One hand tourniquet with locking mechanism

Provided is a tourniquet having two opposing and pivotally movable plates. The plates comprise a clamp that pinches an elastomeric cord. The plates are pivotally biased together by a spring. The cord is attached to a back end of the clamp. A free end of the cord is squeezed by the plates such that a loop of cord is provided. The cord can be pulled from the clamp to reduce the size of the loop. The clamp comprises a safety lock that prevents movement of the plates and slipping of the cord. The safety lock can comprise a button disposed between the plates in the back end of the clamp, preventing the plates from moving together in the back portion, and therefore from moving apart in a front portion that grips the cord. Also, the tourniquet clamp can comprise a dual-sided press connector mechanism for fast release of tourniquet tension.

FIELD OF THE INVENTION

The present invention relates generally to tourniquet devices for blocking blood flow to an injured limb. More particularly, the present invention relates to a tourniquet device that can be applied, adjusted, and released with one hand.

BACKGROUND OF THE INVENTION

Tourniquet devices are commonly used in emergency medicine to stop blood flow to and bleeding from an injured limb. Tourniquets employ a length of cordage tightened around a limb to stop blood flow and allow clotting to occur. After a tourniquet is applied long enough to allow blood clotting or to stabilize the injury, in some cases the tourniquet can be slowly and partially released to prevent damage to the injured limb. It is important for tourniquets to maintain tension reliably; a sudden accidental release of tourniquet tension can result in significant loss of blood and renewed bleeding.

Sometimes it is necessary for an injured person to apply a tourniquet to himself. An injured person losing blood is weak and will be unable to apply a large force. Additionally, a person applying a tourniquet to himself typically will not have favorable leverage to apply force. Therefore, it is important in this case for the tourniquet to be settable with one hand and with a small amount of applied force. Also, the tourniquet should be able to be controllably loosened without unintentionally releasing the tourniquet pressure completely.

Tourniquets are essential in emergency medicine and are standard equipment for military and emergency medical personnel. Tourniquets sometimes need to be carried to remote areas and used in dirty outdoor conditions. For this reason, tourniquets should be small, durable, lightweight and reliable.

U.S. Pat. No. 4,125,115 to Mayo et al. describes a tourniquet employing a semi-elastic belt clamped between a jamming edge and a roller. The tourniquet of Mayo et al. does not provide a mechanism for locking tourniquet tension so that the tourniquet cannot be accidentally released. Mayo et al. has release mechanisms that can be easily triggered accidentally, resulting in sudden and complete loss of tourniquet tension. This is dangerous to injury victims, because sudden loss of the tourniquet can result in significant additional loss of blood.

It would be an advance in the art of emergency medicine and tourniquet design to provide a tourniquet that is reliably lockable and not prone to accidental release. It would also be beneficial to provide a tourniquet that can completely stop blood flow with a relatively small amount of applied force, so that an isolated single injured person can apply the tourniquet to himself.

SUMMARY

The present invention includes a one hand tourniquet having a tourniquet clamp. The tourniquet clamp has two pivotally mounted members, which may be plates, flat plates or other shapes. The members are biased together at a front end and biased apart at a back end. The members may be biased by a torsion spring, for example.

The tourniquet has an elastomeric cord. The elastomeric cord is secured to the back end, and passes between the members at the front end. The cord is therefore pinched between the members. Also included is a safety lock which prevents pivotal movement of the members when locking is desired.

The elastomeric cord can comprise a plurality of elastomeric cords. The elastomeric cords can be separately adjustable. Preferably, the elastomeric cords have a maximum elongation of at least 75%.

The safety lock can comprise a button that is insertable between the members in the back end. The safety lock will prevent the members from moving towards one another in the back end portion of the clamp. The button can comprise a U shape with flexible legs that allows it to be pressed through a hole in one of the members. The button preferably has steps that engage and lock with the hole, thereby preventing movement of the members.

Also, the tourniquet can comprise a dual sided press connector for rapidly releasing the tourniquet. The dual sided press connector can be attached to the back end of the tourniquet clamp.

DETAILED DESCRIPTION

The present invention provides a tourniquet that can be applied with one hand and requires only a small amount of force to completely stop blood flow. The present tourniquet comprises a pair of plates that are pivotally connected and biased together on a front end to form a clamp. The clamp allows elastomeric cord material to be pulled from the tourniquet such that the tourniquet is tightened. The tourniquet also includes a safety lock for preventing the plates from moving after the tourniquet has been set. Preferably, the safety lock comprises a button that jams the plates apart on a back side, thereby preventing the plates from moving apart on the front side. Additionally, the tourniquet may include a dual-sided press connector (e.g. similar to well known connectors sold under the trademarked names FASTEX™ or SIDE SQUEEZE™) for allowing rapid but accident-resistant release of the tourniquet.

FIG. 1shows a perspective view of the tourniquet clamp of the present invention.FIG. 2shows a cross sectional side view of the clamp, in combination with a cord18.

The clamp has a front end20and a back end22. The clamp comprises a top plate or member24and a bottom plate or member26. The plates are pivotally connected at pivot point28. The top plate24has teeth30for grasping a cord18(not shown inFIG. 1) against a roller32. The plates24,26are urged by spring36such that the teeth30and the roller32are biased together. The spring36causes plates24,26to be biased apart at the back end22. As seen inFIG. 2, the cord is pinched between the teeth30and roller32due to the action of the spring36. Preferably, the bottom plate28has a hole25for accommodating the cord18. The cord has a portion17secured to the back end22of the clamp (e.g. by tying or sewing, for example). The cord18may have a handle19for grasping with one hand. The tourniquet has a loop area38for disposing around an injured limb.

In operation, the injured limb (not shown) is disposed in the loop area38. The handle19is grasped and pulled. The clamp allows the loop area38to become smaller, but not larger. In other words, the clamp allows the cord18to pass between the teeth30and roller32in only one direction23.

A benefit of the present invention is that only a small force applied to the handle will create a relatively high tension in the cord18and high compression in the loop area38.

Preferably in the present invention, the cord is made of highly elastic material having a high capability for stretching. For example, the cord can be made of multifilamentary elastic material known by the tradename BUNGEE™ cord. The cord preferably has a capability of at least about 50%, 75%, 100%, or 150% elongation. High elasticity and elongation provides mechanical advantage for the user and therefore allows the user to more easily achieve high tension in the cord18and high compression in the loop area38. The cord can comprise a single round or rectangular cord, or can comprise a wide strap similar in shape to webbing material. Alternatively, the cord can comprise several parallel round cords or wide straps, with each cord or strap having a separate handle19. If several parallel cords are employed, then they can be tightened one cord at a time. One cord at a time tightening allows a weak user to achieve high tension in the cord (since tension is additive) and highly effective isolation of the injured limb. One cord at a time tightening will also provide high tension needed for isolating legs and other limbs that are difficult to isolate by tourniquet.

The plates24,26can be made of stamped steel, molded plastic or other suitable materials. The roller32can also be made of plastic or metal.

A button34provides a safety lock mechanism. Button34is disposed between the plates24,26at the back end22. The button holds the plates24,26apart in the back end, thereby preventing the plates24,26from releasing their grip on the cord18. The button34may have a step35on an external surface that engages hole40in the top plate. The step35holds up the top plate24and prevents it from moving toward the bottom plate26, thereby assuring that the tourniquet clamp does not loosen.

FIGS3and4illustrate insertion and usage of the safety lock button34. Preferably, the safety lock button34has a U shape as shown. The U shape allows legs50a,50bof the button to be flexed by pressing together as illustrated inFIG. 3. When pressed together, the button34can be inserted through hole40in the top plate24. When fully inserted, the legs50a,50bspring back to shape, and the top plate is immobilized by the step35. The button34should have strength and resiliency so that the legs50a,50bare strong enough to withstand compressive forces for a long duration, and so that the legs50a,50bcan flex to allow insertion of the button34. The button34can be made of molded nylon or spring steel, for example.

In operation, the button34is inserted into the tourniquet clamp after the clamp has been tightened to its desired tension. The button34will lock the tourniquet clamp and not allow loosening of the tourniquet. However, in some embodiments, the tourniquet may be tightened further after insertion of the button34.

Alternatively, the button34can be inserted through the hole42in the bottom plate26. In this case the button is inserted into the clamp before it is applied to an injured limb.

In order to remove the button34, and release the tourniquet, the leg50ahaving the step35is pressed inwardly as illustrated by arrow45inFIG. 4. Then, the button can be pressed through the hole42or hole40. Alternatively, both legs50a,50bare pressed together. The leg50amust be pressed sufficiently such that the step35can pass through the hole40.

It is noted that leg50a, located toward the back end22should have a step35; leg50b, located toward the front end20may or may not have a step35.

Hole42in bottom plate26is optional in the invention.

FIG. 5shows an alternative embodiment in which the top plate24does not have hole40. In this case, a top surface of button34presses against the top plate24, thereby locking the tourniquet clamp.

FIGS. 6 and 7illustrate another embodiment of the invention in which a dual sided press connector52is used to attach the cord18to the clamp. InFIG. 6, the dual sided press connector is disconnected; inFIG. 7the dual sided press connector is connected. Dual sided press connectors require a pressing action on both sides of the connector in order to release the mechanism, as illustrated inFIG. 7. In the embodiment ofFIG. 6, the connector has a male portion53with flexible tongs54and barbs56. A female portion55has edges57for engaging the barbs56. However, it is noted that these features are not essential in the dual sided press connector. The present invention requires only that the connector be releasable by pressing from two opposing sides, as illustrated inFIG. 7. A connector that requires two-sided press action for release is unlikely to be accidentally released. This is a great benefit in emergency situations because the accidental release of a tourniquet can be dangerous as it allows further loss of blood. In a particular embodiment, the dual sided press connector is used in combination with the clip34embodiment illustrated inFIGS. 2-5.

Dual sided press connectors are well known in the art and commonly used in backpacks, luggage and the like. For example, U.S. Pat. No. 4,150,464 describes a dual sided press connector. Dual sided press connectors are commonly sold under the tradenames FASTEX™ and SIDE SQUEEZE™. Typically, dual sided press connectors are made from molded nylon or other polymers.

Although the present tourniquet clamp has been described as comprising plates, the invention is not so limited. The tourniquet clamp does not necessarily comprise plates or flat plates. The tourniquet clamp can comprise any curved or shaped members that are pivotally mounted to one another.

It will be clear to one skilled in the art that the above embodiment may be altered in many ways without departing from the scope of the invention. Accordingly, the scope of the invention should be determined by the following claims and their legal equivalents.