T-peel test fixture

Patent metadata

Field	Value
Publication number	US-10078046-B2
Application number	US-201615139888-A
Country	US
Kind code	B2
Filing date	Apr 27, 2016
Priority date	May 6, 2015
Publication date	Sep 18, 2018
Grant date	Sep 18, 2018

Abstract

T-peel test fixture for a vertical test machine. The test fixture includes an upper grip for holding an arm of a peel specimen that has a hangover tail and a lower grip for holding the other arm of the peel specimen. A first rack is connected to a support hanger. The upper grip and the first rack move in a vertical direction at a selected speed. A second rack including a support plate located to support the specimen hangover tail is driven in the vertical direction at one-half the selected speed. The fixture thus supports the hangover tail so that symmetry is maintained with respect to gravity to suppress the interfering effect of gravity on a peel test.

First claim

What is claimed is:

1. T-peel test fixture for use with a vertical test machine comprising;
an upper grip for holding an arm of a peel specimen that has a hangover tail;
a lower grip for holding the other arm of the peel specimen;
a first rack attached to a support hanger, wherein the first rack and the upper grip move in a vertical direction at a selected speed; and
a second rack including a support plate located to support the peel specimen hangover tail, the second rack being driven in the same vertical direction as the first rack at one-half the selected speed;
whereby symmetry of the hangover tail is maintained to suppress the effect of gravity.

2. The T-peel test fixture of claim 1 , wherein a gear train drives the racks and includes two spur gears, one spur gear having twice as many teeth as the other spur gear.

3. The T-peel test fixture of claim 1 , wherein at least one of the upper grip and the lower grip are configured to hold the respective arm by grasping the respective arm of the peel specimen.

4. The T-peel test fixture of claim 3 , wherein grasping the respective arm of the peel specimen further comprises clamping the respective arm of the peel specimen.

5. The T-peel test fixture of claim 1 , further comprising:
a first gear driven by a first shaft, the first gear being coupled to the first rack and having a plurality of teeth;
a second gear driven by a second shaft, the second gear having a plurality of teeth that is twice the amount of teeth as the first gear; and
a third gear coupled to the second shaft and the second rack, the third gear having a plurality of teeth that is half the amount of teeth as the second gear such the second rack is driven in the vertical direction at one-half of the selected speed of the first rack.

6. The T-peel test fixture of claim 1 , wherein the T-peel test fixture is configured such that testing of the peel specimen occurs in only a single mode.

7. The T-peel test fixture of claim 1 , wherein the support plate is configured to support the hangover tail of the peel specimen by supporting the peel specimen across at least a quarter of the length of the peel specimen to suppress the effect of gravity.

8. A test fixture, comprising:
an upper grip for engaging a first arm of a peel specimen that has a hangover tail;
a lower grip for engaging a second arm of the peel specimen;
a first rack attached to a support hanger, the first rack and the upper grip being configured to move vertically such that the movement is substantially perpendicular to a longitudinal axis extending through a substantial length of the peel specimen;
a second rack configured to move vertically such that the movement is substantially perpendicular to the longitudinal axis extending through a substantial length of the peel specimen, the second rack having a longitudinal axis that extends vertically along a length of the second rack; and
a support plate coupled to the second rack, the support plate having a length that extends substantially perpendicular to the longitudinal axis of the second rack such that a face of the plate that likewise has a length that extends substantially perpendicular to the longitudinal axis is configured to support the hangover tail of the peel specimen by supporting the peel specimen across at least a quarter of the length of the peel specimen.

9. The test fixture of claim 8 , further comprising a gear train configured to drive the first and second racks, the gear train including at least two spur gears, one spur gear having twice as many teeth as the other spur gear.

10. The test fixture of claim 8 , wherein the test fixture is configured to perform a T-peel test in which the peel specimen forms a T-like shape between symmetrical interfaces during operation of the test fixture with the peel specimen.

11. The test fixture of claim 8 , wherein at least one of the upper grip and the lower grip are configured to hold the respective arm by grasping the respective arm of the peel specimen.

12. The test fixture of claim 11 , wherein grasping the respective arm of the peel specimen further comprises clamping the respective arm of the peel specimen.

13. The test fixture of claim 8 , further comprising:
a first gear driven by a first shaft, the first gear being coupled to the first rack and having a plurality of teeth;
a second gear driven by a second shaft, the second gear having a plurality of teeth that is twice the amount of teeth as the first gear; and
a third gear coupled to the second shaft and the second rack, the third gear having a plurality of teeth that is half the amount of teeth as the second gear such the second rack is driven in the vertical direction at one-half of the selected speed of the first rack.

14. The test fixture of claim 8 , wherein the test fixture is configured such that testing of the peel specimen occurs in only a single mode.

15. The text fixture of claim 8 , wherein supporting the peel specimen across at least a quarter of the length of the peel specimen suppresses the effect of gravity.

16. A test fixture, comprising:
an upper grip for engaging a first arm of a peel specimen that has a hangover tail;
a lower grip for engaging a second arm of the peel specimen;
a first rack attached to a support hanger and having a first longitudinal axis extending through a substantial length thereof, the first rack being configured to move vertically along a length of the first longitudinal axis with the upper grip moving in a same direction as the first rack;
a second rack disposed substantially parallel to the first rack such that a second longitudinal axis extending through a substantial length of the second rack is substantially parallel to the first longitudinal axis, the second rack being configured to move vertically along a length of the second longitudinal axis; and
a support plate coupled to the second rack and located to support the peel specimen hangover tail,
wherein the first rack and the second rack are collinear along a horizontal axis extending substantially parallel to a longitudinal axis extending through a substantial length of the peel specimen.

17. The text fixture of claim 16 ,
wherein the first rack extends above a top face of the support plate that is configured to receive the peel specimen hangover tail and below a bottom face of the support plate that is opposed to the top face, and
wherein the second rack extends above the top face of the support plate and below the bottom face of the support plate.

18. The test fixture of claim 16 , further comprising a gear train configured to drive the first and second racks, the gear train including at least two spur gears, one spur gear having twice as many teeth as the other spur gear.

19. The test fixture of claim 16 , wherein the test fixture is configured to perform a T-peel test in which the peel specimen forms a T-like shape between symmetrical interfaces during operation of the test fixture with the peel specimen.

20. The text fixture of claim 16 , wherein at least one of the upper grip and the lower grip are configured to hold the respective arm by grasping the respective arm of the peel specimen.

21. The test fixture of claim 20 , wherein grasping the respective arm of the peel specimen further comprises clamping the respective arm of the peel specimen.

22. The test fixture of claim 16 , further comprising:
a first gear driven by a first shaft, the first gear being coupled to the first rack and having a plurality of teeth;

Assignees

• Massachusetts Inst Technology

Inventors

• Padhye Nikhil
• Parks David M

Classifications

• G01N19/04 Primary

  Measuring adhesive force between materials, e.g. of sealing tape, of coating · CPC title

• G01N3/08

  by applying steady tensile or compressive forces (G01N3/28 takes precedence) · CPC title