Apparatus for making bag assembly and method thereof
AssigneeTyco Healthcare Group LP
InventorMark A. Vess
Life of this patent
Estimating the term…
Abstract
A method of and apparatus for forming a bag assembly by RF welding. A single source of RF energy is used to generate a high frequency electric field having a first strength between tube-welding electrodes of opposing die members and a second strength less than the first strength between perimeter-welding electrodes of the opposing die members. Respective portions of the bag assembly are subjected to this variable-strength field simultaneously so that the bag assembly is formed in one welding operation. Stand-offs are used in some embodiments to limit penetration of the electrodes into the weld areas.
Claims22
A method of forming a bag assembly by RF welding, comprising the steps of
- inserting a tubular insert into a lumen of a tube to form a tube assembly,
- placing opposing sheets and the tube assembly at least partially received between the sheets between first and second opposing die members of a welding apparatus, the first die member including a first tube-welding electrode and a first perimeter-welding electrode and the second die member including a second tube-welding electrode and a second perimeter-welding electrode,
- generating from a single source of RF energy a high frequency electric field having a first strength between the tube-welding electrodes of the opposing die members and a second strength less than said first strength between the perimeter-welding electrodes of the opposing die members,
- subjecting the tube assembly and corresponding portions of the sheets surrounding the tube assembly to the high frequency electric field of said first strength for a predetermined amount of time to weld the sheets to the tube along a tube-weld,
- subjecting corresponding portions of the sheets between the perimeter-welding electrodes to the high frequency electric field of said second strength for said predetermined amount of time to weld the sheets together along a bladder perimeter-weld,
- wherein said subjecting steps are performed simultaneously so that the bag assembly is formed in one welding operation.
Welding apparatus for use in one-step welding to form a bag assembly comprising a bag and a tube in fluid communication with the bag, the welding apparatus comprising
- first and second die members opposing one another and defining a space therebetween for receiving opposing sheets and a tube therebetween, the first and second die members including opposing respective first and second perimeter-welding electrodes adapted to weld the sheets together to define a perimeter-weld of the bag and opposing respective first and second tube-welding electrodes adapted to weld the sheets to the tube to define a tube-weld so that the tube is in fluid communication with the bag,
- a single source of high frequency energy electrically connected to the first and second perimeter-welding electrodes and the first and second tube-welding electrodes to produce a high frequency electric field between the perimeter-welding electrodes and the tube-welding electrodes, and
- dielectric material for reducing the strength of the high frequency electric field between the first and second perimeter-welding electrodes as compared to a strength of the high frequency electric field between the first and second tube-welding electrodes so that the sheets are welded to the tube and the sheets are welded together in a single welding operation.
Welding apparatus for manufacturing a bag assembly having a pair of opposing sheets welded together to form a bag for holding a fluid and having a tube in fluid communication with an interior of the bag, the apparatus comprising
- opposing first and second die members including opposing respective first and second perimeter-welding portions for welding the sheets together to form a perimeter-weld of the bag assembly and opposing respective first and second tube-welding portions for welding the sheets to the tube to form a tube-weld of the bag assembly,
- the opposing first and second die members being movable between an open position in which the opposing first and second perimeter-welding portions and the opposing first and second tube-welding portions are spaced apart to permit insertion of the sheets and the tube and removal of the formed bag assembly, and a weld position in which the opposing first and second perimeter-welding portions and the opposing first and second tube-welding portions are closer together and engage the sheets for welding;
- a stop device for limiting movement of the opposing first and second perimeter-welding portions toward each other to prevent excessive displacement of sheet material in the perimeter-weld by engagement with the perimeter-welding portions.
A method of forming a bag assembly, comprising
- placing a bag subassembly, comprising a polymeric tube disposed between opposing polymeric sheets, between opposed die members of a welding apparatus,
- inserting a tubular insert into a lumen of the tube before the tube is welded between the sheets,
- moving the die members toward each other to contact the sheets so that perimeter-welding portions of the die members weld the sheets together to form a perimeter-weld and tube-welding portions of the die members weld the sheets to the tube to form a tube-weld, and
- limiting movement of the perimeter-welding portions of the die members toward each other to prevent excessive displacement of sheet material in the perimeter-weld by engagement with the perimeter-welding portions.
A method as set forth in claim 22 further comprising limiting movement of the tube-welding portions of the die members toward each other to prevent excessive displacement of sheet material in the tube-weld by engagement with the tube-welding portions.
Dependencies are inferred from the claim text.