U.S. patent number 3,901,002 [Application Number 05/452,748] was granted by the patent office on 1975-08-26 for feed advance drive mechanism especially for a packaging machine.
This patent grant is currently assigned to Multivac Sepp Haggenmueller KG. Invention is credited to Arthur Vetter.
United States Patent |
3,901,002 |
Vetter |
August 26, 1975 |
Feed advance drive mechanism especially for a packaging machine
Abstract
The present drive mechanism provides especially for a packaging
machine a non-uniform drive speed for producing packings from a
pair of webs of packing material drawn respectively from a pair of
supply rolls. The drive motor for the feed advance of said webs of
packing material is switched off, preferably when the gear means of
the drive mechanism reach the greatest speed ratio. The packing
tools are switched on when the drive motor is switched off and vice
versa.
Inventors: |
Vetter; Arthur (Groenenbach,
DT) |
Assignee: |
Multivac Sepp Haggenmueller KG
(Wolfertschwenden, DT)
|
Family
ID: |
5875634 |
Appl.
No.: |
05/452,748 |
Filed: |
March 20, 1974 |
Foreign Application Priority Data
|
|
|
|
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Mar 23, 1973 [DT] |
|
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2314462 |
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Current U.S.
Class: |
53/389.3; 74/437;
74/393; 83/222 |
Current CPC
Class: |
B65B
65/02 (20130101); Y10T 83/4493 (20150401); Y10T
74/19884 (20150115); Y10T 74/19555 (20150115) |
Current International
Class: |
B65B
65/00 (20060101); B65B 65/02 (20060101); B65B
041/12 (); B65B 041/14 () |
Field of
Search: |
;53/389,180 ;93/33H
;74/414,432,245C,393,437 ;83/313,222 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: McGehee; Travis S.
Assistant Examiner: Culver; Horace M.
Attorney, Agent or Firm: Fasse; W. G. Roberts; W. W.
Claims
What is claimed is:
1. In a web feed advance drive mechanism for a packing machine for
forming packages from a pair of webs of packing material drawn from
respective supply rolls, said packing machine being of the type
having working tools for forming and sealing said webs, wherein the
feed advance drive includes a drive motor, an output shaft, and
means driving said output shaft by said motor; the improvement
comprising wheeled drive means coupled to said drive motor and to
said output shaft for operating said output shaft with a
non-uniform rotational speed, first control means operatively
responsive to said wheeled drive means for switching said drive
motor off, and further control means responsive to a working tool
in said packing machine for re-energizing said drive motor, said
first control means for switching said motor off comprising means
responsive to said wheeled drive means for switching said motor off
at the instant of the greatest rotational speed ratio of said
wheeled drive means.
2. The drive mechanism of claim 1, wherein said further control
means for said working tools comprises means for energizing said
working tools substantially with the switching off of said drive
motor.
3. The drive mechanism of claim 2, wherein said further switching
means of the control means for re-energizing said drive motor are
responsive to the termination of the operation of said working
tools for re-energizing said drive motor substantially when the
working tools stop.
4. The drive mechanism of claim 1, wherein said drive motor is a
brake motor.
5. The drive mechanism of claim 1, wherein said wheeled drive means
comprises drive gear wheels.
6. The drive mechanism of claim 5, wherein said drive gear wheels
comprises a pair of intermeshing elliptical spur gears each having
its respective rotational axis at one of its focus points of the
ellipses for providing said non-uniform rotational speed.
7. The drive mechanism of claim 5, wherein said drive gear wheels
comprise a pair of intermeshing oval gears having central turning
axes for providing said non-uniform rotational speed.
8. The drive mechanism of claim 5, wherein said drive gear wheels
comprise a circular gear wheel having an eccentric rotational axis
and an oval gear wheel having a central rotational axis, said gear
wheels meshing with each other for providing said non-uniform
rotational speed.
9. In a packing machine of the type comprising conveyor means,
means for feeding an upper and a lower web of packing material to
said conveyor, working tool means for processing said webs as they
are driven by said conveyor, a drive motor, and means coupling said
drive motor to drive said conveyor; the improvement wherein said
coupling means comprises a pair of gears with intermeshed teeth
coupled to non-uniformly drive said conveyor means, whereby the
speed ratio between the rotational speed of said motor and the
speed of said conveyor varies periodically, said coupling means
further comprising switching means for switching said drive motor
off when said ratio reaches its maximum value and wherein said
packing machine further comprises means responsive to said working
tool means for reenergizing said drive motor.
Description
BACKGROUND OF THE INVENTION
In packing machines which produce packages from two webs of packing
material one of the webs of packing material is securely held
between a pair of parallel, periodically driven roller chains
having holding clamps for said web. In such packing machines the
intermittent feed advance of the roller chains is conventionally
provided by means of drive gears having an intermittent or
interrupted turning movement.
A packing machine of this type is described, for example, in U.S.
Pat. No. 3,061,984. A further example of such a packing machine is
described in French Patent application No. 7,240,076. These
references disclose the details of packing machines of the type in
which the feed advance drive mechanism of the present invention may
be employed.
In the known feed advance drive arrangements the feed advance is
accomplished with a comparatively high acceleration at the start
and with a relatively high deceleration at the end of the feed
advance cycle. This can cause spilling where liquids or granular
materials are packaged and the containers are still open.
OBJECTS OF THE INVENTION
In view of the foregoing, it is an object of this invention to
provide a feed advance drive mechanism for a packing machine which
will avoid the disadvantages of the prior art. More specifically
the invention aims at providing a gently operating feed advance
mechanism for a packing machine so that the spilling of liquid or
granular materials in open containers will be avoided. In other
words, the transport of filled, but still open containers must be
assured without spilling.
SUMMARY OF THE INVENTION
In accordance with the invention the above objects are achieved by
providing a feed advance drive mechanism for a packing machine with
a non-uniform turning movement. First switching means are provided
which in response to the drive means switch the motor off. A
control arrangement is provided for controlling the packing tools
of the packing machine. The control arrangement includes second
switching means for re-energizing the drive motor after the
functions of the packing tools have been completed. Incidentally,
said tools include, for example, tools for forming and sealing a
package.
In a particularly advantageous embodiment of the invention, the
first switching means for switching the drive motor off is arranged
in such a manner that the drive motor is switched off at the
instant of the greatest rotational speed ratio of the gear drive.
In other words, the drive motor is switched off at the instant when
the ratio of the speed of an output drive shaft to the speed of the
motor is the greatest.
The feed advance drive mechanism according to the invention is
further arranged so that the control arrangement initiates the
operation of the package forming or sealing tool means at the
instance when the drive motor is switched off. Preferably, the
contol arrangement switches the drive motor on again when the
functions of the forming and/or sealing tools have been completed.
The drive motor is preferably a braking motor.
The wheel drive means of the feed advance drive mechanism in
accordance with the invention may be gears. In order to provide a
non-uniform turning movement, two elliptical spur gears may be
employed whereby the rotational axes of the elliptical gears are
located at the focus points of the respective ellipses.
In a further embodiment of the invention, the gear drive may
provide a non-uniform turning movement by employing two oval gears
having central turning axes. In this arrangement, as in the
arrangement employing elliptical spur gears, the rotational speed
ratio is w=1.
In a modified arrangement in accordance with the invention a
non-uniform turning movement may be accomplished by employing a
normal circular gear having an eccentric rotational axis and
meshing with an oval gear having a central rotational axis. In this
arrangement a rotational speed ratio of w=2 is provided.
BRIEF FIGURE DESCRIPTION
In order that the invention may be clearly understood, it will now
be described with reference to the accompanying drawings,
wherein:
FIG. 1 illustrates a feed advance drive mechanism in accordance
with one embodiment of the invention employing two elliptical
gears, whereby the rotational axes of the gears are located at a
respective focus point of the corresponding ellipses;
FIG. 2 is a plan view of the mechanism of FIG. 1 as viewed in the
direction of the arrow A in FIG. 1;
FIG. 3 illustrates a modification of the mechanism of FIG. 1
employing a pair of oval gears each having a central rotational
axis;
FIG. 4 is a view of a further modification of the feed advance
drive mechanism of FIG. 1, employing a circular gear having an off
center turning axis, and an oval gear having a central turning
axis; and
FIG. 5 is a simplified circuit diagram of a control apparatus that
may be employed in the arrangements of FIGS. 1 to 4.
DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS
FIGS. 1 and 2 illustrate a feed advance drive mechanism in
accordance with one embodiment of the invention. In this
arrangement a drive motor 1, preferably a braking motor, is mounted
on a suitable support 20a as shown in FIG. 1. The support 20a is
part of the frame structure not shown. A sprocket wheel 4 is
rigidly mounted on a shaft 5, the shaft 5 being journaled for
rotation in a frame plate 20, as shown in FIG. 2. The support
member 20a may be secured to the base plate 20 by any suitable
means. The drive motor 1 is provided with a drive sprocket wheel 2.
A roller chain 3 connects the sprocket 4 by means of the sprocket
2.
An elliptical gear wheel 6 is also secured to the shaft 5. The
turning or rotational axis of the elliptical gear 6 is located at
one of the focus points of the respective ellipses. A second
elliptical gear 7 is affixed to a shaft 8, the shaft 8 being
journaled for rotation in the base plate 20. The elliptical gear 7
meshes with the elliptical gear 6. The rotational axis of the gear
7 is also located at one of the focus points of the ellipses of
this gear 7. An exchangeable circular gear 9 is removably affixed
to the shaft 8. For example, a nut 8a may be provided on the end of
the shaft 8 in order to exchange gear 9 for another gear of a
different size. By exchanging the gear 9 different feed advance
movements may be obtained depending on the size of the package to
be produced.
A spur gear 13 is affixed to a shaft 15 which is journaled for
rotation in the base plate 20. A support member 14a is pivotally
mounted on the shaft 15 between the spur gear 13 and the base plate
20, please see FIG. 2. A spur gear 10, meshing with the
exchangeable gear 9 is rotatably supported on a journal 12 carried
by the support member 14a. A spur gear 11 mounted to rotate with
the spur gear 10 on the journal 12 meshes with the spur gear
13.
The support member 14a is provided with an arcuate slot 14b. A
clamping screw 14c extends through the slot 14b and is threaded in
the base plate 20. Upon loosening of the clamping screw 14c, the
support 14a may be shifted whereby the axis of the gears 10 and 11
is rotated about the axis of the spur gear 13 in order to
accommodate gears 9 of different sizes. The support 14a is secured
in the new position by tightening the clamping screw 14c again.
Sprocket wheels 16 are affixed to the shaft 15 on the side of the
base plate 20 opposite the spur gear 13 and endless roller chains
17 are provided on the sprockets 16, whereby the sprockets 16 drive
the chains 17. The endless chains 17 carry suitable clamping
devices (not shown) for moving the lower web of packing material
through the packing machine.
The shaft 15 is also journaled in a further base plate 20b as
appears in FIG. 2. The base plates 20 and 20b are fixedly mounted
as part of the housing (not shown) of the packing machine.
A lower packing web 50 from a supply roll 51 is directed, for
example, by means of roller 52 to the upper side of the drive chain
17, as indicated by the arrow 53, to pass a first working station
54. The working station 54 may, for example, be comprised of
suitable working tools for forming a package from the lower packing
web. In addition, an upper packing web 55 is directed to the chains
17 from a supply roll 56, for example, by means of rollers 57, in
the direction indicated by arrow 58. The web 55, and the web 50
after having passed the station 54, are then directed on the chain
17, with the upper web overlying the lower web 50 to a further work
station 59, for example, a sealing station. The means for feeding
the webs to the conveyor and the processing of the webs to form
packages is conventional.
In order to obtain the necessary intermittent feed advance for the
lower web of packing material, a switching cam 18 is affixed to the
sprocket 4 for engaging a tripping switch in a control apparatus 19
mounted, for example, to the support member 20a. The cam 18 is so
positioned that it will engage the switch in the control apparatus
19 at the instant of the greatest rotational speed ratio between
the gears 6 and 7 in order to switch off the braking motor 1 at
said instant time. At the same time, the control apparatus causes
the operation of the tools 54 and 59 of the packing machine, for
the forming of containers from the lower web of the packing
material and for the sealing of the filled containers with the
upper web of the packing material, if desired, after an evacuation
of the containers. The control apparatus 19 comprises further
switching means for switching on the brake motor 1 following the
termination of the tool operation.
FIG. 3 shows a modification of the arrangement of FIGS. 1 and 2,
wherein the elliptical gears 6 and 7 have been replaced by oval
gears 6b and 7b. The oval gears 6b, 7b are affixed to the shafts 5,
8 at the respective central rotational axes of the oval gears.
In a still further embodiment of the invention, as illustrated in
FIG. 4, the elliptical gears 6, 7 have been replaced by a normal
circular gear 6c and an oval gear 7c meshing with the circular gear
6c. The circular gear 6c is affixed to the shaft 5 at an eccentric
rotational axis, and the oval gear 7c is affixed to the shaft 8 at
a central rotational axis.
Otherwise, the embodiments of the invention illustrated in FIGS. 3
and 4 correspond to the embodiments illustrated in FIGS. 1 and
2.
The switching circuit of FIG. 5 embodies an example of the control
means 19. An ON-OFF switch 30 initially starts the motor 1, whereby
the cam 18 rotates with the gear 4 until it actuates a switch 18'
to open contact 31 and to close contacts 32 and 33. Opening of the
contact 31 stops the motor 1. Closing of contact 32 prepares a
bypass circuit 34 for restarting the motor 1 at the end of an
operational cycle of the tool drive. Closing of contact 33 starts
the tool drive. At the end of any tool drive cycle a cam 38
temporarily operates a switch 37 to close contact 35 and to open
contact 36 whereby the motor 1 is restarted and the tool drive is
stopped. The restarting of the motor 1 moves the cam 18 off the
switch 18' and the motor 1 will run again until cam 18 again
actuates the switch 18'. Thus, the motor 1 will run when the tool
drive is stopped and vice versa.
Although the invention has been described with reference to
specific example embodiments, it is to be understood, that it is
intended to cover all modifications and equivalents within the
scope of the appended claims.
* * * * *