gap
between a sweet held by a sweet carrying device on the feed
conveyor and a corresponding gripping and folding device on the
wrapping head just before the sweet held by the sweet carrying
device is moved into contact with the corresponding gripping and
folding device.
3. Apparatus according to claim 2 wherein wrapping material is
continuously supplied to the feed means for feeding wrappers to the
wrapping head and wherein the wrapping material is fed over a
rotating knife at a speed adjusted to the desired length of the
individual wrappers.
4. Apparatus according to claim 1 wherein each sweet carrying
device includes a base and a pair of gripping jaws mounted on the
base and biased to a closed gripping position.
5. Apparatus according to claim 4 wherein one of the gripping jaws
is fixedly secured to the base and the other gripping jaw is
pivotally connected to the base.
6. Apparatus according to claim 5 wherein each sweet carrying
device also includes a plunger for supporting a sweet, the plunger
being axially slidably housed in the base and positioned between
the gripping jaws.
7. Apparatus according to claim 6 wherein the plunger projects from
the base for engaging a cam comprising the deflection means to move
the plunger and a sweet supported thereby axially towards the
corresponding gripping and folding device, and wherein the
pivotally mounted gripping jaw projects from the base for engaging
a cam to open the gripping jaws.
8. Apparatus according to claim 1 wherein the feed conveyor is a
continuous link chain precisely guided between lateral slideways
and chain wheels.
9. Apparatus according to claim 8 wherein the pitch circles of at
least two of the chain wheels are directly tangent to the circular
path of travel of the gripping and folding devices on the wrapping
head and the intervening portions of the slideways coincide with
this circular path of travel.
10. Apparatus according to claim 1 wherein the gripping and folding
devices are spaced equidistantly about the circumference of the
wrapping head, the spacing between adjacent gripping and folding
devices on the wrapping head being the same as that between
adjacent sweet carrying devices on the feed conveyor.
11. Apparatus according to claim 1 wherein each gripping and
folding device on the wrapping head includes a pair of gripping
jaws, an associated pair of folding arms, and a plunger located
between the gripping jaws and movable radially of the wrapping head
to cooperate with a plunger of a corresponding sweet carrying
device on the feed conveyor during the transfer of a sweet to the
gripping and folding device.
12. Apparatus according to claim 11 wherein the folding arms act
upon a wrapper engaged with a sweet by the gripping jaws to
partially wrap the sweet in the wrapper after the sweet is
transferred to the gripping and folding device.
13. Apparatus according to claim 12 wherein the closure means is a
twisting assembly including a link chain that travels in slideways
around an arcuately-curved, rack-toothed segment and that carries a
plurality of twisting grippers spaced at the same intervals as the
pairs of gripping jaws on the wrapping head.
Description
BACKGROUND AND SUMMARY OF THE INVENTION
This invention relates to apparatus for wrapping sweets or like
small objects. Conventional sweet wrapping machines work
intermittently and comprise a rising and falling plunger, which
pushes the sweets one by one, together with a wrapper placed over
each sweet, through a folding or brush-lined shaft to fold the
wrapper over each sweet into a U-shaped form that partially
envelops the sweet. Each sweet and its wrapper is then engaged by
grippers for permitting the wrapper to be fully closed with the aid
of reciprocating folding and closing instruments. A defect of such
machines is their relatively low performance and the high stress to
which they subject the sweets or other objects during the wrapping
operation, particularly in the case of so-called high speed
machines. Another drawback is the considerable amount of noise and
vibration generated by these machines during their operation due to
the high acceleration and deceleration forces engendered by their
reciprocating parts.
Continuously working machines have therefore already been proposed
in which a sweet receiving means, a wrapper, and a wrapping head
armed with gripping jaws and folding elements are consecutively
provided along the path of a conveyor chain for the sweets.
However, a defect of these machines is that they are excessively
complicated, occupy much space, and are difficult to drive. More
particularly, it is hardly possible to introduce the necessary
wrappers for wrapping the sweets in a well ordered manner.
According to one aspect of the present invention, an apparatus for
continuously wrapping sweets or like small objects is provided by
employing a continuously revolving wrapping head carrying a
plurality of gripping and folding devices at spaced positions about
its circumference and by employing a feed conveyor carrying a
plurality of sweet carrying devices for feeding sweets
consecutively to the wrapping head. The feed conveyor is guided
from a sweet receiving station towards the wrapping head and then
around part of the circumference of the wrapping head where the
feed conveyor travels in synchronism with the wrapping head and
where each sweet carried by one of the sweet carrying devices is
transferred therefrom to a corresponding one of the gripping and
folding devices on the wrapping head.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic side elevational view of a machine for
wrapping sweets which is constructed according to the preferred
embodiment of the present invention and which closes the wrapper by
twisting its two open ends.
FIG. 2 is a fragmentary view of the machine of FIG. 1 on a larger
scale.
FIG. 3 is a top view of the feed table of the machine of FIGS. 1
and 2.
FIG. 4 is an enlarged side view of one of the sweet carrying
devices of FIGS. 1 and 2.
FIG. 5 is an enlarged side view of a portion of one of the gripping
and folding devices of FIGS. 1 and 2.
FIG. 6 is a schematic representation of the twisting mechanism of
FIGS. 1 and 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIGS. 1-3, sweets 1 to be wrapped are deposited on
a conventional rotating feed table 3, which has peripherally open
pockets 4 formed around its circumference, each of these pockets
being adapted for receiving one of the sweets 1. Feed table 3 has a
conical top and is surrounded by a cylindrical retaining ring 2
that defines a trough around the external periphery of the feed
table. The sweets contained in the pockets 4 are carried around in
this trough.
On the delivery side of feed table 3, a gap 10 (see FIG. 3) is
formed in a lower portion of retaining ring 2, and, in addition, an
inwardly projecting deflector 2' is formed from an upper portion of
the retaining ring. The sweets 1 contained in pockets 4 can pass
underneath deflector 2', but surplus sweets are deflected by it so
as to by-pass the delivery point located at the gap 10 in retaining
ring 2. At the delivery point the trough defined between feed table
3 and retaining ring 2 contains a greatly rising ramp 5. During
rotation of feed table 3, the sweets 1 are forced to ride up this
ramp, which lifts them by an amount equal to at least half their
thickness out of their respective pockets 4 (see FIG. 2). In this
position the sweets 1 are consecutively engaged by a finger 9 of an
ejector, which rotates about a shaft 8 above the rim of feed table
3 and which operates to push the sweets radially outward along a
guideway 6 where they are braked by a leaf spring 7.
A feed conveyor, which substantially comprises an endless
articulated link chain 11 running over chain wheels 12, 13, and 14,
is provided for the purpose of transferring the sweets 1 to a
wrapping head 30 described below. In order to conduct link chain 11
along the path indicated in FIG. 2 lateral slideways (not shown)
are provided for the link chain. This precisely guides link chain
11, which carries nine holders 15 for carrier members 16 at
predetermined equidistant intervals.
As illustrated in greater detail and on a larger scale in FIG. 4,
each carrier member 16 carries a fixed gripper arm 17 forming a
trailng element and a movable gripper arm 18 mounted on a pivot 19
of the carrier member. Movable gripper arm 18 has a side arm 20,
which is loaded by a compression spring 21 bearing against the
underside of the head of carrier member 16. In addition, movable
gripper arm 18 has a downward extention 22, which functions as a
cam follower and controls the position of the movable gripper arm.
A plunger 23 having a downward extension 24 is slidably mounted in
carrier member 16 between the two gripper arms. A spring (not
shown) keeps plunger 23 in its normal position shown in FIG. 4. In
this position the head of plunger 23 rests on the top side of the
head of carrier member 16.
A ring 26 is provided on the shaft 25 of chain wheel 12 for the
purpose of opening the movable gripper arm 18. When the downward
extension 22 of movable gripper arm 18 strikes this ring 26, the
gripper arms 17 and 18 open against the resistance of the
compression spring 21 so that the fixed gripper arm 17 can engage a
sweet 1 presented to it between guideway 6 and leaf spring 7 by one
of the ejector fingers 9. As soon as the downward extension 22 of
movable gripper arm 18 rides off ring 26, spring 21 urges the
movable gripper arm to close on the sweet 1 towards the fixed
gripper arm 17 and hold the sweet on the top of plunger 23. As the
link chain 11 revolves in the direction of the arrowheads shown in
FIG. 2 the sweet 1 is withdrawn from between guideway 6 and leaf
spring 7 and conveyed towards the wrapping head 30.
Naturally, the speeds of travel and the working cycles of the
ejector fingers 9 and of the carrier members 16 are suitably
synchronized to ensure that each ejector finger 9 will push a sweet
1 onto the guideway 6 at the appropriate instant for the sweet to
be engaged and gripped by the gripper arms of one of the carrier
members. During the continuous revolution of link chain 11, the
sweets 1 are consecutively conveyed at uniform speed to wrapping
head 30 where they are wrapped into one or more wrappers 40.
Wrapping head 30 consists of a casing coaxially mounted on a shaft
31 for rotation about the central axis of the shaft and the casing.
Pivot pins 32 for mounting gripping and folding devices, each of
which includes a pair of gripping jaws 33 and a pair of folding
arms 36, are mounted at spaced positions along the periphery of
wrapping head 30. The wrapping head 30 shown in FIG. 1 is equipped
with eight pairs of gripping jaws 33 and a corresponding number of
folding arms 36. As best shown in FIGS. 2 and 5, a counter plunger
34 is radially slidably mounted between each pair of gripping jaws
33 and is loaded by a spring 35. Switch, control, and drive means
(not shown) are provided inside the casing of wrapping head 30 to
operate the gripping jaws 33 as well as the folding arms 36 in
appropriate synchronism with the working cycle and ensure that the
wrapping head 30 rotates continuously about its central axis. An
important feature of this invention is that link chain 11 is
arranged to run from chain wheel 14 to chain wheel 13 along a path
that exactly conforms with the circular path of motion of the
folding arms 36 of wrapping head 30 as shown in FIG. 2.
Supply bobbins 38 and 39 for wrapping material are mounted
alongside wrapping head 30 (see FIG. 1). According to the type of
wrapping that is to be produced one or more bands of wrapping
material are continuously drawn off singly or in superposition from
these supply bobbins over guide rollers and a feed track 46 by
draw-off rollers 42 and 43. A knife 45 revolving at a constant
speed and cooperating with a counter knife 44 cuts off lengths of
the band or bands of wrapping material that have been drawn off the
bobbin or bobbins 38 and 39 and thereby forms wrappers 40 of
suitable size (see FIG. 2). The wrapping material is supplied at
the speed of rotation of wrapping head 30 and of link chain 11.
The layout and speed of wrapping head 30 and the pitch of link
chain 11 are so matched that in the region between the two chain
wheels 14 and 13 (i.e. in the transfer region) each carrier member
16 on the link chain will exactly face and register with a pair of
gripping jaws 33 on the wrapping head. The two plungers 23 and 34
will then be coaxial, enclosing a sweet 1 between them, with the
counter plunger 34 bearing yieldingly on the sweet. Immediately
before this position is reached, the leading end of the band or
bands of wrapping material runs in between the sweet 1 and the
counter plunger 34. At the appropriate instant, the rotating knife
45 then cuts off a wrapper 40 of the required length.
During the continued movement of the two cooperating units, the
lower end of plunger 23 eventually rides onto a cam 28 that
displaces plunger 23 towards wrapping head 30 and thereby pushes
the sweet 1 and the wrapper 40, which covers the sweet and is held
in position thereon by the counter plunger 34, between the yielding
gripping jaws 33. This operation causes the wrapper 40 to be folded
over the sweet in the form of a U as shown in FIG. 5. Having thus
delivered its sweet 1, the carrier member 16 then travels over the
chain wheel 13 with the grippers 17 and 18 open and returns to the
receiving station for the reception of another sweet 1.
The sweet 1 accepted by the gripping jaws 33 is completely wrapped
as wrapping head 30 continues to rotate. First, the trailing
folding arm 36, as viewed in the direction of travel, swings in a
counterclockwise direction and folds the trailing projecting edge
of the wrapper 40 over the sweet 1 as indicated by the dotted line
in FIG. 5. When this has been done, the other folding arm 36 folds
the other projecting edge of the wrapper 40 over the folded first
edge. The sweet 1 is now completely enveloped by the wrapper in the
form of a tube. A stationary folding blade 37 (see FIG. 1) assists
the described enveloping operation and keeps the tubular wrapper
closed during the further rotation of wrapping head 30. All that
remains to be done is to close the open ends of the tube. According
to the type of wrapping, diverse kinds of closing tools, such as
folding, welding, pinching and twisting elements, can be used.
In the preferred embodiment of the wrapping machine illustrated in
FIG. 1, the wrapping 40 is completed with the aid of a twisting
assembly comprising twisting grippers 55 positioned on each side of
wrapping head 30 to form two closures by twisting. The twisting
grippers 55 perform this operation as they travel with wrapping
head 30. As shown in both FIGS. 1 and 6, the twisting assembly
further comprises a segment 51 that is provided with rack teeth
around its circumference and that embraces about one quarter of the
circumference of wrapping head 30. Axles 50 carrying chain wheels
52 are provided at the ends of this segment 51. A link chain 53 is
guided in lateral ways over chain wheels 52 and travels at a speed
that conforms with the peripheral speed of wrapping head 30. This
link chain 53 carries eight pairs of twisting grippers 55 in
holders 54 spaced at equidistant intervals therealong. Rotation is
imparted to the twisting grippers 55 by gear wheels 56, which roll
on the rack teeth of the segment 51. Control means (not shown)
operate to close the grippers 55, which then grip the open tubular
ends of the wrapper 40 projecting from both sides of wrapping head
30 and twist them together during the continuation of the described
movements. The wrapper 40 is thus closed and and the wrapping
process completed, after which the grippers 55 are reopened by the
control means. The completely wrapped sweets 41 can now be
dislodged from the open grippers 55 and engaged from behind by an
ejector 57, which ejects them into a chute 58 down which they slide
into a bin (not shown).
The illustrated twisting assembly is exchangeable and can be
replaced by a closing mechanism having tools of a different kind.
According to the nature of the wrapping that is required (pinch or
fold, single or double twist, etc.). It is important that the sweet
should travel at continuously uniform speed from the time it leaves
feed table 3 to the time it is fully wrapped and ejected and that
all the operations needed to complete the wrapping are performed
during this period of uniform movement by synchronously controlled
tools and instruments. Since accelerations and decelerations, as
well as inertial forces, are avoided, the working speed and, hence,
the performance of the wrapping machine can be considerably raised
to provide throughputs easily exceeding 1,000 to 1,500 wrapped
sweets per minute.
* * * * *