JPH019539Y2 - - Google Patents

Description

[Detailed explanation of the invention] This invention is a surgical instrument and
Regarding ceremony equipment. Instruments such as forceps and clamps are often equipped with joint-type fasteners that require high reliability and high precision engagement of the gripping members.

In the joint type fastening section, each of the first and second members has a working part such as a gripping jaw that cooperates with the other member at one end, and has a working part such as a gripping jaw at the other end to control the movement of the working part. A special hinge structure is used in the type of instrument that has an operating part consisting of an annular handle for adjustment. The first member has a bifurcation in the intermediate region such that the acting part and the operating part are joined by two separate elements with a slot in between. A slot passes through the operating portion of the second member, and also extends through the operating portion of the first member on the opposite side of the branching portion. A pin extending across the slot and passing through a hole in the part of the second member in this slot forms the hinge structure, the actuating part being for this purpose a gripping actuator depending on the nature of the instrument. It is subject to operational control. Braided joints are generally recommended for reasons such as strength, little play, and resistance to loosening due to use. These properties are extremely important for special instruments requiring precise cooperation of opposing working parts. For example, surgical clamps have special jaws that compress blood vessels without damaging them, as described in U.S. Pat. No. 3,608,554, issued September 28, 1971.

For surgical instruments such as forceps that are equipped with conventional joint-type binding sections, first align the holes in the two members to be assembled, insert the pins, make the necessary bends by polishing, etc., and then insert the pins. remove the first member, drill a square or star-shaped hole in the branch part of the first member, and
and a second member, inserting a second pin, peening the pin, and finally finishing the device. However, due to the hardening process that follows the setting of the sieve by tapping the pin, stress is generated in the device and this stress continues to remain during use. Exposure of the instruments to superheated steam (autoclaping), repeated mechanical loading during the procedure, and stresses resulting from corrosion caused by various elements during the procedure can effectively destroy the joint, if not for a short period of time. Cracks occur inside and around the area. Instrument failure occurs at the site of this type of crack and poses a serious risk to patient safety if this occurs during surgery.

On the other hand, the above-mentioned hinge pins may be inserted and fitted with taps, and then hardened. However, peening sometimes requires the pins to be tightened if shrinkage occurs during the curing process. This peening creates stresses similar to those that occur during set hardening of the pin. Therefore, there is still a risk of damage to devices made using this other method.

Hinge pins also do not exhibit much resistance to destructive forces. When the hinge pin of a typical conventional appliance breaks, a portion of the pin often falls out. This also poses a serious risk to patient safety if it occurs during surgery.

According to the present invention, the head of the pin is made slightly larger than the hole of the member having the branched part, and the pin has two parts.
are inserted into aligned holes in each member. The pin is electrofusion welded in a two-step process to secure two separate elements at the bifurcation such that the circular weld zone of each of these elements has a penetration depth of 75 to 100 percent, preferably 100 percent. be made into This electric fusion welding is preferably performed in an inert gas atmosphere. The outer surfaces of the two separate elements of the branch are polished;
The pin is also made invisible. Hardening is performed after electric welding, and thus the device according to the present invention has significantly less residual stress at the joint of the joint than in the past, virtually eliminating the risk of breakage during use. Furthermore, even if the hinge pin is damaged, it will not fall off from the instrument because it is welded to the branch element of the first member.

Therefore, it is an object of the present invention to provide a device having a joint part that is much more durable than conventional joint parts and virtually free of compressive stress due to tapping, etc., as well as residual stress due to heat during fusion welding. The object of the present invention is to provide a device which prevents the hinge pin or a portion thereof from being lost in the event of breakage of the hinge pin, and which minimizes the play of the joint in such a device. The purpose is to make it easy to manufacture.

Embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The joint-type surgical scissors, indicated by 12 in FIG. Jaw 2 of member 14
0 is positioned to align with jaws 22 of member 16. The movement of the jaws toward each other is controlled by the operation rings 24 and 26.
It is adjusted by The latching means for appropriately setting the jaw in several positions consist of a ratchet 28 on member 14 and a corresponding tooth 30 on member 16.

The member 14 has a bifurcated portion at the joint, whereby the collar 20 and the ring 24 are connected by separate elements 32, 34 with a slot 36 therebetween. The inner surface of the slot 36 is flat and parallel on both sides. A portion 38 of member 16 finished to fit snugly against the flat inner surface of slot 36 is sandwiched between collar 22 and ring 26 on opposite sides of the branched portion of member 14. Hinge pin (not shown in Figure 1)
passes through the hole in element 38 through the interior of the slot described above. This hinge pin serves to allow adjustment of the jaws by manipulation of the rings 24,26.

As previously stated, these devices are completely conventional. During conventional device fabrication, the forged parts corresponding to the finished parts 14, 16 are forced apart from the corresponding elements 32, 34 of the part 14, the members 16 are inserted between these elements, and the forged parts 14, 16 are expanded. 34 to its normal position. Elements 34, 38, 32
Holes were drilled in the corresponding elements, and temporary pins were inserted into these holes to make jaws and other necessary bends and to keep the parts aligned during machining. After the temporary pins are removed, the members corresponding to elements 32 and 34 are drilled with square holes as shown in Figure 3 or with "star" shaped polygonal holes as shown in Figure 5. It will be done. The elements of the device are then allowed to harden before the termination hinge pin is inserted and fitted with a form iron.
After tapping, the final finishing touch to the device is made. Figures 2, 3, 4 and 5 show two types of splice connections according to the prior art. In FIG. 2, pin 40
is retained by the pin end expanding and filling the square space of the hole in the outer element of the binding part during the tapping stage. Also in the case of FIG. 4, the end of the pin 42 fills the six-point star-shaped hole in the outer element hole with a tap. In each case, it occupies this position by virtue of the integrity of the pin itself. If fracture occurs due to a transverse material defect, the pin may become dislodged into the patient during surgery. As previously mentioned, the splice type connections shown in Figures 2, 3, 4 and 5 remain at risk of failure due to the stress of tapping.

Figures 6, 7, 8, and 9 show the manufacturing sequence of the fusion welding joint joint according to the present invention. As seen in FIG. 6, pins 44 with heads 46 are inserted into aligned holes in the splicing elements. In this case, the inner element of the splice is designated 48 and the outer elements 50,52. The diameter of head 46 is larger than the hole in element 50 and the pin will be retained in the initial fusion weld.

Figure 7 shows the initial fusion welding results. The head 46 is a fusion weld or weld 5 that secures the pin 44 to the element 50.
It has changed to 4. The fusion weld or weld 54 is deep enough to penetrate 100% into the element 50. This is not difficult and the optimum fusion welding time for a given size device can be readily determined. When the penetration depth reaches 100%, element 50 becomes element 48.
There is a sufficient time lag before the current flows to cause welding. Therefore, it is sufficient that the fusion welding time is such that a good welded area with 100% penetration can be formed.

After the first fusion weld, the instrument is inverted and a second fusion weld is made similar to weld 54 or weld 56 by welding the tip of pin 44 to element 52, as shown in FIG. A meeting will take place.

Finally, excess welding material is ground away, and finishing and polishing is performed. The final finish creates smooth surfaces 58, 60 as shown in FIG. In this way, the pin becomes invisible.

According to the present invention, it is recommended to use a special mounting structure as shown in FIGS. 10 and 11 for the above-mentioned drilling and fusion welding operations. The mounting structure consists of a base 62 with clamps of a particular configuration, including fixed clamps 64, 66 and sliding clamps 68, 70. The clamp serves to hold the components of the instrument together as shown for aligning and drilling the holes. As shown in FIG. 11, the base 62 is provided with a recess 72 for drilling and for receiving the tip of the pin. This base is fitted with a gear 74 to rotate it during fusion welding to form a uniform weld.
and a gear mechanism including pinion 76 . Electrode 78 is directly above the pin in FIGS. 10 and 11.

Example: A 410 stainless steel De Bakey round ring handle short clamp with a total length of approximately 12.7 cm (5 in.) has a head diameter of 0.1905 cm (0.075 in.) and a length of 0.495 cm (0.195 in.).
inch) and assembled using the same 410 stainless steel pins. A 0.178 cm (0.078 inch) hole was drilled into the device. Fusion welding was carried out using a current of 32 amperes with the electrode centered directly above the pin and spaced 0.094 cm (0.037 inch) from the pin head. The base was rotated at 10 rpm with two revolutions between each fusion weld. Thus, a 100% weld was created on both sides of the joint of the joint without fusing of the elements in this section.

The conditions described above are the same except that the hole diameter is 0.236 cm (0.093 inch) and the current is 35 amps, the total length is 17.8 cm (7 inch), and the pin length is 0.584 mm.
cm (0.230 inch), pin diameter 0.228 cm (0.090 inch), otherwise same as De Bakey clamp described above.
We have manufactured a clamp for terminally ill blood vessels.

Additionally, under the same conditions as above except that the fusion welding current was 38 amps, the pin length was 0.536 cm.
(0.271 inch), pin diameter 0.236 cm (0.093 inch)
A De Bakey tangential occlusal clamp with a total length of 25.4 cm was assembled.

If the equipment becomes larger, the fusion welding time should be increased, the fusion welding current should be increased, or both should be done at the same time, and when assembling smaller equipment, the fusion welding time should be shortened or the fusion welding current should be increased. Make smaller. The necessary conditions can be easily determined according to the device to be manufactured. moreover,
According to the present invention, it is possible to realize an instrument that accurately provides a homogeneous 100% welded part even if there are errors in the conditions during fusion welding.

The device according to the invention is structurally very strong and has a reliable spliced tie. That is, since no tapping is performed on the pin, stress associated with deformation due to compression, which has been a drawback in conventional devices, does not occur. Furthermore, since quenching is performed after fusion welding, any stresses created during bending, machining, and fusion welding are released as the device hardens. moreover,
The device according to the present invention has many advantages, such as the fact that the hinge pin is fixed to the outer element of the joint joint by fusion welding, so there is no risk of it falling off from the device even if it breaks during use. Brought to you.

Next, embodiments of the present invention will be listed.

(1) Each end of the opposing pin is fusion welded to a separate element, with the fusion zone penetrating at least 75% of the thickness of one of the elements.

(2) The pin shall have a head large enough to prevent it from coming out of the hole in the above element.

(3) The instrument shall be rotated in a plane perpendicular to the axis of the fusion-centered hole.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a joint type clamp according to the present invention, Fig. 2 is a partially cutaway side view of a joint part with a rectangular hole according to the prior art, Fig. 3 is a bottom view of Fig. 2, and Fig. 4 5 is a partially cutaway side view of a joining part provided with a star-shaped hole according to the prior art, FIG. 5 is a bottom view of FIG. 10 is a perspective view of a mounting structure used in manufacturing a joint type surgical instrument according to the present invention, and FIG. 11 is a sectional view of the mounting structure shown in FIG. 10. 12... Instrument, 14... First member, 16...
Second member, 20, 22...Action part, 24, 26
...Operation part, 32, 34... Branch part, 36... Slot, 44... Pin, 54, 56... Welding part,
58, 60...outer surface.

Claims (1)

[Scope of utility model registration request] A first member and a second member each having a working part that cooperates with the working part of the other member at one end and an operating part that restricts the movement of the working part at the other end; A branch part in the middle part of the member sandwiching the slot, a hole penetrating oppositely to both sides of the branch part of the first member, and two holes in the branch part of the first member. A hole in the second member penetrating the corresponding portion, a pin penetrating the hole in the second member, and an end of the pin, and each hole in the branch portion of the first member. A spliced surgical instrument characterized by comprising two fusion welded parts joined to a peripheral part.