| 摘要 |
Repetition pull-through blind riveting apparatus (10), of the type comprising a reusable and reloadable mandrel with an enlarged head which is pulled through each tubular rivet in turn to install the rivet is provided with a safety device (141) for counting the total number of times the mandrel has been pulled. The apparatus includes pneumatically-operated mandrel pulling means, and a counter (132) counts the number of times the pressure of the air powering the pulling device reaches a pressure slightly below that required to pull the mandrel head through a rivet. The counter (132) is arranged to actuate, when a safe limit number of pulls has been counted, both a shut-off valve (137) to shut-off the supply of pressure air to the mandrel pulling means, and a visual indicator (135). The visual Indicator (135) may be actuated at a warning count number rather lower than the safe limit number. The counter (132) can be reset to zero only by use of a separate key (142), when a new mandrel is installed in the rivet placing apparatus. |
