Cross-Reference to Related Applications

[0001] The present application claims priority from Australian Provisional Patent Application No 2015901306 filed on 13 April 2015, the content of which is incorporated herein by reference.

Technical Field

[0002] This invention relates to an improved karabiner. Background

[0003] A karabiner is a spring loaded clip which can be used to link or attach a rope to a harness. A karabiner comprises a generally D- shaped ring of metal along one side of which there is a hinged gate portion, which is generally spring loaded into a closed position.

Movement of the free end of the gate portion allows a rope to be inserted inside the ring. A threaded sleeve is usually provided for screwing over the free end of the gate portion to lock the rope into the ring and prevent accidental release of the rope through the gate. Such karabiners are commonly referred to as "screwgate" karabiners.

[0004] One problem with existing karabiners is that they can be unreliable, particularly when used by inexperienced persons. In particular, the threaded sleeve can sometimes come undone, allowing the karabiner gate to open which is a major safety problem.

[0005] Various other designs of karabiner are known, which instead of the threaded sleeve have a sleeve which is biased into the closed position using alternative locking means. These biasing and locking means may include springs and/or magnets.

[0006] The problem with such karabiner designs is that they are much more complex that a simple screwgate karabiner and are therefore more expensive to make. Further, having more parts they tend to be less reliable, particularly in adverse weather conditions such as extreme cold and wet conditions often experienced by climbers. Also they usually require two hands to open the gate, and often when a person is climbing or working at heights they may not easily be able to use both hands. [0007] Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present disclosure as it existed before the priority date of each claim of this application.

[0008] Throughout this specification the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

Summary

[0009] According to the present invention there is provided a karabiner comprising a generally C-shaped body portion having a first free end and a second free end, a gate having a first end and a second end, the first end of the gate being pivotally mounted to the first free end of the body portion, the gate being pivotable about the first end of the body portion between an open position and a closed position, wherein the exterior of the gate is threaded and a mating internally threaded locking means is provided on the gate which, when the gate is in the closed position, can be rotated to surround the second free end of the body portion, thereby preventing the gate from opening; and including a biasing means, preferably in the form of spring, arranged to bias the locking means towards the second end of the gate.

[0010] Advantageously, the use of the biasing means maintains the locking means over the second free end of the body portion when the gate is in the closed position, preventing accidental opening of the gate. At the same time, the gate can be opened by rotating the locking means to move/translate the locking means away from the second end of the gate. In some cases this may be done using one hand only. The use of a traditional screwgate locking in addition to the biasing means, combines the advantages of a screwgate karabiner with a self-locking karabiner.

[0011] The locking means may be a locking nut which may be located towards the second end of the gate, or alternatively may be a rotatable sleeve which may cover the majority of the gate. [0012] Typically the pitch of the thread on the gate may be in the range of 4mm to 10mm. The screw threads may have a substantially square form.

[0013] The thread will preferably be a double start or triple start thread, and its lead (the linear distance the sleeve of nut travel in one revolution) may be from 10mm to 20mm. In that way a single turn or part turn of the sleeve/nut translates the sleeve/nut a relatively long linear distance along the gate, making the device easier and quicker to operate.

Brief Description of Drawings

[0014] Specific embodiments of the invention will now be described by way of example only and with reference to accompanying drawings in which:-

Figure 1 is a front view of a first embodiment of a karabiner with its gate closed;

Figure 2 is a rear view of the karabiner of Figure 1 with its gate open;

Figure 3 is an isometric view of a second embodiment of a karabiner with its gate closed;

Figure 4 is an isometric view of the karabiner of Figure 3 showing the gate in an open position;

Figure 5 is an exploded view components of the gate of the karabiner of Figure 3 ; and

Figure 6 is a part-exploded view showing the components of Figure 5.

Description of Embodiments

[0015] Referring to Figures 1 and 2 of the drawings, a karabiner 10 comprises a generally C- shaped main body 12 defining opposed first and second free ends 14, 16. A gap 18 is defined between the ends. The gap may be closed by a closing member in the form of a gate 20 which is pivotally mounted to the first free end 14 by a pivot pin 21 . When the gate is closed as shown in Figure 1 the karabiner defines a generally D-shaped closed loop. At the top and bottom of the D the interior of the loop is slightly recessed and rounded at 22 and 24 to provide a rope guide. [0016] In cross-section, the karabiner is generally circular and rounded however the free ends 14, 16 of the main body have a reduced thickness compared to the rest of the main body and have a generally rectangular cross- section.

[0017] The gate 20 is formed from a cylindrical metal cylinder 22 which defines a central slot at each end 24, 26 which is of substantially the same width as the thickness of the free ends so that the ends 24, 26 of the tube can pass over the free ends 14, 16 of the main body, respectively. The slot in the end 24 is open to both sides. The slot in the end 26 is closed to one side by a wall (not shown).

[0018] The first end 24 of the gate is mounted on a pivot pin on the first free end 14 of the main body.

[0019] As is best seen in Figure 2, the free end 16 of the main body is shaped to define a generally triangular spearhead shaped tip 16a and a recess 28 in the one side of the free end 16 that faces the interior of the karabiner.

[0020] The wall of the second end 26 of the gate abuts the side of the tip portion 16a and thus defines a stop which prevents the gate from pivoting outwards of the ring beyond the D shaped closed loop.

[0021] The exterior of the gate 20 is threaded. The thread is a coarse double start screw thread having a pitch of about 8 mm and having a generally square form. A locking nut in the form of a knob 40 which defines a mating threaded bore is mounted on the threaded gate. As the thread is a double start thread, turning the knob through as little as 180° moves the knob about 0.8cm along the gate. This makes it easier to operate the karabiner with one hand.

[0022] A compression coil spring 42 is provided which extends around the exterior of the gate. One end 44 of the coil spring is fixed to the knob. The other end (not shown) is bent through 90° and when the coil spring is under tension abuts one face of the free end 14.

[0023] The spring 42 biases the knob 40 towards the free end 26 of the gate so that when the karabiner is closed, as shown in Figure 1, the knob engages over the free end 16 of the main body and prevents the gate from opening. When the knob is turns it translates/moves along the screw thread away from the free end 26 and disengages from the free end 16 of the main body allowing the gate to open inwards . The spring becomes compressed. Note that the spring acts both to push the knob towards the free end and to rotate the knob.

[0024] Figures 3 to 6 to show a second embodiment of karabiner 110 of the present invention which operates on the same principals as the first embodiment, but instead utilises a spring biased sleeve 112 mounted on a threaded gate 120 (refer to Figure 4).

[0025] In this embodiment, the threaded part 122 of the gate 120 is substantially enclosed by the sleeve 112. The first end 124 of the gate is pivotally mounted to the main body of the karabiner by a pivot pin 121.

[0026] The pitch of the thread is about 4mm and a triple start thread is used hence the lead is about 12mm.

[0027] The sleeve is biased towards the second end of the gate by a coil spring or the like (shown in Figures 5 and 6).

[0028] As is best seen in Figure 4, the second free end 116 of the main body (i.e. the end which is not pivotally attached to the gate), defines a tapered portion with protruding wings at its end forming an inverted T-shape. When the sleeve is in the closed position shown in Figure 3, it covers the end 116 of the body portion and prevents the gate from moving. When rotated (through about 150° although this angle may vary in different embodiments) the sleeve defines a slot 150 (refer to Figure 4) through which the end can pass, allowing the karabiner to open.

[0029] It should be noted however that as the sleeve travels in a linear direction along the gate 120 as it is rotated, as shown in Figure 4, it is not absolutely necessary for the sleeve to define a slot at all, as if the sleeve is able to be rotated sufficiently it will clear the second free end 116 of the body portion of the karabiner.

[0030] Figures 5 and 6 show components of the gate 120 some of which are hidden by the sleeve in the assembled karabiner. In particular Figure 5 shows the gate 120, the threaded end 122 and the second end 124 which defines apertures which receive the pivot pin for mounting the gate to the main body of the karabiner. Also shown in Figure 5 is an inverted T-shaped slot 126 which receives the T-shaped free end of the main body, when the karabiner is closed. [0031] Figures 5 and 6 also show the biasing spring 130 and an inner sleeve 140. Figure 6 in particular shows the inner sleeve 140 and spring mounted on the gate 120. The inner sleeve is provided to bias the spring which is compressed between the inner sleeve and the outer sleeve. In this way the spring is biased to rotate the sleeve and lock the karabiner. A small cut out 142 is defined in one end of the inner sleeve 140 which received the end 130A of the spring. The other end 130B of the spring locates in a slot in an internal flange, not shown, inside the sleeve 112. Figures 5 and 6 also show part of the internal thread 113 on the sleeve which engages with the external thread 122 of the gate.

[0032] It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the above-described embodiments, without departing from the broad general scope of the present disclosure. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.