Assembly method

• US 4,100,666 A
• Filed: 05/02/1977
• Issued: 07/18/1978
• Est. Priority Date: 05/02/1977
• Status: Expired due to Term

• Current Assignee: RM Formed Products Company
• Original Assignee: Modulus Corporation
• Inventors: Payne, William J.
• Primary Examiner(s): Gilden, Leon
• Application Number:
  US05/792,933
• Time in Patent Office: 442 Days
• Field of Search: 29/407, 29/705, 29/720, 73/1 B
• US Class Current: 29/407.04
• CPC Class Codes: G01L 1/02 by hydraulic or pneumatic means
• CPC Class Codes: Y10T 29/49769 Using optical instrument [excludes mere human eyeballing]
• CPC Class Codes: Y10T 29/53022 with means to test work or product
• CPC Class Codes: Y10T 29/53087 with signal, scale, illuminator, or optical viewer

Abstract

An assembly apparatus and method for use in the manufacture of strain indicators of the type in which a window and an indicator area are provided in a fluid filled capsule. Movement of the indicator area with respect to the window gives a visual indication of the load condition of the indicator. The assembly apparatus comprises means to provide for the initial placement of the fluid filled capsule into the tensile member of the strain indicator. Thereafter a compressive force is exerted on the capsule in order to bring the indicator area of the capsule in close proximity to the window with the tensile element in a relaxed condition. Following initial assembly the apparatus of this invention exerts a tensile pull on the tensile member of the strain indicator which causes the indicator area of the capsule to be separated from the window. Gap measuring means are employed to measure the distance between the window and the indicator area with the tensile element in a state of tension. Subsequently, adjustment means are utilized to adjust the gap to a predetermined value at load. The capsule is then fixed to the tensile member and the strain indicator is ready for use.

Claims

1. A method of assembly of a strain indicator comprising the steps of:

(a) providing a tensile element;

(b) providing an indicator, said indicator having means to produce a visual effect which is a function of the strain on said tensile element;

(c) inserting said indicator at least partially into said tensile element;

(d) exerting a tensile pull on said tensile element so as to create a visual effect at said indicator;

(e) optically measuring said visual effect with said tensile member under load;

(f) comparing the results of optical measurement with a standard;

whereby,

the quality of the strain indicator is verified under load.

2. A method of assembly of a strain indicator comprising the steps of:

(a) providing a tensile element;

(b) providing an indicator, said indicator having at least one element which is movable as a function of the strain on said tensile element, the movement of said element producing a visual effect;

(c) operatively interconnecting said indicator to said tensile element;

(d) exerting a tensile pull on said tensile element so as to create movement of said element of said indicator;

(e) optically measuring the degree of movement of said element of said indicator;

(f) comparing the results of optical measurement with a standard;

whereby,

the quality of the strain indicator is verified under load.

3. The method of claim 2 in which the degree of movement of said element of said indicator is measured relative to a fixed element.

4. The method of claim 3 in which there is provided after the comparing step (f) the additional step (g) of adjusting the degree of movement as optically measured under load to a standard.

5. A method of assembly of a strain indicator comprising the steps of:

(a) providing a tensile element having a recess at one end thereof;

(b) providing an indicator having a fixed reference and an indicator area movable with respect to said reference;

(c) providing means to move said indicator area relative to said reference as a function of the strain on said tensile element;

(d) inserting said indicator at least partially into said recess of said tensile element with said indicator area closely adjacent said reference;

(e) exerting a tensile pull on said tensile element so as to create a gap between said indicator area and said reference;

(f) measuring said gap with said tensile element under load;

(g) adjusting said gap to a predetermined value;

(h) releasing the tensile pull on said tensile element.

6. The method of claim 5 in which the tensile pull exerted on said tensile element has a magnitude approximately equal to the design load of said tensile element.

7. The method of claim 5 in which said measuring step (f) is performed by means of optical sensing means which senses a color change in said indicator area.

8. The method of claim 5 in which said adjusting step (g) is performed by moving said reference relative to said indicator area.

9. A method of assembly of a strain indicator comprising the steps of:

(a) providing a tensile element having a recess and an internal abutment means;

(b) providing a fluid filled capsule having a window and an indicator area movable with respect to said window with said capsule fixed to said tensile element, there being provided means at said capsule to bias said indicator area away from said window with said tensile element in a condition of strain, said internal abutment means of said tensile element coacting with said capsule to move said indicator area into close proximity to said window with said tensile element in a relaxed condition;

(c) inserting said capsule at least partially into said recess of said tensile element such that said capsule is in contact with said internal abutment means;

(d) exerting a compressive force on said capsule so as to bring said indicator area in close proximity to said window with said tensile element in a relaxed condition;

(e) exerting a tensile pull on said tensile element so as to create a gap between said window and said indicator area;

(f) measuring said gap with said tensile element under load;

(g) adjusting said gap to a predetermined value with said tensile element under load by means of a movement of said window relative to said indicator area;

(h) fixing said capsule relative to said tensile element; and

(i) releasing said tensile pull on said tensile element so as to cause said indicator area to return to a position of close proximity to said window.