Method and apparatus for welding bags to rings

An apparatus for welding a reinforcing member to a bag-like device or contraceptive device is disclosed. The apparatus includes at least one hollow mandrel. The hollow mandrel has an outer surface with an annular groove for holding the reinforcing member. The apparatus has a means for applying a closed end of the bag-like device into the hollow mandrel and an open end of the bag-like device over the hollow mandrel at the outer surface with the annular groove for welding holding the reinforcing member. The apparatus also includes a welding device for the reinforcing member to the bag-like device. A method for welding the reinforcing member to a bag-like device is also disclosed.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The invention relates to a method and apparatus for forming plastic 
articles. Specifically, the invention relates to a method and apparatus 
for welding a semirigid bead to two sheets of plastic film. 
2. Description of Related Art 
Plastic articles made from two or more sheets or plies of plastic material 
are commonly manufactured for use as bags, gloves, and other devices. Many 
of these plastic articles have rims or beads molded or attached to their 
open ends. When the plastic articles are used as medical devices, their 
method and apparatus for manufacture must provide a consistently high 
quality article that does not tear at the joinder of the film with the 
bead and that is not abrasive when rubbed against the skin. 
U.S. Pat. No. 2,900,779 to Baxter et al. discloses a tool for opening and 
expanding the mouth of a flexible receptacle. The device of this patent 
assembles a "supporting neck ring" to a "flexible and somewhat stretchable 
film material." This device is not designed to open a multiple ply plastic 
article and also apply it over the ring before welding the two elements 
together. 
U.S. Pat. No. 3,247,647 to Koch discloses an applicator device. The device 
of this patent applies a bag over a rigid tubular holder to form a baby 
bottle. This device does not apply a multiple ply plastic article over a 
ring before welding the two elements together. 
The industry lacks a high speed method and apparatus for applying a bead or 
ring to an open end of a multiple ply plastic article such as a bag or 
contraceptive device. 
SUMMARY OF THE INVENTION 
The invention includes an apparatus for welding a reinforcing member to a 
bag-like means. The apparatus includes at least one hollow mandrel, the 
hollow mandrel has an outer surface with an annular groove for holding the 
reinforcing member. The apparatus has a means for applying a closed end of 
the bag-like means into the hollow mandrel and an open end of the bag-like 
means over the hollow mandrel at the outer surface with the annular groove 
for holding the reinforcing member. The apparatus, also, includes a means 
for welding the reinforcing member to the bag-like means. 
The invention is, also, a process of producing collapsible bag-like means 
having the following steps. Placing a reinforcing member into an annular 
groove on an outer surface of at least one hollow mandrel first occurs. 
Opening an open end of the bag-like means with a means for opening having 
a gas injector means for injecting gas into the open end of the bag-like 
means follows. Gripping the opened end of the bag-like means at a 
plurality of sites on a circumference of the open end of the bag-like 
means follows. Extending the open end of the bag-like means occurs. 
Applying a closed end of the bag-like means into the hollow mandrel and 
the open end of the bag-like means over the hollow mandrel at the outer 
surface with an annular groove for holding the reinforcing member follows. 
Lastly, welding the reinforcing member to the bag-like means is performed.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
FIG. 1 illustrates a general arrangement and the numbers shown in the 
arrows correspond to the arrangement shown in FIGS. 2 to 7 described more 
fully below. In FIG. 1, there is shown at 10 a series of bag-like means 
attached to backing paper. 
FIG. 2 illustrates an O-ring pick head 11. The O-ring pick head 11 is 
arranged to pick an O-ring from the top of a stack of O-rings in an O-ring 
feeder tube 12. The O-ring pick head in this position is shown in dashed 
or broken lines and moves downwardly on the top of the stack of O-rings. 
An O-ring gripper 13 releases a single O-ring and the O-ring pick head 11 
then has suction applied to it. The suction applied to the O-ring pick 
head 11 causes the O-ring to be sucked or pulled by a vacuum into a 
corresponding groove in the underside of the O-ring pick head 11. The 
O-ring gripper 13 contacts and retains the remaining O-rings on the tube. 
The arrangement is such that the O-rings are raised upwardly so that the 
O-ring gripper 13 can release the O-rings one at a time. When the O-ring 
pick head 11 has lifted the top ring, the O-ring pick head 11 then rotates 
so as to be over the first position of a four position rotary turntable 
16. The four positions of the rotary turntable 16 are indexed at 
90.degree. to one another. 
In the first position, the O-ring pick head 11 moves downwardly to press an 
O-ring into an annular groove 17 in a pot 18 located on the rotary 
turntable 16. The pot 18 is open at both ends in the preferred embodiment. 
Suction is then applied to the annular groove 17 at the top of the pot 18. 
At the same time, the suction is terminated from the O-ring pick head 11 
and a supply of compressed air is supplied through the O-ring pick head 11 
to assist in transferring the O-ring from the O-ring pick head 11 to the 
pot 18 on the rotary turntable 16. Sensor means (not shown) can be present 
for verifying the presence of an O-ring on the annular groove 17. If no 
O-ring is on the annular groove 17, the O-ring pick head 11 returns to 
transfer another O-ring. When an O-ring has been satisfactorily placed in 
the annular groove 17 at the top of the pot 18, the O-ring pick head 11 
swings away to return to the position above the O-ring feeder tube 12 in 
preparation for the start of another cycle. 
The rotary turntable 16 rotates 90.degree. to transfer the pot 18 having an 
O-ring to the "bag and O-ring welding station". At the bag and O-ring 
welding station, a bag-like means is supplied. The bag-like means, as 
shown at 10 in FIG. 1, are adhered to a backing paper and are spaced apart 
from one another. The bag-like means are adhered along the edge of their 
open end to the backing paper and are open at their right hand sides 
(according to the embodiment shown in FIG. 1) so as to form an entrance to 
each bag-like means. An eight finger gripper assembly 19 (explained in 
detail below) is adapted to grip the open end of a bag-like means. 
FIGS. 3 and 4 illustrate the gripper assembly 19 with a bag-like means 
attached thereto. In order to arrive at this position, the gripper 
assembly 19 is pivoted into a position approximately 10.degree. past the 
vertical. The backing paper with an attached bag-like means is indexed or 
moved into a curved trough. The curved trough bends the two plies of 
plastic film of the bag-like means so that the lower layer of film, that 
is adhered to the backing paper, is stretched about the perimeter of the 
curved trough. The upper layer of plastic film is puckered or rippled. The 
rippled separation between the two plies of plastic film opens the 
bag-like means. A high pressure blast of air is applied to the open end of 
the bag-like means to inflate the bag-like means and the gripper assembly 
19 pivots forward approximately 10.degree. to place the roller fingers 
just inside the mouth of the inflated bag-like means. A double acting twin 
rod cylinder (not shown) drives the actuator plate 43 downwardly and as 
described below. The roller fingers assume a circular shape and in so 
doing grip and stretch the mouth of the bag-like means causing the 
bag-like means to release from the backing paper. 
Bag-like means strip air jets direct high pressure gas or air to ensure 
that the nose or closed end of the bag-like means is also released from 
the backing paper. With the bag-like means still inflated, the gripper 
assembly 19 pivots forward and the nose of the bag-like means is guided 
into and slides down a pivoted curved guide chute 49 and into the pot 18 
on the rotary turntable 16 with the O-ring positioned in the annular 
groove 17. During this movement of the gripper assembly 19, air is 
continuously supplied by an air jet 48. The force of the air jet 48 pivots 
with the gripper assembly 19 to keep the bag-like means inflated. The 
guide chute 49 then pivots back to make room for a weld head 51, shown in 
FIG. 5, to move into position by pivoting from the side and then moving 
downwardly onto the top of the pot 18. 
The weld head 51 then presses down through the hole in the back of the 
gripper assembly 19 formed by the movement of the arms and fingers 
trapping the plastic film of the stretched bag-like means between a heated 
plate and the O-ring beneath. Welding of the plastic film to the O-ring is 
performed for a short time of about 0.3 seconds at a temperature of about 
140.degree. C.+or -10.degree. C. The bag-like means is located over the 
pot 18 such that the plastic film of the bag-like means overlaps and 
descends down the outside of the pot 18. 
FIG. 6 illustrates the position of the elements during the welding 
procedure. The gripper assembly 19 is lowered still further. The further 
lowering of the gripper assembly 19 assists in stripping the annulus of 
excess film formed by the overlap of plastic film over the outer periphery 
of the O-ring and pot 18. The heat of the welding procedure causes 
weakness in the plastic film so that the gripper fingers can easily strip 
the surplus plastic film and a neat weld is formed without any surplus 
plastic film attached to the weld. 
The weld head 51 then lifts and pivots back to the side of the machine and 
the gripper assembly 19 begins to pivot back towards the rest position. At 
approximately 45.degree. the gripper assembly 19 pauses and the curved 
guide chute 49 pivots forward to shield and protect the recently welded 
bag-like means in the rotary turntable 16. The double acting twin rod 
cylinder then lifts the actuator plate 43 causing the gripper fingers to 
contract and release the bag-like means. While this procedure is 
occurring, high velocity air jets cause the annulus of excess film to be 
blown away from the pot 18 and deposited to scrap. The gripper assembly 19 
then completes the return to the initial position of about 10.degree. past 
the vertical. 
The four position rotary turntable 16 then moves 90.degree. to a spare 
station and then through a further 90.degree. taking the newly formed 
bag-like means to a product removal station. At the product removal 
station, a vacuum through the annular groove 17 of the pot 18 is 
terminated. A product removal head 52 holds the welded product and pivots 
through a 180.degree. arc. A vacuum is initiated through an annulus 53 on 
the product removal head 52, thus, enabling the product removal head 52 to 
pick the newly formed welded bag-like means from the rotary turntable 16. 
The welded bag-like means and removal head 52 rotate through a 180.degree. 
arc so that the welded bag-like means can be inverted under a transfer 
tube. The welded bag-like means is then inflated and the vacuum through 
the annulus 53 to the product removal head 52 is terminated to cause the 
welded bag-like means to be launched up the transfer tube. The welded 
bag-like means is pushed by various air jets along the transfer tube 54 
and into platens (not shown). The platens can be used to transfer the 
welded bag-like means to a testing station. 
FIGS. 8, 9, and 10 illustrate the gripper assembly 19 in detail. The 
gripper assembly 19 comprises two fixed finger rollers 20 and two sets of 
movable finger rollers 21, 22, 23, and 24 which are mounted on the ends of 
two sets of arms on each side of a center line running through the gripper 
assembly 19. Each set has arms 25, 26, and 27 with pins 30, 31, and 32 
extending through slots 33, 34, and 35 in a cam plate 36. The lower ends 
of the arms are connected by further pins 37, 38, and 39 through slots 40, 
41, and 42 through an actuator plate 43. The actuator plate 43 is movable 
between upper and lower positions as shown in the "split views" of the 
left and right hand sides, respectively, of FIG. 8. 
The lower pin 24 is mounted on a rod which is directly connected to the 
actuator plate 43. Each of the gripper fingers have rollers 44 and these 
can be seen in FIG. 9. FIG. 9 illustrates the rollers 44 mounted on a 
fixed pin 45. The fixed pin 45 is mounted on the end of the respective arm 
and has an enlarged head 46. The enlarged head 46 serves to retain a 
roller sleeve 47. The roller sleeve 47 is rotatable on the pin 45. The 
roller sleeve 47 has an enlarged shoulder 48 at its outer end. In 
operation the gripper fingers move from a first position where they are 
all grouped together into a second position where they form a circular 
shape caused by the cam plate or actuator plate 43 moving downwardly. 
The invention includes a process for welding a reinforcing member to a 
bag-like means. The process involves placing a reinforcing member into an 
annular groove on an outer surface of at least one hollow mandrel. Then, 
opening an open end of the bag-like means with a means for opening having 
a gas injector means for injecting gas into the open end of the bag-like 
means is performed. Gripping the opened end of the bag-like means at a 
plurality of sites on a circumference of the open end of the bag-like 
means occurs. Extending the open end of the bag-like means and applying a 
closed end of the bag-like means into the hollow mandrel and the open end 
of the bag-like means over the hollow mandrel at the outer surface with an 
annular groove for holding the reinforcing member is performed. Welding 
the reinforcing member to the bag-like member follows. 
The process can further comprise ejecting the welded bag-like means from 
the mandrel. The process step of gripping can be performed by a plurality 
of prongs. The prongs are positionable within the open end of the bag-like 
means at individual sites on the circumference of the open end of the 
bag-like means. The step of extending the open end of the bag-like means 
can be performed by a cam member whereby operation of the cam member 
positions the prongs in one of two conditions. The two conditions are a 
first condition wherein the prongs are gathered together in a 
substantially linear position for insertion into the opened open end of 
the bag-like means. A second condition can be one wherein the prongs are 
separated from one another to extend the open end of said bag-like means.