US-12618616-B2 - Heater system for catheter manufacturing

US12618616B2US 12618616 B2US12618616 B2US 12618616B2US-12618616-B2

Abstract

The invention is directed to a heating assembly for catheter manufacture which includes a heating element having a central vertical passage and a plurality of gas flow passages in communication with the central passage. The passages are at an angle relative to the central passage increasing heat transfer surface area. The invention may also include an iris assembly. The iris assembly includes a plurality of discs having slits which are offset relative to another disc. The invention may also include an insulation chamber surrounding the heating element. The flow of gas previously heated by the exterior of the thermos coupler and heating element is restricted by the insulation chamber for passage through the gas flow passages and into the central passage, so that the gas receives additional heat for exposure to sheathing material to be bound to a catheter.

Inventors

Edward John Matthees

Assignees

Edward John Matthees

Dates

Publication Date: 20260505
Application Date: 20230711

Claims (17)

1 . A heating assembly for a catheter manufacture machine, said heating assembly comprising: an elongate heating element having a outer diameter, a central vertical passage, an upper end and a lower end, said heating element having a longitudinal axis, said central vertical passage extending in the direction of said longitudinal axis, said central vertical passage being centrally disposed relative to said heating element traversing said upper end and said lower end; and a plurality of first gas flow passages traversing said outer diameter, said first gas flow passages extending from said outer diameter at an angle relative to said longitudinal axis traversing an inner diameter of said central vertical passage proximate to said upper end, wherein said first gas flow passages traversing said outer diameter are constructed and arranged as a gas inlet and said first gas flow passages traversing said inner diameter are constructed and arranged as a gas outlet for gas entering into the central vertical passage, said first gas flow passages traversing said outer diameter at a first distance from said upper end which is larger than a second distance between said first gas flow passages traversing said inner diameter and said upper end, said first gas flow passages being further constructed and arranged for passage of previously heated gas exterior to said heating element into said central vertical passage.
2 . The heating assembly according to claim 1 , said heating element further comprising a plurality of second gas flow passages traversing said outer diameter, said second gas flow passages extending from said outer diameter at an angle relative to said longitudinal axis traversing said inner diameter proximate to said lower end.
3 . The heating assembly according to claim 2 , wherein said second gas flow passages traversing said outer diameter are constructed and arranged as a second gas inlet and said second gas flow passages traversing said inner diameter are constructed and arranged as a second gas outlet for said gas entering into said central vertical passage, said second gas flow passages traversing said outer diameter at a third distance from said lower end which is smaller than a fourth distance between said second gas flow passages traversing said inner diameter and said lower end, said second gas flow passages being further constructed and arranged for passage of said previously heated gas exterior to said heating element into said central vertical passage.
4 . The heating assembly according to claim 3 , wherein at least one of said central vertical passage, said first gas flow passages and said second gas flow passages comprising surface area increasing geometries.
5 . The heating assembly according to claim 4 , wherein said heating element is formed of copper alloy material.
6 . The heating assembly according to claim 5 , said heating assembly further comprising an iris/variable orifice positioned below said lower end.
7 . The heating assembly according to claim 6 , said iris/variable orifice comprising a plurality of sealing discs, each of said sealing discs having a plurality of centrally located slits and a primary slit.
8 . The heating assembly according to claim 7 , wherein said primary slit on a first sealing disc is positioned in a first direction and said primary slit on a second sealing disc is positioned at a second direction offset relative to said first direction.
9 . The heating assembly according to claim 8 , wherein said primary slit on a third sealing disc is positioned in a third direction, said third direction being offset relative to said first direction and said second direction.
10 . The heating assembly according to claim 9 , wherein a catheter body and sheathing material are centrally disposed along said longitudinal axis within said central vertical passage and said catheter body and said sheathing material pass centrally through said iris/variable orifice.
11 . The heating assembly according to claim 10 , said heater assembly further comprising a insulation chamber having a insulation chamber interior, said heating element being positioned in said insulation chamber interior.
12 . The heating assembly according to claim 11 , said heating assembly further comprising a bottom plate, said insulation chamber comprising a front panel, a rear panel, a left panel, and a right panel extending upwardly from said bottom plate, said bottom plate supporting said heating element.
13 . The heating assembly according to claim 12 , said bottom plate having a centrally located bottom plate catheter orifice, wherein said catheter body and said sheathing material enter said central vertical passage through said bottom plate catheter orifice.
14 . The heating assembly according to claim 13 , said heating assembly further comprising a top plate, said top plate having a centrally aligned top plate gas outflow opening, wherein said catheter body and said sheathing material exit said central vertical passage proximate to said top plate gas outflow opening.
15 . The heating assembly according to claim 14 , said bottom plate having a plurality of lower openings.
16 . The heating assembly according to claim 15 , wherein said iris/variable orifice is disposed below and is in contact with said bottom plate proximate to said bottom plate catheter orifice.
17 . The heating assembly according to claim 16 , wherein said insulation chamber restricts escape of heated gas from said insulation chamber interior, said heated gas within said insulation chamber interior entering into said first gas flow passages and said second gas flow passages for inflow into said central vertical passage.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Patent Application Ser. No. 63/388,280 filed Jul. 12, 2022 the entire contents of which being incorporated by reference herein in its entirety. FIELD OF THE INVENTION A heater assembly for the main tubular body of a medical catheter manufacturing device. BACKGROUND During the formation of the main tubular body of a medical catheter, a heating element is activated and drawn along a vertically disposed multi-layered catheter body. The heating element is used to heat shrink a polymer around the exterior of the main catheter body shaft as well as heating the multi-layers of the catheter body. The shrink polymer is not a component of the finished catheter its purpose is to transmit heat energy to and provide radial compression force to bond or reflow the multi layers of the finished catheter body forming a contiguous tube/catheter for future use in a medical procedure. The shrink polymer is removed after the catheter has been heat processed. In the past some catheter manufacturing devices required that the inner heating element be cooled prior to a size exchange during the formation of a larger or smaller diameter catheter. The external stainless-steel component of the heating element for the known catheter manufacturing devices also served as an attachment point for the catheter manufacturing device and functioned as the interface between the resistive element heat source and thermo-couple mount, increasing alignment and quality control difficulties in alignment between the center line of the inside diameter of the heating element and the catheter body and sheathing material combination. The external stainless-steel component of the heating element for the known catheter manufacturing devices has a low coefficient of thermal conductivity and provides inefficient conductive heat transfer during the catheter formation process. The known catheter manufacturing devices required a manual stabilization procedure after the loading of the components of the catheter body and sheathing material prior to the formation process. Also, the known catheter manufacturing devices were deficient in the stabilization and the centering of the catheter body and to the sheathing material relative to the heating unit prior to and during the catheter sheathing process. In addition, the inner heating element for the known catheter manufacturing devices is relatively large with respect to the catheter being manufactured, resulting in inconsistencies in positioning, leading to non-uniform heating about the circumference and deviations in tolerances, adversely effecting the sheathing procedure resulting in a percentage of scrap from this process. Most catheter manufacturing devices process multiple catheters per cycle by means of duplicate heating elements mounted on one moving carriage. Other known catheter manufacturing devices have also required the inclusion of an extender mandrill and heat shrink to prevent pre-heating of the catheter body and sheathing material as loaded in the 1st, 2nd, 3rd and/or remaining 10 positions, prior to a heating cycle initiation. Also, the air heated by the known heating elements has well over half of its heat energy not used for processing product. Known catheter manufacturing devices have electrical resistive heaters which are at least two times as long and at least twice the diameter of the envisioned device. Known catheter manufacturing devices resistive heaters capacity is needed to heat the stainless-steel tube which in turn heats the exchangeable inner copper alloy tube. This waste heat produced by the outer surfaces of the resistive heater, stainless steel tube and minimal amount from the top and bottom of the copper alloy tube is dissipated into the surrounding environment which leads to higher cooling costs for the controlled environments needed for the sterile manufacturing of the catheters. In many known catheter manufacturing devices ambient or cool air enters the heating element proximate to a bottom, and the air is heated by the interior of the heating element. The heated air effectuates a heat transfer to the sheathing polymers and the catheter body. The lower portion of the heating element does not heat the ambient or cool air to desired temperature instantly, where a lower portion length of the heating element is not able to transfer sufficient energy to shrink the sheathing polymers to the catheter body nor transfer sufficient heat for fusion to the catheter body layers. Similarly some of the upper portion of the heating element cannot provide the required processing temperature for catheter formation. In the known catheter manufacturing devices most air heated is dissipated into the surrounding environment as waste heat. The art referred to and/or described above is not intended to constitute an admission that any patent, publication or other information referred to herein is “prior art” wit