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(11) | EP 0 478 162 B1 |
| (12) | EUROPEAN PATENT SPECIFICATION |
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| (54) |
Rivet setting tool Nietsetzgerät Outil de rivetage |
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| Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention). |
[0001] The present invention relates to rivet setting tools which rely on air pressure as the motive force (see for example US-A-4 598 571).
[0002] It is generally understood by rivet tool operators that rivet tool speed is a function of the supplied air pressure and accordingly operators tend to increase air pressure to increase their throughput. Such tools however, are designed for operation within a selected pressure range and when operated above this range the mechanisms will wear at a high rate.
[0003] It is accordingly an object of the present invention to prevent rivet tool operation above the allowable pressure range.
[0004] Other objects and advantages of the present invention will become apparent from the following portion of this specification and from the accompanying drawing which illustrates in accordance with the mandate of the patent statutes a presently preferred embodiment incorporating the principles of the invention.
REFERRING TO THE DRAWINGS:
[0005]
Figure 1 is an elevational cross sectional view of a portion of a rivet tool made in accordance with the teachings of the present invention;
Figure 2 is a view similar to that of Figure 1 showing the valve in the open position.
[0006] The rivet setting tool 10 includes a molded trigger 12 pivotal about a trigger point 13 and having a cam surface 14 along its bottom for engaging a displaceable molded cam follower in the form of a cylindrical rod holder 16. Displaceable up and down within the vertical bore 17 of the rod holder 16 is a push rod 18 which is retained by a retaining pin 19 located within a suitable slot 20 in the push rod holder 16. Compressively located between the head portion 24 of the push rod and the bottom shoulder 26 of the rod holder are outer and inner springs 28. The ends of the slot 20 determine the fully retracted and fully extended positions of the push rod relative to the rod holder 16.
[0007] Located below this pressure regulator assembly is a conical face double acting poppet valve 30 which is supported within a suitable bore 32 which communicates with the bore 34 in which the pressure regulator assembly is located. In normal operation, when the trigger 12 is released (the fully illustrated position) pressurized inlet air from an external supply, which enters via an opening 36 into the poppet valve bore 32 below the valve, forces the lower valve seal 38 into a closed position elevating the pressure regulator assembly and returning the trigger to its deactivated position. At this time, air from the tool chamber will pass through a conduit 40, through the poppet valve and through the open exhaust side of the valve to an exhaust port 44. During normal operation, pulling the trigger will lower the pressure regulator assembly sealing the upper valve seal 46 against the valve body 48 and opening the inlet side connecting supply air through conduit 40 to the tool chamber.
[0008] The strength of the springs 28 is selected so that should inlet air pressure exceed a specified pressure the springs will compress allowing downward displacement of the rod holder 16 relative to the stationary push rod 18 when the trigger is depressed to activate the system. The inlet side of the valve accordingly will remain sealed and the outlet side will continue to connect the tool chamber to exhaust therefore preventing tool operation at an excessive pressure which could damage the tool.
a two way poppet valve (30) for alternately connecting an air line (40) from the tool chamber to inlet (36) and exhaust (44) lines, said valve (30) including a body (48) and a spool assembly having upper (46) and lower (38) valve seals,
a trigger (12) displaceable between release and depressed position and having a cam surface (14), and
a retractable rod assembly located between said trigger (12) and said spool assembly and displaceable between upper and lower positions including
a push rod (18) having a head portion (24), characterised in that the rod assembly further includes
rod holder means (16) for supporting said push rod (18) for selected movement between advanced and retracted positions relative to said rod holder means (16), and
spring means (28) compressively located between said push rod head portion (24) and said rod holder means (16) for maintaining said push rod (18) at said advanced position and for resisting displacement of said push rod (18) to said retracted position,
the strength of said spring means (28) being selected so that so long as the operating air pressure is less than a maximum pressure, depression of said trigger (12) will displace said rod assembly with said push rod (18) at said advanced position from said upper position to said lower position thereby opening the inlet side of said poppet valve (30) but that when the operating pressure exceeds the maximum pressure the pressure will overcome said spring (28) displacing said push rod (18) from said advanced position to said retracted position whereby the inlet side of said poppet valve (30) will be closed.
ein Zweiwege-Tellerventil (30) zum wechselnden Verbinden einer Luftleitung (40) von der Werkzeugkammer mit einer Einlaß-(36) und Auslaß-(44)-Leitung, wobei das Ventil (30) einen Körper (48) und eine Spulenanordnung mit einer oberen (46) und einer unteren (38) Ventildichtung aufweist,
einen Triggerschalter (12), der verschiebbar zwischen einer gelösten und einer gedrückten Position ist und eine Nockenoberfläche (14) hat, und
eine zurückziehbare Stangenanordnung, die zwischen dem Triggerschalter (12) und der Spulenanordnung angeordnet ist und die verschiebbar zwischen einer oberen und einer unteren Position ist, die eine Stößelstange (18) mit einem Kopfabschnitt (24) aufweist,
dadurch gekennzeichnet, daß
die Stangenanordnung des weiteren aufweist:
eine Stangenhalteeinrichtung (16) zum Stützen der Stößelstange (18) für eine ausgewählte Bewegung zwischen einer vorgezogenen und einer zurückgezogenen Position relativ zu der Stangenhalteeinrichtung (16), und
eine Federeinrichtung (28), die zusammendrückbar zwischen dem Kopfabschnitt (24) der Stößelstange und der Stangenhalteeinrichtung (16) angeordnet ist, und zwar zum Halten der Stößelstange (18) in der vorgezogenen Position und um einer Verschiebung der Stößelstange (18) in die zurückgezogene Position Widerstand entgegenzusetzen.
wobei die Stärke der Federeinrichtung (28) so ausgewählt ist, so daß, solange der Betriebsluftdruck kleiner als ein maximaler Druck ist, ein Drücken des Triggerschalters (12) die Stangenanordnung mit der Stößelstange (18) verschieben wird bei der vorgezogenen Position von der oberen Position in die untere Position, wodurch die Einlaßseite des Tellerventils (30) geöffnet wird, aber daß, wenn der Betriebsdruck den Maximaldruck übersteigt, der Druck die Feder (28) überwinden wird, was die Stößelstange (18) von der vorgezogenen Position in die zurückgezogene Position verschiebt, wodurch die Einlaßseite des Tellerventils (30) geschlossen werden wird.
- une soupape à champignon (30) à deux voies qui est destinée à relier alternativement une conduite d'air (40) de la chambre de l'outil à des conduites d'entrée (36) et d'échappement (44) et qui comprend un corps (48) et un ensemble tiroir ayant des garnitures d'étanchéité de soupape supérieure (46) et inférieure (38) ;
- une gâchette (12) mobile entre une position relâchée et une position pressée, et possédant une surface de came (14) ; et
- un ensemble tige rétractable qui est placé entre ces gâchettes (12) et ensemble
tiroir, qui peut se déplacer entre des positions supérieure et inférieure, et qui
comprend une tige poussoir (18) ayant une partie tête (24) ;
caractérisé en ce que l'ensemble tige comprend en outre
- un moyen (16) formant monture de tige, destiné à supporter cette tige poussoir (18) pour lui permettre de décrire un mouvement choisi entre une position avancée et une position rétractée par rapport à ce moyen (16) formant monture de tige ; et
- un moyen à ressort (28) placé en compression entre cette partie (24) de tête de la tige poussoir et ce moyen (16) formant monture de tige pour maintenir cette tige poussoir (18) dans cette position avancée et pour résister au déplacement de cette tige poussoir (18) vers cette position rétractée ;
- la force de ce moyen à ressort (28) étant choisie de manière qu'aussi longtemps que la pression d'air de travail est inférieure à une pression maximum, l'enfoncement de cette gâchette (12) déplace cet ensemble tige avec cette tige poussoir (18) pour le placer dans cette position avancée, en allant de cette position supérieure à cette position inférieure, pour ouvrir ainsi le côté de cette soupape à champignon (30) mais que, lorsque la pression de travail excède la pression maximum, la pression surmonte l'effet de ce moyen à ressort (28), en faisant passer cette tige poussoir (18) de cette position avancée à cette position rétractée, de sorte que le côté d'entrée de cette soupape à champignon (30) sera fermé.