Method and apparatus for applying labels in the molds of a plastic blow molding machine

A method and apparatus for applying labels in the molds of a plastic blow molding machine of the type wherein a plurality of sets of molds are mounted on a wheel rotatable about a horizontal axis and the molds are moved toward and away from one another to enclose a parison and the parison is then blown to the confines of the cavity between the mold sections which comprises successively die punching labels from a web directly onto vacuum cups and delivering the labels successively between the mold sections by moving the vacuum cups between the mold sections and thereafter moving the cups laterally into the cavities of the mold sections.

This invention relates to plastic blow molding machines and particularly to 
machines for delivering labels to an open mold so that they can be adhered 
to the plastic article when the mold is closed about a parison and the 
parison is blown to the confines of the mold. 
BACKGROUND AND SUMMARY OF THE INVENTION 
It is common to make hollow plastic articles such as containers by closing 
a mold about a heated parison and blowing the parison outwardly against 
the confines of the mold to form the hollow article. More recently, it has 
been suggested that labels can be delivered to an open mold and deposited 
in the cavity of the mold so that when the mold is closed and the parison 
is blown, the labels become adhered to and become a part of the blown 
hollow article. 
In certain types of machines, the space for delivery of the label into the 
open mold is limited because of the construction of the machine. More 
specifically, in one type of blow molding apparatus, a plurality of sets 
of molds are mounted on a wheel rotatable about a horizontal axis and the 
molds are moved toward and away from one another to enclose a parison and 
the parison is then blown by application of air to the confines of the 
cavity between the mold sections as the wheel rotates. In such an 
arrangement, the space is extremely limited and the problem of placement 
of labels in the open mold is difficult. The blown articles are usually 
taken out of the blow molding apparatus adjacent the twelve o'clock 
position and the extruded parison is introduced at the three o'clock 
position such that the area during which the molds are open therebetween 
is limited. Where two labels are to be delivered for placement on opposite 
sides of the hollow article, the problem is more difficult. The problem is 
further complicated when the molds have plural cavities and labels are to 
be delivered simultaneously to the plural cavities. 
In U.S. Pat. No. 4,680,000, there is disclosed and claimed a method and 
apparatus for applying labels in the molds of a plastic blow molding 
machine comprises removable labels successively from one or more 
magazines, depositing the labels on an endless conveyor which transports 
the labels to a position adjacent an open mold and laterally transferring 
the labels from the conveyor to a position within the molds such that when 
the mold closes about a plastic parison and the parison is blown, the 
labels become adhered to the blown plastic bottle. Such an arrangement 
necessitates the use of an endless conveyor interposed between the 
magazine and the mold sections. Accordingly, the labels must be first 
formed then handled and delivered into the magazine, rmmoved from the 
magazine positioned properly on the endless conveyor and then removed from 
the endless conveyor and delivered to the mold sections. These actions 
contribute to the possibility of loosing control of the position of the 
labels thereby being misaligned on the blown container especially where 
the labels are thin and made of plastic. 
U.S. Pat. No. 4,397,625 shows a labeler utilized with a rotating blow 
molding machine which has pick up heads that remove labels from magazines 
and deliver them to the mold cavities. This arrangement also has the 
disadvantages of the need for placement of the labels in magazines and 
removal therefrom. 
Accordingly, among the objectives of the present invention are to provide a 
method and apparatus for delivering labels between the sections of an open 
mold of a wheel or rotary type blow molding machine which obviates the 
need for magazines and conveyors thereby minimizing the likelihood of 
misalignment of the label; which will accommodate various size labels; and 
which will deliver labels to both sides of the cavity if desired. 
In accordance with the invention the method and apparatus for applying 
labels in the molds of a plastic blow molding machine of the type wherein 
a plurality of sets of molds are mounted on a wheel rotatable about a 
horizontal axis and the molds are moved toward and away from one another 
to enclose a parison and the parison is then blown to the confines of the 
cavity between the mold sections which comprises successively die punching 
labels from a web onto vacuum cups and delivering the labels successively 
between the mold sections by moving the vacuum cups between the mold 
sections and thereafter moving the cups laterally into the cavities of the 
mold sections.

DESCRIPTION 
Referring to FIG. 1, the invention is particularly applicable to a blow 
molding apparatus comprising a wheel plate 10 whch is mounted on a shaft 
11 extending horizontally for rotation on a frame and a plurality of sets 
of molds are provided in circumferentially spaced relation about the wheel 
plate 10, each set comprising a pair of mold sections 12, 13, a second 
mold section 14 being mounted on the wheel plate 10 movable toward and 
away from one another to close and open the mold. As the wheel rotates, 
where the molds are open, an extruder (not shown) delivers a parison 
between an open mold so that when the mold is closed, the parison can be 
blown to form the hollow article such as a container. At another position, 
the hollow articles are removed by a take out mechanism 14. The blow 
molding apparatus may be of the type shown in U.S. Pat. Nos. 4,523,904, 
4,523,904 or 4,397,625, which are incorporated herein by reference. 
In accordance with the invention, the label applying mechanism 15 is 
constructed and arranged to simultaneously die cut labels L from a web W 
onto vacuum cups V and deliver them to the open mold sections 12, 14 which 
are moved axially, as shown toward and away from one another to close or 
open. The mold sections 12, 14 can be also positioned on the wheel plate 
10 for movement radially relative to one another. 
More specifically, the web from a roll is fed about rollers 16 past a die 
punch 17 and the remaining portion of the web is fed over a roller 18. 
Each vacuum cup V is mounted on a movable head 19 for transverse movement 
on a cross slide 20 in a groove 21. The position of the cross slide 21 is 
controlled by an L-shaped lever 22 having a long arm 23 and a short arm 
24. The head 19 forms a pair of slides 28 movable on slide bars 25 on a 
frame 26. The head 19 is movable toward and away from the molds by a crank 
27 on frame 26 that is connected to the slide 28 on the slide bars 25 
(FIGS. 1, 2) and is driven by a motor M. 
A tension spring 29 is associated with each lever 22 and has one end fixed 
to the head 19 and the other end fixed to the long arm 23 of lever 22 to 
urge the respective vacuum cross slide 20 inwardly relative to the head 
19. 
Referring to FIG. 4, when the head is in position adjacent the die punches 
17, the cross slides 20 and vacuum cups are held adjacent the punches 17 
so that when the punches are actuated a label L is cut and delivered to 
each set of vacuum cups V. When the mold sections are in the open 
position, the head 19 is moved to the position shown in FIG. 5. As the 
head 19 moves adjacent fixed cams 30 (FIG. 4), the cams 30 engage a roller 
31 on the short arm 24 of lever 22 and moves the cross slides 20 and, in 
turn, the vacuum cups V supporting the labels L into the cavities C of the 
respective mold sections thereby delivering the labels to the cavities. 
Each cross slide 20 is provided with a vacuum inlet 32 and vacuum passage 
33 delivering vacuums to the respective vacuum cups V. 
It can be appreciated that if only one label L is to be used, the apparatus 
can be modified by eliminating one set of lever 22, cross slide 20 and 
associated vacuum cups V. 
It can thus be seen that there has been provided a method and apparatus for 
delivering labels between the mold sections of a rotary blowing machine in 
order to provide labels on the hollow containers that are formed which 
accurately delivers labels to the cavities without need for the label 
magazines and endless conveyors.