Patent Description:
<CIT> describes a hook fastener with a sliding gate urged by a spring to close the mouth of the hook. It may be used for releasable fastening of elongate flexible members such as belts, slings, tethers, lines, ropes, chains, and the like. A drawback of this fastener is the separate manual action that the user must perform - turning the keeper - to place the gate in its latched closed state. It will therefore be understood that a need exists to provide a higher degree of security or protection against unintentional release that would be available if the need for this separate manual action could be avoided. A further prior art fastener is known from <CIT>. It is an object of the present invention to address the above need or, more generally, to provide an improved auto-locking gated fasteners.

According to one aspect of the present invention there is provided a fastener for releasably securing a member according to claim <NUM>, the fastener comprising:.

The resilient means preferably comprises a member or assembly that is resilient, such as a spring (for instance, a helical spring, a leaf spring, a cantilever spring, a gas spring), an elastic member (such as an elastomeric block), or the like.

The latches may be of any known type of latch, such as a sliding latch, a pivoting latch, or a combined sliding and pivoting latch, and may be made self-closing through the provision of resilient latch-closing means such as a spring (for instance, a helical spring, a leaf spring, a cantilever spring, a gas spring), an elastic member (such as an elastomeric block), or the like.

Preferably the recess is disposed proximate one longitudinal end of the body.

Preferably the recess is defined by a hook-shaped portion of the body. Preferably the hook-shaped portion has a non-reentrant form.

Preferably the latches are alike, each latch comprising a latch lever mounted by a pivot to rotate about a respective substantially transverse pivot axis.

Preferably the latch levers are elongated generally axially and both substantially transverse pivot axes substantially lie in a transverse plane.

Preferably the pivot axes are disposed intermediate opposite first and second ends of the latch levers, one of the first and second ends of each latch lever abutting a shoulder on the shank.

Preferably a slot extends through the shank and is substantially axially aligned, opposing ends of a latch spring received in the slot abut respective ones of the latch levers to urge the one of the first and second ends inwardly.

Preferably the second ends project from a concave circumferential surface of the gate, most preferably from a conical concave surface.

Axles may be held in respective openings in the gate, each axle pivotably supporting one of the latch levers. However, preferably a one-piece retainer extends through each latch lever to define each pivot.

Preferably channels in a periphery of the gate receive sections of the one-piece retainer. Preferably the one-piece retainer comprises a length of wire formed first in a U-shape with two parallel arms that are inserted through the latch levers before ends of the arms are bent together to form a loop to permanently retain the latch levers and latch spring.

Preferably the resilient means comprises a helical spring that extends about the shank, one end of the helical spring engaging the gate and the other end engaging a fixture proximate one end of the shank.

Preferably the fixture is held in an aperture that extends substantially transversely through the shaft.

Preferably the fixture comprises one end of an elongate flexible member, such as a wire rope.

This invention provides a fastener which is effective and efficient in operational use, and which by requiring three independent release actions (two separate latches and sliding of the gate) and automatic locking offers protection against unintentional release.

Preferred forms of the present invention will now be described by way of example with reference to the accompanying drawings, wherein:.

Referring to <FIG>, a first embodiment of a fastener <NUM> according to the invention generally comprises an elongate body <NUM> with a recess <NUM> formed proximate a first longitudinal end <NUM> and a shank <NUM> that may extend to an opposing longitudinal end <NUM>. The first longitudinal end <NUM> may consist of a hook-shaped portion of the body <NUM> that defines the recess <NUM>. The body <NUM> may have a generally elongate form with both ends <NUM>, <NUM> having a like cross section. The recess <NUM> extends generally transversely and may taper to narrow in the longitudinal direction from an elongate mouth <NUM> aligned approximately with the outer surface of the shank <NUM> to its closed end <NUM>. The closed end <NUM> may be concave and define a radiused face. The recess <NUM> may be relatively shallow in transverse dimension, so as not to extend across an imaginary central longitudinal plane of the body <NUM> (not shown). A slot <NUM> may extend through the body <NUM>, and may be elongated longitudinally and intersect, at least partially, with the recess <NUM>. Near an inner end of the slot <NUM> the body includes transversely opposing shoulders <NUM>. Planar faces <NUM> may be provided on an exterior of the body <NUM> and aligned longitudinally. An aperture <NUM> may extend transversely through the longitudinal end <NUM>.

The hook-shaped portion of the end <NUM> of the body <NUM> may have a non-reentrant form, as best seen in <FIG>. At a tip of the free end <NUM> of the hook-shaped portion, the surface of the recess <NUM> defines a tangent <NUM>. The tangent <NUM> may be approximately parallel to an opposing face <NUM> of the recess <NUM> (or opened from that angle) to provide the non-reentrant form,avoiding the need for the member received in the recess <NUM> to pass through a throat section before reaching the closed end <NUM>. This shape is distinguished from a re-entrant form (not shown) in which the tangent <NUM> is closed, by rotation in the direction <NUM>, such that the free end <NUM> bounds a throat section of the recess <NUM>. The fastener <NUM> further comprises a gate <NUM>, resilient means in the form of a compression spring <NUM>, a pair of latch levers 24a, 24b, a one-piece retainer <NUM> and a tether <NUM>.

The gate <NUM> has a sleeve-like form with a central opening <NUM> complementary to the shank <NUM> which is received therein such that the gate <NUM> can slide axially on the shank <NUM> between the closed position (<FIG> and <FIG>) where it closes the mouth <NUM> by extending over it, and an open position (<FIG>) where the gate <NUM> is retracted to expose part of the mouth <NUM> for the insertion of a member (not shown) therein. Thus, in the closed position, the recess <NUM> bounds a transversely extending through-hole. Internal abutments <NUM> in the aperture <NUM> may be provided for engagement with the faces <NUM> to prevent rotation of the gate <NUM>, and to abut stop facets <NUM> (as in the closed position) and thereby limit the travel of the gate <NUM> toward the end <NUM> of the body <NUM>. Axially aligned slots <NUM> may extend through diametrically opposing sides of the gate <NUM> to receive respective ones of the latch levers 24a, 24b. Transversely opposing concavities <NUM> in the outer axial end of the gate <NUM> may be provided for registration, in the closed position, with the closed end <NUM> such that a member (not shown) that is received in the recess <NUM> and elongated transversely also projects through both concavities <NUM>. For receipt in the recess <NUM>, the member may be another length of wire rope, a pin, a D-ring or a chain link, or the like, which includes an elongate section, as with a cross-section of substantially constant diameter throughout its length. Opposing longitudinal edges of the elongate section may be disposed adjacent the concave closed end <NUM> and the opposing concave ends <NUM> of the concavities <NUM>. Depending upon the transverse dimensions of the elongate section and the limit the travel of the gate <NUM> toward the end <NUM>, the elongate section may be clamped between the ends <NUM>, <NUM> and effectively loaded in double shear, or it may be free to move transversely relative to the fastener <NUM>. The one-piece retainer <NUM> may be formed of wire initially in a U-shape, as shown in <FIG>, with two parallel arms <NUM>, <NUM> that each provide a pivot to support one of the latch levers 24a, 24b. The two parallel arms <NUM>, <NUM> are inserted through respective openings <NUM> in the gate <NUM> and through openings <NUM> in the latch levers 24a, 24b before ends 25a, 30a of the arms <NUM>, <NUM> are bent together to form a loop to permanently retain the latch levers 24a, 24b. Channels <NUM>, <NUM>, <NUM> in a periphery of the gate <NUM> receive sections of the one-piece retainer <NUM> such that it is recessed within the periphery of the gate <NUM>, as best seen in <FIG>. In this manner pivot axes of both levers substantially lie in the same transverse plane.

The latch levers 24a, 24b are alike, with the opening <NUM> defining the pivot axis disposed intermediate first and second longitudinal ends <NUM>, <NUM>. The first end <NUM> of each latch lever may include a nub <NUM> that receives one end of a spring <NUM>, while the second end <NUM> is configured to abut one of the shoulders <NUM> in the closed position. In this way, the spring <NUM> acts to urge the ends <NUM> apart and the ends <NUM> inwardly, making the latch levers 24a, 24b self-closing. <FIG> perhaps best shows the second ends <NUM> of the latch levers 24a, 24b projecting from a circumferential surface <NUM> of the gate <NUM> that a conical concave form, an ergonomic feature to provide for comfortable location of a user's thumb and fingers over the top of the latch levers 24a, 24b.

The helical compression spring <NUM> extends about the shank <NUM> and has one end that may engage the gate <NUM> and another end that may engage a fixture in the form of a wire rope <NUM>, or a like elongate flexible member, proximate the longitudinal end <NUM>. In this embodiment, the end of the wire rope <NUM> is formed in a loop <NUM> that passes through the aperture <NUM> and formed by the wire rope <NUM> being turned back on itself and permanently fixed to itself, as by a crimp <NUM>. The end <NUM> of the body <NUM> may be crimped directly to the wire rope <NUM> at the end of the loop <NUM> for preventing any relative movement between the body <NUM> and wire rope <NUM>, such as sliding of the wire rope <NUM> through the aperture <NUM>.

Since the latch levers 24a, 24b have an independent latching action, both must be pressed by the user to release the gate <NUM> to slide, and their opposing arrangement means this can be readily achieved by grasping them between forefinger and thumb as shown in <FIG>. This figure also shows that the loop formed in the wire rope <NUM> may also conveniently be grasped, securing the body while the gate <NUM> is withdrawn, thus providing single-handed operation. The release of these two latch levers 24a, 24b and the sliding of the gate <NUM> comprise three independent actions that must each be performed to release the fastener <NUM>, thus mitigating the possibility of an unintended release occurring. Furthermore, as the levers 24a, 24b are self-closing and the sliding gate <NUM> is spring-biased to its closed state, the fastener <NUM> locks automatically upon release by the user.

In the further embodiments of the invention that follow like numbers are used to refer to like components from the first embodiment.

<FIG> illustrates a second embodiment of the fastener <NUM> which is of like construction to the first embodiment <NUM> except for the loop in the wire rope <NUM>, one end of the wire rope <NUM> is instead fixed to the end <NUM> by a permanent connection, such as by the end <NUM> of the body <NUM> being crimped directly to an end <NUM> of the wire rope <NUM>. Using this embodiment to secure a length of the wire rope <NUM> in the recess <NUM> secure openable loop <NUM> is formed using the wire rope <NUM>.

In the third embodiment or fastener <NUM> shown in <FIG>, a D-ring <NUM> is received in the aperture <NUM> and connected to a textile web <NUM>, as by a loop in the web <NUM> through the D-ring <NUM>.

The fourth embodiment of the fastener <NUM> shown in <FIG> employs like components to perform the same function but instead of the gate being closed by a compression spring, it is closed by a tension spring <NUM>. With tension spring <NUM> fixed to the end <NUM> of the body <NUM> as by one hooked end extending about the loop of wire rope <NUM> and to the gate <NUM> by another hooked end received in a hole in the gate <NUM>, the gate <NUM> is urged toward the end to its closed position (shown in <FIG>). The concavity <NUM> is disposed in an intermediate position between the axial ends of the gate <NUM> and is U-shaped so that in the closed position an integral tongue portion <NUM> of the gate <NUM> extends over the mouth of the recess <NUM>.

In another preferred embodiment shown in <FIG>, and perhaps best illustrated by <FIG>, the hook-shaped end <NUM> of the fastener <NUM> and recess <NUM> defined thereby may have substantially larger transverse dimensions than the adjacent shank <NUM> of the body <NUM>, as may be required depending on the application. To accommodate this geometry, instead of the gate lying over the mouth of the recess in the closed position, the gate <NUM> may have an interface <NUM> that abuts a complementary interface <NUM> on the body <NUM> at the end of the hook-shaped portion. These interfaces <NUM>, <NUM> may have a stepped form that provides a degree of interlocking in the closed position whereby the gate <NUM> contributes to the stability of the hook-shaped end.

<FIG> shows that the body <NUM> may include a head part <NUM> the projects radially outwardly of the shank <NUM> to provide bearing for one end of the compression spring <NUM> wherein the wire-rope-receiving aperture <NUM> extends through the head part <NUM>.

<FIG> shows a sixth embodiment of the fastener <NUM> in which the latch levers 524a, 524b remain pivotally mounted to the gate <NUM>, but where the biasing single spring <NUM> is replaced by two separate springs (not shown), such as torsion springs mounted about the respective latch pivots, each biasing a respective one of the latch levers 524a, 524b to its latched position, Advantageously, this avoids the need for the through-extending slot <NUM> in the shank <NUM>. In addition, the gate <NUM> may be made free to rotate about the longitudinal axis of the shank, as the shoulder <NUM> defines an annular face <NUM> that lies in a transverse plane and which therefore abuts the latch levers 524a, 524b at any angle of relative rotation between the gate <NUM> and the shank <NUM> about the longitudinal axis.

A two-part coupling may comprise a fastener <NUM> and a complementary coupler <NUM> releasably fixable in one axial end of the gate <NUM>, as shown in <FIG>. Fastener <NUM> is like that of any of the preceding fasteners <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> except for the shape of the end <NUM> of the elongate body <NUM>, where there is an axially-extending channel in the hook-shaped end <NUM> that extends into the recess <NUM>, where this channel receives an axially-extending portion <NUM> of the coupler <NUM>. The coupler <NUM> has a hook-shaped end <NUM> complementary to both the gate <NUM> and the hook-shaped end <NUM> and is engaged therewith such that extending the gate <NUM> (to the position shown) secures the coupler <NUM> to protrude from the axial end of the gate <NUM>. Although modified by the axially-extending channel, an elongate member received in the recess <NUM> and extending transversely, as to form the loop <NUM>, remains fastened and cannot escape the recess <NUM> in the axial direction. By providing a coupler <NUM> on a tool, for instance, a fastener of the invention secured to a tether can be used for tethering the tool.

Claim 1:
A fastener (<NUM>) for releasably securing a member, the fastener (<NUM>) comprising
a body (<NUM>) including a shank (<NUM>) and a recess (<NUM>), the recess (<NUM>) configured for receiving the member;
a gate (<NUM>) mounted to slide axially on the shank (<NUM>) between a closed position closing a mouth of the recess (<NUM>) for retaining the member, and an open position resilient means (<NUM>) engaging the gate (<NUM>) and the shank (<NUM>) to urge the gate (<NUM>) to the closed position, and
a pair of latches, the latches mounted on opposing sides of the gate (<NUM>), wherein each latch is self-closing and engages the body (<NUM>) for holding the gate (<NUM>) in the closed position.