Ultrasonically welded joint

• US 5,782,575 A
• Filed: 04/23/1996
• Issued: 07/21/1998
• Est. Priority Date: 02/24/1993
• Status: Expired due to Term

• Current Assignee: Deka Products Limited Partnership
• Original Assignee: Deka Products Limited Partnership
• Inventors: Vincent, Douglas E., Durand, Kevin A.
• Primary Examiner(s): KIM, HARRY CHONG HYUN
• Application Number:
  US08/636,287
• Time in Patent Office: 819 Days
• Field of Search: 403/270, 403/269, 403/265, 403/271, 403/24, 403/404, 403/291, 156/580.2, 156/73.1
• US Class Current: 403/270
• CPC Class Codes: A61M 39/22 Valves or arrangement of valves A61M39/02, A61M39/0247, A61M39/16 take precedence; regulating valves in infusion systems A61M5/16881; in devices worn by the patient for the reception of urine, faeces, catamenial or other discharge, or in colostomy devices A61F5/4405
• CPC Class Codes: A61M 39/24 Check- or non-return valves
• CPC Class Codes: A61M 39/28 Clamping means for squeezing flexible tubes, e.g. roller clamps tube strippers A61M1/83
• CPC Class Codes: A61M 5/152 pressurised by contraction of elastic reservoirs containers for dispensing contents by contraction of an elastic bag provided therein, in general B65D83/0061
• CPC Class Codes: A61M 5/162 Needle sets, i.e. connections by puncture between reservoir and tube ; Connections between reservoir and tube in jet-action syringes A61M5/30; connectors for tubes having sealed ends and a needle for piercing them A61M39/14
• CPC Class Codes: A61M 5/16809 by repeated filling and emptying of an intermediate volume pressure infusion using positive displacement pumps A61M5/142
• CPC Class Codes: A61M 5/16813 by controlling the degree of opening of the flow line
• CPC Class Codes: A61M 5/16854 by monitoring line pressure
• CPC Class Codes: A61M 5/36 with means for eliminating or preventing injection or infusion of air into body dialysis systems, blood oxygenators A61M1/14; haemofiltration equipment A61M1/34; automatic tube cut-off A61M39/281
• CPC Class Codes: A61M 5/365 Air detectors A61M5/1684 takes precedence; in extracorporeal blood circuits A61M1/3626
• CPC Class Codes: B29C 65/08 using ultrasonic vibrations non-plastics element to plastics elements B29C65/645
• CPC Class Codes: B29C 66/112 Single lapped joints
• CPC Class Codes: B29C 66/114 Single butt joints
• CPC Class Codes: B29C 66/242 said joint lines being closed, i.e. forming closed contours
• CPC Class Codes: B29C 66/30223 said melt initiators being rib-like
• CPC Class Codes: B29C 66/30325 making use of cavities belonging to at least one of the parts to be joined
• CPC Class Codes: B29C 66/53461 joining substantially flat covers and/or substantially flat bottoms to open ends of container bodies
• CPC Class Codes: B29C 66/71 characterised by the composition of the plastics material of the parts to be joined welding bar compositions B29C65/125
• CPC Class Codes: B29C 66/712 the composition of one of the parts to be joined being different from the composition of the other part
• CPC Class Codes: B29C 66/73921 characterised by the materials of both parts being thermoplastics
• CPC Class Codes: B29C 66/8322 : Joining or pressing tools reciprocating along one axis
• CPC Class Codes: B29C 66/9513 : characterised by specific vibration frequency values or ranges
• CPC Class Codes: B29C 66/9516 : by controlling their vibration amplitude
• CPC Class Codes: B29K 2027/06 : PVC, i.e. polyvinylchloride
• CPC Class Codes: B29K 2033/08 : Polymers of acrylic acid esters, e.g. PMA, i.e. polymethylacrylate
• CPC Class Codes: B29K 2055/02 : ABS polymers, i.e. acrylonitrile-butadiene-styrene polymers
• CPC Class Codes: B29K 2069/00 : Use of PC, i.e. polycarbonates or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2075/00 : Use of PU, i.e. polyureas or polyurethanes or derivatives thereof, as moulding material
• CPC Class Codes: B67D 7/0255 : squeezing collapsible or flexible storage containers for dispensing beverages on draught B67D1/0462
• CPC Class Codes: F16K 31/004 : actuated by piezoelectric means
• CPC Class Codes: G01F 1/34 : by measuring pressure or differential pressure
• CPC Class Codes: G01F 1/66 : by measuring frequency, phase shift or propagation time of electromagnetic or other waves, e.g. using ultrasonic flowmeters
• CPC Class Codes: G01F 17/00 : Methods or apparatus for determining the capacity of containers or cavities, or the volume of solid bodies measuring linear dimensions to determine volume G01B
• CPC Class Codes: G01P 13/0066 : by using differences of pressure in the fluid
• CPC Class Codes: Y10T 403/47 : Molded joint
• CPC Class Codes: Y10T 403/477 : Fusion bond, e.g., weld, etc.

Abstract

A process is provided for ultrasonically welding a rigid thermoplastic, such as acrylic, and a flexible thermoplastic, such a polyvinyl chloride (PVC) doped with plasticizers. The rigid piece includes an energy director where the joint is to be located. The energy director includes first and second ridges running the length of the joint and a groove running between the first and second ridges. The energy director is placed against one side of the flexible piece, and an ultrasonic horn against the other side opposite the energy director. The two pieces are then welded together using standard ultrasonic technology. The shape of the energy director promotes the melting and flow of both pieces as they are being welded together.

Claims

1. A joint connecting a thermoplastic flexible membrane, having first and second surfaces, the first and second surfaces being parallel to each other, and a thermoplastic rigid material, formed from the process of:

providing on the rigid material an energy director comprising first and second ridges running substantially parallel to each other, and a groove running between the first and second ridges, wherein the first ridge has a first side adjacent the groove and a second side opposite the groove, wherein the first ridge'"'"'s first side is steeper than the first ridge'"'"'s second side;

placing an ultrasonic horn against the first surface of the membrane;

placing the energy director against the second surface of the membrane opposite the ultrasonic horn; and

applying vibrations to the horn so as to weld ultrasonically the membrane and the rigid material to nether,

wherein, in the welded joint, the rigid material has first and second protrusions corresponding to the first and second ridges, with the groove between said first and second protrusions running along the length of the joint, and

wherein, in the welded joint, the first surface of the flexible membrane faces away from the rigid material and being unsupported, and the second surface of the flexible membrane faces towards the rigid material and has a protrusion extending into the rigid material'"'"'s groove.

2. A joint connecting a thermoplastic flexible membrane and a thermoplastic rigid material wherein the rigid material has

a rigid base,

first and second protrusions extending from said rigid base, and

a groove between said first and second protrusions running along the length of the joint, and

wherein the flexible membrane has

first and second surfaces, the first surface facing away from the rigid material and being unsupported, the second surface facing towards the rigid base and having a protrusion extending into the rigid material'"'"'s groove,

the flexible membrane and the rigid material having been ultrasonically welded together, and

wherein a portion of the rigid material'"'"'s first protrusion overlaps some of the flexible membrane'"'"'s protrusion in the rigid material'"'"'s groove so that a portion of the flexible membrane is between the first protrusion and the rigid base and a portion of the first protrusion is between the flexible membrane'"'"'s protrusion and the membrane'"'"'s first surface.

3. A joint according to claim 2, wherein a portion of the rigid material'"'"'s second protrusion also overlaps some of the flexible membrane'"'"'s protrusion in the rigid material'"'"'s groove so that a portion of the flexible membrane is between the second protrusion and the rigid base and a portion of the second protrusion is between the flexible membrane'"'"'s protrusion and the membrane'"'"'s first surface.

4. A joint according to claim 3, wherein the rigid material is acrylic and the flexible membrane is polyvinyl chloride.