Method for manufacturing long, slender lamina stack from nonuniform laminae

• US 6,163,949 A
• Filed: 10/12/1999
• Issued: 12/26/2000
• Est. Priority Date: 06/05/1996
• Status: Expired due to Term

• Current Assignee: L.H. Carbide Corporation (L.H. Industries Corp.)
• Original Assignee: L.H. Carbide Corporation (L.H. Industries Corp.)
• Inventors: Neuenschwander, Thomas R.
• Primary Examiner(s): Young, Lee
• Assistant Examiner(s): Chang, Rick Kiltae
• Application Number:
  US09/416,446
• Time in Patent Office: 441 Days
• Field of Search: 29/521, 310/216, 310/217, 428/64, 428/65, 428/133
• US Class Current: 29/521
• CPC Class Codes: B21D 28/02 Punching blanks or articles with or without obtaining scrap cutting nails or pins from strips or sheet material B21G3/26; Notching
• CPC Class Codes: B21D 28/10 Incompletely punching in such a manner that the parts are still coherent with the work
• CPC Class Codes: B21D 28/22 Notching the peripheries of circular blanks, e.g. laminations for dynamo-electric machines
• CPC Class Codes: B21D 28/246 Selection of punches
• CPC Class Codes: B21D 35/00 Combined processes according to or processes combined with methods covered by groups B21D1/00 - B21D31/00 B21D21/00 takes precedence
• CPC Class Codes: H02K 15/024 with slots
• CPC Class Codes: H02K 2201/09 Magnetic cores comprising laminations characterised by being fastened by caulking
• CPC Class Codes: Y10T 29/49009 Dynamoelectric machine
• CPC Class Codes: Y10T 29/49012 Rotor
• CPC Class Codes: Y10T 29/49078 Laminated
• CPC Class Codes: Y10T 29/49936 Surface interlocking
• CPC Class Codes: Y10T 29/53143 Motor or generator
• CPC Class Codes: Y10T 29/5317 Laminated device
• CPC Class Codes: Y10T 428/24289 Embedded or interlocked

Abstract

A method of manufacturing an elongate stack of interlocked laminae in a die assembly. The method includes the steps of stamping a first lamina having generally opposed first and second edges in the strip stock material, stamping at least one first interlock means for engaging another lamina in the first lamina, separating the first lamina from the strip stock material, placing the first lamina into the choke passageway, the first and second edges of the first lamina frictionally engaging the choke passageway, stamping a second lamina having first and second elongate edges in the strip stock material, stamping at least one second interlock means for engaging another lamina in the second lamina, at least partially engaging the first and second interlocking means, separating the second lamina from the strip stock material, placing the second lamina into the choke passageway, and frictionally engaging the choke passageway along the first and second elongate edges of only one of the first and second laminae.

Claims

1. A method of manufacturing an elongate stack of interlocked laminae in a die assembly having means for guiding strip stock material through the die assembly, stamping means and a choke passageway, said method comprising the steps of:

stamping a first lamina, said first lamina having a first outside perimeter shape and having generally opposed first, second, third, and fourth edges in the strip stock material;

stamping at least one first interlock element in the first lamina;

separating the first lamina from the strip stock material;

placing the first lamina into the choke passageway;

stamping a second lamina, said second lamina having a second outside perimeter shape, which is different than said first outside perimeter shape, and having first, second, third, and fourth edges in the strip stock material;

stamping at least one second interlock element in the second lamina;

at least partially engaging the first and second interlock elements;

separating the second lamina from the strip stock material;

placing the second lamina into the choke passageway; and

frictionally engaging the choke passageway along the third and fourth edges of only one of the first and second laminae.

2. The method of claim 1, further comprising a step of stamping one of a notch and a protrusion at one of the first and second edges of one of the first and second laminae.

3. The method of claim 2, wherein said step of stamping one of a notch and a protrusion occurs at a die assembly blanking station.

4. The method of claim 2, further comprising one of a step of sliding a notch provided in a lamina over a ridge provided in the choke passageway and a step of sliding a protrusion provided on a lamina in a groove provided in the choke passageway.

5. The method of claim 1, further comprising a step of urging the second lamina into complete interlocking engagement with the first lamina after the step of at least partially engaging the first and second interlock elements.

6. The method of claim 1, wherein one of the first and second interlock elements comprises a protuberance extending from a first surface of one lamina, and an other of the first and second interlock elements comprises a recess provided in a second surface of another lamina, the first and second surfaces disposed adjacent one another, the protuberance received in the recess.

7. A method of manufacturing an elongate stack of interlocked laminae in a die assembly having means for guiding strip stock material through the die assembly, stamping means and a choke passageway, said method comprising the steps of:

stamping a first lamina in the stock material;

stamping at least one first interlock element in the first lamina;

separating the first lamina from the strip stock material to yield a first laminar segment, said first segment having a first outside perimeter shape which has a first edge;

placing the first laminar segment into the choke passageway;

stamping a second lamina in the stock material;

stamping at least one second interlock element in the second lamina;

at least partially engaging the first and second interlocking elements;

separating the second lamina from the strip stock material to yield a second laminar segment having a second outside perimeter shape which has a first edge said second perimeter shape different than the first outside perimeter shape; and

placing the second laminar segment into the choke passageway, the first edge of only one of the first and second laminar segments frictionally engaging the choke passageway.

8. A method of manufacturing an elongate stack of interlocked laminae in a die assembly having means for guiding strip stock material through the die assembly, stamping means and a choke passageway, said method comprising the steps of:

stamping a first lamina, said first lamina having a first outside perimeter shape and having generally opposed first, second, third, and fourth edges in the strip stock material;

separating the first lamina from the strip stock material;

placing the first lamina into the choke passageway;

stamping a second lamina, said second lamina having a second outside perimeter shape, which is different than said first outside perimeter shape, and having first, second, third, and fourth edges in the strip stock material;

at least partially engaging the first and second laminae;

separating the second lamina from the strip stock material;

placing the second lamina into the choke passageway;

and frictionally engaging the choke passageway along the third and fourth edges of only one of the first and second laminae.

9. A method of manufacturing a stack of attached laminae in a progressive die assembly having means for guiding planar stock material through the progressive die assembly, stamping means and a choke passageway, said method comprising the steps of:

feeding the stock material progressively through a plurality of stations in the die assembly;

stamping a first lamina having a first outer perimeter configuration in the stock material at a first station;

separating the first lamina from the stock material;

placing the first lamina into the choke passageway;

stamping a second lamina having a second outer perimeter configuration which differs from the first outer perimeter configuration in the stock material;

separating the second lamina from the stock material;

placing the second lamina into the choke passageway;

attaching the first and second lamina to each other;

engaging the choke passageway with at least one of the first and second laminae; and

obtaining the completed stack, which comprises attached first and second laminae, from the progressive die assembly.

10. The method of claim 9, wherein said engaging step comprises engaging a surface of the choke passageway with an edge of at least one of the first and second laminae.

11. The method of claim 9, wherein one of the first and second outer perimeter configurations is substantially devoid of sharp edges.

12. The method of claim 11, wherein one of the first and second outer perimeter configurations is substantially rounded.

13. The method of claim 9, wherein the first and second outer perimeter configurations are substantially similar in shape and differ in size.

14. The method of claim 9, wherein said attaching step comprises mechanically interlocking the first and second laminae together.

15. The method of claim 9, wherein at least one of the first and second laminae are substantially elongate.

16. A method of manufacturing a stack of interlocked laminae in a die assembly having means for guiding strip stock material through the die assembly, stamping means and a choke passageway, said method comprising the steps of:

stamping a first lamina having a generally circular edge of a first diameter in the strip stock material;

separating the first lamina from the strip stock material;

placing the first lamina into the choke passageway;

stamping a second lamina having a generally circular edge of a second diameter which differs from the first diameter in the strip stock material;

at least partially engaging the first and second laminae;

separating the second lamina from the strip stock material;

placing the second lamina into the choke passageway;

and frictionally engaging the choke passageway along the generally circular edge of only one of the first and second laminae.