US 6,604,664 B2Granted

Safe trigger with time delay for pneumatic fastener driving tools

AssigneeIllinois Tool Works Inc.

InventorJames W. Robinson

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Abstract

A pneumatic fastener-driving tool is disclosed wherein not only rapid-fire bump-firing or trigger-firing modes of operation are permitted wherein either one of the trigger member and workpiece contact element components can be depressed before the other one of the trigger member and workpiece contact element components depending upon the particular mode of operation that the operator personnel chooses to employ, however, the tool is also rendered safe for transportation by operator personnel between job sites or work sites in view of the fact that if the workpiece contact element is not depressed, as a result of not being disposed in contact or engagement with a workpiece, within a predetermined period of time subsequent to the performance of the last fastener discharge or firing operation, then the tool is pneumatically disabled and can only be again enabled if the proper sequential activation of the tool is performed wherein the workpiece contact element must be engaged with a workpiece prior to the depression or activation of the tool trigger. Accordingly, after the expiration or lapse of the aforenoted predetermined period of time, should the operator personnel carry or transport the tool with the trigger member nevertheless depressed, the tool will not fire or discharge a fastener even if the workpiece contact element is depressed due to the fact that the tool has already been pneumatically disabled.

Claims39

Dependent claims

A pneumatic fastener driving tool having a magazine housing a plurality of fasteners to be driven, comprising:

a source of compressed air;
a main valve for causing the firing of a fastener from a tool magazine when said main valve is vented to atmosphere;
a pilot valve assembly comprising a pilot valve member movably mounted upon said pilot valve assembly between a first position at which a first fluid flow path from said source of compressed air to said main valve is defined within said pilot valve assembly so as to permit pressurization of said main valve with said compressed air in preparation for firing a fastener from the tool magazine, and a second position at which a second fluid flow path from said main valve to atmosphere is defined within said pilot valve assembly so as to permit venting of said compressed air from said main valve when a fastener from the tool magazine is to be fired;
a tool trigger movable between depressed and released states;
a workpiece contact element movable between depressed and released states;
and
fluid flow control means for enabling said tool to fire a fastener during a first fastener-firing operational cycle of said tool only if said workpiece contact element is sequentially depressed prior to the depression of said tool trigger, for enabling said tool to fire a fastener during a fastener-firing operational cycle of said tool subsequent to said first fastener-firing operational cycle of said tool regardless of the sequence in which said tool trigger is depressed with respect to the depression of said workpiece contact element, and for disabling said tool such that said tool cannot fire a fastener during an intended fastener-firing operational cycle of said tool if subsequent to said first fastener-firing operational cycle of said tool, said work-piece contact element is not moved to its depressed state within a predetermined period of time.

4 more elements

A pneumatic fastener driving tool having a magazine housing a plurality of fasteners to be driven, comprising:

a source of compressed air;
a main valve for causing the firing of a fastener from a tool magazine when said main valve is vented to atmosphere;
a pilot valve assembly comprising a pilot valve member movably mounted upon said pilot valve assembly between a first position at which a first fluid flow path from said source of compressed air to said main valve is defined within said pilot valve assembly so as to permit pressurization of said main valve with said compressed air in preparation for firing a fastener from the tool magazine, and a second position at which a second fluid flow path from said main valve to atmosphere is defined within said pilot valve assembly so as to permit venting of said compressed air from said main valve when a fastener from the tool magazine is to be fired;
a tool trigger movable between depressed and released states;
a workpiece contact element movable between depressed and released states;
and
fluid flow control means for enabling said tool to fire a fastener during a first fastener-firing operational cycle of said tool only if said workpiece contact element is sequentially depressed prior to the depression of said tool trigger, and for enabling said tool to fire a fastener during a fastener-firing operational cycle of said tool subsequent to said first fastener-firing operational cycle of said tool regardless of the sequence in which said tool trigger is depressed with respect to the depression of said workpiece contact element only if said workpiece contact element is moved to its depressed state within a predetermined period of time, otherwise said tool is disabled.

4 more elements

Dependencies are inferred from the claim text.