Securing machine parts together with the aid of connecting pins

• US 5,046,246 A
• Filed: 09/12/1990
• Issued: 09/10/1991
• Est. Priority Date: 09/12/1990
• Status: Expired due to Term

• Current Assignee: Siemens Energy Incorporated (Siemens AG)
• Original Assignee: Westinghouse Electric Company LLC (Brookfield Asset Management Incorporated)
• Inventors: Freudenthal, Jon P., Reames, Eddie J., Lloyd, Phillip D., Shepard, Spencer H., Partington, Albert J.
• Primary Examiner(s): Echols, P. W.
• Assistant Examiner(s): Bryant, David P.
• Application Number:
  US07/580,990
• Time in Patent Office: 363 Days
• Field of Search: 29/889, 29/889.2, 29/889.21, 29/889.71, 29/890.125, 29/407, 29/433, 29/447, 29/525, 29/525.1, 29/418, 416/217, 416/220 R
• US Class Current: 29/889.21
• CPC Class Codes: F01D 5/3053 by means of pins
• CPC Class Codes: Y10T 29/49321 Assembling individual fluid flow interacting members, e.g., blades, vanes, buckets, on rotary support member
• CPC Class Codes: Y10T 29/49337 Composite blade
• CPC Class Codes: Y10T 29/49776 Pressure, force, or weight determining
• CPC Class Codes: Y10T 29/49799 Providing transitory integral holding or handling portion
• CPC Class Codes: Y10T 29/49838 by stringing
• CPC Class Codes: Y10T 29/49865 by temperature differential [e.g., shrink fit]
• CPC Class Codes: Y10T 29/49945 by driven force fit

Abstract

Machine parts are connected together to form an assembly by means of pins which form an interference fit with passages in the parts and whose ends are flush with two opposed surfaces of the assembly. Each pin is provided with an annular groove spaced from one end of the pin by a distance equal to the distance between the opposed surfaces. A positioning member is seated in the groove and the pin is inserted into an associated passage so that the positioning member bears against one opposed surface. After a tight fit is achieved, the protruding portion of the pin is broken away.

A device is provided for testing the tightness of an inserted pin. The device may engage the annular groove and apply a tensile test force. Alternatively, after the end of the pin has been broken away, the device may bear against the end of the remaining pin portion and apply a compressive test force.

Claims

1. A method for securing machine parts together to form an assembly having two opposed surfaces, the parts being formed to define a passage receiving at least one connecting pin which extends between, and is substantially flush with, the two opposed surfaces of the assembly, comprising;

providing a connecting pin having a length greater than the distance between the two opposed surfaces;

forming a groove in the connecting pin at a distance from a first end of the pin which is equal to the distance between the two opposed surfaces;

mounting a positioning member in the groove and inserting the pin into the passage so that the first end is flush with one opposed surface and the positioning member bears against the other opposed surface; and

breaking off the pin at the groove so that the portion of the pin between the first end and the groove remains secured in the passage.

2. A method as defined in claim 1 further comprising removing the positioning member from the groove after said step of inserting and before said step of breaking off.

3. A method as defined in claim 1 further comprising temporarily shrinking the pin prior to said step of inserting.

4. A method as defined in claim 1 wherein said step of inserting is carried out so that a portion of the pin remote from the first end projects away from the other opposed surface of the assembly, and said step of breaking off is carried out to remove substantially the entire projecting portion of the pin.

5. A method as defined in claim 4 wherein said step of breaking off is carried out by striking the projecting portion of the pin in a direction transverse to the length of the pin.

6. A method as defined in claim 1 further comprising providing the pin with a weakened region at a location which will be flush with the other opposed surface of the assembly when the positioning member bears against the other opposed surface.

7. A method as defined in claim 1 further comprising, after said step of inserting, and before said step of breaking off, testing the resistance of the pin to movement in the passage.

8. A method as defined in claim 7 wherein said step of testing comprises removing the positioning member from the groove, engaging the groove with a tensile force gage, and applying a tensile force to the pin via the gage.

9. A method as defined in claim 8 wherein the gage has a force indicator and said step of testing further comprises monitoring the force indicator during said step of applying a tensile force.

10. A method as defined in claim 1 further comprising, after said step of breaking off, applying a controlled compressive force to the pin in the direction of the length of the pin in order to test the resistance of the pin to movement in the passage.

11. A method as defined in claim 10 wherein said step of applying a compressive force to the pin comprises engaging one end of the pin with a compressive force gage, and applying the compressive force to the pin via the gage.

12. A method as defined in claim 11 wherein the gage has a force indicator and said step of applying a compressive force further comprises monitoring the force indicator while applying the compressive force.