Abstract:
The instant invention is a locking mechanism contained within a carabiner&#39;s straight or bent gate. The locking mechanism incorporates a pivoting link that can be moved to abut against a transverse pin, thereby immobilizing the gate return spring, which prevents opening movement of the gate. The transverse pin is a material able to resist and distribute forces attempting to open the locked gate. The spring pin is notched to engage the transverse pin thereby simplifying assembly of the carabiner. A low profile protrusion is pushed in the direction of opening the gate to switch the mechanism to the unlocked position. Similarly, another low profile protrusion is pushed in the direction of closing the gate to switch the mechanism to the locked position. The locking and unlocking protrusions are located adjacent the gate hinge so that the gate can be conveniently unlocked, opened, closed and relocked with the fingers of one hand.

Description:
RELATED APPLICATIONS 
       [0001]    The instant invention is related to Provisional Application No. 60/816,774 entitled “Snap Lock Carabiner,” filed Jun. 26, 2006, the disclosure of which is incorporated herein by reference. 
     
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The instant invention is generally related to climbing aids for rock climbers. More particularly, this invention is related to mechanical devices that link climbing aids together. 
         [0004]    2. Description of the Prior Art 
         [0005]    Climbers utilize rope, slings and a variety of mechanical clevices as climbing aids to assist and protect their movement over rock. The climbing aids serve as a means to anchor the climber to the rock for the purpose of either preventing or arresting a fall. 
         [0006]    A carabiner is a mechanical device used to link rope, slings and other climbing aids together. A carabiner is essentially a device used, for example, to attach a climber&#39;s body harness to the climbing rope. It is also used to link the climbing rope to anchors placed in or over the rock. 
         [0007]    A typical carabiner is palm sized, and either an oblong, oval or “D” shaped ring of a lightweight, high strength material, usually a heat-treated aluminum alloy. One side of the carabiner has a hinged arm that serves as an inward opening gate. The gate is spring loaded to remain normally closed. The normally closed, inward opening gate facilitates insertion of climbing aids such as rope, but impedes inadvertent removal. Objects are released from the carabiner after manually pushing open the gate. 
         [0008]    The closing force is provided by a stout compression spring that is housed within the carabiner gate. The spring axis is offset from the pivot pin so that the spring force is directed to close the gate. A link is employed to transfer the spring force to the carabiner body at an appropriate distance from the pivot pin. 
         [0009]    The opening end of the gate incorporates an interlocking mechanism that engages the carabiner body when the gate is closed. The interlocking mechanism is typically a transverse pin that mates with a hooked notch in the carabiner body. Another popular configuration includes a keyed arrangement that mates with the carabiner body. These interlocking arrangements allow a closed gate to carry part of the load imposed on the carabiner. Consequently, the carabiner is significantly stronger when the gate is closed. The ultimate strength of a carabiner with the gate open is typically 65% lower than with the gate closed. 
         [0010]    During a climb and especially in the event of a fall, the climber&#39;s safety is dependent on the security of numerous carabiner links. Consequently, it is imperative that every carabiner in the chain be able to withstand not only the weight of the climber but also the inertial forces generated when the rope arrests a fall. 
         [0011]    As the climber progresses upward, the carabiners in a protective chain of climbing aids often rub against the rock. Occasionally, a carabiner gate will catch on a rock or other object, or the rope itself, and may be pushed or pulled open without the climber&#39;s knowledge. A carabiner can slap against the rock during a fall causing inertial loads that overcome the closing force of the spring and momentarily open the gate. Also, a rope moving rapidly through a carabiner during a fall can cause the carabiner body to vibrate sufficiently to shake the gate open. 
         [0012]    Whenever the gate is opened, even momentarily, there is significant risk that a rope or other attached climbing aid will be inadvertently released. Furthermore, if a sudden load is applied to the carabiner at the instant that the gate is open, the ultimate strength of the carabiner will be significantly compromised and possibly fail. Such occurrences are well known and are considered a significant problem by the climbing community. Consequently, climbers pay careful attention to the placement and orientation of carabiners in order to minimize the chance of an inadvertent opening of the gate. 
         [0013]    Climbers often use two carabiners joined by a short length of looped webbing, a combination called a quickdraw. One of the quickdraw carabiners is clipped to an anchor placed in or on the rock. The other quickdraw carabiner is clipped to the climber&#39;s rope. The quickdraw allows the rope to pull toward the centerline between staggered anchors thereby providing a less resistive path from the belay point to the climber. 
         [0014]    A quickdraw requires the use of two carabiners to attach a rope to a single anchor. Assembling quickdraws with smaller, lightweight carabiners minimizes the weight and bulk penalty of using two carabiners. 
         [0015]    A properly placed quickdraw may have the additional benefit of reducing the chance of an inadvertent opening of the gate. Unfortunately this is often not the case. For example, if the rope is incorrectly threaded through the carabiner, a moving rope can twist the carabiner and expose the gate to a sideward opening force. If the rope is pulled across or around the gate, the gate can be inadvertently opened. 
         [0016]    A climber must be very careful when placing and clipping into a quickdraw. The dangling carabiner (the carabiner that will be clipped to the climbers rope) must be oriented so that its gate is away from the rock face. When the rope is clipped in, it must run along the spine of the carabiner, not across the gate. 
         [0017]    Many carabiners have a bent gate to facilitate clipping the rope. The gate is bent inward slightly which serves to guide the rope to the opening end. The dangling carabiner of quickdraw configurations customarily has a bent gate. 
         [0018]    Placing the rope into the quickdraw&#39;s dangling carabiner requires skill and dexterity. Usually the climber is hanging on to the rock surface with one hand, and has only one hand free to clip in the rope. Depending on which hand is free, and the location and orientation of the carabiner relative to the climber, a variation of two techniques is typically used: 1. The carabiner is stabilized with the middle finger, and the rope is clipped in with the thumb and index fingers; or 2. Stabilize the carabiner with the thumb, and clip the rope using the index and middle fingers. No matter the technique used, the carabiner gate must open easily and without hesitation. 
         [0019]    There are situations where the risk of an inadvertent opening of the gate is unacceptable, For example, the carabiner used to attach the climbing rope to the climber&#39;s body harness must never open inadvertently. Similarly, the carabiner used to attach a belay device to the climber&#39;s harness must never open inadvertently. Consequently, harness attachments and the like require greater security, for example, two parallel carabiners or a single carabiner with a locking gate. 
         [0020]    Greater security can be obtained by using two carabiners side-by-side with the gates opening in opposite directions. However, extra carabiners solely for the purpose of parallel placement are undesirable because they add considerably to the weight and bulk that the climber must carry. 
         [0021]    To avoid the need for side-by-side carabiners, various mechanical means have been developed to directly lock the carabiner gate closed. For example, a popular locking configuration incorporates a sleeve that is threaded, nut like, to the gate. The sleeve can be screwed along the length of the gate, either toward the hinge, or toward the opening end. The sleeve is screwed into the locking position after the rope or other climbing aids have been clipped into the carabiner. In one configuration the gate is locked closed by screwing the sleeve until it crosses the opening end of the gate and jams against the adjacent body of the carabiner. In an alternate configuration the gate is immobilized when the sleeve is screwed over the hinge. Locking or unlocking a carabiner with a threaded sleeve is not instantaneous, that is, it takes time to thread the sleeve from the unlocked position to the locked position and the reverse. 
         [0022]    Unfortunately, threaded locking sleeves undesirably add bulk and weight to the carabiner. Threaded locking sleeves are also inherently troublesome. The threads can become clogged with dirt or ice. The sleeve can inadvertently screw out of the locked position when the carabiner rubs across the rock. Furthermore, the gate and threaded cleave mechanism require precise machining and assembly alignment, both of which add to manufacturing cost. 
         [0023]    Other solutions of the prior art include gates equipped with spring loaded sliding and/or rotary sleeves. Sliding and/or rotary sleeves function similarly to threaded sleeves, and are often designed to lock automatically and nearly instantaneously when the gate closes. Sliding and rotary sleeves share the same problems as threaded sleeves, and are especially costly to manufacture. 
         [0024]    The increased bulk, weight and cost of the prior art limits the number of locking carabiners that a climber carries during a climb or is willing to buy. Consequently, there may be situations during a climb when the climber is compelled to use a non-locking carabiner although a locking type would be preferable or safer. 
         [0025]    Although the security of quickdraw applications would benefit from the use of locking carabiners, quickdraws do not incorporate locking carabiners because state-of-the-art locking carabiners are relatively heavy and bulky. The need to be able to easily and instantly clip a rope using only one hand make spring-loaded auto-locking gates especially inappropriate for quick draw use. Furthermore, locking sleeves can only be mounted on straight gates, whereas most quickdraw configurations utilize a bent gate carabiner. 
         [0026]    The instant invention is a carabiner incorporating a mechanism that securely and reliably locks the gate closed with the flick of a finger. The inventive locking mechanism is contained inside the gate; therefore it does not add bulk or weight to the carabiner and is less susceptible to jamming by contamination. The inventive locking mechanism has a snap action toggle that maintains the gate unlocked until the climber desires to lock it. The instant invention is ideally suited for quickdraw applications because there is not a weight or bulk penalty, it works with bent gates, and the gate will remain unlocked for clipping a rope, but can be easily and quickly locked after the rope is in place. 
       SUMMARY OF THE INVENTION 
       [0027]    The instant invention is a locking mechanism contained within a carabiner&#39;s straight or bent gate. The locking mechanism incorporates a pivoting link that can be moved to abut against a transverse pin, thereby immobilizing the gate return spring, which prevents opening movement of the gate. The transverse pin is a material able to resist and distribute forces attempting to open the locked gate. The spring pin is notched to engage the transverse pin thereby simplifying assembly of the carabiner. A low profile protrusion is pushed in the direction of opening the gate to switch the mechanism to the unlocked position. Similarly, another low profile protrusion is pushed in the direction of closing the gate to switch the mechanism to the locked position. The locking and unlocking protrusions are located adjacent the gate hinge so that the gate can be conveniently unlocked, opened, closed and relocked with the fingers of one hand. 
     
     
       DESCRIPTION OF THE DRAWINGS  
         [0028]    A detailed description of the invention is made with reference to the accompanying drawings wherein like numerals designate corresponding parts in the several FIGS. 
           [0029]      FIG. 1  is a pictorial view of two inventive carabiners in a quickdraw application linking rope and an anchor. 
           [0030]      FIG. 2  is a side elevation view of a bent gate carabiner incorporating the inventive locking mechanism. 
           [0031]      FIG. 3  is a top view of the carabiner as seen in the direction  3 - 3  of  FIG. 2 . 
           [0032]      FIG. 4  is a partial sectional view of the inventive carabiner, taken along a cut corresponding to line  4 - 4  of  FIG. 3 , showing the locking mechanism locked. 
           [0033]      FIG. 5  is a partial close-up sectional view of the carabiner of  FIG. 4 . 
           [0034]      FIG. 6  is a sectional view of the carabiner, taken along a cut corresponding to line  6 - 6  of  FIG. 5 . 
           [0035]      FIG. 7  is a partial sectional view of the carabiner of  FIG. 4 , showing the gate open. 
           [0036]      FIG. 8  is a partial sectional view showing a straight gate carabiner incorporating an alternate configuration of the inventive locking mechanism. 
           [0037]      FIG. 9  is a partial close-up sectional view of the carabiner of  FIG. 8 . 
           [0038]      FIG. 10  is a partial sectional view of the carabiner of  FIG. 5 , showing the gate open. 
           [0039]      FIG. 11  is a partial sectional view showing yet another alternate configuration. 
           [0040]      FIG. 12  is a partial sectional view showing a carabiner incorporating yet another alternate configuration of the inventive locking mechanism 
           [0041]      FIG. 13  is a partial close-up sectional view of the carabiner of  FIG. 12 . 
           [0042]      FIG. 14  is a partial sectional view of the carabiner of  FIG. 12 , showing the gate open. 
           [0043]      FIG. 15  is a partial sectional view showing yet another alternate configuration. 
           [0044]      FIG. 16  is a partial sectional view showing yet another alternate configuration. 
           [0045]      FIG. 17  is a pictorial view showing one hand unlocking the inventive locking mechanism. 
           [0046]      FIG. 18  is a partial sectional view of a typical Prior Art non-locking carabiner. 
           [0047]      FIG. 19  is a partial sectional view of a typical Prior Art locking carabiner. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0048]    The following detailed description is of the best presently contemplated modes of carrying out the invention. This description is not to be taken in a limiting sense, but is made merely for purposes of illustrating the general principles of the invention. 
         [0049]    Referring to  FIG. 1 , two inventive carabiners  10  are shown linked by looped webbing  14  to form a quickdraw configuration. One inventive carabiner  10  has a straight gate and is clipped to piton  16 , which is anchored to rock wall  18 . The other inventive carabiner has a bent gate and is clipped to climbing rope  12 . Piton  16  is representative of one of many types of anchors used by climbers.  FIG. 1  exemplifies one of the ways that carabiners are used to link climbing aids together. Referring to  FIG. 2 , carabiner  10  includes body  20  and gate  30 . Body  20  and gate  30  are fabricated from a lightweight, high strength material, for example aluminum alloy type 7075 heat treated to condition T6. 
         [0050]    The preferred configuration of the inventive locking mechanism is illustrated by  FIGS. 2-7 . The terms “top” and “bottom”; “above” and “below” refer to the orientation of carabiner  10  shown by  FIG. 2 . 
         [0051]    Referring to  FIG. 3 , gate  30  is slotted at both ends by slots  32  and  34 . Leg end  22  of body  20  nests loosely within the confines of slot  32 . Gate  30  is hinged to body  20  by pin  36  which transverses slot  32  through a slip-fitting hole in leg end  22 . 
         [0052]    The carabiner pictured in  FIGS. 2-7  uses a keyed arrangement to interlock the opening end of gate  30  to leg end  24  of body  20 . Slot  34  is machined or formed to mate with a corresponding bulbous extension of leg end  24 . The interlocking relationship serves to hold the gate closed when high tensile load is deform body  20 , thereby enabling gate  30  to carry part of the load transmitted through body  20 . Consequently, the carabiner is significantly stronger when the gate is closed. 
         [0053]    The inventive locking mechanism is located within gate  30 .  FIG. 4  pictures gate  30  bent at mid-length, however as seen in  FIG. 8 , the carabiner can also have a straight gate. The inventive locking mechanism is locked or unlocked by pivoting control link  60 . A finger moves control link  60  by pushing either protrusion  64  or protrusion  66 . Protrusion  64  extends a short distance above gate  30  when the inventive locking mechanism is locked. Protrusion  66  extends a short distance below gate  30  when the inventive locking mechanism is unlocked. 
         [0054]    The operation of control link  60  is intuitive because protrusions  64  and  66  are located so that the gate locks when protrusion  66  is pushed in the direction of closing gate  30 , and the gate unlocks when protrusion  64  is pushed in the direction of opening gate  30 . This intuitive control of the locking mechanism avoids confusion and is especially valuable when a climber is faced with demanding or strenuous conditions. Furthermore, as a safety feature the location of protrusion  66  causes the gate to lock or remain locked if a rope or other climbing aid clipped inside the inventive carabiner inadvertently pushes against protrusion  66 . 
         [0055]    Referring to  FIG. 5 , gate  30  is urged to the closed position by the combined action of compression spring  40 , spring pin  50  and control link  60 . Compression spring  40  and spring pin  50  are loosely contained within hole  42 . Hole  42  opens into slot  32 . 
         [0056]    Compression spring  40  is typically fabricated by coiling a corrosion resistant material, for example 17-7 PH stainless steel spring wire. Spring pin  50  is fabricated by machining a corrosion resistant material, for example brass or stainless steel. Machining, swaging or forging a corrosion resistant material, for example brass or stainless steel, are typical ways to fabricate control link  60 . 
         [0057]    Compression spring  40 , in conjunction with spring pin  50 , applies a force against compression surface  62  of control link  60 . Control link  60  transmits the force through tip  68  to notch  26  on body  20 . Notch  26  is adjacent but offset inward from the center of hinge pin  36 . The offset distance provides the leverage that pushes gate  30  closed. To keep gate  30  firmly closed, compression spring  40  is somewhat compressed even when gate  30  is closed. 
         [0058]    Referring again to  FIGS. 2 and 3 , control link  60  is located within slot  32  adjacent leg  22  of body  20 . Control link  60  protrudes a short distance above the top of gate  30  at  64 , and a short distance below gate  30  at  66 . Sufficient clearance is provided between slot  32  and control link  60  so that control link  60  can move without binding. 
         [0059]    Control link  60  pivots around tip  68 . Tip  68  nests within notch  26 . Referring to  FIG. 7 , when an external force (depicted by the outline arrow in  FIG. 7 ) causes gate  30  to open, control link  60  pushes spring pin  50  into hole  42 , compressing spring  40 . Opening movement of gate  30  carries control link  60  with it, causing tip  68  to pivot at notch  26 . For gate  30  to open, that portion of control link  60  having compression surface  62  must move with pin  50  into hole  42  and recess  43  adjacent hole  42 . When gate  30  is open, the force of spring  40  against control link  60  urges gate  30  to return to the closed position. 
         [0060]    Referring to  FIG. 5 , control link  60  can be moved to a down position or an up position by pushing in the direction of outline arrows “A” or “B” respectively. Control link  60  moves in a short arc from one position to the other by pivoting tip  68  within notch  26 . The pushing of control link  60  by force “A” is facilitated by protrusion  64 . The pushing of control link  60  by force “B” is facilitated by protrusion  66 . Moving control link  60  in the direction of arrow “A” causes control link  60  to move to the unlocked position. Moving control link  60  in the direction of arrow “B” causes control link  60  to move to the locked position (control link  60  is shown in the locked position as a dashed line in  FIG. 5 .) 
         [0061]    Referring to the locked position shown in  FIGS. 4 and 5 , control link  60  has pivoted so that compression surface  62  no longer completely aligns with surface  52 , but also abuts locking surface  92  of pin  90 . Pin  90  transverses gate  30 . The abutment of compression surface  62  with locking surface  92  immobilizes control link  60 , which consequently immobilizes gate  30 . 
         [0062]    When control link  60  moves between the locked and unlocked positions, compression surface  62  slides across surface  52 . Smooth movement of control link  60  is facilitated when surfaces  52 ,  92  and  62  line-up and are relatively smooth. Furthermore, movement of control link  60  is also facilitated when surface  52  is perpendicular to an intersection with the pivot point of control link  60 . Accordingly, the center axis of hole  42  approximately intersects notch  26  on body  20 . 
         [0063]    Forming compression surface  62  as an arc or spherical surface having radius  60   r  centered at tip  68  facilitates pivotal movement of control link  60 . As best seen in  FIGS. 4 and 5 , spring  40  forces surface  52  against surface  62 , and portions of surfaces  62  and  52  are always in contact. Consequently friction holds control link  60  either in the locked or unlocked position. 
         [0064]    The tangential relationship of surfaces  52  and  62  with respect to notch  26 , and their relative locations within gate  30  with respect to pin  90 , are chosen to enable control link  60  to have two stable positions, either locked or unlocked. As such, control link  60  operates as a switch that can be pivoted from one stable position to the other by either pushing against protrusion  64  or protrusion  66 . Movement from the locked to the unlocked position, and the opposite, produces an audible “snap” that can be heard by the climber. In addition, the position of control link  60 , either up or down, provides a visual and tactile indication of the state of the inventive locking mechanism. 
         [0065]    As described supra, when compression surface  62  abuts surface  92 , gate  30  cannot move. For the inventive carabiner to be assembled and lock properly, dimensions must be chosen and manufacturing tolerances controlled so that compression surface  62  will make proper contact with locking surface  92  when gate  30  is closed and locked. 
         [0066]    A small amount of clearance between surfaces  62  and  92  is required to allow pivotal movement of control link  60  to and from the locked position. On the other hand, if too large a gap exists between surfaces  62  and  92 , for example due to excessive tolerance stack-up or wear and tear, unwanted movement of gate  30  will occur before the two surfaces engage. Conversely, if the fit is too tight it will be difficult to assemble the carabiner and it may not be possible to move control link  60  to the locked position. 
         [0067]    Pin  90  is preferably hardened steel so there will be little or no wear of the pin over the lifetime of the inventive carabiner clue to locking and unlocking movement of control link  60 . Furthermore, dimensional variations clue to tolerance stack-up can be compensated by slightly changing the curvature of compression surface  62  so that locking movement of control link  60  progressively engages locking surface  92  of pin  90 . 
         [0068]    The preferred configuration incorporates pin  90  to distribute forces from compression surface  62  into the structure of gate  30 . For the preferred configuration of  FIGS. 2-7 , pin  90  at least partially overhangs the opening of hole  42 . The intersection of pin  90  with hole  42  allows locating pin  90  and hole  42  within the space constraints of a bent gate. Spring pin  50  is notched at  51  to provide clearance around the overhanging portion of pin  90 . Pin  90  advantageously holds spring  40  and spring pin  50  inside hole  42  during subassembly, which significantly helps the assembly process. 
         [0069]      FIGS. 8-10  picture an alternate configuration of the inventive locking mechanism that works the same as described for the configuration of  FIGS. 2-7 . As examples of other carabiner configurations that can incorporate the inventive locking mechanism,  FIGS. 8-10  show gate  30  straight and the opening end of the gate uses a pin and slot interlocking configuration to engage the carabiner body when the gate is closed. 
         [0070]    The opening end of gate  30  includes pin  38  which transverses slot  34 . When gate  30  is closed, pin  38  rests against the top of notch  28  in body  20 , thereby limiting the closing movement of gate  30 . Notch  28  also serves to capture pin  38  when high tensile loads deform body  20 , thereby enabling gate  30  to carry part of the load transmitted through body  20 . Consequently, the carabiner is significantly stronger when the gate is closed. 
         [0071]    Referring to  FIG. 9 , pin  90  does not overhang the opening of hole  42 , consequently spring pin  50  does not need notch  51  nor does gate  30  need recess  43  adjacent the opening of hole  42 . Although the number of machining steps needed to fabricate this configuration is reduced, assembly is somewhat more difficult because the spring and spring pin are not retained by pin  90  during subassembly. 
         [0072]    Referring to  FIG. 11 , there is shown a configuration of the inventive carabiner in which surface  93  is machined a part of gate  30 . The material of choice for gate  30  is a lightweight, high strength material, for example aluminum alloy type 7075. The configuration of  FIG. 11  is not ideal because although an aluminum alloy is a strong material, its surface is relatively soft and wears quickly in comparison to a harder material, for example steel. Repeated locking and unlocking of control link  60  will eventually wear a relatively soft surface  93 , resulting in unwanted movement of gate  30  when the inventive carabiner is locked. 
         [0073]      FIGS. 12-14  show an alternate configuration that provides adjustment for the location of locking surface  92 . Setscrew  91  is provided so that the location of locking surface  92  can be adjusted relative to compression surface  62  to compensate for dimensional variations of the various components. Screwing setscrew  91  in or out with respect to gate  30  adjusts the location of surface  92 , thereby providing the proper clearance between surfaces  62  and  92 . End  94  of setscrew  91  is configured to facilitate adjustment by a screwdriver or socket-driver or-the-like after the carabiner has been assembled. 
         [0074]    During assembly of the inventive carabiner, setscrew  91  is retracted to provide ample clearance between the various components. After the inventive carabiner is assembled, control link  60  is moved to the locked position and setscrew  91  adjusted until locking surface  92  just makes contact with surface  62 . At the point where locking surface  92  makes proper contact with surface  62 , gate  30  will be unable to open unless control link  60  is moved to the unlocked position. After setscrew  91  is properly adjusted, a thread locking-compound, for example locktite, or a high-strength epoxy can be used to preserve the adjustment and strengthen the threads. 
         [0075]    Referring to the unlocked position shown in  FIG. 13 , the movement of control link  60  in direction “A” has moved compression surface  62  away from setscrew  91  and surface  92 . When compression surface  62  completely lines-up with surface  52  of spring pin  50 , control link  60  will be able to move axially with spring pin  50  into hole  42 ; therefore gate  30  can be opened as shown in  FIG. 14 . 
         [0076]      FIG. 15  shows an alternate configuration in which the length of control link  60  can be adjusted by threading screw  91   a  into the blunt end of control link  60 . Screw  91   a  is adjusted to provide the proper clearance between surfaces  62  and  92 . Screw  91  a must be adjusted before assembly, an arrangement that is not as convenient as the configuration of  FIG. 12 . Other configurations can be used to adjust the length of control link  60 , for example control link  60  can be configured as two parts that mate together without threads that provide an adjustment for length by using shims or spacers or-the-like between the two parts. 
         [0077]      FIG. 16  shows another alternate configuration in which the location of notch  26  can be adjusted. Screw  91   b  threads into the leg end of body  20 . Screw  91   b  is adjusted to provide the proper clearance between surfaces  62  and  92 . Screw  91   b  is configured to facilitate adjustment by a screwdriver or socket-driver or-the-like after the carabiner has been assembled. 
         [0078]    Climbers are often in precarious positions in which only one hand is available to insert a rope into a carabiner (typically the other hand is occupied holding on to another climbing aid or the rock surface). Under such circumstances it is imperative that the carabiner be unlocked and easily opened. Because the inventive locking carabiner has two stable positions, either locked or unlocked, and control link  60  can be easily moved with one finger; a climber can unlock the carabiner (if it is not already unlocked), open and close gate  30  as many times as need, and when appropriate, lock the carabiner, all with the use of one hand.  FIG. 17  illustrates one of the many ways the inventive carabiner can be unlocked with one hand, 
         [0079]      FIG. 18  is a partial cross section of a typical prior art, non-locking carabiner. A comparison of the inventive configuration of  FIG. 4  with  FIG. 18  will reveal that conversion to the preferred inventive locking configuration requires the replacement of link  161  with control link  60  and the addition of spring pin  50  and pin  90 . Gate  30  must be appropriately machined to accommodate control link  60  and pin  90 . Because the gate return spring provides the force that, in addition to closing the gate, holds the inventive locking mechanism either in the locked or unlocked positions, the new components and accompanying modifications can be incorporated with little addition to the manufacturing cost of a basic carabiner. Consequently, a carabiner incorporating the preferred inventive locking mechanism can be sold with a relatively small price increase over the cost of a non-locking version. 
         [0080]      FIG. 19  is a partial cross section of a typical prior art locking carabiner. Sleeve  100  is threaded nut-like to gate  30  and can be screwed along the length of gate  30  either toward or away from leg end  24  of body  20 .  FIG. 19  pictures sleeve  100  in position against leg end  24 , thereby immobilizing gate  30 . The prior art configuration illustrated by  FIG. 19  is securely locked when sleeve  100  is jammed against leg end  24 . 
         [0081]    The prior art configuration illustrated by  FIG. 19  is considered by climbers to be the “gold standard” of locked security and is the preferred configuration for attaching climbing rope, rappelling and belay equipment and-the-like to the climber&#39;s body harness. However the locking carabiner of  FIG. 19  is not suitable for quickdraw use due to its weight and the possibility that the gate may be locked or will lock when a climber is trying to clip a rope. Furthermore, the locking sleeve of  FIG. 19  will not function on a bent gate carabiner. 
         [0082]    Other variations on the shape and/or relative locations of the carabiner body, gate, spring, linkage and lock release are contemplated. For example the locking mechanism could conceivably be reversed in orientation so that the tip in the control member pivots within a notch in the gate and the spring assembly is located within a hole in the leg end of the body. It is understood that those skilled in the art may conceive of modifications and/or changes to the invention described above. Any such modifications or changes that fall within the purview of the description are intended to be included therein as well. This description is intended to be illustrative and is not intended to be limitative. The scope of the invention is limited only by the scope of the claims appended hereto.