Fit and finish methods

Patent metadata

Field	Value
Publication number	US-9623813-B2
Application number	US-201314079973-A
Country	US
Kind code	B2
Filing date	Nov 14, 2013
Priority date	Nov 14, 2013
Publication date	Apr 18, 2017
Grant date	Apr 18, 2017

Abstract

Fit and finish methods using shape memory polymers (“SMP”) are disclosed herein. In an example of the fit and finish method, a first part and a second part are positioned adjacent to one another such that a shape memory polymer in a temporary shape is adjacent to a gap between the first part and the second part. The SMP is heated to a switching temperature of the SMP, which causes the SMP to initiate conversion to a permanent shape so that the SMP extends into the gap to close the gap between the first part and the second part.

First claim

What is claimed is:

1. A fit and finish method, comprising:
positioning non-overlapping ends of a first part and a second part adjacent to one another such that a shape memory polymer in a temporary shape is adjacent to a gap between the non-overlapping ends of the first part and the second part; and
heating the shape memory polymer to a switching temperature of the shape memory polymer, thereby causing the shape memory polymer to initiate conversion to a permanent shape so that the shape memory polymer extends into the gap to close the gap between the non-overlapping ends of the first part and the second part.

2. The fit and finish method as defined in claim 1 wherein prior to positioning the first part and the second part, the method further comprises setting the temporary shape of the shape memory polymer by:
heating the shape memory polymer to the switching temperature;
applying a force to the heated shape memory polymer to conform the heated shape memory polymer to the temporary shape which is bent at an angle from an axis of the gap; and
cooling the shape memory polymer in the temporary shape below the switching temperature, thereby setting the shape memory polymer in the temporary shape.

3. The fit and finish method as defined in claim 1 , further comprising:
inserting a non-shape memory material lace strip into the gap before positioning the first part and the second part; and
locking the non-shape memory material lace strip in the gap upon initiating the conversion of the shape memory polymer to the permanent shape.

4. The fit and finish method as defined in claim 1 wherein:
the shape memory polymer is attached to at least a portion of a perimeter of the first part; and
the shape memory polymer in the permanent shape has a beveled edge that conforms to a beveled edge of a mating surface of the second part to form a seam between the first part and the second part.

5. The fit and finish method as defined in claim 1 wherein prior to positioning the first part and the second part, the method further comprises setting the temporary shape of the shape memory polymer by:
heating the shape memory polymer to the switching temperature;
applying a force to the heated shape memory polymer to conform the heated shape memory polymer to the temporary shape which has a dimension in a cross gap direction that is smaller than a dimension in the cross gap direction of the permanent shape; and
cooling the shape memory polymer in the temporary shape below the switching temperature, thereby setting the shape memory polymer in the temporary shape.

6. The fit and finish method as defined in claim 1 wherein:
the shape memory polymer is a shape memory polymer foam that is incorporated into an adjustable cap that is attached to the first part; and
prior to positioning the first part and the second part, the method further comprises setting the temporary shape of the shape memory polymer by:
heating the shape memory polymer foam to the switching temperature;
applying a force to the adjustable cap to conform the heated shape memory polymer foam to the temporary shape which has a dimension in a cross gap direction that is smaller than a dimension in the cross gap direction of the permanent shape; and
cooling the shape memory polymer foam in the temporary shape below the switching temperature, thereby setting the shape memory polymer foam in the temporary shape.

7. A fit and finish method, comprising:
heating a shape memory polymer in its temporary shape to a switching temperature of the shape memory polymer, thereby initiating a conversion of the shape memory polymer to a permanent shape; and
while the conversion is taking place, installing the shape memory polymer between non-overlapping ends of a first part and a second part so that when the shape memory polymer attempts to convert to the permanent shape, the shape memory polymer fills a gap between the non-overlapping ends of the first and second parts.

8. The fit and finish method as defined in claim 7 wherein:
prior to heating, the method further includes attaching the shape memory polymer in its temporary shape to a perimeter of the first part; and
installing the shape memory polymer between the first part and the second part includes inserting the first part having the shape memory polymer thereon into the second part.

9. The fit and finish method as defined in claim 7 wherein the shape memory polymer is a lace strip.

10. The fit and finish method as defined in claim 7 wherein:
the shape memory polymer is a band having a cap attached thereto;
prior to heating, the method further includes attaching the shape memory polymer in its temporary shape to an end of the first part; and
installing the shape memory polymer between the first part and the second part includes inserting the first part relative to the second part so that when the permanent shape is obtained, the cap is moved into contact with the second part.

11. The fit and finish method as defined in claim 7 wherein the shape memory polymer is a lace strip, and wherein prior to heating, the method further includes setting the temporary shape by:
heating the shape memory polymer to the switching temperature;
applying a force to the heated shape memory polymer to conform the heated shape memory polymer to a desired shape for the temporary shape; and
cooling the shape memory polymer below the switching temperature, thereby setting the shape memory polymer in the temporary shape.

12. The fit and finish method as defined in claim 11 wherein the temporary shape for the lace strip is narrower than the gap between the non-overlapping ends of the first and second parts.

13. The fit and finish method as defined in claim 11 wherein installing the shape memory polymer between the non-overlapping ends of the first part and the second part includes inserting the lace strip between the non-overlapping ends of the first and second parts so that when the permanent shape is obtained, the lace strip is moved into contact with the non-overlapping ends of the first part and the second part.

14. The fit and finish method as defined in claim 7 wherein the shape memory polymer is a coating on at least a portion of a non-shape memory material lace strip, and wherein prior to heating, the method further includes setting the temporary shape by:
heating the shape memory polymer to the switching temperature;
applying a force to the heated shape memory polymer to place the heated shape memory polymer on a surface of the non-shape memory material lace strip and to conform the heated shape memory polymer to a shape of the at least the portion of the non-shape memory material lace strip; and
cooling the shape memory polymer below the switching temperature, thereby setting the shape memory polymer in the temporary shape.

15. The fit and finish method as defined in claim 14 wherein the shape of the at least the portion of the lace strip is narrower than the gap between the non-overlapping ends of the first and second parts.

16. The fit and finish method as defined in claim 14 wherein installing the shape memory polymer between the non-overlapping ends of the first part and the second part includes inserting the at least the portion of the non-shape memory material lace strip having the shape memory polymer coating thereon between the non-overlapping ends of the first part and the second part.

17. The fit and finish method as defined in claim 3 wherein:
the first part is a windshield;
the non-shape memory material lace strip is a trim piece along a perimeter of th

Assignees

• Gm Global Tech Operations Llc

Inventors

• Browne Alan L
• Johnson Nancy L

Classifications

• B29C65/70

  by moulding (using a particular moulding technique, see the relevant technique {, e.g. by injection B29C45/14467}) · CPC title

• B29C65/00

  Joining {or sealing} of preformed parts {, e.g. welding of plastics materials}; Apparatus therefor {(general aspects of processes or apparatus for joining preformed parts B29C66/00; using porous material formed by internal pressure generated therein for joining preformed parts B29C44/1228, B29C44/326)} · CPC title

• B29C61/06

  Making preforms having internal stresses, e.g. plastic memory · CPC title

• B29C61/04

  Thermal expansion · CPC title

• B29L2031/3005

  Body finishings · CPC title