RU171075U1 - DISPOSABLE SYRINGE FOR ONE TIME APPLICATION - Google Patents

Abstract

A single-use syringe for single use is intended for injections and other medical procedures related to the infusion or suction of a liquid. The device is a medical syringe with a piston cuff, the piston of which is made of elastic material in the form of a double cuff, in which the rear cuff located on the side of the rod has a smaller diameter and does not come into contact with the inner surface of the housing in a free state. The tightness of the syringe during fluid collection is ensured by the back cuff due to interaction with a rigid expansion ring, with an interference fit installed directly in the housing directly behind the piston from the stem side: the moving piston with the back cuff pushes the expansion ring, as a result of which the lip of the cuff expands all the way into the inner surface of the housing. During the release of fluid, the tightness of the interface between the piston tip moving towards the stationary body is ensured by a front cuff of normal diameter. In this case, the expanding ring remains in the extreme position achieved during the set. As a result, the back cuff is compressed to the original diameter during the process of fluid release and, without contact with the expanding ring, cannot ensure the tightness of the syringe when trying to re-set.

Description

The claimed technical solution can be used in the field of medicine.

Known [1] is a three-component disposable syringe, which contains a hollow cylindrical body with a tip and a piston made of elastic material, moved inside the body using a rod.

The disadvantages of this device include the possibility of its use an unlimited number of times.

A medical syringe with a piston cuff [2] is also known, the piston of which is made in the form of a double cuff of elastic material.

The disadvantages of this device include the possibility of its use an unlimited number of times.

As the closest analogue, a medical syringe with a piston-cuff [2], the piston of which is made in the form of a double cuff from an elastic material, was selected.

The disadvantages of this device include the possibility of its use an unlimited number of times.

The task to which the claimed technical solution is directed is to ensure that only one syringe filling-emptying cycle is possible.

The problem is solved due to the fact that in the design of a medical syringe with a piston-cuff, the piston of which is made in the form of a double cuff of elastic material, the following difference is provided: the working edge of the back cuff directed toward the rod, the outer diameter of which in the free state is less than the inner diameter of the case , is pressed against the inner surface of the housing due to the abutment in a rigid expansion ring installed with an interference fit into the syringe body directly behind the piston from the side of the rod.

The technical result of using the utility model is the ability to carry out only one cycle of filling-emptying the syringe.

1. Sabitov V.Kh. Medical instruments. - M .: Medicine, 1985, 175 p.

2. Trusov M.M., Babkin S.I. Medical syringe with piston cuff. Copyright certificate for the invention of the USSR No. 125879. 1960.

The technical nature and principle of the utility model is illustrated by drawings, which depict:

FIG. 1 - Scheme of a disposable syringe for single use, in a free state without an expanding ring (a) and in the initial state (b). 1 - housing; 2 - the piston; 3 - stock; 4 - tip; 5 - front cuff of the piston; 6 - a back cuff of the piston; 7 - expanding ring.

FIG. 2 - Scheme of operation of a disposable syringe for single use (thick arrows indicate the direction of movement of the rod; thin arrows indicate the direction of movement of the liquid; dotted lines indicate the direction of movement of air), and a set of fluid; b - the position reached by the piston at the end of the set; in - release of fluid; g - an attempt to re-fluid.

The ability to implement the claimed utility model is shown by the following examples.

The outer diameter of the working edge of the front lip (5) of the piston (2) located on the tip side (4) in the free state exceeds the internal diameter of the housing (1), and the diameter of the working edge of the rear lip (6) of the piston is smaller than the internal diameter of the housing. For this reason, the piston in the absence of an expanding ring (7) is sealed in the syringe body only by the working edge of the front cuff (Fig. 1a). In the initial state (Fig. 1b), the piston (2) is pushed all the way into the housing (1) together with an expanding ring (7), which, abutting against the piston from the side of the rod, extends the elastic rear working edge until it contacts the inner surface of the housing throughout circles. At the first fluid collection (Fig. 2a), the piston moves along the axis of the syringe away from the tip, pushing in front of it an expanding ring that presses the working edge of the back cuff to the inner surface of the housing, which ensures the tightness of the syringe during fluid collection. When the piston stops in the extreme position (Fig. 2b) achieved during the set, the tightness is ensured by the working edge of the front cuff pressed against the inner surface of the housing due to the elasticity of the material of which the piston is made. When the liquid is discharged (Fig. 2c), the piston moves towards the tip, and the expanding ring that is not attached to the piston, due to the interference, remains in the extreme position reached during the set. The remaining free working edge of the back cuff is compressed and ceases to contact the inner surface of the syringe body. In this case, the tightness of the syringe is ensured by the working edge of the front cuff, which is pressed against the inner surface of the housing by the excess pressure that occurs inside the housing under the action of a moving piston. When you try to re-fluid (Fig. 2d) in the housing there is a vacuum, squeezing the working edge of the front cuff from the wall of the housing, as a result of which the syringe is filled with air through the occurring leaks between the piston and the housing.

The claimed utility model is used as follows.

The device is used as a regular medical syringe and does not require any additional actions from the operator.

Claims (1)

A disposable single-use syringe, which is a medical syringe with a piston-cuff, the piston of which is made in the form of a double cuff of elastic material, characterized in that the working edge of the back cuff directed toward the rod, the outer diameter of which in the free state is smaller than the inner diameter of the case, is pressed to the inner surface of the housing due to the abutment in a rigid expansion ring mounted with an interference fit into the syringe body directly behind the piston from the stem side.

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