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US 6,439,085 B1Granted
Double arm pawl for autofeed screwdriver
OwnerG. Lyle Habermehl, Troy D. Hale +1inventors
InventorsG. Lyle Habermehl, Troy D. Hale, Paul Townsend Scherer
Life of this patent
Estimating the term…
Abstract
A blocking and/or advance pawl mechanism for an autofeed fastener driving tool with at least one of the pawl arms maintained rearward of a next fastener to be driven from a strip holding fasteners spaced in a row.
Claims20
An apparatus for sequentially driving fasteners from a fastener strip comprising a plurality of fasteners secured in a row in a holding strip, the apparatus comprising:
- a slide body having a lateral screwstrip receiving channelway and a guideway bore intersecting the channelway, the channelway configured to slidably receive the strip;
- an elongate driver shaft having a shaft axis of rotation, said shaft including a fastener driving bit for engaging and driving fasteners in succession into a workpiece, said shaft being journalled and longitudinally slidably housed in said bore for reciprocal movement relative the slide body between an engaged position and a withdrawn position;
- an advance mechanism mounted to said slide body for incrementally forwardly advancing the strip carrying the screws in the strip with the axis of each screw to pass in succession along a plane of advance within the channelway into the bore, said advance mechanism including a linkage member housed in said slide body and reciprocally movable between an advanced position and a retracted position as a function of cyclical reciprocal relative movement of the slide body and driver shaft,
- a pawl pivotally mounted on the linkage member for pivoting between a first blocking position and a second passage position,
- the pawl having a first arm with a first screw engaging surface and a second arm with a second screw engaging surface,
- in the first blocking position, both the first and second engagement surfaces are positioned in the plane of advance such that the first engagement surface blocks any screw in the screwstrip immediately forward of the first engagement surface from movement relative the first engagement surface rearwardly past the first engagement surface and the second engagement surface blocks any screw in the screwstrip immediately forward of the second engagement surface for movement relative the second engagement surface rearwardly past the second engagement surface,
- in the second passage position, both the first and second engagement surfaces are positioned out of the plane of advance such that they do not block screws in the screwstrip forward of the first or second engagement surfaces from movement relative the first and second engagement surfaces rearwardly past the first or second engagement surfaces.
4 more elements
An apparatus for sequentially driving fasteners from a fastener strip comprising a plurality of fasteners secured in a row in a holding strip, the apparatus comprising:
- a fastener driving mechanism defining a fastener driving position;
- a fastener advance mechanism mounted to said fastener driving mechanism and including a fastener advancement member reciprocally moveable relative to said fastener driving mechanism between an advanced position and a retracted position;
- a pawl pivotally mounted to said fastener advancement member and having a first arm with a first fastener engaging surface and a second arm with a second fastener engaging surface, said pawl being pivotable between a first blocking position and a second passage position;
- said first arm being in engagement with a first fastener and said second arm being in engagement with a second fastener when said pawl is in said first blocking position.
1 more element
Dependencies are inferred from the claim text.