So you are a design engineer, who urgently needs a coupling drawing to drop into an application you are working on, but can't seem to find the drawing online. What should you do?
First, before doing anything else, go to the coupling manufacturer's website and check out the product page for the product you are seeking out. In many cases, inclusive of Lovejoy, you will find that 3D STEP files are readily available.
Manufacturers generally make these readily available because they want to make life easy for designers, and little proprietary knowledge is at risk (given their STEP files are generally outline drawings with no tolerances). Worth noting, manufactures may and do change trivial dimensions on public drawings to make piracy much more difficult.
Assuming the manufacture does not have a STEP file available (or a STEP file is insufficient for you needs)...
1. Call the manufacturer and ask for an application specialist or engineer to discuss your specific application & need for a drawing. (Most multipurpose customer service agents will be reluctant to release potential proprietary knowledge, so elevating your case quickly is preferable.)
2. Once you get a hold of an application specialist, clearly identify who you are, what you are doing, why you need the drawing, and when you need it by. (Application engineers are specifically employed to help users, you, get the answers you need... but they also must ensure they are acting in the best interests of the company. The more open and honest you are in regarding your situation, the more comfortable they will be at going above and beyond to service you.)
3. If drawings are not readily available and/or the application specialist is unable/unwilling to provide the requested information... be prepared to communicate the impact of their inaction in dollars and cents. (Again, application engineers have a very vested interest in helping their company grow and remain profitable... and dollars should get their attention.)
4. As a last resort... should dollars and cents not get the application engineers attention, it will certainly gain the attention of that company's sales staff. Either by calling into the company or searching the company's website... identify and call the most relevant corporate sales person for you/your situation and repeat steps 2 and 3.
5. If steps 1 through 4 fail to get you the drawing you seek... throw in the towel with whatever manufacturer you've been calling... and contact Lovejoy! (Perhaps we should have made this step 1?)
Recommended Follow-On Reading: To refresh or increase your awareness of a broad range of coupling types, please consider checking out the following: Flexible Coupling Basics - A Quick Primer