Method of joining structures made of incompatible polymers

Abstract

A first structure made of a first polymer is joined to a second structure made of an incompatible second polymer by the steps of welding small bands of compatible tubing or material to the first structure to create raised structures or ribs, and mechanically linking the second structure with the ribs or raised structures at the desired attachment point. The mechanical linkage may be accomplished by using heat shrinking or mechanical compression (such as crimping) to force the incompatible second polymer around the ribs or raised structures or, in the case of raised structures formed as threads or nubs, by inter-engagement between the threads or nubs on the first structure and corresponding structures, such as internal threading, nub-receiving slots, or internal surfaces, of the second structure. The option of using the welded raised structures as threads or nubs for a threaded, bayonet, pin-and-slot, snap-fit, or similar connection enables the second structure to be removed from the first structure and replaced whenever the second structure becomes worn during use. The first structure may be an surgical laser fiber with an ETFE buffer layer, and the second structure is a protective structure may be made of PTFE, PET, FEP or PFA.

Claims

1. A method of joining a first structure made of a first polymer to a second structure made of an incompatible second polymer, comprising the steps of: welding small bands of compatible tubing or material to the first structure to create raised structures or ribs; and mechanically linking the second structure made of the incompatible second polymer with the ribs or raised structures at a desired attachment point of the first and second structures.

2. The method of claim 1, wherein the step of mechanically linking the second structure with the ribs or raised structures comprises the step of using heat shrinking to force the incompatible second polymer around the ribs or raised structures.

3. The method of claim 1, wherein the step of mechanically linking the second structure with the ribs or raised structures comprises the step of using mechanical compression to force the incompatible second polymer around the ribs or raised structures.

4. The method of claim 1, wherein the ribs or raised structures form threads or nubs, and the step of mechanically linking the second structure with the ribs or raised structures comprising the step of attaching the second structure to the first structure by inter-engagement between the threads or nubs on the first structure and corresponding internal threading, nub-receiving slots, or surfaces of the second structure to form a threaded, bayonet, pin-and-slot, snap-fit, or otherwise removable connection.

5. The method of claim 1, wherein the first structure is an surgical laser fiber with an ETFE buffer layer, and the second structure is a protective structure to be attached to the ETFE buffer layer and made of an incompatible polymer.

6. The method of claim 1, wherein the incompatible polymer of the second structure is made of PTFE, PET, FEP or PFA.

7. The method of claim 1, wherein the first structure is made of ETFE and the second structure is made of PTFE, PET, FEP or PFA.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a side view of two structures made of incompatible polymers that have been joined by the method of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(2) Throughout the following description and drawings, like reference numbers/characters refer to like elements. It should be understood that, although specific exemplary embodiments are discussed herein there is no intent to limit the scope of present invention to such embodiments. To the contrary, it should be understood that the exemplary embodiments discussed herein are for illustrative purposes, and that modified and alternative embodiments may be implemented without departing from the scope of the present invention.

(3) As illustrated in FIG. 1, a surgical laser fiber is stripped to expose a buffer layer 1 and a core or core/cladding section 5. A soft protective structure 3 having a generally cylindrical shape is to be attached to the end section of the buffer layer 1. The soft protective structure 3 may have a standoff structure of the type disclosed in PCT Publication No. WO 2017/192869 or Provisional Patent Appl. Ser. No. 62/648,108, in which the distal end of the protective structure extends beyond a tip of the fiber to serve as a standoff that prevents contact between the tip of the fiber and a stone during laser lithotripsy, although the principles of the invention are not limited to protective structures that extend beyond the tip of a fiber, but instead may include guiding structures, ferrules, or any other polymer structure intended to be attached to the fiber.

(4) The buffer layer 1 is made of a first polymer such as ETFE, while the protective structure 3 is made of an incompatible polymer such as PTFE, PET, FEP or PFA. In order to attach the protective structure 3 to the buffer layer 1, bands of a material that is compatible with the material of the buffer layer 1, i.e., material that is compatible with ETFE in the illustrated example, is welded to the buffer layer 1 to form ribs, threads, or nubs 2. The material of the ribs, threads, or nubs 2 may be ETFE or another compatible material.

(5) The protective tip 3 may then be secured to the buffer 1 by one of two methods. The first attachment method is to use mechanical compression, such as provided by a heat shrink or crimp sleeve 4 to force material of the protective tip 3 around the ribs, threads, or nubs 2.

(6) The second attachment method is to utilize the welded-on bands as threads or nubs, and removably attach the protective tip 3 to the buffer layer 1 by pushing, twisting or turning in order to cause inter-engagement of internal threads, slots, or surfaces of the protective tip with the threads or nubs 2, resulting in a threaded, bayonet, push and twist, snap-fit, or similar removable connection or coupling between the protective tip and the optical fiber. In the case of a threaded connection, the protective tip may be also be rotated to adjust a distance or set back between the distal end of the protective tip and the distal end of the fiber.