Pneumatically-operated repetition riveting tool

1. A hydro-pneumatically operated repetition riveting tool, which tool includes:

gripping means for releasably gripping an elongated mandrel at a position remote from the mandrel head, which gripping means comprises a housing with an internal taper, and a plurality of mandrel-gripping jaws which are urged into contact with the mandrel by means of the internal taper;

hydraulic retraction means for retracting the mandrel, thereby to pull the head of the mandrel through a rivet on the mandrel and adjacent the head, thereby to place the rivet;

return means for returning the mandrel forwardly again after placing a rivet;

and rivet feeding means for feeding rivets forwardly towards the mandrel head;

in which the return means is pneumatically powered;

and in which the housing of the gripping means comprises a first part and a second part, spring means for urging the first and second parts relatively apart from each other, and limiting means for limiting the movement apart of the first and second parts under the urging of the spring means.

2. A tool as claimed in claim 1 , in which the gripping means also provides the return means.

3. A tool as claimed in claim 2 , in which the return and gripping means is pneumatically powered by air which is routed to it between two concentric cylindrical sleeves, one of which has a closed end.

4. A tool as claimed in claim 1 , in which the rivet-feeding means comprises a pneumatically operated piston, which tool includes a space which can accommodate, at different stages in the operation of the tool, either a part of the rivet feeding means or a part of the mandrel gripping means.

5. A tool as claimed in claim 4 , together with means for independently controlling the feed of pneumatic pressure to the rivet feeding means, whereby air loss through the aforesaid space is minimized.

6. A tool as claimed in claim 1 , including means for supplying additional pneumatic pressure to assist in the return of the mandrel forwardly as aforesaid.

7. A tool as claimed in claim 1 , which is constructed around a block having running through it the necessary air feed bores or channels.

8. A tool as claimed in claim 1 , in which the gripping means also provides the return means, and the rivet-feeding means comprises a pneumatically operated piston, and including means for supplying additional pneumatic pressure to assist in the return of the mandrel forwardly as aforesaid, the tool being constructed around a block, which block contains three bores or channels, the first of which provides means for supplying pneumatic pressure to the gripping and return means, the second of which provides means for supplying pneumatic pressure to the rivet feeding means, and the third of which provides the aforesaid means for supplying the aforesaid additional pneumatic pressure to assist in return of the mandrel.

9. A tool as claimed in claim 1 , including hydraulic connection means for connecting hydraulic power to the hydraulic retraction means, which connection means is interchangeable with other connection means of a different external configuration, thereby to provide the optimum configuration for handling and operation of the tool.