And the very reason I brought them up is the thermal cycling they will have to undergo when used in a battery system.....................where the board is mounted to the battery as in this case rather than the other way around which is more usual. They are also extremely useful in the contact connections between power supplies and the busbar in high current applications for the same reasons. John -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Brooks,Bill Sent: Monday, June 26, 2006 12:48 PM To: [log in to unmask] Subject: Re: [TN] Belleville washer history http://www.raymondasia.com/cat_belleville.htm Depending on the application... they are useful in mounting things that must not come loose under vibration or extreme variations in temperature... they maintain a fairly constant pressure against the mounting surfaces and fasteners... Very useful indeed... not old or outdated at all. Bill Brooks PCB Design Engineer, C.I.D.+ Tel: (760)597-1500 Fax: (760)597-1510 Datron World Communications, Inc. Vista, California -----Original Message----- From: Stadem, Richard D. [mailto:[log in to unmask]] Sent: Monday, June 26, 2006 12:40 PM To: [log in to unmask] Subject: Re: [TN] Belleville washer history Au contraire. Spring washers are used in so many electronic devices that I cannot even begin to count them. Some applications that I know of are the space shuttle, cruise missiles, satellites, torpedoes, land mines, high-end audiophile stereo systems, medical devices, almost every computer ever made uses them to fasten the motherboard to the case. They are very, very common. They are used extensively on nearly every automobile ever made. -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Dehoyos, Ramon Sent: Monday, June 26, 2006 2:13 PM To: [log in to unmask] Subject: Re: [TN] Belleville washer history Apparently it is an old invention that is not very popular like the split or star washer. Unless you are in the race car arena or other circles where the Belleville washer is used, it is like a new invented washer. It is to me. Ramon -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Drew meyer Sent: Monday, June 26, 2006 2:37 PM To: [log in to unmask] Subject: [TN] Belleville washer history Lee, This is what I found during a search for the answer to your question. FROM:Belleville Springs Ltd Arthur Street, Lakeside REDDITCH Worcs B98 8JY United Kingdom Conical shaped disc springs were first conceived in the mid-1800's and the invention was subsequently called a Belleville Washer after its inventor Julian Belleville, who received a patent for the product in 1867. Drew Meyer --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------