Claims
- 1. A masonry expansion bolt adapted to be anchored within a bolt hole comprising:
- an elongated shank portion of generally circular cross-section having a diameter equal to or slightly less than that of the bolt hole,
- a wedging section extending at least along a portion of said shank including a plurality of peripheral ridges in longitudinally spaced relation to each other, the space between adjacent of said ridges being in the form of an annular channel of generally trapezoidal cross-section with an inner surface parallel to and concentric with the longitudinal axis of said bolt, a forward side inclined radially outward at an obtuse angle to said inner surface, and a rearward side also inclined radially outward at an obtuse angle to said inner surface, said channel also having an annular groove of generally V-shaped cross-section recessed into its inner surface at its rearward side, the rearward side of said V-shaped groove being an extension of the rearward side of said channel inclined radially inwardly in the same plane as said rearward side of said channel, and the forward side of said V-shaped groove diverging away from the rearward side at a right angle thereto, and
- resilient wedging means in the form of an annular wire ring of substantially square cross-section normally disposed in said channel forwardly of said groove with one of its flat sides positioned adjacent and parallel to the inner surface of said channel, the crosssectional dimension of said wire between opposite of its flat sides being greater than the depth of said channel, said wire ring also being slidable longitudinally rearwardly in said channel in response to urging in that direction of force applied to its outer periphery and rotatable about its annular longitudinal axis in response to limiting resistance to said rearward sliding movement on its inner rearward edge by said inclined rearward side of said channel such that said inner rearward edge is rotatable into and retained by said V-shaped groove in a position with its outer forward edge rotated to protrude radially outward beyond the peripheral surface of said bolt into engagement with the walls of said hole with said one flat side of said wire ring bearing against said forward side of said V-shaped groove to restrain said bolt from longitudinal retraction from said hole, the diagonal dimension of said substantially square cross-section being greater than the combined depths of said channel said v-shaped groove by an amount which is more than the difference between said dimension between the opposite flat sides and the depth of the channel, said wedging section being in the form of a threaded section in which said channel extends spirally therealong, and said wedging means is defined by a number of turns of a coiled spring wire extending along said channel.
Parent Case Info
This application is a division of Ser. No. 422,537, filed Jan. 2, 1974, U.S. Pat. No. 3,967,525, granted July 6, 1976 entitled SPRING ACTION EXPANSION BOLT.
US Referenced Citations (2)
Divisions (1)
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Number |
Date |
Country |
Parent |
422537 |
Jan 1974 |
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