Originally Posted by
quiltedsunshine
The spring goes in the side first. Then the tab goes into the slot with the bump covering the spring. The hinge is open. Then you push the hinge back as hard as you can. Then flip the hinge closed. If the next time you flip the tab, it falls apart again, then the hinge is bent and you won't be able to repair it. I believe the Kenmore JO1313 bobbin case would replace it very well. The retail for about $3.00.
That is how I remember it. On the particular BC I worked on after everything was put in place a small screw was screwed into the finger tab from the bobbin side or back end. This kept the works from flying out. There is a anvil like BC holder that makes the screwdriving easier. The bobbin case was for a Singer 95 and 96 industrial so construction might vary from Class 15.