The claimed group of inventions relates to a field of medicine, in particular, to medical equipment, as well as to a field of manufacturing fittings for belt systems, especially for those which may be used in providing a first aid to arrest an external arterial hemorrhage coming from injured limbs. Additionally, the belt buckle and the belt drawing mechanism may be used not only in structures of hemostatic mechanical devices of a “tourniquet” type, but in other belt systems as well.

At present, various hemostatic “tourniquet” type devices are known, and their developers were focused on providing a hemostatic strap (a tourniquet) having such mandatory properties as a possibility of ease and quick application and removal; rigidity and reliability of stretching and tensioning elements; efficiency and speed of hemorrhage arrest; lack of elements which may damage skin and arteries, as well as result in a tissue necrosis, while twisting the strap on a limb; performing a metered compression of tissues, thereby enabling a uniform pressure; compliance with sanitary and hygienic requirements; usability in combat and other extremal conditions. Developers have resolved the posed tasks in various ways, but some aspects have not been considered.

The prior art teaches the most widespread strap being Combat-Application- Toumiquet (CAT) [US 7,842,067, US 7,892,253 and further improvements] that is a part of equipment of worldwide armies and special operation units, in particular, military personnel of NATO and USA armies. The tourniquet comprises a tensionbearing element (a belt strip) having a “Velcro” fastener for fixation on a limb, a single buckle, a windlass rod, a windlass clamp having a double-sided tapered intake, a lock and a buttress, a windlass belt, a stabilization plate in a form of a reinforced tapered contact bar.

In the opinion of the developer of the proposed group on inventions, together with confirmed high convenience and efficiency, the CAT straps have the following relative drawbacks. In view of a non-removable structure of the strap, its re-use is impossible, since it is not possible to clean the belt strip from dirt and blood completely or to replace it.

The fixation of the belt strip on the limb by means of the “Velcro” fastener cannot provide a sufficient reliability of the strap operation in difficult conditions (water, dirt etc.).

Fixation of the windlass is performed by its installation into the lock that is arranged statically on the belt, thereby restricting a control of a tension degree. If the strap is applied over clothes, rolling of the windlass may become more difficult in view of engagement of the windlass with folds of the clothes or a pattern of the limb. The belt buckle is tensioned by rolling the windlass and screwing the belt buckle which requires applying of a significant muscle force. The most effective rolling may be made with both hands, while it is rather hard to make it with one hand which may become crucial in case of a self-aid. Besides, rolling of the windlass requires to dispose the hand in an initial position after one rolling and to repeat the movement until the required tension degree is achieved, thereby affecting the speed of the tensioning process. Besides, it is necessary for the user to apply significant forces of windlass rods (windlass) predominantly with fingers which is rather difficult and inconvenient in case of hard tensioning. If the windlass rod is lost, it will be affected by a resistance force and become to unwind.

Also, other structures of the hemostatic strap are known, but the drawbacks of the previous analogue are not considered at all or considered partially. At the same time, the operation principle is also based on the rolling of the tension-bearing element (belt, belt strip) by means of the windlass or windlass rod. The tensionbearing element itself is non-removable, thus, it cannot be replaced, while the whole device cannot be used again.

Also, an extremity tourniquet with a locking buckle is known [CA3040323]. The tourniquet for occluding hemorrhage in a distal portion of a person's limb comprises: a tension-bearing element being a belt having a plurality of openings which are spaced apart from each other along a length of the belt; a buckle having a pin for engaging with one opening of the plurality of the openings after a basic tension is reached; a movable element being a slider having a contact surface for the belt, wherein a frame and the slider together form a passage for receiving the belt that passes through the opening, along and in contact with the contact surface of a slider strip. A tension increasing mechanism is made according to a Spanish windlass principle and comprises a winding element that is attached to the tensionbearing element and acts effectively to shorten a portion of the tension-bearing element and forms a loop. The buckle is constantly attached to an opposite, second or inner end of the belt by means of the loop of the belt that is fixed around a portion of the buckle. A substrate may be made of a corresponding rigid plastic resin or a sheet metal, while the belt may have a thread.

As used herein, the term “constantly attached” means that removal and re-use cannot be easily accomplished by a user and cannot be easily performed without using equipment that is similar to the one that is required during first manufacture of the tourniquet.

In this device, in contrast to the previous analogue, the belt is fixed on the limb by means of the openings and the buckle with the pin. In view of this, it is not possible to effectively adjust the tension degree, since the pin cannot be fixed in areas between the openings. A tourniquet for restricting a flow of blood is known [EP 1753344], the tourniquet comprises a first elongated element including: a first end for a loop through a second end comprising a buckle; characterized in that the first elongated element further comprises: a surface comprising both a hook and a loop; a pocket. The tourniquet further comprises: a second elongated element that is arranged in the pocket, wherein a portion of the second elongated element is connected to the first end of the first elongated element; a windlass that is engaged to the second elongated element, wherein the windlass is rotated to create a stretching force in the second elongated element. Therewith, a compression force is applied to a body part, thereby restricting the blood flow within the body part. At least one hook or fastening belt is connected to the first elongated element in order to engage with a portion of the windlass and to avoid any back rotation of the windlass after the stretching force is applied.

Also, a hemostatic tourniquet is known [RU 2642271], the tourniquet comprises an elastic strip of the tourniquet and a locking device of start and end areas of the elastic strip of the tourniquet in a location of the tourniquet application, where the locking device is made in a form of a plate having at least two transverse slots arranged along its longitudinal sides, wherein a width of the slot is 0.75-0.8 of a thickness of the tourniquet strip, and a length of the slot is equal to a width of the tourniquet strip, and the transverse slot, from one side of the plate, is intended for arranging the start area of the elastic strip of the tourniquet, while the transverse slot, from another side of the plate, is intended for arranging the end area of the elastic strip.

Drawbacks of this analogue lie in that the locking element does not allow to tension the elastic strip rather quickly and strongly. The structure of the locking element does not enable to make any further fixation sufficiently reliable. Besides, it is almost impossible to apply this tourniquet with one hand in combat and other extremal conditions.

A hemostatic strap-type tourniquet is known [RU 177 273], the tourniquet comprises a base made of a high strength fabric with a means for fixing a position of the wristlet and a carabiner, the means is attached to the base by means of a pull-cord, as well as a belt with a buckle that can be fixed to the base by means of the carabiner to form a girth loop, characterized in that the base is made of a belt strip and at least a portion of its surface, from a side that is intended to be applied to a body, comprises a patch made of an elastic material that is permanently bound to said surface, A sling with a collar is fixed on the base with its both ends, bound to the belt that is made of a belt tape through a metal frame that is arranged on the sling in a freely movable fashion, and a buckle is made as a self-clamping buckle. The buckle consists of a frame and a toothed fastener hingedly connected between each other, the toothed fastener has a hole for fastening in the carabiner.

A protective strip, at least on a portion of its surface, is made as a loop strip, and at least a portion of an external surface of a bracket is provided with areas which are provided with a' hook strip. The protective strip is made fully replaceable after being used by pulling it from beneath the bracket and mounting a new one. After the protective strip is removed from the used and released tourniquet, the protective strip is released by means of a “Velcro” fastener, while the tourniquet is sent to washing/cleaning/sanitary treatment etc. In order to re-use the tourniquet, after the required treatment is performed, a new protective strip is mounted on the tourniquet by means of its fixation by means of the “Velcro” fastener.

When developing this analogue, the inventors have made a step towards making the tourniquet structure reusable. However, eventually, to this end, the tourniquet, including its fabric base, must undergo special sanitary treatment which is not effective in terms of good removal of dirt and required disinfection. The removable protective strip does not resolve this problem, since the fabric base is the most contaminated element. It is not recommended to re-use this tourniquet.

Therefore, at present, there are numerous different modifications of hemostatic tourniquets which operation usually comes either to circular tying of the limb with elastic material or to creation of a compression force due to rotation of a handle (the windlass). Fixation of the belt on the limb is usually performed by means of the “Velcro” fastener or toothed mechanism, thereby making the adjustment of loop size inconvenient and slow. None of the mentioned analogues has been taken as a prototype by the inventor of the claimed group of inventions.

Technical tasks of the claimed invention are as follows:

- to provide a hemostatic tourniquet structure that could avoid a problem of mandatory conduction of additional drawing manipulations which are intended not to arrest the hemorrhage, but to fix a drawing mechanism in recesses of a fixation element of the tourniquet;

- to avoid a problem of self-untwisting of the belt and/or the drawing mechanism of the tourniquet during drawing it around a damaged limb;

- to avoid a problem of any possible pinching of clothes and/or skin of the injured person during drawing of the tourniquet.

Another technical task is to provide a reusable hemostatic tourniquet.

The posed technical tasks are resolved by a screw mechanical hemostatic tourniquet and its components as described hereinafter. A belt drawing mechanism comprises a housing that is provided with an opening for installing a forcing screw, the forcing screw itself having a large thread pitch and a drawing bar having a threaded through opening. Therewith, the forcing screw is installed in a rollable fashion both in the opening of the housing and in the opening of the drawing bar by means of rolling of a windlass rod connected thereto in a clockwise or a counterclockwise direction, thereby moving the drawing bar towards a head of the forcing screw and in an opposite direction depending on a rotation direction of the windlass rod.

In a preferable embodiment of the belt drawing mechanism, the head of the screw is provided with a deep slot that is designed to receive the windlass rod, and they are connected between each other by means of a screw connection.

In a preferable embodiment of the belt drawing mechanism, a foldable handle is used as the windlass rod 8.

In a preferable embodiment of the belt drawing mechanism, an anti-friction washer is arranged between the opening of the housing and the head of the forcing screw.

In a preferable embodiment of the belt drawing mechanism, the drawing bar, on both its sides, has protrusions for a directed movement along lateral edges of the housing.

In a preferable embodiment, the belt drawing mechanism comprises at least three rollers 14 with the belt 3 passed therethrough, and the rollers are inserted into the openings 15 of the housing 5, while at least one of the rollers 14 is fixed on the housing 5 by means of a bolt connection.

A belt buckle that consists of a plate having at least two slots, while a fixation spring is placed over them on top of the plate, and the fixation spring is shaped as two interconnected loops and has such a width L that in extended state (due to tension of the belt 3 that is fixed on the limb of the injured person and passed to the belt buckle 2 from its both ends), edges of the spring extend to external limits of the slots of the plate, thereby clamping and reliably fixing the belt in the belt buckle.

In a preferable embodiment of the belt buckle, the fixation spring is made Z- shaped and has bent ends.

The screw mechanical hemostatic tourniquet that consists of the belt, as well as of the above-mentioned belt drawing mechanism and the belt buckle in which the belt is loaded. Therewith, the belt is provided with at least one opening through which it is fixed on the drawing bar by means of the forcing screw. In a preferable embodiment, the screw mechanical hemostatic tourniquet comprises a protective cover that is a plate provided with at least two openings in which the belt is passed.

In a preferable embodiment of the screw mechanical hemostatic tourniquet, the edges of the opening of the belt are reinforced with a grummet.

In a preferable embodiment of the screw mechanical hemostatic tourniquet, at least one end of the belt is made as a loop.

A technical effect is that, firstly, this hemostatic tourniquet allows to tie the limb of the injured person so good that the hemorrhage is arrested, but at the same time to avoid putting too much pressure on it, owing to the structure of the belt drawing mechanism that enables to stop the belt drawing process once the hemorrhage is arrested and not to rotate the drawing mechanism further in order to fix the windlass rod by a fixation element as it is made when using the prior art hemostatic tourniquets. Besides, this structure of the hemostatic tourniquet significantly reduces the requirement in application of the muscle force during drawing of the belt, allows to avoid engagement and pinching of clothes of the injured person during installation of the tourniquet, and allows to install the tourniquet on the damaged limb using at least one hand. Secondly, owing to the structure of all components of the tourniquet, it is possible to replace the belt with a new one without any additional efforts, as well as to re-use other components after disinfection thereof, thereby making the screw mechanical hemostatic tourniquet reusable.

The essence of the claimed group of inventions is explained by the description below and schematic drawings, where:

Fig. la - The belt drawing mechanism with the windlass rod in an unfolded position and a roller that is secured on the housing with a bolt connection;

Fig. lb - The belt drawing mechanism with the windlass rod in a folded position with the opening of the tension bar shown in detail;

Fig. 2a - The belt buckle;

Fig. 2b - The plate of the belt buckle;

Fig. 3 - General view of the screw mechanical hemostatic tourniquet;

Fig. 4 - The protective cover.

The provided drawings and the description below illustrate only possible embodiments of the claimed group of inventions, rather than limit their scope of legal protection. A technical essence of each invention of the claimed group of inventions shall be determined only by a set of essential features which are stated in the claims.

The essence of the invention is as follows.

A screw mechanical hemostatic tourniquet (Fig. 3) consists of a belt 3, as well as a belt drawing mechanism 1 and a belt buckle 2 in which the belt is loaded. The tourniquet may further comprise a protective cover 4 in which the belt 3 is loaded as well. The belt 3 of the hemostatic tourniquet that is shown as loaded into the components of the hemostatic tourniquet in Fig. 3 comprises at least one opening that may be reinforced with a grummet.

The belt drawing mechanism that is illustrated in Fig. la and Fig. lb in detail comprises a housing 5 that is provided with an opening 6 for inserting a forcing screw 7, the forcing screw 7 itself having a large thread pitch and a drawing bar 10 having a threaded through opening 11. The forcing screw 7 is mounted in a rotatable fashion both in the opening 6 of the housing 5 and in the opening 11 of the drawing bar 10 by means of rolling of a windlass rod 8 connected to the forcing screw 7, thereby moving the drawing bar 10 towards a head of the forcing screw 7 or in an opposite direction depending on a rotation direction of the windlass rod 8.

This structure of the belt drawing mechanism avoids any probability of pinching of clothes and/or skin of an injured person during drawing of the tourniquet on a limb.

In a preferable embodiment of the belt drawing mechanism, a foldable handle that is convenient in terms of transportation and storage is used as the windlass rod 8, and the handle is inserted into a slot of the head of the forcing screw 7, and they are secured to each other by means of a screw connection.

In a preferable embodiment, an anti-friction washer 9 is arranged between the opening 6 of the housing 5 and the head of the forcing screw 7 in order to provide a more firm abutment of the forcing screw 7 to the housing 5 of the belt drawing mechanism 1.

In a preferable embodiment, the drawing bar 10, on both its sides, has protrusions 13 which allow a directed movement of the bar 10 along lateral edges 12 of the housing.5 during rolling of the forcing screw 7.

During loading of the belt 3 into the belt drawing mechanism 1 which is illustrated in Fig. 3, the drawing bar 10 is held with fingers of one hand, and the forcing screw 7 is rotated by rolling the windlass rod 8 with another hand until a gap is formed between the forcing screw 7 and the bar 10 which is necessary for passing the belt 3. In a location of the opening (reinforced with the grummet) of the belt 3, the latter is beaded onto a lower portion of the forcing screw 7, then the forcing screw 7 is loaded by rotating the windlass rod 8 in the opposite direction into the drawing bar 10, while the belt 3 is laid over the bar 10 on both sides from its slot.

In order to provide further fixation of the belt 3 in the belt drawing mechanism 1, the housing 5 may be provided with openings 15 for inserting at least three rollers 14 therein which the belt 3 is passed through, thereby securing at least one of the rollers on the housing 5 by means of a bolt connection.

The claimed structure of the belt drawing mechanism 1 enables to use it in any belt systems, rather than merely as an element of the hemostatic tourniquet.

Preferably, the belt 3 of the hemostatic tourniquet is made from an elastic and load-resistant material having reinforced edges in order to prolong its service life and to withstand loads. Besides, at least one of ends of the belt 3 may be made in a form of a loop that is formed by linking a free end of the belt to its base in order to improve a tying process of both ends of the belt around the limb of the injured person.

The tourniquet belt buckle illustrated in Fig. 2a consists of a plate 16 that is illustrated in Fig. 2b that is provided with at least two slots 17, while a fixation spring 18 is placed over them on top of the plate 16. The fixation spring is shaped as two interconnected loops and has such a width L that in an extended state (due to tension of the belt 3 that is fixed on the limb of the injured person and passed to the belt buckle 2 from its both ends), edges of the spring 18 extend to external limits of the slots 17 of the plate 16, thereby clamping and reliably fixing the belt 3 in the belt buckle 2, thereby avoiding any possible loosening of the belt 3 drawing on the limb.

In a preferable embodiment of the belt buckle, the fixation spring 18 is made Z-shaped and has bent ends. They do not allow the passed belt to extend beyond the loops of the fixation spring 18.

Fixation of the belt in the belt buckle is performed as follows. The first end of the belt is carried to a first portion of the first opening 17 of the plate 16 that is separated by the fixation spring 18, thereby directing the first end of the belt upwards. Then, the same (the first) end of the belt 3 is passed around the first loop of the fixation spring 18. This is performed by loading the first end of the belt 3 into a second portion of the first opening 17 of the plate 16 that is separated by the fixation spring 18, thereby directing the first end of the belt downwards and towards the base of the belt. The second free end of the belt is loaded into the second opening 17 of the plate 16 in the same way.

The protective cover 4 is a plate that is provided with at least two openings for passing the belt 3. This element avoids pinching of the skin or clothes of the injured person in the location of loading of the belt into the components of the screw mechanical hemostatic tourniquet.

The screw mechanical tourniquet is assembled in the following way. Firstly, the belt is fixed in the belt drawing mechanism 1 in the above-mentioned way. Then, if necessary, the ends of the belt are passed into the openings of the protective cover 4 in the same direction as follows: one end of the belt 3 is passed into one opening of the cover 4. Afterwards, two free ends of the belt 3 are passed around the limb of the injured person and loaded into the belt buckle in the above- mentioned way.

Drawing of the screw mechanical hemostatic tourniquet on the limb of the injured person is performed in the following way. Free ends of the belt are tensioned in a direction that is opposite to each other until a maximum possible drawing level of the belt is reached, thereby completing a first step of the tourniquet drawing on the limb of the injured person. Then, at a second step, the belt is finally drawn by rotating the forcing screw 7 of the belt drawing mechanism 1 by means of the windlass rod 8. During this manipulation, the forcing screw 7 is rotated in the opening 11 of the drawing bar 10, thereby lifting it along lateral edges 12 of the housing 5 towards the head of the forcing screw 7, thereby lifting the portion of the belt 3 that surrounds it together with the bar 10. By means of the windlass rod 8, the rotation of the forcing screw 7 is continued in the same direction until the hemorrhage is arrested.

Owing to the structure of the belt drawing mechanism 1 , after the windlass rod 8 is released, the force of the final drawing of the belt is not loosened in any case. The loosening is possible only due to rotation of the forcing screw 7 in the opening of the drawing bar in the opposite direction.

Owing to the structure of the belt buckle, during tensioning of the belt on the limb of the injured person, the fixation spring is extended, thereby resulting in abutment of the belt band to the edge of the opening of the plate, thereby avoiding a disbanding and free movement of the belt in the buckle.

After the screw mechanical hemostatic tourniquet has been used, the belt 3 can be easily removed, since there are no permanent fixations, e.g., places of joining of the belt between the components of the hemostatic tourniquet, by passing its ends in the opposite direction.

All the structural elements of the claimed- tourniquet, except for the belt, are preferably made from a rigid solid material, e.g., metal, plastic etc., which has a high service life, which is resistant to damages and which is easy to wash and disinfect. After the necessary sanitary treatment is completed, a new belt is installed on the screw mechanism and the buckle, and the device is ready to be used again.