RU162572U1 - DEVICE FOR INSTALLING AND REMOVING CERAMIC SCREWS - Google Patents

Abstract

A device for installing and removing ceramic screws, including a handle with a head, a collet clamp with petals mounted in the handle on the side opposite to the handle head, and a sleeve that compresses the collet clamp by means of a spring, the number of petals of the collet clamp is equal to the number of faces of the screw head, and the inner surfaces the petals of the collet clamp are made flat, characterized in that it is equipped with a tensioner mounted with the possibility of axial displacement between the handle head and the spring of the collet clamp, in which Ohm installed an additional spring, tedious with calibrated force.

Description

The utility model relates to medicine, namely to traumatology and orthopedics, and can be used in surgical treatment of spinal deformities when installing an endocorrector using ceramic screws.

A device for installing and removing screws (screwdriver-screw holder, patent RU 1653750, MKI A61B 17/60, publ. 07.06.91) for use in osteosynthesis operations, containing a rod with a sting at one end and a handle at the other, a spring-loaded sleeve with a grip mounted on the rod. The screwdriver is designed to install screws with a slot or a crosswise socket.

The disadvantages of a screwdriver include the impossibility of installing ceramic screws having internal screwdriving elements (cross, hexagon, sprocket, spline), since the screw head is destroyed during screwing due to the high fragility of the ceramic. Ceramic screws can be screwed with the external coverage of the screw head, which may be in the form of a polyhedron, for example a square. Another drawback of a screwdriver-screw holder is the lack of structural elements in it, which allows to reliably hold the head of the screw when screwing it into the bone. In the process of twisting, the screwdriver can come off the screw head, since the holding force of the screw head is determined by the spring, which cannot be stiff due to the need for easy installation of the screw in the screwdriver. In addition, in the process of screwing in the screw, the axis of the screw may skew relative to the axis of the screwdriver.

The closest in technical essence to the proposed one is a device for installing and removing a screw, containing a handle with a crimping sleeve and a head wound on the rod of the collet clamp (patent RU 2157132, MKI A61B 17/88, publ. 10.10.2000).

The disadvantage of this device is the inconvenience in operation, namely, the long duration and complexity of the pine screw installation in the device, namely when installing the screw in the device, it is necessary to simultaneously hold the screw in the required orientation relative to the device (without skewing) and simultaneously screw the collet clamp into the compression sleeve. It can also be considered as a drawback that the unbalanced clamping force of the screw head determined by the screw-nut pair for tightening the collet clamp of the device into the compression sleeve. At high tightening forces, the faces of a ceramic screw can be destroyed; with a low tightening force, the screw can skew the device relative to the device or the petals of the collet from the screw head can slip off during operation.

The objective (technical result) of the utility model is to increase ease of use, namely, improving the quality of surgical treatment with reducing injury to body tissues and reducing the duration of the operation.

The problem is solved in that the device for installing and removing ceramic screws includes a handle with a head, a collet clamp with petals mounted in the handle from the side opposite the handle head, and a sleeve crimping the collet with a spring. The number of petals of the collet clamp is equal to the number of faces of the screw head, and the inner surfaces of the petals of the collet clamp are made flat. The device is also equipped with a tensioner installed between the handle head and the collet clamp spring, in which an additional spring is installed, forced with a calibrated force.

The essence of the proposed device is illustrated by drawings. In FIG. 1 presents the proposed device in assembled form; in FIG. 2 - device unit - tensioner; in FIG. 3 is a cross-section of a tensioner along AA of FIG. 2.

The proposed device for installing and removing ceramic screws (Fig. 1) contains a handle 1 with a head. On the handle 1, on the side opposite to the head of the handle, a collet clamp 3 fixed by a sleeve 2 is installed. The inner surfaces of the petals of the collet clamp 3 are made flat to reliably grasp the faces of the screw head. The number of petals of the collet clamp 3 is equal to the number of faces of the screw head. The collet clamp 3 is pulled into the sleeve 2 by a spring 4 with a slight force. Between the head of the handle 1 and the spring 4 of the collet clamp 3, a tensioner 5 is installed, with the possibility of axial displacement. An additional spring 6 is installed in the tensioner 5 (Fig. 2), forced with a calibrated force by means of a nut 7 held against rotation by the lock 8 in the groove 9 relative to the tensioner 5 (Fig. 2, 3).

Work with a screwdriver is as follows.

Pretensioner 5 is unscrewed so that a gap “H = (3 ... 5) mm” is formed between tensioner 5 and handle 1. Then, with a palm of your hand, press tensioner 5, choosing clearance “H”, thereby removing collet clip 3 from sleeve 2. the petals of the collet clamp 3 diverge, and the screw head is installed in them. Having stopped the preloading of the tensioner 5 to the handle 1, the screw head is clamped with the petals of the collet clamp 3 using the spring 4, which biases the tensioner 5. The gripping force of the screw head is small, determined by the force of the spring 4, and the position of the screw in the petals of the collet clamp 3 can be adjusted. The additional spring 6 (Fig. 2) is involuntarily by means of a nut 7 installed in the tensioner 5. The nut 7 is kept from turning relative to the tensioner 5 by the lock 8 in the groove 9 of the tensioner 5. The axial displacement of the tensioner 5 between the handle head 1 and the spring 4 is carried out by the collet pull clamp 3. After clamping the screw head with the petals of the collet clamp 3, tighten the tensioner 5 without pressing, first to select the clearance “H”, and then a few more turns - at the same time, an additional spring 6 in the tensioner 5 starts to work, creating a calibrated mustache The grip of the screw head for transmitting torque during the final screwing of the screw.

The proposed design of the device provides for the capture of the screw head in the collet clamp by the force of two springs - "weak", ensuring that the screw is held in the collet clamp with a small force, allowing you to adjust the position of the screw in the screwdriver without danger of damaging the screw head and the "strong" creating the clamping force of the screw head in collet clamp, providing the necessary torque when screwing in the screw and reliable fixing of the screw in the screwdriver. This eliminates the occurrence of skew and slipping of the collet petals from the screw head during surgery, which facilitates the work of the surgeon in the wound, reduces the morbidity of surgical intervention.

Claims (1)

A device for installing and removing ceramic screws, including a handle with a head, a collet clamp with petals mounted in the handle on the side opposite to the handle head, and a sleeve that compresses the collet clamp by means of a spring, the number of petals of the collet clamp is equal to the number of faces of the screw head, and the inner surfaces the petals of the collet clamp are made flat, characterized in that it is equipped with a tensioner mounted with the possibility of axial displacement between the handle head and the spring of the collet clamp, in which Ohm installed an additional spring, tedious with calibrated force.

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